Forage Yield of Intercropped Corn and Soybean in Various Planting Patterns1

Abstract

AbstractCorn (Zea mays L.) and soybean (Glycine max L. Merr.) were intercropped in various planting patterns in 1980, 1981, and 1982 on a Hadley fine sandy loam (coarse‐silty, mixed, nonacid, mesic Typic Udifluvent) to determine if corn:soybean mixtures might provide silage superior to pure corn for ruminants. All but one of the intercrop planting patterns produced dry matter (DM) yields similar to corn monoculture in the 1st year even when as many as half the corn rows were replaced with soybean. All intercrop planting patterns in 1981 produced similar DM yields to corn monoculture, but in 1982 intercrop DM yields were significantly lower than corn monoculture DM yields. Dry matter yields per row of intercropped soybeans were 6 to 32% less than yields per row of soybeans in monoculture. However, the DM yield per row of intercropped corn was increased 21 to 53% compared to yield per row of monoculture corn and compensated for the reduced DM yield of soybean. Yields for monocultures were computed at various proportions of corn and soybean in the harvested mixture and compared with intercrop yields. All intercrop patterns produced more DM than would be obtained from monocultures at the same yield‐ratio as in the intercrop. Protein Concentration was increased from 69 to 81 g kg−1 for corn monoculture to 88 to 108 g kg−1 for the various intercropping patterns. All intercrops produced 8 to 17% more total protein ha−1 than corn monoculture. The intercrop pattern where alternate corn rows were replaced by soybean rows produced the largest increases in protein concentration although DM yield was reduced by 14% in the 3rd year.