Submitted to: Field Crops Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/14/2011
Publication Date: 8/22/2011
Citation: Calderon, F.J., Vigil, M.F., Nielsen, D.C., Benjamin, J.G., Poss, D.J. 2012. Water use and yields of no-till managed dryland grasspea and yellow pea under different planting configurations. Field Crops Research. 125:179-185. Interpretive Summary: This manuscript is significant because we show how Grasspeas (GP) compare to the more common yellow pea (FP)in two planting configurations. Our research shows that Grasspea is a legume species well adapted to the climate of the High Plains, with comparable yields but longer season than the more common Admiral yellow field pea. The GP has somewhat lower grain water use efficiency and leaves less precipitation recharge time for a subsequent winter crop compared to FP, which are important considerations for Central Great Plains dryland systems. The GP dried the soil more than FP during the growing season during the two driest years of the experiment. Grasspea had more biomass accumulation and N accumulation in the biomass and grain than FP, indicating better N fixing capacity. Central Great Plains dryland agriculture will benefit from a variety of N fixing grain crops and studies such as this are necessary for better informed planting decisions.
Technical Abstract: Grasspea (GP) (Lathyrus sativus) is a drought-tolerant legume that can be grown for forage and grain. It has potential value to be used as a nitrogen-fixing crop in dryland rotations with non-legume grain crops. However, the agronomics of GP for the Central Great Plains region have not been investigated. We carried out a 3-year field experiment to compare dryland GP with Admiral yellow field pea (FP) (Pisum sativum) in two planting configurations: 1) a wide row spacing with lower population (WL) with 76-cm rows with 75 kg seeds planted per ha, and 2) a narrower row spacing with a higher population (NH) with 19-cm rows with 136 kg seeds planted per ha. We measured the biomass, grain yield, N content, and soil water use. Our results show that the NH treatment out-yielded the WL treatment in both pea species. The GP had higher yield than FP on the lowest yielding year, while FP yielded better when overall yields were higher. Biomass production was also higher for the NH configuration, and GP was a higher biomass producer than FP over the 3-year study. The GP had higher N concentration in shoots and seed compared to FP, indicating higher N-fixing capacity. The FP matured faster than GP, and had marginally higher grain water use efficiency than GP. Our results show that GP is a viable alternative legume for the Central Great Plains, with comparable yields in low precipitation years. However, the longer growing season required by GP to mature has water use implications in years with reduced water availability in mid to late summer.