Assessing Legumes for Forage Sorghum Based Intercropping Systems in the Southern High Plains

1. Tucumcari, NM Clovis, NM SD WY N NE CO Fastest growing dairy industry in the country KS OK NM TX Ogallala Aquifer Region Figure 1. Experimental locations in relation to Ogallala aquifer and dairy industry. Ogallala States Evaporation 0.75 -1.0m Leaching Figure 2. Forage sorghum (cv. FS-5) and pole bean (cv. Genuine Cornfield) intercropping at Clovis, NM in 2009. Management practices are developed to apply most inputs uniformly over the area (eg. frequent pivot irrigation) and small seedlings do not have capacity to use those resources from the inter row area. Lablab Lima bean Figure 3. Promising legumes for intercropping (Tucumcari, NM in 2008). Sangu Angadi*1, Sultan Begna*1, M.R. Umesh*1, Mark Marsalis**1, Andy Cole3, Prasanna Gowda3, Leonard Lauriault*2, K. Annadurai4, and Robert Hagevoort1 *Dept of Plant and Environmental Sciences, **Dept. of Extension Plant Science & 1Agriculture Science Centers at Clovis and 2Tucumcari, New Mexico State University, Clovis, NM 88101 3USDA-ARS, Bushland, TX 79403, 4Tamil Nadu Agricultural University, Kumulur, India Eastern New Mexico and West Texas experienced a large influx of dairies in the last two decades. Demand for good quality forages by these dairies and declining water in Ogallala aquifer are compelling to improve water use efficiency in forage production systems. In a typical silage sorghum production system inter row spacing is >75cm and for the first half of the growing season inter row space is not occupied completely by the main crop. Intercropping is a system of growing two diverse species of crops on a piece of land that may help to improve the use of both above ground and below ground resources more efficiently in the above situation. Selection of crops, crop varieties, management practices are important in designing a intercropping system. Protein rich, better adapted legume species as an intercrop is expected to improve total biomass production, resource use efficiency and forage quality. Competition for sunlight, nutrients and water will also play an important role. Better understanding of these competitions and their responses to management practices will help in designing sustainable intercropping system. OBJECTIVES INTRODUCTION Assessing Legumes for Forage Sorghum Based Intercropping Systems in the Southern High Plains RESULTS • Identification of shade tolerant legume species for intercropping with forage sorghum for improving biomass production, resource use efficiency, and forage quality • Evaluate spatial arrangements of sorghum-legume intercropping systems to reduce competition and enhance complementary interaction • Test the intercropping systems under deficit irrigation management to assess sustainability under reduced water availability • Understand resource use patterns and competition in intercropping systems • Spatial extrapolation of results to the Southern Great Plains to estimate water savings over the region where sorghum+legume intercropping can be adopted Intercepted PAR (%) Dry Matter (t ha-1) N Days after seeding (d) MATERIALS AND METHODS Figure 5. Seasonal pattern of biomass accumulation and light interception by sorghum legume intercropping system at Clovis, NM in 2008. Locations: Clovis (08 & 09) and Tucumcari (08), NM Crops & Varieties: Forage Sorghum: FS-5 Legumes : Lablab (Rongai & Rio Verde), Cowpea (Iron&Clay), Polebean (Genuine Cornfield & Scarlet Emperor), Pigeonpea (GA-1), Limabean (Willow leaf), Spring pea (Tall Telephone), Forage Soybean (Tyrone) Population: 250,000 ha-1 (Sorghum) and 150,000 ha-1 (Legumes) SUMMARY • Preliminary results indicate that Sorghum+legume intercropping system is promising to improve forage productivity. Early in the season biomass contribution by legumes to total biomass is higher and it gradually decreases by the final harvest (≈ 5 -15%) • Intercropped legume improved radiation interception by using the sunlight not used by the sorghum crop. Improvement in radiation interception by intercropping systems lasted for the initial 65 days. • Selection of legumes is very important. Lablab, lima bean, cowpea are promising • Early maturity of legume varieties is a problem. Longer duration or more indeterminate legume varieties will improve intercropping systems further • Forage sorghum varieties with shorter stature or more erect leaves will also help the system • Results are also indicating better spatial arrangement to enhance light reaching legumes will improve system productivity. Under deficit irrigation, legume contribution may improve. Legume Dry Matter (t ha-1) Sorghum Acknowledgement: We thank USDA-CSREES-NRI-Water and Watersheds (Grant #2007-35102-18120) program for funding this research. We also thank the New Mexico State University, Agricultural Experiment Station for the support and Dr. Sharad Phatak, Univ of Georgia and Dr. Ray Smith, Texas A&M Univ for providing pigeon pea and lablab seeds, respectively. Technical help from Aaron Scott, Joleen Szaloy, Miguel Nunez, Cecily Strait, Jessie Nunej, Wahby Ahmed and others is greatly appreciated.. Sorghum + Cowpea (Iron Clay) Sorghum + Lima bean (Willow leaf) Sorghum + Polebean (Genuine) Sorghum + Lablab (Rio Verde) Sorghum + Lablab (Rongai) Sole Sorghum Sorghum + Soybean (Tyrone) For more information: Sangu Angadi: angadis@nmsu.edu Ph: 575-985-2292 Ex105 Figure 4. Biomass production by different sorghum legume intercropping systems at Clovis, NM in 2009.