Multiple Cropping Soybean with Oats and Barley1

Abstract

AbstractMultiple cropping and relay intercropping of soybean [Glycine max(L.) Merr.] with small grains was studied as an alternative cropping system or areas that are traditionally oriented towards production of feed for dairy cattle (Bosspp.). The objective was to evaluate multiple cropping of small grains harvested as forage and soybean harvested as seed in a dairy forage area of the north central United States. One oat (Avena sativaL.) cultivar, two barleys (Hordeum vulgareL.), and the soybean cv. Hodgson were grown in relay intercropping, double cropping, and sole cropping systems on a Plano silt loam soil (fine‐silty, mixed, mesic Typic Argiudoll) at Arlington, WI in 1977 and 1978. Relay intercropping systems were established by planting soybean into unthinned stands of small grains or by removing rows of small grains shortly after emergence and later planting soybean in the gaps. Double‐cropped soybean was planted after barley and oats were harvested as forage. Early soybean checks (sole cropping) were planted on the same date that relay intercropped soybean was planted, and late soybean checks were planted on the same date that: double‐cropped soybean was planted. Soybean row widths in all systems were 0.41‐, 0.75‐, and 0.90‐m. Early soybean checks were more productive than soybean relay intercropped in both thinned and unthinned stands of oats and barley, but late soybean checks were not always more productive than double‐cropped soybean. Yields of soybean relay intercropped in 0.45‐m rows were higher in thinned stands of barley and oats than in unthinned stands. Differences were not as large in wider rows. Cultivar differences in forage yield were not associated with consistent differences in yields of relay intercropped and double‐cropped soybean. The most productive cropping sequence was a double‐cropping system that had a forage yield of 4.93 Mg ha‒1and a soybean yield of 2.21 Mg ha‒1.