Sustain Water Quality and Agricultural Productivity

Nov 16-19, 2004, Tampa, FL

Progress Report on Microirrigation at New Mexico State University, 2004

Period Covered:1-2003 to 12-2003

Annual Meeting Date:11-16-2004 to 11-19-2004

Participants:Mick O’Neill

New Mexico State University

Agricultural Science Center at Farmington

 

Accomplishments and Impacts:
 

The 2003 field crop trial investigating tape depth placement on a sandy loam soil was harvested and data compiled after the 2003 W-128 Annual Meeting.
 

Crop Stand
Four tape depths were evaluated in an SDI trial with different field crops.  The rotation in 2003 alfalfa, corn, and potatoes.   Potatoes and corn were planted at four tape depths during April and May, respectively.  Reseeding of alfalfa plots was necessary due to poor germination during the 2002 season. This was carried out in June, 2003. 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 high of 98% in the 15?cm treatment to a low of 64% in the 30-cm treatment.  The linear reduction in plant stand with increasing tape depth had a coefficient of regression (r2) equal to 0.96.  Corn stand in the 15?cm and 20-cm depth treatments were not significantly different at the 0.05 level.
 

Water Application
Total application to alfalfa amounted to 886 mm.  Application rates for second season alfalfa were based on equations developed at the Center in Farmington, NM for relating ET to Julian days (Smeal, Personal Communication, 2001).The application to alfalfa was under-irrigated 338 mm and did not keep up with evaporative demand.  The total application to corn of 876 mm was an excess of 150 mm according to calculations developed by Smeal (Personal Communication, 2001).  This was the result of over applications at the beginning of the season to promote germination and an excess at the end of the season after the crop had reached physiological maturity.  Potatoes were irrigated 56 mm over the target application (Smeal, Personal Communication, 2001) for a total of 968 mm.
 

Yield
There were no significant differences between tape depth treatments for any of the four alfalfa harvests.  Mean alfalfa yield varied from 2.69 Mgha-1 for cut-1 to 1.12 Mgha-1 for cut-4.  Total alfalfa yield for all four treatments averaged 8.96 Mgha-1.  Corn yield, on the other hand, was significantly different between tape depth treatments due significant stand differences.  Grain yield ranged from 11.0 Mgha-1 for the 30-cm treatment to 17.9 Mgha-1 for the 15-cm treatment.  Based on Chicago Board of Trade prices of $6.27 per hectare on Dec 12, 2003, the farm gate value of corn ranged from $1,097 to $1,798 per hectare.  Full potato plots and samples taken from two 6-m rows in each plot were used to determine total yield and the size distribution and specific gravity of potatoes grown with subsurface drip irrigation.  There were no significant differences between treatments for these traits.  Mean total potato yield from the full plots was 35.3 9 Mgha-1 while mean total yield from the sample plots was 43.7 Mgha-1.  Ten potatoes from each plot were randomly selected on Aug 22 and Sept 26, 2003.  These samples were delivered to the NAPI Agricultural Testing and Research lab for quality determination.  Standard procedures were used to determine sugar, color and defects (Onken, Personal Communication, 2003). Internal and external defects were high on both dates.  Total defects were significantly different for the samples taken on Aug 12 with the 30-cm having the greatest defects at 17%.  Defects were generally scab on the skin and brown spots inside the tuber.  These defects rendered the crop as seconds to be used in processed products such as soups and stew.
 

Project Impacts
 

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 performed well with 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.
 

Sufficient data have been collected to determine that the deeper treatments are too deep for satisfactory germination and crop development, especially for alfalfa and potatoes.  Corn significantly produced the greatest yield at the 15-cm and 20-cm depths. This was a direct result of superior germination and emergence at these depths.  As part of a regional project, this trial will be modified to investigate the water and nitrogen requirements of drip irrigated corn using tape injected at the 15-cm depth.
 

Hybrid Poplar Production with Drip Irrigation
 

Seasonal growth characteristics for the 2003 hybrid poplar trial investigating adaptation potential in the Four Corners region were evaluated and data compiled after the 2003 W-128 Annual Meeting.
 

Of the ten Populus sp. evaluated for production in the semi-arid Four Corners region, seven had P. trichocarpa, two had P. deltoides, and one had P. nigra female parentage.  There were two clones each with P. maximowiczii and P. nigra male parentage and six clones with P. deltoides male parentage.  Johnson and Johnson (2003) suggest that hybrid poplar breeding programs for the semi-arid regions of eastern Washington and Oregon should include P. nigra as one of the parents to increase resistance to poplar-and-willow borer (Cryptorhynchus lapathi) and reduce water stress.  In this trial, NM-6, OP-367, and 311-91 all had P. nigra parentage, although NM-6 was developed from a female P. nigra parent while OP?367 and 311-93 were derived from male P. nigra parents.
 

Irrigation application rates were based on equations derived from Boardman, OR and developed at the Center for relating ET to Julian days (Smeal, Personal Communication, 2001).  Total ET amounted to 660 mm while total application was 686 mm for the poplar trees.
 

A Minolta SPAD-502 chlorophyll meter was used to obtain indicators of chlorosis for all trees.  Although OP-367 had the highest SPAD reading of 42.5 on July 1, 2003, some chlorosis was still evident.  SPAD readings taken on August 19 increased in all clones.  OP-367 again had the highest mean SPAD reading at 50.7 while 52-225, 195-529, and Eridano exhibited the lowest readings.  A final evaluation on September 15 again indicated that OP-367 had the highest SPAD reading at 50.3.  As in 2002, OP 367 was again the tallest clone; after two seasons reaching a mean height of 4.1 m.  The second tallest clones were 311-93 and 58-280.  The shortest clones were NM-6 and Eridano at 2.5 m and 2.3 m, respectively.  OP-367 had the largest basal diameter of 9.1 cm.  This was followed by 311-93, 58-280 and 49-177.  DBH followed the same pattern as height with OP-367 having the greatest DBH of 4.5 cm followed by 311-93 and 58-280.  Eridano and NM-6 had the smallest DBH of 1.5 and 1.3 cm, respectively.  Maximum wood volume was obtained by OP-367 at 2.9 m3ha-1 followed by 58-280, 311-93, and 49-177.
 

Linear functions significantly represented the relationship of SPAD readings with height, basal diameter and DBH.  A quadratic function was a better indicator of the relationship between SPAD readings and wood volume obtained at the end of the second season.
 

Project Impacts
 

Clearly, capitalizing on genetic variability is crucial for hybrid poplar to be successful in arid and semi-arid regions with alkaline soils.  Chlorosis, due to reduced chlorophyll production, is the principal visual symptom of iron deficiencies.  Quantitative chlorosis evaluations in 2003 identified OP-367 with the highest greenness level. All entries responded to iron chelate injection through the irrigation system but OP-367 was the only clone to obtain a SPAD reading ? 50.
 

OP-367 was the tallest clone after two seasons.  It was followed in height by 311-93 and 58-280 in 2003.  OP-367 was also superior for basal diameter, DBH, and wood volume in 2003.  Wood volume obtained by OP-367 after two seasons was 43% greater than the next tallest clone, 58?280.  Both OP-367 and 311-93 have P. nigra male parental germplasm, a trait considered important for poplar breeding programs in arid and semi-arid regions.
 

In a tree screening program, rapid and repeatable predictors of growth characteristics are required to identify superior clones for further evaluations. In this, trial, regression analysis was used to describe a number of growth characteristics based on the relative leaf greenness during the growing season.  Regression was satisfactorily used in 2003 to describe the relationship between seasonal SPAD readings and the growth characteristics of height, basal diameter, DBH, and wood volume.
 

A broad range of hybrid poplar germplasm with P. deltoides, P. maximowiczii, P. nigra, and P. trichocarpa parentage was evaluated in Farmington, NM to identify suitable clones for production in the semi-arid Four Corners region.  OP-367 was superior in most characteristics measured during the initial two-year growth period.  Irrigation applications were determined by using replacement ET calculations extrapolated from Boardman, OR.  The equations appeared to underestimate water requirements as OP-367 produced more biomass in Boardman and Malheur, OR, environments somewhat more temperate than that of Farmington.  Regression analysis of leaf color with growth characteristics was a satisfactory tool for identifying superior clones. Results from this trial will form the basis for the selection of material to be used in an extensive conservation program based on poplar production.  Further research is required to quantify water use and nutrient requirements of a wider range of germplasm adapted to alkaline soils in arid and semi-arid regions.
 

Based on our observations, it appears that the hybrid OP-367 shows the most promise for high pH soils typical of the area.  OP-367 clearly exhibits the least chlorosis, greatest height, and diameter at ground level and will likely be advanced to larger scale trials in following seasons.
 

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

Publications

Martin, E.C. and M.K. O’Neill (ed). 2004. Fourth Annual Four Corners Irrigation Workshop. July 10-11, 2003. Shiprock, NM. University of Arizona Technical Report. 51p. http://cals.arizona.edu/pubs/water/abe001.pdf

O’Neill, M.K. and K. Lombard. 2004. Hybrid poplar production under drip irrigation in the Four Corners region. In: O’Neill, M.K. (ed). Thirty-seventh Annual Progress Report: 2003 Cropping Season. NMSU Agricultural Science Center at Farmington. Agricultural Experiment Station and Cooperative Extension Service. New Mexico State University. Las Cruces, New Mexico, USA. 

O’Neill M.K. and E.C Martin. 2004. Workshop Introduction. In: Martin, E.C. and M.K. O’Neill. (ed). Proceedings: Fourth Annual Four Corners Irrigation Workshop. July 10-11, 2003. Shiprock, NM. University of Arizona Technical Report. 51p.

O’Neill, M.K., R. Pablo, and T Begay. 2004. Subsurface drip irrigation for field crops. In: O’Neill, M.K. (ed). Thirty-seventh Annual Progress Report: 2003 Cropping Season. NMSU Agricultural Science Center at Farmington. Agricultural Experiment Station and Cooperative Extension Service. New Mexico State University. Las Cruces, New Mexico, USA.  http://www.cropinfo.net/W-128/StateReports/2001/NMSUAnnRpt2001W-128.htm

O’Neill, M.K., D. Smeal, R.N. Arnold, and K. Lombard. 2004. Growth and survival of drip-irrigated hybrid poplar in the semi-arid Four Corners region. Submitted to Western Journal of Applied Forestry. 

Presentations

O’Neill, M.K. 2004. Drip irrigation for hybrid poplar trees. Fifth Annual Four Corners Irrigation Workshop. July 15-16, 2004. Durango, CO.

O’Neill, M.K., D. Smeal, R.N. Arnold, K. Lombard and J. Mexal. 2004. Establishment of hybrid poplar in semi-arid temperate zones. 1st World Agroforestry Congress. June 27 – July 2, 2004. Orlando, FL. http://conference.ifas.ufl.edu/wca/Abstracts2.pdf. p. 325.

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