Third Year Results of 2002-2006 Drip-Irrigated Alfalfa Forage Variety Trail


 Third Year Results of the 2002-2006 drip-irrigated Alfalfa Forage Variety Trial

 

 

Eric P. Eldredge, Clinton C. Shock, and Lamont D. Saunders

Malheur Experiment Station

Oregon State University

Ontario, OR, 2004

 

 

Introduction

 

The purpose of this trial is to compare the productivity and hay quality of alfalfa varieties in the Treasure Valley area of Malheur County. The trial also provides information about the adaptation of alfalfa hay production to drip irrigation. In this trial, over 5 years, 10 proprietary varieties are being compared to 2 public check varieties. This trial was established with a portable sprinkler-irrigation system and then grown with a subsurface drip-irrigation system.

 

Methods

 

The trial was established on Owyhee silt loam where winter wheat was the previous crop and alfalfa had not been grown for more than 10 years. Pathfinder (Nelson Irrigation Corp., Walla Walla, WA) drip tape (15 mil thick, 0.22 gal/min/100-ft flow rate, 12-inch emitter spacing) was shanked in at a depth of 12 inches on 30-inch spacing between the drip tapes. Plots were 5 ft wide by 20 ft long in a randomized complete block design with each entry replicated five times. Further details of the establishment of this trial were reported previously (Eldredge et al. 2003).

 

Gramoxone® at 2 pint/acre plus Sencor® at 1.5 pint/acre were applied for weed control on March 11, 2004. No irrigations were applied before the first cutting in 2004. After the first cutting, irrigations were semi-automated using a valve controller (DIG Corp. Vista, CA) initially programmed to apply a 1-inch irrigation twice weekly, on Mondays and Thursdays. Alfalfa crop evapotranspiration (ETc) was calculated based on data collected by an AgriMet (U.S. Bureau of Reclamation, Boise, ID) weather station located on the Malheur Experiment Station. Soil moisture was monitored by six Watermark soil moisture sensors model 200SS (Irrometer Co. Inc., Riverside, CA) installed at 12-inch depth in the center of six alfalfa plots, midway between drip tapes. Sensors were connected to an AM400 data logger (M.K. Hansen, East Wenatchee, WA) equipped with a thermistor to correct soil moisture calculations for soil temperature. Water applied was measured by a totalizing water meter on the inlet of the irrigation system. A rodenticide, Maki bromadiolone supercade bait (Liphatech, Inc., Milwaukee, WI), was applied in rodent tunnels on July 22 with a gopher probe (Eagle Industries, Chatsworth, CA).

 

The alfalfa was harvested at bud stage on May 14, June 17, July 19, August 13, and September 22, 2004. A 3-ft by 20-ft swath was cut from the center of each plot with a flail mower, and the alfalfa was weighed. Ten samples of alfalfa were hand cut from border areas of plots over the entire field on the same day just before each cutting, quickly weighed, dried in a forage drier at 140°F with forced air, and reweighed to determine the average alfalfa moisture content at each cutting. Yield was reported as tons per acre of alfalfa hay at 88 percent dry matter.

 

Samples of alfalfa from approximately 1 ft of row per plot were taken June 16, before the second cutting, to measure forage quality. The forage quality samples were dried, ground in a Wiley mill (Thomas Scientific, Swedesboro, NJ) to pass through a 1-mm screen, subsampled, and sent to the Oregon State University Forage Quality Lab at Klamath Falls, Oregon, where they were reground in a UDY mill (UDY Corp., Ft. Collins, CO) to pass through a 0.5-mm screen. Near infrared spectroscopy (NIRS) was used to estimate percent dry matter, percent crude protein, percent acid detergent fiber (ADF), percent neutral detergent fiber (NDF), percent fat, and percent ash. Relative forage quality (RFQ) was calculated by the formula:

 

RFQ = (DMI * TDNL) / 1.23

where:

DMI = dry matter intake (for alfalfa hay), and

DMI = (((0.120 * 1350) / (NDF/100)) + (NDFD - 45) * 0.374) / 1350 * 100, and

NDFD = dNDF48 / NDF * 100, and

dNDF48 = digestible NDF as a percentage of dry matter, as determined by a 48-hour in vitro digestion test,

TDNL = total digestible nutrients [for legume (alfalfa hay)]

TDNL = (NFC * 0.98) + (protein * 0.93) + (fat * 0.97 * 2.25) + ((NDF-2) * (NDFD/100))

NFC = 100 - ((NDF - 2) + protein + 2.5 + ash), and 1.23 was chosen as the denominator to adjust the scale to match the RFV scale at 100 = full bloom alfalfa.

 

Quality standards based on RFQ are: Supreme, RFQ higher than 185; Premium, RFQ 170-184; Good, RFQ 150-169; Fair, RFQ 130-149, and Low, RFQ below 129. RFQ estimates voluntary energy intake when the hay is the only source of energy and protein for ruminants. Hay with a higher RFQ requires less grain or feed concentrate to formulate dairy rations.

 

Results and Discussion

 

Rodents chewed holes in the drip tape and continued to be a problem in this trial. During the winter, voles burrowed down to the drip tape and chewed holes that were found and repaired at the first irrigation. The rodenticide applied in the vole tunnels was effective until the grain crop adjacent to the alfalfa trial was harvested. After the grain harvest, a new population of voles gradually colonized the alfalfa trial. A gopher that moved into the trial was promptly exterminated.

 

Soil moisture was monitored at the 12-inch depth after first cutting (Fig. 1). After June 8, the soil remained uniformly moist in the –20 to –30 kPa (centibar) range for the rest of the irrigation season.

 

The total irrigation water applied was less than the season-long accumulated alfalfa crop evapotranspiration (Fig. 2). The irrigation system was turned off for harvest operations and to repair leaks. Smaller irrigations, from 0.01 to 0.38 inch, were applied on seven dates through the summer in order to check for leaks or following repairs to the drip tape. Accumulated season-long alfalfa ETc from March 5 to October 10 totaled 43.38 inches, and the drip irrigation measured by the water meter, plus rain, totaled 31.81 inches or 73.3 percent of accumulated season-long alfalfa ETc.

 

The average third-year total hay yield was 7.9 ton/acre (Table 1). The first-cutting average yield was 2.5 ton/acre, with ‘SX1002A’ ‘Masterpiece‘, and ‘SX1001A’ yielding among the highest. In the second cutting ‘Ruccus’, Masterpiece, ‘Tango’, ‘Orestan’, and ‘Somerset’ were among the highest yielding varieties. In the third cutting, Ruccus, ‘Lahontan’, Masterpiece, Orestan, and Tango were among the highest yielding varieties.  In the fourth cutting, Ruccus, Tango, Orestan, and Lahontan were among the highest yielding. In the fifth cutting, Ruccus, ‘Plumas’, and Somerset were among the highest yielding varieties. In total yield of five cuttings, Ruccus, with 8.4 ton/acre, Masterpiece, with 8.2 ton/acre, and Tango, SX1002A, and Orestan each with 8.0 ton/acre, were among the highest yielding.

 

The crude protein averaged 25.6 percent in the second cutting, and ranged from 24.3 percent for Orestan to 26.7 percent for Somerset. Acid detergent fiber, ADF, averaged 26.7 percent. Neutral detergent fiber, NDF, averaged 31.2 percent. Relative forage quality averaged 245, with all varieties in the “Supreme” quality range. SX1005A, Plumas, Somerset, and Masterpiece produced hay with RFQ scores higher than 247.

 

Total hay production in the first 3 years averaged 18.3 ton/acre (Table 2). The varieties Ruccus, at 20.1 ton/acre; Tango, at 19.4 ton/acre; and Masterpiece, at 19.3 ton/acre were among the highest yielding.

 

Information on the disease, nematode, and insect resistance of the varieties in this trial was provided by the participating seed companies and/or the North American Alfalfa Improvement Council (Table 3). Most alfalfa varieties have some resistance to the diseases and pests that could limit hay production. Growers should choose varieties that have stronger resistance ratings for disease or pest problems known to be present in their fields. The yield potential of a variety should be evaluated based on performance in replicated trials at multiple sites over multiple years.

 

References

 

Eldredge, E.P, C.C. Shock, and L. D. Saunders. 2003. First year results of the 2002 to 2006 alfalfa forage variety trial. Oregon State University Special Report 1048:14-17. Available online at www.cropinfo.net/AnnualReports/2002/B5aDripAlf02.htm


Text Box: 6/1Text Box: 6/8Text Box: 6/15Text Box: 6/22Text Box: 6/29Text Box: 7/6Text Box: 7/13Text Box: 7/20Text Box: 7/27Text Box: 8/3Text Box: 8/10Text Box: 8/17Text Box: 8/24Text Box: 8/31Text Box: 9/7Text Box: Soil water potential, kPa

Figure 1. Soil moisture in the drip-irrigated alfalfa variety trial during the 2004 growing season, Malheur Experiment Station, Oregon State University, Ontario, OR.

 

Text Box: 3/1Text Box: 3/15Text Box: 3/29Text Box: 4/12Text Box: 4/26Text Box: 5/10Text Box: 5/24Text Box: 6/7Text Box: 6/21Text Box: 7/5Text Box: 7/19Text Box: 8/2Text Box: 8/16Text Box: 8/30Text Box: 9/13Text Box: 9/27Text Box: 10/11Text Box: Inch

Figure 2. Accumulated irrigation applied plus rain compared to the AgriMet accumulated evapotranspiration (ETc) for alfalfa grown for hay, Malheur Experiment Station, Oregon State University, Ontario, OR 2004.

Table 1. Alfalfa variety hay yields and second-cutting crude protein*, ADF*, NDF*, and relative forage quality for 2004, Malheur Experiment Station, Oregon State University, Ontario, OR.

 

Cutting date

2004

Crude

 

 

Relative

Variety

5/14

6/17

7/19

8/13

9/22

total

protein

ADF

NDF

forage quality

 

------------------ton/acre§----------------

-------% of DW-------

RFQ

Ruccus

2.4

1.4

2.0

1.2

1.3

8.4

26.0

27.0

31.5

239

Masterpiece

2.7

1.3

1.9

1.1

1.2

8.2

25.1

26.1

30.7

251

Tango

2.5

1.3

1.9

1.2

1.2

8.0

25.2

28.0

32.9

228

SX1002A

2.9

1.2

1.7

1.1

1.2

8.0

25.1

27.4

32.3

233

Orestan

2.4

1.3

1.9

1.2

1.2

8.0

24.3

29.0

34.2

213

Lahontan

2.3

1.2

2.0

1.2

1.2

7.9

25.8

26.7

31.3

243

Plumas

2.6

1.2

1.8

1.0

1.3

7.9

26.6

24.9

29.2

267

SX1001A

2.7

1.2

1.7

1.0

1.2

7.9

25.4

26.3

31.2

244

Somerset

2.4

1.3

1.8

1.1

1.3

7.9

26.7

26.1

30.3

253

SX1003A

2.5

1.2

1.6

1.0

1.2

7.5

25.5

26.5

31.0

246

SX1005A

2.5

1.1

1.7

1.0

1.1

7.4

26.4

25.1

29.1

271

SX1004A

2.3

1.2

1.5

1.0

1.2

7.4

25.5

26.8

31.2

247

Mean

2.5

1.2

1.8

1.1

1.2

7.9

25.6

26.7

31.2

245

LSD (0.05)

0.29

0.09

0.18

0.07

0.10

0.47

1.27

1.74

2.26

23.7

*Based on percent of dry weight.  ADF: acid detergent fiber. NDF: neutral detergent fiber.

§Yield at 88 percent dry matter. DW: dry weight.

 

Table 2. Alfalfa variety hay yields in the first 3 years of the 2002-2006

drip-irrigated alfalfa variety trial, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.

 

Yield

Variety

2002*

2003

2004

Cumulative

 

-------------------ton/acre------------------

Ruccus

2.6

9.1

8.4

20.1

Tango

2.5

9.0

8.0

19.4

Masterpiece

2.4

8.7

8.2

19.3

Somerset

2.4

8.5

7.9

18.8

Orestan

2.2

8.4

8.0

18.7

Plumas

2.6

8.1

7.9

18.5

Lahontan

2.0

8.1

7.9

18.1

SX1001A

2.1

8.0

7.9

18.0

SX1002A

1.9

7.7

8.0

17.7

SX1005A

2.4

7.7

7.4

17.5

SX1004A

2.1

7.5

7.4

16.9

SX1003A

2.0

7.0

7.5

16.5

Mean

2.3

8.2

7.9

18.3

LSD (0.05)

0.40

0.54

0.47

0.94

*Two cuttings, 8/6 and 9/5/2002.     Yield at 88 percent dry matter.

Table 3. Variety source, year of release, fall dormancy, and level of resistance to pests and diseases for 12 alfalfa varieties in the 2002-2006 drip-irrigated forage variety trial, Malheur Experiment Station, Oregon State University, Ontario, OR, 2004.

 

 

Release

 

Pest Resistance rating

Variety

Source

year

FD*

BW

FW

VW

PRR

AN

SAA

PA

SN

AP

RKN

Orestan

public

1934

3

R

-

-

-

-

-

-

-

-

-

Lahontan

public

1954

6

MR

LR

-

LR

-

MR

LR

R

-

-

Tango

Eureka Seeds

1997

6

MR

HR

HR

HR

HR

HR

HR

MR

-

R

Plumas

Eureka Seeds

1997

4

HR

HR

R

HR

HR

R

R

HR

R

MR

Masterpiece

Simplot Agribusiness

2000

4

HR

HR

R

HR

HR

R

-

HR

R

R

Somerset

Croplan Genetics

2000

3

HR

HR

HR

HR

HR

R

-

R

HR

-

Ruccus

Target Seed

2001

5

R

HR

R

HR

MR

R

R

R

-

MR

SX1001A§

Seedex

-

-

-

-

-

-

-

-

-

-

-

-

SX1002A

Seedex

-

-

-

-

-

-

-

-

-

-

-

-

SX1003A

Seedex

-

-

-

-

-

-

-

-

-

-

-

-

SX1004A

Seedex

-

-

-

-

-

-

-

-

-

-

-

-

SX1005A

Seedex

-

-

-

-

-

-

-

-

-

-

-

-

*FD: fall dormancy, BW: bacterial wilt, FW: Fusarium wilt, VW: Verticillium wilt, PRR: Phytophthora root rot, AN: Anthracnose, SAA: spotted alfalfa aphid, PA: pea aphid, SN: stem nematode, AP: Aphanomyces, RKN: root knot nematode (northern).

 

Pest resistance rating: >50 percent = HR (high resistance), 31-50 percent = R (resistant),

15-30 percent  = MR (moderate resistance), 6-14 percent = LR (low resistance).

 

Fall Dormancy: 1 = Norseman, 2 = Vernal, 3 = Ranger, 4 = Saranac, 5 = DuPuits, 6 = Lahontan,

7 = Mesilla, 8 = Moapa 69, 9 = CUF 101.

 

§Experimental varieties, not released, pest resistance data not available.