Biomass production, root system and nitrogen accumulation in maize affected by forage grasses in consortium and nitrogen fertilization

Abstract

The dynamics of nitrogen (N) in the soil is directly or indirectly affected by cultivated plants and production systems. Conservation systems such as no-tillage can, over time, improve the efficiency of N use, where pH, C / N ratio and microbial activity are the main regulating factors. Forages of the genus Urochloa (Sin Brachiaria) and Megathyrsus (Sin. Panicum) can alter the availability of N in the soil by modifying ammonification and nitrification rates, affecting yield and nutrient accumulation by maize (Zea mays L.) cultivated in succession. The objective of this study was to evaluate the effect of forage grasses U. ruziziensis, U. brizantha and M. maximum on maize performance in a consortium system, evaluating biomass and grain yield, N accumulation and morphological parameters of the corn. Thus, an experiment will be conducted under field conditions in Botucatu, SP, during the 2018/2019 harvest. The experimental design will be a randomized complete block design with subdivision plots, with three species of forage grasses (U. ruziziensis, U. brizantha and P. maximum) and N doses (control, 90, 180 and 270 kg ha-1) applied in corn. The corn will be sown in December, together with the forage grasses, without soil disturbance. Dry biomass and N content in the root system will be evaluated, as well as the dry biomass and N accumulation in the aerial part of the corn. Morphological characteristics of the root system will be analyzed through a specific computer program. The results obtained will be submitted to ANOVA and the means separated using Fisher's LSD test (Pd0.05).