Intercropping Tropical Vine Legumes and Maize for Silage in Temperate Climates

ABSTRACT

Maize silage is used extensively in American dairy rations. Increasing protein content would enhance maize silage quality. This study examined nine forage legume species (Austrian winter pea, common bean, cowpea, lablab, scarlet runner bean, sesbania, sunn hemp, tropical kudzu, and velvet bean) grown in mixture with maize plants in Wisconsin, in the U.S. Plants were evaluated for growth throughout the growing season, harvest forage dry matter content, total dry matter yield, and forage mixture components. Of the forage legumes tested, common bean, lablab, scarlet runner bean, sunn hemp, and velvet bean were most successfully intercropped with maize. The common bean entry was the most aggressive forage legume, comprising 23% on a dry-matter basis of the final harvested forage mixture. The lablab entry, despite a slow start, became more productive during the late growing season and comprised 7.4% on a dry-matter basis of the final harvested forage mixture. Harvested forage moisture ranged from 299 g kg⁻¹ to 364 g kg⁻¹ of dry matter. Except for the common bean mixture, which had a lower forage dry-matter yield, the mixtures did not differ from one another or the pure maize control for dry-matter accumulation per unit area. Similar to forage dry-matter yields, stover forage mixture fractions were not significantly different among entries, except for the common bean-maize mixture. Grain yields were inversely proportional to the amount of legume present.

KEYWORDS:

• Maize silage
• intercropping
• tropical forage legumes
• biomass
• moisture
• growth rate