W-128 Home Page
 
Usefulness of Fingings
Objective 1 Accomplishments
Objective 2 Accomplishments
Objective 3 Accomplishments
Objective 4 Accomplishments
Summary of 2003 Presentations to Growers
Summary of 2003 Journal Articles
Summary of 2003 Professional Presentations
Summary of 2003 Reports in the Popular Press and Others
 
W-128 Annual Report 2003                                         January 10, 2004

Microirrigation Technologies for Protection of Natural Resources
and Optimum Production
 

Objectives of this project

Objective 1.  To evaluate and refine microirrigation management strategies to promote natural resource protection and optimal crop production

Objective 2.  To improve, modify, and evaluate microirrigation system design and components for natural resource protection and optimum production

Objective 3.  To assess and develop decision criteria for adoption of microirrigation technologies.

Objective 4. To promote appropriate microirrigation technologies through formal and informal educational activities

Format the reports from each state follow the following format:

1. Progress of Work and Principal Accomplishments
2. Usefulness of Findings
3. Work Planned
4. Publications
5. Presentations
6. Students

The information from some states is complete.  The California report has the outline  format repeated, since the individual reports have not been integrated.
 

I. Arizona (for more details, follow this link)

Muluneh Yitayew

1. Progress of Work and Principal Accomplishments

Objective 1  To evaluate and refine microirrigation management strategies to promote natural resource protection and optimal crop production

a. A three year comparative water-yield study was done for field corn in Southeast Arizona, using both drip and furrow irrigation methods, and four different levels of irrigation within each irrigation method.  The Arizona Irrigation Scheduling (AZSCHED) software determined irrigation frequencies and amounts.  The four levels of irrigation treatments were 125%, 100%, 75% and 50% of the AZSCHED prescribed irrigation amounts.  Three important observations were made during the course of this study.
- The average seasonal crop water requirement (ET) for an average maximum yield of 11.1 Mg/ha was 886 mm.
- Yields from drip-irrigated plots were not significantly different from the yields of furrow-irrigated plots.
- The production function for field corn in SE Arizona was defined.b. A crop coefficient curve for field corn was developed as a function of heat units, and to subsequently compare the experimentally determined crop coefficient curve to the existing crop coefficient curve in the Arizona Irrigation Scheduling (AZSCHED) software.  The study was performed with subsurface-drip-irrigated field corn in Southeast Arizona.  AZSCHED determined irrigation amounts and frequencies based on inputs of weather data, water holding capacity of the soil, management allowed depletion, and application efficiency.   A water balance approach was used to develop an experimentally determined curve.  The study shows that the crop coefficient curve for field corn in AZSCHED did not represent the crop coefficient estimated from field data.

The shape of the crop coefficient curve for field corn in AZSCHED was different than the experimentally determined curve.  The crop coefficient curve that was modified to fit the data from the field is believed to be a better representation than the original curve in AZSCHED.  Although the modified curve is shifted to the right with an increased peak, the seasonal water requirement is actually lower for the modified curve.  It is important to note that these conclusions are based on one season of data.
c. The effect of salinity was studied on corn yield to analyze: a) the salinity effects on grain yield, plant growth and root development of field corn, b) the effect of salts application on silking and tasseling, c) the salinity response function for field corn under arid conditions and d) the distribution of salts within the root zone.

Corn yield, shoot growth, plant height and root development decreased with salt applications. While silking and tasseling were delayed in those plots that salt solution was injected. All these variables were analyzed statistically and there was significant difference between the four treatments during the different growth stages for the two corn seasons established.

  Although the highest concentration of salts was accumulated in the shallow layer, salinity greatly affected distribution of corn roots in the soil and this influenced the uptake of water and nutrients. During the vegetative stage of the plant, roots grew rapidly. After this stage root growth generally increased at a slower rate than shoot growth and after the reproductive stage root dry mass declined, which has been associated with the translocation of N in the roots to the developing ear.

2. Usefulness of Findings

Production function, crop coefficient, and the water use efficiency of corn was established for arid environments under SDI.  The result can be used as benchmark for irrigation design and management in growing corn in arid areas of the world.
 
The salinity study reveled that corn under subsurface drip irrigation can tolerate higher salinity levels than what is reported in the literature.   This is a significant finding in that it will help farmers save water by using poor quality water and lower leaching fraction and achieve a good yield level.

Determining the threshold salinity value for corn and the yield reduction per unit of salinity under subsurface drip irrigation will help farmers also develop best management practices necessary when using poor quality water for SDI.

3. Work Planned for 2004

TTo participate in developing the new project proposal and carry out research on the specific objectives relevant to Arizona’s irrigated agriculture.

II. California

A. Ken Shackel, U.C. Davis.

1. Progress of Work and Principal Accomplishments

Objective 1:  In dried plums (prunes), grower demonstration plots demonstrated substantial water savings (>50%) by allowing mild to moderate deficits in SWP (to -15 bar by harvest) with only positive effects on economic yield.  In almonds, a third year of grower plots demonstrating the use of RDI to reduce hull rot and improve nut harvestability was completed and showed no negative effects on yield or nut size.  In almonds, a study was completed and published demonstrating that barking injury may be due to a previously unrecognized vertical motion in shaker harvesting.  Since barking injury has been widely regarded as related to irrigation management, this finding will convince almond growers that RDI management can be practiced without fear of increasing shaker injury.

Objective 4:  Presentations were made demonstrating the benefits of RDI at the annual statewide dried plum and almond industry group meetings.  An industry sponsored survey of dried plum growers showed that 6% of the growers state wide are using the pressure chamber to schedule irrigation.

2. Usefulness of Findings

Objective 1: Plant-based RDI has allowed substantial reductions (40 - 50+%) in irrigation water applied to prune trees, while maintaining or improving economic yields.  Water savings in almonds have depended on soil type and depth, with the most substantial savings (over 35%) on the deepest soils. 

3. Work Planned

Objective 1:  Prune and almond RDI demonstration plots will be continued in 2004, and a yield and fruit quality summary for the 3-4 year prune sites will be compiled to evaluate any medium-term effects.

Objective 4: Presentations will be made informing growers of the benefits of site-specific management of deficit irrigation at the annual meetings of a number of industry groups, including the California almond board, the California dried-plum (formerly prune) board, and the walnut and cling peach boards.

4. Publications

Abdel-Fattah, H.M., K.A. Shackel, DC Slaughter. 2003a.  Methodology for determining
almond shaker displacement and frequency.  Applied Engineering in Agriculture
19:141-144.

Abdel-Fattah, H.M., K.A. Shackel, DC Slaughter. 2003b.  Substantial vertical tree
displacements occur during almond shaker harvesting.  Applied Engineering in
Agriculture 19:145-150.

5. Presentations

Annual meeting of the California Almond Board, December, 2002

Annual meeting of the California Dried Plum Advisory board, December, 2002

6. Graduate students

Tiesen Cao, Ph.D., plant biology, UCD
Cayle Little, MS, horticulture, UCD
 

B. Jan W. Hopmans, University of California Davis

1. Progress of Work and Principal Accomplishments

Proper water and soil management is essential for both sustainable agriculture and integrated food production. In general, irrigation scheduling is based on the water balance method, however, using localized irrigation, it is difficult to evaluate most of water balance terms. An additional complication arises from the non uniformity of to compensate for root suberization and relative root inactivity in the non-wetted soil. Therefore, efficient water management in micro-irrigated rooting systems depends on knowledge of the spatial and temporal distribution of root water uptake, as well as on the ability to predict variations of soil water status in the root zone after irrigation. Whereas much is known about root morphology, including the spatial distribution of roots under localized water application, information to date on the spatial and temporal distribution of root water and nutrient uptake is limited, especially for partially wetted soils.

Objective 1.  To provide experimental data for the development, verification and calibration of multi-dimensional root water uptake model, thereby improving microirrigation scheduling and management, a field study was initiated in a micro-sprinkler irrigated almond orchard. Micro-irrigation research was carried out at the Nickel’s Estate Experimental orchard, 90 km north of Davis, California, in the Sacramento River Valley.  The orchard was planted in 1990 with four different varieties of almond trees with six years old almond trees (Prunus amygdalus) varieties using a tree spacing of 6.6 x 4.8 m. The trees in the experimental orchard were irrigated by surface drip, subsurface drip, and microsprinklers. Previous years’ experiments indicated that there was an advantage, as measured by tree yield and growth, to wetting a larger soil volume under the coarse-textured, low water holding capacity soils of the Marine Ave. orchard.  This gave an advantage to the microsprinkler-irrigated trees in the orchard.  The soil hydraulic and root water uptake parameters, characterizing the spatial geometry of the rooting system in the three-dimensional spatial domain were optimized, minimizing the residuals between measured and simulated water content data for the sprinkler-irrigated almond tree during a 16-day period, following irrigation.With the optimized root water uptake parameters, simulated and measured water contents during the 16-day period were in excellent agreement for each of the investigated root water uptake models. Most significantly, the spatial variation in flux density decreased when simplifying multi-dimensional root water uptake to fewer dimensions, thereby justifying the proposed multi-dimensional approach.  Despite that water application was non uniform, soil moisture uniformity prior to irrigation was large, and was caused by differential root water uptake in the surface soil. Throughout the experiments, the roots of the almond tree were capable to redirect their areas of maximum root activity towards the zones of the most favorable water regime, thereby resulting in fairly uniform water content distributions. Typically, zones of maximum root water uptake developed from the tree trunk towards the outer regions of the root zone, shifting to wetter parts of the root zone domain. Consequently, soil water depletion patterns formed a radial pattern around the tree trunk. It was concluded that factors controlling root water uptake in irrigated tree crops are (1) spatial distribution of active roots, (2) root zone water  distribution, and (3) distance from the tree trunk.

Simulated spatial variations in drainage rate and root water uptake using the multi-dimensional root water uptake models  decreased when simplifying multi-dimensional soil water flow and root water uptake to decreasing spatial dimensions.  This may have large implications for chemical transport in root zones, as drainage rates and corresponding chemical transport rates will vary according to root water uptake distribution.  It was shown that spatial variability of drainage rates were large, with values increasing as corresponding root water uptake values decrease. The increasing accurate spatial description of root water uptake and soil water flow with increasing spatial dimension is essential to improve model predictions of water fluxes and contaminant transport through the root zone. Moreover, total chemical load to the groundwater will depend on local concentration and fluxes, and their spatial variability.

Objective 2.  In their recent review of root water and nutrient uptake modeling, Hopmans and Bristow (2001) concluded that progress in the basic understanding of transport processes in the soil-plant-atmosphere continuum (SPAC) has been slow, specifically regarding interfacial fluxes at the root-soil interface. They speculated that the so-called knowledge gap of plant responses to water and nutrient limitations is caused by the historical neglect of studies of below ground processes.  Consequently, water and nutrient uptake in plant growth and soil hydrological models are mostly described in an empirical way, often lacking a sound biophysical basis. This is unfortunate, as the exchange of water and nutrients is the unifying linkage between the plant root and surrounding soil environment. The simplified sink approach is adequate for non stressed plant growth conditions, and may work adequately for uniform soil conditions. However, it is clear that a different approach is needed if water and/or nutrient resources become limited. Increasingly, recommended micro-irrigation practices tactically allocate water and fertilizers, thereby maximizing their application efficiency and minimizing fertilizer losses through leaching towards the groundwater, so as to keep environmental effects of crop production within acceptableental conditions. This includes knowledge of the crops responses to the availability of spatially distributed soil water and plant-available nutrients, using a multi-dimensional modeling approach.

2. Usefulness of Findings

a. The root modeling research has led to various publications that point out the need of a much improved understanding of the functioning of plant roots in stressed soil conditions, especially in micro-irrigation systems;
b. Invitations to present the root modeling research, nationally and internationally, to find approaches  that quantify the role of micro-irrigation in efficient water management, minimizing crop water stress and plant nutrient leaching.

4. Publications

Bassoi, L.H., J.W. Hopmans, L.A. de C. Jorge, C.M. De Alencar, and J.A.M.E. Silva.
2003. Grapevine root distribution in drip and microsprinkler irrigation using monolith and the soil profile  method. Scientia Agricola. Vol. 60(2): 377-387.

Hopmans, J.W., and K.L. Bristow. 2001. Current capabilities and future needs of root
water and nutrient uptake modeling. Advances in Agronomy. Volume 77: 104-175,
2002.

Vrugt, J.A., M.T. van Wijk, J.W. Hopmans, and J. Simunke. 2001. One, two, and
three- dimensional  root water uptake functions for transient modeling. Water Resour.
Res. 37:2457-2470.

Teruel, D.A., D. Dourado-Neto, J.W. Hopmans, and K. Reichardt. 2001. Structural
changes in soybean root system as a response to soil phosphorus availability. Scientia
Agricola. Vol. 58:5-60 (In Portuguese).

Vrugt, J.A., J.W. Hopmans and J. Simunek. 2001. Calibration of a two-dimensional
root water uptake. Soil Sci. Soc. Amer. J. 65:1027-1037.
 

C. David J. Hills, U.C. Davis

1. Progress of Work and Principal Accomplishments

Objective 2: To improve, modify, and evaluate microirrigation system design and components for natural resource protection and optimal crop production.

a. GPS auto-guidance system for subsurface drip-tape installation and maintenance. A GPS auto-guidance system was developed for placing and maintaining subsurface drip-tape in row crops. The objectives of this project were to determine the effect of spacing between cultivator disks and tractor forward speed on plant damage and the effect of deep tillage operations on drip tape damage. Two sets of split-plot field experiments were conducted (one using processing tomato transplants and the other using direct seeded tomatoes) on the U.C. Davis campus.  The results indicated that no significant plant damage occurred at 11.2 km/h forward speed and 5 cm cultivator disk spacing from the plant line. Additionally there was no significant damage to drip tape when fertilizer shanks were operated 5 cm from the drip tape at 5.6 km/h travel speed.

b. Microirrigation lateral design for site-specific agriculture. Current design procedures for microirrigation systems are based on uniformity of water application. However, it is generally known that plant water requirements are non uniform within an agricultural unit, and, therefore, uniform application of water may not be efficient. A simple design procedure was developed for laterals with unequal emitter discharge rates to match variable plant water requirements, and unequal emitter spacings to match the need for unequal plant spacings. In phase one, a step-by-step (SBS) model was built to simulate the effects of study variables on lateral hydraulics.  In phase two, field experiments were conducted to verify the SBS model.  The percentage difference between theoretical and experimental results was satisfactory and ranged between ±6.0%.In the third phase, the segment-based analysis (SBA) technique was developed to simplify the procedure of calculating head loss in non uniform laterals. The SBA technique transformed the lateral into a virtual lateral divided into a number of equal-length segments and replaced existing emitters by a virtual emitter positioned at the center of each segment. Accuracy levels of ±5.0% were attained by using five segments. A graphical lateral design tool was developed for readily designing site specific laterals. 

2. Usefulness of Findings

a. Subsurface drip irrigation has the potential for improving water use efficiency, reducing weed growth, and improving overall energy efficiency. The GPS guidance system allowed for automatic steering of the tractor and implements close to the buried drip-tape and plants without causing damage to either while operating at relatively high operational ground speeds.

b.: Current design procedures for microirrigation systems are based on uniformity of water application. This project is developing site-specific guidelines for optimizing natural resources and minimizing environmental concerns by treating each plant differently with respect to irrigation input.

4. Publications

Abidine, A. Z., B. C. Heidman, S. K. Upadhyaya, and D. J. Hills.  2002.  Application of
RTK GPS based auto-guidance system in agricultural production.  American  Society
of Agricultural Engineers Paper Number 02-1152.  11 pages including 2 tables and 5
figures.  July.

Aziz Z. Abidine, Brian C. Heidman, Shrini K. Upadhyaya, and David J. Hills. In Press.
Application of RTK GPS based auto-guidance system in agricultural production,
California Agriculture.

Talozi, S. A., and D. J. Hills.  2002.  Hydraulic design considerations for microirrigation
laterals in landscape.  American Society of Agricultural Engineers Paper  Number
02-2249.  23 pages including 1 table and 11 figures.  July.

6. Graduate Students

Brian C. Heidman
Samer A. Talozi
 

D. Tom Trout, Jim Ayars and Dave Bryla,  USDA-ARS, Fresno, Ca, W-128 Report
2003

1. Progress of Work and Principal Accomplishments

Showed in a 3 year field trial that young peach trees used subsurface drip, surface drip and furrow irrigation water more efficiently than water applied with microsprays.  Young trees irrigated with microsprays required 72% more irrigation water to maintain the same stem water potential as with subsurface drip irrigation, and 100% more water to achieve the same growth.  The reason for this difference is primarily the high soil evaporation with microsprays on young trees.

Installed and tested a weighing lysimeter to determine crop coefficients for vegetable crops including broccoli, lettuce, peppers, and onion.  Installed a field facility to compare surface drip, SDI, and furrow irrigation management and water use for vegetable crops.

Determined that about 50% of the microirrigation systems in the California Central Valley used higher pump pressures than should be required for these systems.  Twenty five percent of the systems had pump pressures in excess of 40 psi.  Sources of the excess pressure loss included undersized filters and piping, excessive pressure regulation, and excessive pressure at the emitter. 

Developed equipment and management practices to safely and effectively apply soil fumigants through drip irrigation systems.  Showed that efficacy of drip-applied fumigants equaled or exceeded those applied through traditional shank application.  Drip fumigation has been commercialized and over 10% of California strawberries were drip fumigated in 2002.

Developed and patented a device to measure pressure in thin-walled drip tape without puncturing the tape.  The “squeezer” measures to force require to compress the tape a certain amount, and converts the force to a pressure.

4. Publications

Trout, T.J. and J. Gartung.   Energy Use for Microirrigation.  In.  Energy, climate,
environment and water - issues and opportunities for irrigation and drainage.  Proc. of
joint US CID and ASCE Env. and Water Resources Inst., San Luis Obispo, CA July
10-13, 2002.  pp. 465-474.

Ajwa, H.A., T. Trout, J. Mueller, S. Wilhelm, S.D. Nelson, R. Soppe, and D. Shatley.
Application of alternative fumigants through drip irrigation systems.  Phytopathology
92(12):1349-1355.  2002.

Kincaid, D.C. and T.J. Trout.  Squeezer: a device for indirect pressure measurement in
thin-wall drip irrigation tubing.  Appl. Engr. in Agri. 18(6):685-690.  2002

Kincaid, D.C. and T.J. Trout.  Fluid pressure measurement by mechanical compression
of thin-walled tubing. U.S. Patent #6,622,565. 2003.  (Patent).

Bryla, D.R., T.J. Trout, J.E. Ayars, and R.S. Johnson.  Irrigation management
practices for maximizing growth and improving crop water use efficiency in young
peach trees. Hort Science (In Print)

Trout, T.J., and H.A. Ajwa.  Application of soil fumigants through micro-irrigation
systems.  Paper #032021 presented at the 2003 Ann. Meet. of the ASAE, Las Vegas,
NV.

Publications in the Popular Press:

Plump peaches that require less water to grow are the goal of research.  The Wall
Street Journal and the L.A. Times, Nov. 2, 2000.

Scientist's hard work bears fruit.  The Fresno Bee, Nov. 98, 2000.

Putting down roots.  Western Fruit Grower, Apr., 2001

How much water and fertilizer do young trees need?  The Good Fruit Grower, July,
2001

Eye in the dirt.  California Farmer, Feb. 2002 (cover article and photo)

Camera exposes tree root behavior for peach producers.  Capital Press, Apr.,, 4, 2002.

Got Uniformity?  Device puts the squeeze on drip irrigation pressure differences.  The
Grower, Sept/Oct, 2003.

New Pressure Tester Helps Fine-Tune Irrigation Systems.  Agricultural Research. July
2003.

Effectiveness of drip fumigation examined in strawberry fields.  Ag Alert, Oct., 2003.

5. Presentations

Bryla, D.R., Trout, T.J., Ayars, J.E., Johnson, R.S. 2000. Irrigation management
practices for improving water and nutrient use efficiency and crop productivity in young
peach trees. National Irrigation Symposium. Proceedings of the 4th Decennial
Symposium (Addendum), Phoenix, Arizona, Nov. 14-16.

Bryla, D.R., Trout, T.J., Johnson, R.S., Ayars, J.E. 2001. Improving growth in young
peach trees by subsurface drip irrigation. HortScience 36:462-463.

Bryla, D.R., Sefton, R.K., Soppe, R., Gartung, J.L., Trout, T.J., Ayars, J.E. 2002.
Irrigation strategies for improving productivity and water use efficiency of vegetable
crops in central California. 2002 Annual Meetings of the ASA-CSSA-SSSA,
Indianapolis, Indiana, Nov. 10-14.

Bryla, D.R. 2003. Water requirements and yield of peach trees irrigated by microjet
sprinklers and subsurface drip. 4th International Symposium on Irrigation of
Horticultural Crops, University of California, Davis, California, Sept. 1-5.
 

III. Florida

Larry Parsons, University of Florida - IFAS, Citrus Research and Education Center
Lake Alfred, FL 33850
Craig D. Stanley, University of Florida

1. Progress of Work and Principal Accomplishments

Objective 1.  To evaluate and refine microirrigation management strategies to promote natural resource protection and optimal crop production.

a)  A sod irrigation management study was initiated to evaluate different types of subirrigation systems (seepage, subsurface tile and fully-enclosed subirrigation) and provide information to improve irrigation scheduling.  A 127-acre commercial sod production site with subsurface tile was chosen and 62 water table monitoring wells were installed.  GIS techniques were used to visually evaluate grower Results from the first data collection period revealed grower management using water table monitoring achieved high efficiency irrigation since the cumulative Penman ET for the sampling period was 244 mm, and total rainfall was 205 mm and applied water was 52.4 mm (257.4 mm rainfall and irrigation combined).

b)  A study to determine tomato and green pepper transplant water requirements using microirrigation, fully enclosed and seepage subirrigation was initiated.  The spring 2003 (initiated in March 2003) study was designed to accomplish the task of differing the establishment period by varying the transplanting date resulting in establishment periods of 0, 5, 10, and 15 days. In all cases, the target water table level for establishment was set at 22 inches which was controlled using float switches controlling solenoid valves which turned irrigation an and off as needed. First season results indicated that for tomato, plant height was not affected by either establishment period or irrigation system.  Plant width showed some separation among establishment treatments (not irrigation system), but primarily the 15-day treatment exhibited more branching which contributed to more plant width.  Minimal differences were detected with respect to number of nodes for either main treatments.  Significant differences for fresh and dry weights again showed separation of the 15-day establishment treatment, but no differences among irrigation systems.

c) A study to create a simulation model to describe solute flow in a mulched bed based on hydraulic and thermal properties of the soil included measuring soil bed temperatures in microirrigated and subirrigated growing situations, with and without tomato plants.  Each of 12 subplots had 32 thermocouple arranged in a grid fashion and connected to multiplexers and data loggers measuring temperature at 15-minute intervals, 24 hr per day for the entire growing season.  Data is still being analyzed.

4. Publications

Fereres, E., D. A. Goldhamer, L. R. Parsons. 2003.  Irrigation water management of
horticultural crops. HortScience 38(5): 1036-1042.

Parsons, L.  2003.  New book on water and citrus.  Florida Grower 96(2): 34

Parsons, L.  2003.  Best management practices for fertilization.  Florida Grower 96(2):
38-39.

Parsons, L.  2003.  Improving fertilization practices.  Florida Grower 96(6): 22.

Parsons, L.  2003.  Shedding light on blight.  Florida Grower 96(8): 64.

Parsons, L.  2003.  Jim Griffiths: The voice of experience.  Florida Grower 96(10): 20.

Stanley, C. D., R. A. Clarke, B. L. McNeal, and B. W. MacLeod.  2003.  Relationship
of Chlorophyll a Concentration to Seasonal Water Quality in Lake Manatee, Florida.
EDIS publication DLN SS430.  Cooperative Extension Service, Institute of Food and
Agricultural Sciences, University of Florida.

Stanley, C. D  and B. K. Harbaugh.  2003.  Subirrigated Caladium Tuber Production
and Water Use as Affected by Water Table Level.  Florida. EDIS publication DLN
SS247.  Cooperative Extension Service, Institute of Food and Agricultural Sciences,
University of Florida.

Stanley, C. D.  and G. A. Clark.  2003.  Effect of Reduced Water Table and Fertility
Levels on Subirrigated Tomato Production in Southwest Florida.  EDIS publication DLN
SS249.  Cooperative Extension Service, Institute of Food and Agricultural Sciences,
University of Florida.

Stanley, C. D., R. A. Clarke, B. L. McNeal, and B. W. Macleod.  2003.  Impact of
agricultural land use on nitrate levels in Lake Manatee, Florida.  EDIS publication DLN
SS428.  Cooperative Extension Service, Institute of Food and Agricultural Sciences,
University of Florida.

5. Presentations

Etxeberria, E. and L. Parsons. 2003. Reduced fall and winter irrigation increases brix
and delays flowering in Florida citrus.  HortScience 38(5): 839.

6. Graduate Students

Wonsook Ha - Ph.D. student
Arne Olsen - Ph.D. student
 

IV. Guam (for more details, follow this link)

P. Singh, University of Guam

1. Progress of Work and Principal Accomplishments

a. Field experiment to evaluate the susceptibility to clogging for five popular drip lines was setup in February of 2003 at Yigo Agricultural Experiment Station, Guam. Delta T-Tape from Toro, Typhoon 20 from Netafim, Turbulent Twinwall 9” and 24” from Chapin, and Submatic 24” from Submatic were selected for evaluation.  The design setup consisted of a set of three drip lines 50 feet long and 3 feet apart for each type.  Each set was connected to a submain.  Each submain was connected to the main via an electronic water meter and a solenoid valve.  A filter and pressure regulator were installed on the mainline.  A datalogger was programmed to activate irrigation twice a day for 10 minutes each time.  The pressure regulator was set at 10 psi.  Ten emitters were randomly selected from each type of drip line and emitter flow was measured once every month.  Water samples were also collected for chemical analysis.

The mean flow rate, standard deviation, and percent decrease in flow rate of each set of ten emitters for each drip line type are presented in table 1 and graph 1 for the duration February, 2003 to September, 2003. The Toro Delta T-Tape had the lowest clogging at 6.6% while the Chapin Turbulent Twin 24” had the highest clogging at 51.7%.  Finally, extreme drops in flow rate and high standard deviations for the Netafim, Submatic, and Chapin 24” drip lines are the result of a some or most of the ten sample emitters clogging considerably (50 to 100 percent drop in flow rate). Table 2 lists the dates and  number of emitters with over a 50% decrease in flow for each drip line type.

b. Field studies were conducted over two seasons to determine the Optimal Wetted Soil
Volume (OWSV) for growing watermelon in the shallow (19.6cm average soil depth), high pH Guam Cobbly Clay soil of Northern Guam.  Watermelon (Citrullus lanutus) variety China Baby was transplanted on March 4, 2002 and again on April 8, 2003 in a random block design with twelve rows, three replications and four treatments. Treatment numbers reflect drip line per row configurations of  1, 2, 3, and 4 drip lines. Drip  line spacing - based on soil wetting pattern field tests – of 20.32 cm was use.  Plant spacing was 1.22m in rows 3.05m apart. Pre-plant soil analysis showed a mean pH of 7.32 in 2002 and 7.80 in 2003. For 2002, organic matter was 6.25%, phosphorous 6.31 ppm, and potassium 20.23 ppm. In 2003 organic matter was 5%, phosphorous 24 ppm, and Potassium 14 ppm. switching tensiometers were used to maintain a  -20 cb soil moisture tension for all treatments. Phosphorous was banded at a rate of  280 kg/ha for both experiments. nitrogen and potassium was applied based on soil analysis, extension recommendation , and plant petiole sampling. Total amounts of N and K were kept equal for all treatments. Potassium amounts for 2002 and 2003 were 225 kg/ha while Nitrogen amounts for 2002 and 2003 were 140 kg/ha and 168 kg/ha respectively.  

Black polyethylene plastic mulch was used  to control weeds, provide a uniform soil moisture level between irrigations, and to prevent leaching of N and K nutrients during heavy rains. Row covers were used until flowering to reduce pesticide use. Twelve stainless steel drainage lysimeters were installed in the middle of each row prior to the first experiment.  Irrigation amount, leachate amount, leachate N-P-K concentrations, plant petiole N and K concentrations, soil salinity, soil moisture tension, plant canopy area, diseased/deformed fruit types and amounts, and fresh harvest weight were all measured.  Irrigation  amounts for both years are shown in figure 1. Use of one drip line per row required a significantly higher number of irrigation events and a higher number of fertigation events to deliver the desired amount of fertilizer. The average number of irrigation and fertigation events for both seasons are given in figure 2. Yield amounts, which show no significant differences between treatments or between seasons are given in figure 3. Treatment 1 had the highest water use efficiency for both seasons as shown in figure 4. The tensiometer setup and numbering configurations used is shown in schematic 1 while measurements for treatments one and three are shown in figures 5 and 6, and reflect soil moisture uptake patterns in the early and later stages of crop development.

2. Usefulness of Findings

a. Drip lines from the same manufacturer may clog at a different rate.  The information will provide another evaluation parameter for farmers to consider while choosing a drip line.

b. Yields for one, two, three, or four drip line configurations under black plastic mulch are the same, while water use efficiency is best when using one drip line.   The number of irrigation and fertigation events for 1 drip is higher than for 2, 3, or 4 drip lines and results in higher man hours for irrigation management. Also, the fertilizer need amounts for the one drip line treatment were difficult to meet, especially early in plant development, because of the soil wetting pattern and slower rate of irrigation amount.  We are recommending a two drip line configuration to farmers in Northern Guam and are in the process of producing an irrigation / fertigation schedule technical bulletin.

3. Future Plan of Work

a. Continue to evaluate drip lines from different manufacturers in terms of clogging potential.
b. Evaluate four drip line irrigation schedules to determine the optimal schedule for growing watermelon in the shallow fast draining soils of Northern Guam.
c. Evaluate nitrogen fertigation rates with respect to optimal watermelon production.

4. Publications

Singh, P., Brown, R.W., Matanane, F. 2002. Guam Agricultural Climatic Data
System: 1999 Climatic Data and Summaries. Guam Agriculture Experiment Station
Technical Bulletin 389.

Singh, P., Schlub, R., Cruz, F. 2002. Irrigation, Fertigation, and Drainage chapter in
Eggplant, Pepper, and Tomato Production Guide for Guam, Guam Cooperative
Extension, pp. 36-39.

Singh, P., Brown, R.W. 2003. Evaluation of a Microirrigation System Design
Parameter for Watermelon in Tropical Shallow Soils. The 24th CAS Conference,
March 2003. Abstract.

5. Presentations at workshops

Farmers Workshop.  June, 2003.  This workshop was held for microirrigation
technology transfer and information dissemination for watermelon production.

Summer internship program for high school students. July 2003. Trained one
student  in microirrigation.
 

V. Idaho (for more details, follow this link)

Howard Neibling, Biological and Agricultural Engineering, University of Idaho

1. Progress of Work and Principal Accomplishments

Objective 1:  To evaluate and refine microirrigation management strategies to promote natural resource protection and optimal crop production. (including irrigation scheduling tools)

A project was developed in 2002 to demonstrate Watermark soil moisture sensors with Hansen data loggers as a tool for improved irrigation scheduling.  One aspect of the project was to compare water use and crop yield and quality on a portion of each field managed by the farmer with that managed with soil sensors.  Five grower fields were selected and irrigation scheduling modified during the 2003 growing season based on soil moisture sensor readings.  Because of the record high temperatures during this year, modifications in the growers irrigation scheduling were not as pronounced as would be expected during a normal season. One of the major keys to grower usage was a set of laminated cards showing the remaining usable soil water in inches and as % available, and the water depth required to refill each foot of soil to field capacity for a range of watermark readings for 4 soil textural classes.

Objective 2:  To improve, modify, and evaluate microirrigation system design and components for natural resource protection and optimal production.

Widening the spacing between adjacent tapes can reduce cost.  Maximum spacing is a function of crop, spacing and discharge of emitters along each tape and soil capillarity.  One cooperator in Custer County wanted to use SDI to water the entire soil surface for establishment and maintenance of native grasses and other near-stream vegetation.  Maximum effective spacing for that soil type and native grasses and shrubs was unknown so tests were performed to evaluate several tape spacings.   The soil profile was about 6-8 inches of silt loam soil, underlain by a number of layers of silt/gravel.  Based on tests, a spacing of 30 inches along the tape and 42 inches between tapes when buried 6-8 inches deep gave acceptable performance.  About 90 acres of tape were installed.  Wetting fronts at the surface were separated by about a 6- 10-inch dry soil strip.  The dry strip was narrower at the tape depth.  Winter precipitation should germinate grass seed in this area and water from the drip system will be sufficiently close to support grass growth in this initially dry zone. This site can now be used as a demonstration site for those interested in a similar application. 

Tape spacing was also evaluated at a second site on a Portneuf silt loam near Twin Falls.  Tape spacings for irrigated pasture were 24 and 48 inches.  After about 7 days of run time, the initially very dry soil was completely wetted at the surface for the 24-inch spacing.  On the second portion of the area, near complete wetting on the 24-inch spacing was achieved in 3 days with a 12 hour on- 12 hour off cycle.  The wetting fronts are still far apart at the surface on the 48-inch spacing .
 
Objective 4:  To promote appropriate microirrigation technologies through formal and informal educational activities. A cooperative study with Jason Ellsworth and Brad Brown on optimization of irrigation and fertility variables was conducted at Kimberly and Parma.  Crop yield and quality data, soil moisture data and soil fertility data were collected from each field.  Irrigation method was surface drip irrigation.  Results will be presented this winter.

Urban Water Management Demonstration Projects: Information on improved water management and water-saving opportunities for the use of microirrigation must be delivered to individual homeowners.  To affect a change in irrigation management, each individual must be motivated by desire to conserve and protect the environment, or by potential water cost savings.

2. Usefulness of Findings

Irrigation scheduling improvements were demonstrated using Hansen AM 400 dataloggers and Watermark sensors.

3. Future Plans

Educational materials will be developed cooperatively with interested county extension faculty to address both aspects.  Two major barriers to technology transfer are 1) the ability to deliver the information to the target audience, and 2) the ability to convince the audience that the desired change is beneficial and worthwhile.  Portions of the project approach are designed to address each barrier.  Public service announcements highlighting various aspects of water conservation will be developed by a joint University of Idaho / media effort.  Another possibility is a daily water use graphic in the local TV weather segment.

Demonstration projects are required to show that suggested management changes can save water and yet produce the desired lawn appearance.  Proposed sites are in Twin Falls at the KMVT lawn and two homeowner sites and a cooperative effort with the city of Twin Falls in a city park.  In addition, three sites in Jerome will be established.  A commercially available soil moisture sensor / sprinkler control device will be installed at each site to allow sprinkler to operate only when water is really needed.  At each site, measurements to be made include: daily metered water applied on conventional and improved management areas, soil moisture monitoring at 1, 2 and 3 foot depths using Watermark sensors and Hansen data loggers, weekly soil moisture monitoring by neutron probe (if cooperators approve), and evaluation of lawn appearance.  Historical water use per unit ET and measured current water use per unit ET will be used to evaluate water savings on project sites.  Information generated from demonstration sites on water savings, lawn appearance and the success of alternative irrigation system controls will be made available on the web site for public access, and will be used as the basis of water conservation educational efforts during late summer 2003, spring 2004 and summer 2004.

An initial version of a lawn and tree irrigation web site was developed using water-quality related funding.  The site is CD-based and is currently being tested by a number of interested county faculty.  It will be enlarged and improved as a part of the new urban water conservation project that received funding in September.

4. Publications

Qureshi, Z.A. 2003. Impact of Late-Season Irrigation Management on Malting Barley
Yield and Quality. Ph.D. Dissertation. Biological and Agricultural Engineering
Department, University of Idaho. Moscow, ID. 220pp.

Neibling, W.H., M. Colt, S. Bell, J. Robbins. 2003. Watering Home Lawns and
Landscapes. University of Idaho Current information Series #1098. 8pp.

5. Presentations

a. Urban programs discussing microirrigation applications and irrigation scheduling:

Neibling, W.H. "Irrigation management in the home lawn and garden". Presented at
the master gardener training, Hailey, ID.

Neibling, W.H. "Irrigation management in the home lawn and garden". Presented at
the master gardener training, Jerome, ID.

Neibling, W.H. "Irrigation management in the home lawn and garden". Presented at
the master gardener training, Twin Falls, ID.

Neibling, W.H.  "Types of equipment and irrigation strategies for roses". Presented at
the Twin Falls Rose Society meeting, 6/12/03.

b. Agricultural programs discussing irrigation scheduling tools:

Neibling, W.H. "Plant and soil properties important to irrigation system design and
management". Presented to irrigation equipment dealer employees at the annual
dealer employee workshop at the Idaho Irrigation Equipment Association Show.

Qureshi, Z and W.H. Neibling. "Coordination of irrigation and harvest of alfalfa to
minimize drying time without sacrificing yield.  Presented at the 2003 Idaho Irrigation
Equipment Association Show, Idaho Falls on both January 8th and 9th.

Qureshi, Z and W.H. Neibling. "Coordination of irrigation and harvest of alfalfa to
minimize drying time without sacrificing yield.  Presented at the 2003 Idaho Irrigation
Equipment Association Show, Idaho Falls on both January 8th and 9th.

Neibling, W.H. "Using Hansen meter output to schedule irrigation on potatoes in
different soils". Presented at the IDWR / UI Irrigation field day, Rexburg, ID, 6/17/03.

Neibling, W.H. and W. Weihing. "How much water do you really need?"  Presented at
the UI / IDWR irrigation workshop, Montpelier, ID.

Neibling, W.H. "Alfalfa water use efficiency and management: the risks of deficit
irrigation" Presented at the general session of the Western Alfalfa and Forage
Conference, Reno, NV. About 600 attended

Neibling, W.H. "Managing center pivot systems in forage production"  Presented as a
breakout session at the Western Alfalfa and Forage Conference, Reno, NV. About 120
and 70 attended the two sessions.

Neibling, W.H. "The risks of deficit irrigation in alfalfa production"  Presented at the
2003 Washington Hay Growers annual meeting, Pasco, WA. About 200 attended

Neibling, W.H. "Managing center pivot systems in forage production".  Presented at
the 2003 Washington Hay Growers Meeting, Pasco, WA. About 200 attended.

Neibling, W.H. "Alfalfa Water Use Efficiency and Management". Presented at the
2003 Oregon Hay Growers meeting, Christmas Valley and Burns, OR. About 20 and
50 attended.

Neibling, W.H. "Managing center pivot irrigation". Presented at the 2003 Oregon Hay
Growers Meeting, Christmas Valley and Burns, OR. About 20 and 50 attended.

Neibling, W.H. "Management of alfalfa under water-short conditions, and late season
irrigation of malting barley". Presented at the 2003 San Luis Valley Haygrowers
Meeting, Monte Vista, CO. About 150 attended.

Neibling, W.H.  "Irrigating alfalfa under water-short conditions". Presented at the
Blaine/Camas Alfalfa School, Fairfield, ID. About 20 attended.

Neibling, W.H.  "Managing alfalfa irrigation during water-short periods". Presented at
the Eastern Idaho Hay Growers Meeting, Rexburg, ID. About 30 attended.

Neibling, W.H. "Using soil moisture sensing equipment for water management in
alfalfa production". Presented at the UI Forage Field Day, Kimberly, ID. About 60
attended.

6. Graduate students

Zahid A. Qureshi, Ph.D. Biological and Agricultural Engineering  (graduated May 2003)
 

VI. Iowa (for more details, follow this link)

Henry G. Taber, Department of Horticulture
Vince Lawson, Department of Outlying Farms
 both of Iowa State University, Ames, IA 50011

1. Progress of Work and Principal Accomplishments

Iowa research was carried out on objectives 1 and 4.

Objective 1.  The research was conducted at the Muscatine Research Farm (eastern Iowa along the Mississippi river).  This site is an excessively drained coarse sand (sandy, mesic Entic Hapludoll) with 93% sand, 1-5% clay, organic matter of 1-3% and AWC of 0.5-0.7 inch/foot.

Objective 1.  The research was conducted at the Muscatine Research Farm (eastern Iowa along the Mississippi river).  This site is an excessively drained coarse sand (sandy, mesic Entic Hapludoll) with 93% sand, 1-5% clay, organic matter of 1-3% and AWC of 0.5-0.7 inch/foot.

Sweet bell peppers grown in twin-rows on black plastic mulch was the test crop to evaluate 3 irrigation scheduling methods using 2 in-line emitter spacings.  The irrigation methods were:

a. Soil tension = irrigation event triggered when daily readings of a 6-inch tensiometer reached 10-12 cb.  Water amount to apply determined as 50% depletion of AWC and brought back to field capacity.
b. Smittle crop coefficient = daily ET (modified Penman equation) X Smittle crop coef. (developed in GA under similar soil type and planting arrangements) determined daily amounts of water to apply.
c. Crop canopy = daily ET X crop canopy cover (never < 40%).

The 2 in-line emitter spacings were 6-inch and 12-inch Chapin twin wall cane tubing that delivered 0.3 gpm/100 ft.  The water amount called for by the methods was applied twice daily, at 8 AM and 2 PM.

Irrigation using the 6-inch tensiometer setting of 10 to 12 cbresulted in 32.6% more total fruit produced compared with the Smittle crop coefficient method.  Further, the marketable yield was doubled.  But cull fruit accounted for 67% of total fruit indicating none of the watering methods were suitable for commercial production.  Cull fruit were mostly small and misshapen.  By the second harvest significant root plugging of emitters was evident.

Tensiometer readings in all plots reflected the water amounts applied, i.e. the Smittle and crop canopy methods (both based on ET measurement) tended to run drier than the tensiometer based method.  The reference ET for the period was 12.24 inches.  The crop ET for the crop canopy treatment was 9.6 inches and the Smittle method 10.88 inches. Even though total water quantity was similar among treatments, the tensiometer method applied 383 gallons/plot more water prior to July 8, compared to 270 gals/plot for the crop canopy and Smittle methods, which resulted in more branching and flower development.  There was no difference in yield between the two emitter tape spacings.  Marketable fruit size and fruit shape was similar in all treatments at 5.7 ounces each and a 0.99 length/diameter ratio, respectively.

Objective 4.  A tensiometer demonstration trial was conducted with 4 Amish growers (underrepresented clients, small farmers) of greenhouse tomatoes in SE Iowa.  Their growing medium was field soil which was previously cropped with alfalfa.  Although they installed microirrigation tubing they did not know when to water or how much to apply.  Two equipment stations, each containing a 6-inch and 12-inch tensiometer, were established in each greenhouse and growers instructed on their use.  Results indicated considerable soil moisture tension variability within a greenhouse.  Also, acceptance of this water scheduling method differed among growers. 

2. Usefulness of Findings

The field day and grower demonstrations offered participants the opportunity to observe microirrigation in a field setting.  Growers were able to gain ‘hands-on’ experience with the system that, in some cases, improved tomato yield and quality.

4. Publications

Taber, H. G. (Ed.).  Annual Fruit/Vegetable Progress Report.  2002.  Iowa State Univ.
Coop. Ext. FG-601, pp.65.

5. Presentations

Muscatine Island Summer Field Day and Tour, July 14, 2002.  Participants visited a
200 acre microirrigation melon farm.

Presentation at field day by H. G. Taber, Irrigation scheduling techniques for
pepper production.

6.  Students

Darin Enderton, undergraduate horticulture student.
 

VII. Kansas

Freddie R. Lamm, Northwest Research-Extension Center
Gary A. Clark, Department of Biological and Agricultural Engineering
Mahbub  Alam, Southwest Research-Extension Center, all three from Kansas State University

1. Progress of Work and Principal Accomplishments

The Kansas W128 members had several accomplishments in 2003.  Approximately 30 students were exposed to training and educational opportunities related to microirrigation.  This included one graduate student who is investigating issues related to wastewater utilization through microirrigation systems.  There were two refereed journal articles concerning subsurface drip irrigation accepted in 2003 and are currently in press.   Two articles related to microirrigation were also published in the Encyclopedia of Water Science.  In addition, two other international proceeding papers and four cooperative extension papers were published.  Eight presentations were made at the international, national and regional levels in 2003 with approximately 250-300 meeting participants.

2. Usefulness of Findings

Microirrigation continues to grow in the Great Plains region as more information about installation, operation, maintenance and irrigation management is developed by Kansas State University.

4. Publications

Camp, C. A. and F. R. Lamm.  2003.  Irrigation systems, subsurface drip.
Encyclopedia of Water Science.  pp. 560-564.

Clark, G. A. 2003. Irrigation design steps and elements. Encyclopedia of Water
Science.  pp. 454-458 .

Lamm, F. R., A. J. Schlegel, and G. A. Clark. 2003. Development of a Best
Management Practice for Nitrogen Fertigation of Corn Using SDI. Appl. Engr in Agric.
(In press)

Lamm, F. R. and T. P. Trooien.   2003.   Subsurface drip irrigation for corn production:
a review of 10 years of research in Kansas.  Special issue of Irrigation Science (In
press).

Lamm, F. R. and T. P. Trooien.  2003.  Effect of dripline depth on field corn production
in Kansas.  In Proc. Irrigation Assn. Int’l. Irrigation Technical Conf., November 18-20,
2003, San Diego, CA..   Available from Irrigation Assn., Falls Church VA.

Lamm, F. R.,  2002.  Advantages and disadvantages of subsurface drip irrigation.  In
Proc. International Meeting on Advances in Drip/Micro Irrigation, Puerto de La Cruz,
Tenerife, Canary Islands, December 2-5, 2002. Instituto Canario de Investigaciones
Agrarias, Canary Islands. 13 pp.

Lamm, F. R. , D. H. Rogers, M. Alam and G. A. Clark.  2003. Design considerations
for subsurface drip irrigation (SDI) systems.  KSU Cooperative Ext. Irrigation Mgmt.
Series, MF-2578. 8 pp.

Rogers, D. H.,  Lamm, F. R.,  M. Alam, and G. M. Powell.  2003.  Shock chlorination
for treatment for irrigation wells.  KSU Cooperative Ext. Irrigation Mgmt. Series,
MF-2589.  4 pp.

Rogers, D. H.,  Lamm, F. R.,  and M. Alam.  2003.  Subsurface drip irrigation systems
(SDI) water quality assessment guidelines.  KSU Cooperative Ext. Irrigation Mgmt.
Series, MF-2575.  8 pp.

Rogers, D. H.,  Lamm, F. R.,  and M. Alam.  2003.  Subsurface drip irrigation (SDI)
components: Minimum requirements.  KSU Cooperative Ext. Irrigation Mgmt. Series,
MF-2576.  4 pp.

5. Presentations

Lamm, F. R. and T. P. Trooien.  2003.  Effect of dripline depth on field corn production
in Kansas.  A presentation at the Irrigation Assn. International . Irrigation Technical
Conference, November 18-20, 2003, San Diego, CA..   Available from Irrigation Assn.,
Falls Church VA.

Lamm, F. R.,  2002.  Advantages and disadvantages of subsurface drip irrigation.  A
presentation at the International Meeting on Advances in Drip/Micro Irrigation, Puerto
de La Cruz, Tenerife, Canary Islands, December 2-5, 2002. Instituto Canario de
Investigaciones Agrarias, Canary Islands.

Lamm, F. R., D. M. O’Brien,  D. H. Rogers, and T. J . Dumler. 2003.  Center pivot
sprinkler and SDI economic comparisons.  A presentation at the Central Plains
Irrigation Short Course, Colby, KS., Feb. 4-5, 2003.

Lamm, F. R.  2003.  KSU research for corn production using SDI: 14 years of
progress.   A presentation at the Central Plains Irrigation Short Course, Colby, KS.,
Feb. 4-5, 2003.

Lamm, F. R., D. H. Rogers, and W. E. Spurgeon.  2003.  Design and management
considerations for subsurface drip irrigation systems.  A presentation at the Central
Plains Irrigation Short Course, Colby, KS., Feb. 4-5, 2003.

Rogers, D. H., F. R. Lamm, and M. Alam.  2003.  SDI water quality assessment
guidelines.  A presentation at the Central Plains Irrigation Short Course, Colby, KS.,
Feb. 4-5, 2003.

Alam, M., D. H. Rogers, F. R. Lamm and T. P. Trooien.  2003.  Filtration: A basic
component for SDI to avoid clogging hazards.  A presentation at the Central Plains
Irrigation Short Course, Colby, KS., Feb. 4-5, 2003.

Lamm, F. R., A. J. Schlegel, and G. A. Clark. 2003. Nitrogen fertilization for corn
production using SDI.  A presentation at the Water and the Future of Kansas
Conference, Manhattan, KS., March 11, 2003.

6. Student Activities and Educational Programs By Objective

Objective 1.
Student Activities:
· The effects of chlorine dosing with livestock lagoon wastewater on fecal coliform bacteria and residual chlorine were evaluated.  (1 graduate student – Matt Steele)  · Lab tests were conducted to determine the effect of NH4-N concentrations in livestock lagoon water on required chlorine dosing to maintain a free residual chlorine level of 1-2 ppm.  (1 graduate student – Matt Steele)

Objective 2.
Student Activities:
· A field study with four different microirrigation tubing products and livestock lagoon wastewater was continued.  All four products were heavy wall, polyethylene pipe drip tubing products.  Two were designed for use with wastewater, and two had pressure compensating emitters.  The products range in cost from $0.40/m to over $0.80/m.  The study is evaluating the long-term performance and maintenance requirements of those products.  (1 undergraduate student – Jeremy Huser)
· A lab study was conducted to evaluate the effects of varying water temperature on drip emitter water discharge rates.  Two different products and two wall thickness values were evaluated.  These tests were a continuation of the drip tape performance standard tests. [Presented as a student poster at the Kansas Section ASAE meeting, 10/17/03] (2 undergraduate students – Jeremy Huser and Marsha Roberts) 

Objective 4.
Educational Programs
· The livestock Wastewater SDI system is part of the Kansas State University, Waste Management Learning Center.  An on-site overview on the use of microirrigation technologies for wastewater application was conducted for three undergraduate lab classes (about 15 students in each class) of Biological and Agricultural Engineering (BAE) and Agricultural Technology Management (ATM) majors at Kansas State University. 

Student Activities:
· A local producer with a relatively new SDI system had severe plugging after his first year of operation.  The nature and cause of his plugging was evaluated.  An acid treatment scheme was tested in the lab and then implemented on his field.  After three treatments his field based flow rates increased by 33%. (2 undergraduate students – Jeremy Huser and Matt Steele)
 

VIII. New Mexico

Mick O’Neill, New Mexico State university, Farmington

1. Progress of Work and Principal Accomplishments

a. Subsurface Drip Irrigation (SDI) on Field Crops

An 8-acre SDI trial was established in 2002 after system installation in 2001.  Four tape depths were evaluated with different field crops.   During 2002 alfalfa, beans, corn, and potatoes were grown at each of the different tape depths.  The rotation for 2003, which required a low-residue crop to follow a high residue crop, included alfalfa, corn, and potatoes.   Crops were evaluated and stand establishment, water-use, and final yield.

During 2002, alfalfa germinated only in areas immediately above the tape.  In order to improve plant stand in 2003, alfalfa was drilled into the existing stand and sprinkler irrigated approximately every other day for one month.  Growth of the existing stand improved but satisfactory emergence of the newly planted material was not obtained.  It is known that allelopathic competition can prevent germination of reseeded alfalfa from several weeks to over one year.  It appears that this was the case for poor establishment of reseeded alfalfa in 2003. 

Small, two-row planting equipment for potatoes was used in the large plots (25 x 400 feet) to successfully obtain uniform plant stands in all tape depth treatments.  Corn stand were directly related to tape depth ranging from a low of 64% in the 9-inch treatment to a high of 98% in the 3-inch treatment.
 
Weed control was improved during 2003 but tractor-mounted spray applications still leave much to be desired.  Soil applied herbicides are not adequately activated by incorporation because of limited rainfall or no sprinkler irrigation.  RoundUp performs well in genetically modified crops such as RoundUp Ready corn but the choices are limited.  Injection of herbicides through the drip system may hold promise.Gopher damage continues to plague the project.  Exorbitant time is devoted to splicing drip tape rather than completing other critical duties, especially early in the season when tape damage leads directly to reduced crop stands.  In closed canopy stands like alfalfa, damaged drip tape may go unnoticed until harvesting operations when swathers are bogged down in wet areas.  Drip tape buried at the deeper depths is difficult to find and may take 1-2 man-hours per gopher strike to repair.

Management of appropriate water application levels at four drip-tape depths is difficult when investigating different crops.  This is especially true with potato, which requires a favorably moist environment in the tuber profile for optimum production.  Given a uniform water application across all tape depths, the shallow depth treatments are too wet and the deep depth treatments are too dry.

b. Hybrid Poplar Production with Drip Irrigation

In an attempt to address several of the problems associated with SDI, especially the problems associated with gopher damage to buried drip tape, a 2-acre surface drip trial was established in 2002 to determine the production potential of hybrid poplar in the Four Corners region.  Ten hybrid poplar clones were selected.  Another trial was established in 2003 with the same ten clones plus an additional ten clones.  This trial was repeated at the OSU Malheur Experiment Station to investigate adaptation of poplar hybrids to elevated pH at two sites.

Growth and chlorosis differences were noted both years between the clones grown in an alkali soil with a pH of 8.2.  Clones that established well in 2002 and demonstrated superior growth rates also grow satisfactorily in 2003. Visual rankings of chlorosis were obtained in 2002 and a Minolta chlorophyll meter was used in 2003 to determine differences between hybrid clones.  Iron chelate was injected through the drip irrigation systems and clones responded favorable as indicated by increased SPAD readings.  Screening for growth rates and chlorosis ratings will provide information for the successful selection of clones adapted to a semi-arid environment with elevated soil pH characteristic of the Four Corners region. 

Gopher damage has been virtually eliminated.  During the two seasons, there have been five gopher strikes.  This is because the dripper tubing is heavier than the drip tape used in the SDI system and it is on the soil surface, which is out of the normal gopher habitat.  It is easy to see damaged dripper tubing lying on the surface thereby permitting rapid repairs.

Discussions with representatives from a large commercial farm and an excelsior manufacturing company have lead to the rapid dissemination of poplar production in the area.  Western Excelsior, which currently harvests aspen from the San Juan National forest, is interested in sustainable wood production for their factory.  The Navajo Agricultural Products Industry has agreed to initiate a 250-acre hybrid poplar plantation to begin to provide the wood required by Western Excelsior.  Cuttings of clones selected from research carried out by this project will be planted in the Spring of 2004.  Future plantations will be planted in successive years until Western Excelsior has ample supplies for their long-term requirements.

4. Publications

O’Neill, Mick, Renae Pablo, and Todd Begay 2003. Subsurface drip irrigation for field
crops. In: O’Neill, M.K., R.N. Arnold, D. Smeal, T. Jim, C.K. Owen, and K.D. Kohler.
2003. Thirty-sixth Annual Progress Report: 2002 Cropping Season. NMSU Agricultural
Science Center at Farmington. Agricultural Experiment Station and Cooperative
Extension Service. New Mexico State University. Las Cruces, New Mexico, USA. pp.
127-139.
http://aghort.nmsu.edu/Faculty-files/Farmington-NMSU-%20AnnRpt-2002%20.pdf

O’Neill, Mick and Kevin Lombard. 2003. Hybrid poplar production under drip irrigation
in the Four Corners region. In: O’Neill, M.K., R.N. Arnold, D. Smeal, T. Jim, C.K.

Owen, and K.D. Kohler. 2003. Thirty-sixth Annual Progress Report: 2002 Cropping
Season. NMSU Agricultural Science Center at Farmington. Agricultural Experiment
Station and Cooperative Extension Service. New Mexico State University. Las Cruces,
New Mexico, USA. pp. 140-143.
http://aghort.nmsu.edu/Faculty-files/Farmington-NMSU-%20AnnRpt-2002%20.pdf

5. Presentations

O’Neill, Mick, Kevin Lombard, Dan Smeal, and Rick Arnold. 2003. Hybrid poplar for the
Four Corners region. NMSU College of Agriculture, Annual All College Conference.
January 6-8, 2003. New Mexico State University. Las Cruces, New Mexico, USA.

O’Neill, Mick. 2003. Drip Irrigation. Seminar presented at the Nenahnezad Chapter
House, Navajo Nation. March 13, 2003. Nenahnezad, NM.

O’Neill, Mick, John Mexal, and Kevin Lombard. 2003. Establishment of hybrid poplar
under drip irrigation in the semi-arid Four Corners region. 8th North American
Agroforestry Conference. June 23-25, 2003. Corvallis, Oregon, USA.

O’Neill, Mick. 2003. Overview of Oregon trip with particular attention on drip irrigation
of hybrid poplar. Presentation to management of the Navajo Agricultural Products
Industry. July 29, 2003. Farmington, NM.

O’Neill, Mick. 2003. Highlights of drip-irrigated hybrid poplar plantation. Briefing to
management of the Navajo Agricultural Products Industry. August 14 & 18, 2003.
Farmington, NM.

O’Neill, Mick. 2003. Highlights of drip-irrigated hybrid poplar plantation. Briefing to
management of Western Excelsior, Inc. September 18, 2003. Farmington, NM.
F. Personnel Development

O’Neill, Mick and Renae Pablo. 2003. Visit to Potlatch Corporation Poplar Plantation.
June 18-19, 2003. Boardman, OR.

O’Neill, Mick and Renae Pablo. 2003. Visit to OSU Malheur Experiment Station. June
19-21, 2003. Ontario, OR.

O’Neill, Mick and Renae Pablo. 2003. Attended the 8th North American Agroforestry
Conference. June 22-25, 2003. Corvallis, OR.

6. Students supervised

Renae Pablo, M.S. NMSU Agronomy and Horticulture Department
Kevin Lombard, Ph.D. NMSU Agronomy and Horticulture Department
 

IX. New York

Alan N. Lakso,  Dept. of Horticultural Sciences, Geneva Station
email:   anl2@cornell.edu
http://www.nysaes.cornell.edu/hort/faculty/lakso/

Cooperators
  Terence L. Robinson   Pomology  Cornell, Geneva
  Robert M. Pool  Viticulture  Cornell, Geneva
  Gerry White   Ag Economics  Cornell, Ithaca
  Martin Goffinet  Plant Anatomy Cornell, Geneva
  David Eissentstat  Root Biology  Penn. State Univ.
  Terry Bates   Viticulture  Cornell, Fredonia
  Richard Dunst   Viticulture  Cornell, Fredonia

1. Progress of Work and Principal Accomplishments


Objective 1 - To evaluate and refine microirrigation management strategies to promote natural resource protection and optimal crop production.

 Wine production in NY and the Eastern US has increased dramatically in the last 20 years.  It has been noted in dry years is that grapevines that are stressed too much produce white wines that have poor flavor development, very poor aging characteristics and the development of specific unpleasant aromas (red wines are not affected in the same way).  These effects have been related to excessive water stress and poor nitrogen in the grape juice.  So, beginning in 2001 we have examined the effects of irrigation and nitrogen interactions on 'Riesling' grapevine productivity, fruit composition and wine characteristics.  In 2001 there was a late-season drought that reduced leaf function, berry size and ripening of the non-irrigated vines.  Wines were made and after only 6 months differences were noted with the irrigated vines showing more typical flavor development and fewer of the characteristics of poor-aging wines.  Tasting at 18 months showed further declines in the stressed wines.  2002 was even drier with severe mid-season stress and late-season stress although the stress was relieved about 3 weeks before harvest.  Wines again were made although more fruit rot disease occurred in some of the irrigated plots that had more leaf area and thus denser canopies.  This interaction made analysis more difficult.  The 2003 season was much wetter and cooler than average.  No clear irrigation effects were seen due to the weather.Objective 3 - To assess and develop decision criteria for adoption of microirrigation technologies.

Apple growers in the Northeast US are increasingly interested in irrigation due to several significant drought periods in the past 5 years.  Crop coefficients from arid climates due to the complexity of the microclimate of large discontinuous canopies, internal physiological factors affecting conductance, and different advective components (from cool lakes vs.. hot, dry areas).  In 2002 we estimated water use by multiple replicate apple trees with sap flow gauges calibrated for shorter periods with whole canopy gas exchange chambers. The orchard tested was a mature slender spindle system on M.9 dwarfing rootstock with about 55% cover or light interception. We found that for the heat-pulse gauges used, the direct calibration with the gas exchange chambers was needed as the gauges gave greatly varying estimates on replicate trees.  Mid-season healthy average orchard water use averaged about 3.0 mm ha-1 (21 mm week-1) from mid-June until the end of July.  The estimates were compared to estimates of ET for a reference grass (by the current FAO modified equation) and to published apple crop coefficients. The actual Kc values peaked at about 0.8 in early July, lower than published values.  There was not a good correlation between daily estimates by sap flow vs. (Eto x Kc).  The results showed that the published Kc values for apples for arid climates are approximately 30% too high for the Northeast.

Meteorological measures confirmed that there were almost no gradients of humidity from the canopy to the bulk air, i.e. essentially no boundary layer.  This means that VPD as well as stomatal conductance were important regulators of tree water use in addition to net radiation.  A further modification of the Penman-Monteith equation to include the minimal boundary layer, as well as light and VPD effects on stomatal conductance led to improved estimates of tree water use in the variable climate of NY.Objective 4 - To promote appropriate microirrigation technologies through formal and informal educational activities.

 The results of these studies have been communicated to growers via popular publications (see below) and seminars presented at growers meetings in the Northeast region.  Also results have been incorporated into the fruit crop physiology component of a graduate class on Woody Crop Physiology at Cornell University.  The work on apple water use was the focus of a Ph.D. thesis at Cornell University by Danilo Dragoni in the Department of Horticultural Sciences at Geneva.

2. Usefulness of Findings

This continuing work on juice grape irrigation has led more grape growers to put in drip irrigation systems, especially for newly planted Niagara grapes that is a growth component of the industry.  This work led to the NY industry research award, attesting to its impact on the grape and wine industry.  Also there has been a significant increase in grower interest in and installations of irrigation systems for apples and wine grapes in New York and elsewhere in the Northeast.  For example, in 1999 a local evening grape grower meeting on irrigation drew 7 growers, but the same in 2002 drew over 60 growers.  Irrigation is now considered an important management tool by many growers in the Northeast who previously assumed it was not necessary.

A. Lakso was awarded the 2003 New York Wine and Grape Foundation's Outstanding Research Award for significant research contributions to the grape and wine industries.  This was based in large part on the irrigation research.

4. Publications

Lakso, A.N.  2002.  Getting a "feel" for water stress.  Finger Lakes Vineyard Notes
No. 7 (July 23), pp. 3-4.

Lakso, A.N., D.M. Eissenstat, L. Comas and R. Dunst.  2002.  Effects of Irrigation and
Pruning on Concord Grape Productivity and Seasonal Root Development.  2002 Proc.
Irrig. Association (CD-ROM)

Lakso, A.N. 2003. Water relations of apples.  P. 167-194.  In: Apples: botany,
production and uses.  D.C. Ferree and I.A. Warrington (eds.), CAB International,
Wallingford, Oxon, UK.

Lakso, A.N., D.M. Eissenstat, L. Comas and R. Dunst.  2003.  Effects of Irrigation and
Pruning on Concord Grape Productivity and Seasonal Root Development.  International
Water and Irrigation 23 (2)32-34.

Anderson, L.J.,  L.H. Comas, A.N. Lakso and D.M. Eissenstat.  2003.  Multiple factors
in root survivorship: a four-year study in Concord grape.  New Phytologist 158(3):
489-501.

Li, K-T., A.N. Lakso, R.M. Piccioni, and T.L. Robinson. 2003.  Summer pruning
reduces whole-canopy carbon fixation and transpiration in apple trees. J. Horticultural
Science and Biotechnology (in press)

5. Presentations

a. Grower Presentations:
• NY Wine Industry Workshop, Geneva, NY 2003 -  Water stress/irrigation and wine
quality problems
• Western NY Tree Fruit Schools (2) – Water Stress and Water use in Apples
• Viticulture 2003 Regional Grape Symposium
- Water Balance in vineyards
- Irrigation in Juice Grapes

b. Scientific Presentations:
•  Invited Dept. Seminar, Horticulture Department, Michigan State University
•  American Society for Enology and Viticulture / Eastern Section – Grapevine water
use in NY
•  International Symposium on Irrigation of Horticultural Crops – Davis CA – Measuring
and modeling water use in apple trees in the humid Northeast US
 

X. Oregon

Clint Shock, Erik Feibert, Eric Eldredge, and Monty Saunders,
Malheur Experiment Station, OSU, 595 Onion Ave., Ontario, OR 97914 (541)
889-2174 Clinton.Shock@oregonstate.edu

Marvin Butler and Claudia Campbell, Central Oregon Agricultural Research
Center, OSU, 850 Dogwood Lane, Madras, OR 97741 (541) 475-7107

Jim Klauser, Clearwater Supply, Ontario, OR

Ali I. Akin, Researcher, Ankara Nuclear Agriculture and Animal Research
Center, 06105 Saray/Ankara, Turkey

Levent A. Unlenen, Agricultural Engineer, Nigde Patates Arastirma, Enstitusu Mudurlugu, Nigde, Turkey, 51100.

1. Progress of Work and Principal Accomplishments

Drip irrigation systems were tested in 2002 and 2003 on alfalfa for seed, alfalfa for hay, potato, onion for seed and for bulbs, poplar for saw logs, yew, sugar beet, and carrot for seed.  Treatments are being evaluated based on crop yield, crop quality, and water use.  Grids of sensors are being used to examine the vertical and horizontal movement of water through the soil profile from drip tapes.  Various soil moisture monitoring equipment was evaluated for irrigation scheduling in growers' fields.

a.  In 2002 and 2003 demonstrations in growers' fields showed that that onions required relatively little fertilizer N when irrigated with SDI. b.  For onion production on 42-44 inch beds with 0.22 gal/min/100 foot tape, growers use irrigation set times of 4-6 hours in April and May, 6-8 hours in June, and 8-12 hours in July and August.  Our initial research on the irrigation criteria for drip irrigated onion used high frequency drip irrigation with set times of about 1 hour.  In 2002 and 2003 we tested irrigation duration as a variable, to determine if longer sets would result in more water being applied or differences in bulb yield or quality.

c.  Ultra-low-flow drip tape was compared to low-flow drip tape in onion and potato.

d.  Three small commercial drip-irrigated potato fields were planted in Oregon and Idaho in 2003; 3, 5 and 10 acre fields.  Growers plan to expand their acreage in 2004. tile potato planter was designed and built in 2003 to allow variable distance between potato rows, between seed pieces within the rows, and variable drip tape placement with respect to the potato rows.  Three different drip-irrigated potato planting configurations were tested at two potato plant populations.  This trial was planted by us, both at Ontario, OR, and Patterson, WA, in the Columbia Basin.

f.  We seek to identify potato varieties adapted to drip irrigation.  Eleven potato varieties were compared for bulking rate, yield, grade, and quality under drip irrigation in 2003. g.  Irrigation criterion for alfalfa seed production was examined for the third year in 2003.  Alfalfa seed yield using SDI was highest with about 14 acre-inches of water per acre, compared to wetter or drier treatments.

h.  The semi-permanent subsurface drip irrigation (SDI) system in the alfalfa seed field is being converted to serve rotation crops.  Wheat and corn are planned for 2004 and 2005.

i.  A demonstration area compared alfalfa variety forage performance under SDI.

j.  Water use efficiency of SDI was greater than micro-sprinklers for poplar saw log production in 2002.

k.  Poplar clones are being screened for tolerance to alkaline soil with a surface drip irrigation system.  This trial is being conducted by Mick O'Neill at Farmington, NM, and by us at Ontario, OR. l.  In cooperation with OSU, Central Oregon growers compared drip irrigation systems to sprinkler irrigation systems for carrot and onion seed production.  Carrot seed production with drip irrigation resulted in water savings and increased seed yield.

m.  Carrot grown for seed is a very important high-value crop in central Oregon.  Disease tolerances are low in the crop, particularly to Xanthomonas campestris pv carotae, Alternaria radicina and A. dauci.  Employing a subsurface drip system to deliver irrigation water may decrease potential for disease infection and spread within the carrot canopy and may provide long term benefits of decreasing water and fertilizer use.

n.  Several types of soil moisture sensors have been compared for irrigation scheduling over the last three years.  Three types of data loggers have been used to automatically read Watermark soil moisture sensors; two of which simplify data collection for growers.

2. Usefulness of Findings

Micro irrigation has the potential to reduce water use, leaving more water in streams and reservoirs.  Surface water contamination of streams can be less with micro irrigation and groundwater contamination by nitrate and pesticides can be sharply lower.  The environmental benefits of micro irrigation can only be achieved if micro irrigation proves to be economically feasible through reductions in other costs not related to the added costs of the micro irrigation system and improvements in crop yield or quality.  

Drip-irrigated onion has expanded to 3,000 acres in the Treasure Valley and above 8,000 acres in the Pacific Northwest.  There were 1,800 acres in Malheur County alone, with vastly reduced N inputs and no irrigation-induced erosion and associated pollutant runoff.  Thirty to 40 percent less water was required using SDI.

3. Work Planned

In 2004 drip irrigation trials will continue on onions, potatoes, corn, and poplar for saw logs as described above in the accomplishments parts. a, c, e, f, h, j, and k..  Soil moisture sensors will be continue to be evaluated for irrigation scheduling of micro irrigation systems.

4. Publications

a. Refereed  Articles

Shock, C.C., E.B.G. Feibert, L.D. Saunders, and S.R. James. 2003. Umatilla Russet
and Russet Legend potato yield and quality response to irrigation. HortScience. In
Press for October.

Shock, C.C., 2003. Soil water potential measurement by granular matrix sensors.  In
Stewart, B.A. and T.A. Howell, (eds). The Encyclopedia of Water Science. Marcel
Dekker. p 899-903.

Eldredge, E.P., C.C. Shock, and L.D. Saunders. 2003. Early and late harvest potato
cultivar response to drip irrigation. Acta Horticulturae. In press.

b. Publications for Users

2002 Central Oregon Agricultural Research Center Annual Report
Weber, Mike, Brad Holliday, Marvin Butler, Claudia Campbell, Jim Klauzer, Leroy
Buck, Tom Kirsch, Rich Lewis, Harold Siegenhagen, and Stan Sullivan. 2003. Drip
irrigation on commercial seed carrots and onions in 2002.
http://eesc.orst.edu/agcomwebfile/edmat/html/SR/SR1046/166.htm

Oregon State University Agricultural Experiment Station, Special Report 1048.  Also
available on the web at http://www.cropinfo.net/AnnualReports/2002/index.html

Eldredge, E.P., C.C. Shock, and L.D. Saunders. 2003. First year results of the 2002
to 2006 alfalfa forage variety trial. p 14-17.
http://www.cropinfo.net/AnnualReports/2002/B5aDripAlf02.htm

Shock, C.C., L.D. Saunders, G. Tschida, L.D. Saunders, and J. Klauzer. 2003.
Relationship between water stress and seed yield of two drip-irrigated alfalfa varieties
2002. p 18-30. http://www.cropinfo.net/AnnualReports/2002/Alfseed02.htm

Shock, C.C. and J. Klauzer. 2003. Growers conserve nitrogen fertilizer on
drip-irrigated onion. p 61-63.
http://www.cropinfo.net/AnnualReports/2002/OnionDripNitrogen02.htm

Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2003. Irrigation frequency, drip tape
flow rate, and onion performance. p 64-70.
http://www.cropinfo.net/AnnualReports/2002/OnionDrip02.htm

Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2003. Micro-irrigation alternatives for
hybrid poplar production, 2002 Trial. p 110-118.
http://www.cropinfo.net/AnnualReports/2002/Popirr2002.htm

Shock, C.C., E.B.G. Feibert, and J. Eaton. 2003. Effect of pruning severity on the
annual growth of hybrid poplar. p 119-124. (Conducted on micro-irrigated poplar).
http://www.cropinfo.net/AnnualReports/2002/popprune2002.htm

Shock, C.C.,  E.P. Eldredge, and L.D. Saunders. 2003. Tuber bulking rate and quality
of processing potato clones in relation to planting date. p 152-158. (Drip irrigated
potato clone performance).
http://www.cropinfo.net/AnnualReports/2002/EarlyHarvProcVars.htm

Akin, A.I., L.A. Unlenen, E.P. Eldredge, C.C. Shock, E.B.G. Feibert, and L.D.
Saunders. 2003. Processing potato production with low-flow drip tape or ultra-low-flow
tape. p 167-172.
http://www.cropinfo.net/AnnualReports/2002/PotatoDripFlowAnRep2002.htm

Shock, C.C., K. Kimberling, A. Tschida, K. Nelson, L. Jensen, and C.A. Shock, 2003.
Soil moisture based irrigation scheduling to improve crops and the environment. p
227-234.
http://www.cropinfo.net/AnnualReports/2002/Hansen2002.htm

Shock, C.C., A. Akin, L.A. Unlenen, E.B.G. Feibert, K. Nelson and A. Tschida. 2003.
A comparison of soil water potential and soil water content sensors. p 235-240.
http://www.cropinfo.net/AnnualReports/2002/sensortest02.htm

c. Published only on the web

Shock, C.C. and S. Sullivan. 2003. Owyhee 5th Grade Field Day (This is a web site
with a virtual field day on it sponsored by the Owyhee Watershed Council).  This site
was first published in 2002 and entirely rewritten for 2003.  (The field day includes an
introduction to irrigation methods, ideas of water use, and options for erosion control).
http://www.cropinfo.net/owyheefieldday.htm

d.. Articles in the Popular Press

Educational tour: farmers, residents to daylong agriculture presentation. Larry Meyer.
Argus Observer. July 11, 2003. 111:162 pA1-A2.

Malheur Experiment Station field day showcases research. Karen Strickler. July 24,
2003. Western Canyon Chronicle. p11-16.

Onions on drip. Karen Gentry. The Vegetable Growers News. August 2003. p1 and 4.

5. Presentations

a. Invited Presentations

Shock, C. C. 2003. Automation of drip irrigation research.  WSU Prosser, WA.
January 13.

Shock, C. C. 2003. Alfalfa seed drip irrigation research. Oregon and Idaho Alfalfa
Seed Growers' Winter Meeting, Four Rivers Cultural Center, Ontario, OR January 15.

Butler, Marvin. 2003. Drip irrigation on carrots grown for seed. Columbia Basin Seed
Association Meeting, Moses lake, WA. Jan 21.

Shock, C.C. 2003. Potato irrigation management. Potato Production Workshop,
Oregon Potato Conference, January 27.

Shock, C.C. 2003.  Avoiding potato dark-ends. Potato Production Workshop, Oregon
Potato Conference, January 27.

b. Reports at Professional Meetings

Shock, C.C., A. I. Akin, L. A. Unlenen, Erik B. G. Feibert, and Cedric A. Shock, 2003.
Precise irrigation scheduling using soil moisture sensors.  International Irrigation Show
2003 Proceedings, The Irrigation Association. San Diego, CA. November 18-20. 12p.
Shock, C.C., E.B.G. Feibert, and L.D. Saunders. 2003. Drip irrigation frequency and
drip tape flow rate affect onion performance? American Society of Agronomy, Denver,
CO.

c. Reports to Growers At Field Days

Central Oregon Farm Fair, Feb. 5-6.

Butler, M. 2003. Drip irrigation on carrots grown for seed.

Malheur Experiment Station Field Day, July 9.

Feibert, E.B.G. and C.C. Shock. 2003. Optimal irrigation scheduling and N fertilization
management for drip-irrigated onion production.

Feibert, E.B.G. and C.C. Shock. 2003. Can onion production benefit from ultra low
flow tape?  Will this increase the yield of drip-irrigate onions?  What irrigation
frequency is needed?

Shock, C.C. 2003. Monitoring soil moisture movement under low flow and ultra low
flow drip tape and irrigation strategies for drip-irrigated onion.

Feibert, E.B.G. and R. Flock. 2003. Micro irrigation management of poplar for saw log
and peeler log production.

Feibert, E.B.G. and R. Flock. 2003. Selection of poplar cultivars for their productivity
under drip irrigation on alkaline soils.

Eldredge, E.P. and C.C. Shock. 2003. Bulking rate of potato cultivars under drip
irrigation.

Shock, C.A. 2003. Automation of reading Watermarks for irrigation scheduling in
onions.

Eldredge, E.P., C.C. Shock, et al. 2003. Usefulness of Vydate for drip-irrigated
potato?

Shock, C.C., E.P. Eldredge, et. al. 2003. Planting configurations for drip-irrigated
Umatilla potato.

Shock, C.C., E.P. Eldredge, et. al. 2003. A trial to examine the relationship between
plant population and marketable yield for drip-irrigated red potato production.
.
Malheur County Drip Irrigation Field Tour, July

Shock, C.C. and E.P. Eldredge. 2003. Alfalfa variety performance using buried drip
irrigation.

Klauzer, J. and C.C. Shock. 2003. Planting configurations and irrigation options for
potato.

Larson, L. et al. 2003. Water filtration for drip irrigation systems.

Jensen, L. and C. Yano. 2003. Vydate use in drip-irrigated onion.

Jensen, L., C. Yano, and C.C. Shock. 2003. Irrigation practices in drip-irrigated onion.

Shock, C.A, C.C. Shock, M.K. Hansen, and A. Hawkins. 2003. Automated reading of
soil moisture sensors for irrigation scheduling in drip-irrigated onion.

6. Students

Benjamin Horn, Treasure Valley C.C., Payette, ID
Susan Sullivan,  University of Oregon, Ontario, OR
Brian Noble, Treasure Valley C.C., Vale, OR
James, Auw,  Albertson College of ID, Ontario, OR
David McPeak, Treasure Valley C.C., Nyssa, OR
Brandon Hoxie, University of Idaho, Payette, ID
Rebecca Flock, Grove City College, Vale, OR
Cedric Shock, University of Oregon, Ontario, OR
Caroline Weber, University of Puget Sound, Madras, OR
 

XI. Texas

Steve Evett, Soil Scientist, Lead Scientist - Crop Water Use and Irrigation
Research Team, Soil and Water Management Research Unit
USDA-ARS, P.O. Drawer 10 (2300 Experiment Station Road), Bushland, Texas
79012 USA 806-356-5775, FAX: 806-356-5750
srevett@cprl.ars.usda.gov, http:/www.cprl.ars.usda.gov/programs/

3. Work Planned

We took our drip experiments out of production this year while we designed a new, larger, more field sized drip irrigation facility. Paul Colaizzi is leading the design effort for this facility and has already installed the head works (pump, filters, flow meters, etc.). We are finalizing the design and layout of the drip lines in the field, which is about 20 acres.

Unfortunately, we have nothing to report for this year except that we are actively planning new drip research activities. Our research will involve comparing the effect of different drip tape depths on soil temperatures, uniformity of seed bed wetting, and uniformity of emergence, using both conventional 30-inch bed spacings and a wide bed with two rows of plants on either side of a buried tape, with a larger interrow.  Emergence is the biggest unresolved problem we have with drip here.

XII. Virgin Islands

A. M. Palada

4. Publications

Palada, M.C., S.M.A. Crossman, A.M. Davis and J.A. Kowalski.  2003.  Yield and
irrigation water use of vegetables grown with plastic and straw mulch in the Virgin
Islands.  International Water & Irrigation 23:21-25.

Palada, M.C., D.A. O’Keefe and J.M. Mitchell.  2003.  Yield and water use of hot
peppers under three irrigation regimes.  HortScience 38(5):707 (abstract).

Palada, M.C., J.M. Mitchell and D.A. O’Keefe.  2003.  Growth and yield response of
Puerto Rican sweet pepper to levels of drip irrigation in the Virgin Islands.  Proc.
Caribbean Food Crops Society (CFCS) 39th Annual Meeting, Grenada (in press).

5. Presentations

Caribbean Food Crops Society Annual Conference, Grenada

Centennial Conference of American Society for Horticultural Sciences, Rhode Island

Third World Congress on Medicinal and Aromatic Plants, Thailand

Sixth International Workshop on Herbal Medicines in the Caribbean, Trinidad

Workshop on Drip Irrigation of Hot Peppers during World Food Day, St. Croix, Virgin
Islands

Training Workshop on Production and Post Harvest of Chili Peppers and Okra, Accra,
Ghana

First Agricultural Forum: Prospects for Sustainable Agriculture for the Virgin Islands,
St. Croix, Virgin Islands

6. Students

Emilie Cramet, Institut Universitaire Professionnalise, Quimper, France
Lucie Dromer, Institut Universitaire Professionnalise, Quimper, France
Kwasi Henry, University of the Virgin Islands, St. Croix
Erickson Thomas, University of the Virgin Islands, St. Croix
 

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