The effects of crop rotation systems on maize agronomic traits under no-tillage in optimal and dry cropping seasons.

The purpose of this research was to evaluate the crop rotations effects on agronomic traits of maize cultivated in spring-summer in optimal (OCS) and dry cropping seasons (DCS). The experimental design was set up in a randomized complete block and the treatments were arranged in a factorial (8 x 2), consisting of 8 crop rotation systems and two cropping seasons (OCS and DCS), with four replications. The following variables were determined; plant height, height of the first ear insertion, number of kernels per ear, ear diameter and length, number of kernel per ear, 1000-kernel weight and grain yield. In OCS, 1000-kernel weight and grain yield were 20.30 and 60.80% respectively, which means higher than DCS. The crop rotation systems affected the agronomic traits of maize only in OCS. The crop rotation with soybean/niger/maize, soybean/crambe/maize, soybean/rapeseed/maize and soybean/sunflower/maize resulted in higher grain yield. The effects of drought on agronomic traits of maize resulted in higher impact than the crop rotations systems assessed in this research. The amount of 752 mm of rainfall in maize cropping season was not enough for maize development and yield. This study guided alternatives of new cover crops to insert in crop rotation system