Integrating Crops and Livestock by Ley Farming in North Dakota

Patrick M. Carr and Woodrow W. PolandNorth Dakota State University ~ Dickinson Research Extension Center

INTRODUCTION

Spring wheat ( spp.) was grown on over 1 million ha insouthwestern North Dakota in 2005 (USDA, 2005). Expected returns tolabor and management ranged from -$82 ha for hard red spring wheat( L. emend. Thell.) grown after fallow to - 11 ha for durumwheat ( L.) grown after wheat (A. Swenson, personalcommunication, 2004). Diversification strategies are needed toenhance wheat production economics.

Wheat is rotated with legume pasture in Australian ley farming. Benefitsoffered by ley farming compared with wheat-fallow include moreprofitable wheat production (Boyce et al., 1991), pest suppression(Loomis and Conner, 1992), and reduced fertilizer inputs (Gierson et al.,1991). Important characteristics of the legume pasture species includethe abilities to produce adequate amounts of forage to support grazingand to regenerate successfully from the soil seed bank.

Triticum

T. aestivum $T. turgidum

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Cattle grazing regenerated legume pasture following spring wheat in the northern U.S. GreatPlains.

OBJECTIVES

(1) Identify legume species that produce enough forage to supportgrazing and can regenerate successfully from the soil seed bank

(2) Determine if grazed legume pasture can be rotated with wheatsuccessfully in southwestern North Dakota, USA

(3) Determine the impact of ley farming on wheat grain yield and thesoil N pool in the northern U.S. Great Plains

MATERIALS & METHODS

Small-plot studies

Large-plot study

Thirty-one legume species were included in three field experiments at the Dickinson Research Extension Center (46 53' N, 102 49' W, 760m elevation) during 1999-2002. Forage dry matter (DM) yield was determined along with the ability to regenerate from the soil seedbank. Legume species were arranged in a randomized complete block with treatments replicated three times. The experiments wereanalyzed separately using the ANOVA procedure from SAS (SAS Inst., 1985). The Ryan-Einot-Bariel-Welsch multiple range test was used toseparate treatment means at the < 0.05 level.

Hard red spring wheat was grown following a 2-yr legume phase during 2001-2003. Legume species which regenerated from the soilseed bank following a 1-yr wheat phase were identified. Forage DM yield of the regenerating legume species was determined.

Alternative cropping systems are being compared in an on-going study: (1) a 2-yr rotation of spring wheat and field pea (L.), (2) a 3-yr rotation of spring wheat followed by a 2-yr alfalfa ( L.) phase, and (3) a 3-yr rotation of spring wheatfollowed by a 2-yr birdsfoot trefoil ( L.) phase. Spring wheat and field pea are harvested for grain while legume cropsare grazed by beef cattle ( L.). All phases of each system occur each yr in 1-ha plots arranged in a randomized completeblock with treatments replicated three times.

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Pisum sativumMedicago sativum

Lotus corniculatusBos taurus

Spring wheat following a 2-yr stand of birdsfoot trefoil.

Cattle grazing birdsfoot trefoil pasture that is rotated with springwheat.

Birdsfoot trefoil following regeneration from the soil seed bank.

Forage crop 1999 2000 2000 2001 2001 2002

Birdsfoot trefoil Norcen 2.3 aH

2.0 ab 2.1 a 2.9 ab 1.8 a 2.5 ab

Black medic George 3.7 a 0.9 b 2.6 a 1.6 a 2.7 a 0.2 a

Red clover Red Gold --I

-- 2.6 a 1.9 ab 2.6 a 4.9 b

Alfalfa Ladak 3.6 a 3.8 a 2.6 a 5.9 b 3.1 a 4.2 b

and 2001 in southwestern North Dakota.

I-- = No data because treatment was not included in this experiment.

HLetters differing in columns indicate differences between forage crop treatments at the P < 0.05 level using

Table 1. Dry matter yield of forage produced by legume species in the establishment year (first year) and

after regeneration from the soil seed bank in three experiments (Exp. 1-3) seeded in 1999, 2000,

Exp. 3

------------------------------------------- Mg ha-1

-----------------------------------------

Exp. 1 Exp. 2

the Ryan-Einot-Bariel Welsch multple range test.

REFERENCESCarr, P.M., W.W. Poland, and L.J. Tisor. 2005a.

Carr, P.M., W.W. Poland, and L.J. Tisor. 2005b.

Grierson I., B. Bull, and R. Graham. 1991.

Loomis R.S., and D.J. Connor. 1992.

SAS Institute. 1985.

USDA National Agricultural Statistics Service. 2005.

Forage legume regeneration from the soil seedbank in western North Dakota. Agron. J. 97:505-513.

Natural reseeding of forage legumes followingwheat in western North Dakota. Agron. J. 97: 1270-1277.

Soil management and fertilizer strategies. p. 134-145.V. Squires and P.G. Tow (ed.) Dryland farming: A systems approach. Sydney Univ. Press,

Sydney.

Crop ecology. Productivity and management inagricultural systems. Cambridge Univ. Press, Cambridge. 538p.

SAS procedures for personal computers. Version 6 ed. SAS Inst. Inc., Cary, NC,USA.

2005 North Dakota wheat varieties [Online].Available at http://www.nass.usda.gov/nd/whtvr05.pdf (verified 18 Oct. 2005). USDA-NASS,Washington, DC.

In

SUMMARY

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Management strategies must be developed so wheat grain yieldand soil NO -N levels are maintained or enhanced by ley farmingcompared with other cropping systems

Research is needed to determine the economic returns and energycycling that can result if ley farming is adopted in the northern U.S.Great Plains.

Birdsfoot trefoil has the greatest near-term potential as a self-regenerating pasture species if rotated with wheat in southwesternNorth Dakota using a system patterned after Australian leyfarming.

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Exp. 1 Exp. 2 Exp .3 Exp. 1 Exp. 2 Exp. 3

Legume name Cultivar 2001 2002 2003 2002 2003 2004

Birdsfoot trefoil Norcen 1944 bI

884 a 1006 a 304 a 650 a 1485 a

Black medic George 3634 a 1150 a 939 a 549 b 1692 b 4376 b

Red clover Red Gold --§

1203 a 1204 a -- 574 a 272 a

Alfalfa Ladak 1381 b 1306 a 952 a -- -- --

---------------plants m2------------------

the Ryan-Einot-Bariel Welsch multple range test.

§No data because the treatment was not included (red clover) or did not regenerate from the soil seed bank

(alfalfa).

Table 2. Spring wheat grain yield and regenerated legume plants following the wheat phase in three field

Wheat grain yield Legume plants

experiments (Exp. 1-3) during 2001-2004 in southwestern North North DakotaH.

HLegume species were established two years prior to seeding wheat.

ILetters differing in columns indicate differences between forage crop treatments at theP < 0.05 level using

---------------- kg ha-1

----------------

RESULTS AND DISCUSSION

Small-plot studies

Large-plot study

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Birdsfoot trefoil produced > 3 Mg ha forage DM in two of threesmall-plot field experiments following wheat.Black medic ( L.) and red clover (

L.) produced < 2 Mg ha forage DM following wheat intwo of three field experiments.Results of these studies have been published (Carr et al., 2005a, b).

Wheat grain yields and soil NO -N levels were reduced up to 40% insome yr following alfalfa and birdsfoot trefoil compared with peas.

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Medicago lupulina Trifoliumpratense

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RESULTS

Dickinson Research Extension Center

A 2-yr old stand of birdsfoot trefoil just prior to grazing in early June.