Composition, Forage Production, and Costs Are Variable in Three‐Way Cover Crop Mixes as Fall Forage

Abstract

Core Ideas Brassicas predominate percent composition of mixture in a warmer, higher‐moisture year. Grasses and legumes produce more forage mass in cooler, lower‐moisture environment. Oats and barley produced more forage mass than wheat or rye for 90 days after planting. Radishes produced more forage mass than turnips. Winter pea yielded more forage mass than berseem clover. The purpose of this study is to evaluate plant species composition and forage mass production in three‐way cover crop mixtures and evaluate costs associated with specific plant species in a mixture. A 2‐year study (2014 and 2015) was completed in a randomized complete block design with 16 mixtures composed of a grass/brassica/legume combination based on four grass species, two brassica species, and two legume species. Brassicas and grasses together contributed between 54 and 100% of the total forage mass in mixtures. Brassicas were a greater portion of the composition in 2014 than 2015 while grasses and legumes made up a higher percentage of the composition in 2015 than 2014. Oats (Avena sativa) produced more forage mass than barley (Hordeum vulgare) with wheat (Triticum aestivium) and rye (Secale cereal) producing the lowest forage mass. Radish (Raphanus sativus) produced more forage mass than turnip (Brassica rapa), and winter pea (Pisum sativum subsp. arvense) had greater forage mass production than berseem clover (Trifolium alexandrinum). In six of eight mixtures, radish growth altered grass composition within year; peas contributed little to the biomass composition regardless of year, and all brassicas had a higher percent biomass production in 2014 than 2015. As fall forage for cattle, oats are the most economical option for grass. Both radish and turnip are similarly priced based on production; and clover is a cheaper legume option, even with limited growth.