Relay Intercropping with Cover Crops Improved Autumn Forage Potential of Sweet Maize Stover
Agriculture Science Center, New Mexico State University, Tucumcari, NM 88401, USA
Sustainable Agriculture Science Center, New Mexico State University, Alcalde, NM 87511, USA
Department of Economics and International Business, New Mexico State University, Las Cruces, NM 88003, USA
Department Agricultural Economics and Agricultural Business, New Mexico State University, Las Cruces, NM 88003, USA
ARS Fort Keogh Livestock and Range Research Laboratory, United States Department of Agriculture (USDA), Miles City, MT 59301, USA
Animal and Range Sciences Department, New Mexico State University, Las Cruces, NM 88003, USA
Author to whom correspondence should be addressed.
Agriculture 2018, 8(7), 103; https://doi.org/10.3390/agriculture8070103
Received: 6 June 2018 / Revised: 21 June 2018 / Accepted: 25 June 2018 / Published: 2 July 2018
Maize (Zea mays L.) stover is used globally as winter feed for livestock but the nutritive value is low, requiring supplementation. A 2-year randomized complete block study with three replicates at New Mexico State University’s Alcalde Sustainable Agriculture Science Center compared sweet maize (Zea mays var. rugosa; maize-alone) with sweet maize relay intercropped with oat (Avena sativa L.; maize-oat) or turnip (Brassica rapa L.; maize-turnip). Relay intercropping had no effect (p > 0.05) on sweet maize stover dry matter (DM) yield and there was no difference in aboveground biomass DM yield of the intercropped species. Turnip aboveground biomass had greater crude protein concentration and 48-h in vitro dry matter disappearance (IVDMD) than oat aboveground biomass. Relay intercropping with turnip improved sweet maize stover IVDMD (443, 439, and 515 g IVDMD kg−1 for maize-alone, maize-oat, and maize-turnip, respectively, p < 0.0001). Intercropping increased animal gains compared to maize-alone (0.36, 0.52, and 0.59 kg/day for maize-alone, maize-oat, and maize-turnip, respectively, p < 0.02), likely due to provision of additional crude protein. Relay intercropping oat or turnip into sweet maize is viable for improving sweet maize stover for fall forage. In addition turnip, specifically, had a positive effect on stover nutritive value.