Australian Journal of Crop Science | 2019
Corn + white clover intercropping under management of herbicides and nitrogen levels
Abstract
Intercropping cash crops with perennial pasture legumes can improve crop-livestock systems. In these systems, interspecific competition can affect crop yield, unless suppressed by herbicides. An experiment was carried out to determine whether established stands of white clover pasture, suppressed with herbicides, could be used as living mulch in no-tillage intercropping systems with corn. Treatments were arranged in a completed randomized block design with four replications in a 3 x 4 factorial scheme being three herbicide suppression as follows: (i) broadcast application of Paraquat/Diuron (Gramocil ® ) + 2,4-D (Aminol ® ) at rates of 300 + 806 g i.a ha -1 , respectively and (ii) glyphosate (Zapp Qi ® ) + 2,4-D at rates of 1080 + 806 g i.a ha -1 , both applied sequentially seven days before and 15 days after corn sowing, and glyphosate + glyphosate (1080 + 1080 g i.a ha -1 ) applied sequentially 21 days before and 15 days after corn sowing and the 2 nd factor four nitrogen rates (0, 60, 120, 180 kg ha -1 ). The results showed that Nitrogen input is an important element for the optimization of corn + clover intercrop, combined with herbicide suppression to minimize competition effects on the main crop. The corn grain yields ranged from 6.9 to 12.3 Mg ha -1 which achieved greatest under the glyphosate + glyphosate (Gly + Gly) treatment. Based on these results, it is possible to use white clover in intercropping systems with corn crop with autogenic clover regrowth after corn harvest.