Effect of Planting Sequence and Time, and Nitrogen on Maize Legume Intercrop Yield

Abstract

Productivity of maize (Zea mays L.) legume intercrops is determined by soil, management, and environment. Planting sequence and time and N fertilization are easily controlled management factors but their effects on intercrop yields are not well understood. Maize grown in monoculture or intercropped with polebean (Phaseolus vulgaris L.) or cowpea (Vigna unguiculata [L.] Warp.) was studied for two growing seasons at Morgantown, WV. Crops were seeded in the following sequences: maize before legume, both at the same time, and legume before maize. Planting times were early May or mid June. Nitrogen was applied at 0 or 160 kg ha−1. Maize grain and forage, legume grain and forage, and total forage production were determined on a dry matter basis. Intercropping (average of all treatments) reduced maize grain and forage yields compared to maize in monoculture but had no effect on total forage production. However, total forage production was greatest when the seeding sequence was maize intercropped at the same time or before cowpea. Cowpea never produced grain, but forage production was almost double that of polebean. Maize produced most forage when seeded before the legumes, and the legumes produced most forage when seeded before maize. Early planting increased maize production and decreased legume production. Nitrogen increased maize grain, maize forage, and total forage yields but had not effect on legume forage production. It is concluded that maize/legume intercrops show promise for increasing forage production in temperate areas and more research on planting times and densities, weed control, harvesting and management is needed.

Intercropping Maize and Faba Bean for Silage Under Swedish Climate Conditions

“…In order to increase the yield of faba bean, and thereby the protein yield, sowing time of the faba bean could be delayed [9], but this technique involves a risk of the soil becoming too dry in spring, which may result in that the faba bean may not emerge at all. It should be noted that in the present study, the sowing time for faba bean was already delayed by almost 1 month compared with the normal time for cultivation of faba bean in Sweden.…”

“…Therefore, locally produced forage protein such as peas and faba bean is desired. One way to increase the protein content in maize forage is by intercropping maize with legumes [9,12,25].…”