Single and multispecies dual‐purpose cover crop productivity, nutritive value, and profitability

Abstract

AbstractReplacing long fallow periods with dual‐purpose forage cover crops increases productivity and profitability of dryland crop rotations. However, little information is available on specific forage cover crops mixtures that optimizes productivity, nutritive value, and profitability. The objective of this research was to quantify forage productivity, nutritive value, and profitability of spring‐planted single or mixed species cover crops in a winter wheat (Triticum aestivum L.)–grain sorghum [Sorghum bicolor (L.) Moench]–fallow (WSF) crop rotation. This study was conducted from 2015 to 2017 at the Kansas State University Hearting Beason Ranch near Brownell, KS. The experimental design was a split‐plot randomized complete block with four replications. The main plots were three crop phases of the WSF rotation (wheat–sorghum–fallow, sorghum–fallow–wheat, and fallow–wheat–sorghum), and subplots were five spring‐planted cover crop treatments: (a) spring oat (Avena sativa L.), (b) spring triticale [×Triticosecale Wittm. ex A. Camus (Secale × Triticum)], (c) oat and triticale mixture (OT, two‐species mixture), (d) oat, triticale, and pea (Pisum sativum L.) (OTP, three‐species mixture), and (e) oat, triticale, pea, radish (Raphanus sativus L.), turnips (Brassica campestris L.), and buckwheat (Fagopyrum esculentum Moench) (six‐species mixture). Results showed that cover crop forage accumulation was 33–35% greater in sole triticale and OT mixture compared with sole spring oat or cocktail treatments. Multispecies mixtures, cocktail and OTP cover crops, had significantly greater available energy, digestibility, and dry matter intake based on measured crude protein, acid and netural detergent fiber, and in vitro dry matter digestibility compared with single species (oat or triticale). Net return was US$100 ha–1 greater for the OT treatment compared with the multispecies mixtures. We concluded that greater productivity and net return, along with adequate nutritive value, from sole triticale and OT mixture made them better dual‐purpose forage cover crop alternatives.