| Abstrakt: |
To make more intensive use of increasingly‐scarce and expensive farmland, farmers in the North‐Central region of the United States are developing considerable interest in double‐cropping systems involving feed production. Therefore, forage production and quality were evaluated in double‐cropping systems involving corn (Zea maysL.), soybeans [Glycine max(L.) Merr.], and grain sorghum [Sorghum bicolor(L.) Moench] no‐till planted following conventionally‐planted spring oats (Avena sativaL.) for forage. The 2‐year field studies were undertaken on two soil types, Plano silt loam [fine‐silty, mixed, mesic Typic Argiudoll (Exp. I)] and Fayette silt loam [fine‐silty, mixed, mesic Typic Hapludalf (Exp. II)] at two separate locations in Wisconsin. The effects of irrigation and weed control practices (chemical and cultural) on the second crops were investigated. The 2‐year average forage yields of corn, soybeans, and grain sorghum were 5820, 2660, and 3890 kg ha−1, respectively. Cultivation generally resulted in better weed control than herbicides. Irrigation increased forage yields of corn, soybeans, and grain sorghum by 31, 38, and 32%, respectively. Soybeans produced the highest crude protein (CP) ha−1but the lowest quantity of digestible dry matter (DM), estimated by the in vitro dry matter digestibility (IVDMD) technique. Corn produced the highest amount of digestible DM ha−1but had the lowest CP percentage. Grain sorghum had thelowest IVDMD and produced the lowest CP ha−1. Based on 2‐year averages, the oats‐corn double‐cropping system produced the most forage, CP and digestible DM. Double‐cropping yields show considerable promise, when compared with present yields under a one crop system. |
Plný text