Generally, in tropical and subtropical agroecosystems, the efficiency of nitrogen (N) fertilization is low, inducing a temporal variability of crop yield, economic losses, and environmental impacts. Variable-rate N fertilization (VRF), based on optical spectrometry crop sensors, could increase the N use efficiency (NUE). The objective of this study was to evaluate the corn grain yield and N fertilization efficiency under VRF determined by an optical sensor in comparison to the traditional single-application N fertilization (TSF). With this purpose, three experiments […]

Soil compaction at high intensity degrees is a hardly reversible process in the no-till system (NT), mainly in clayey soils. Generally, its occurrence in croplands is often irregular and restricted to areas with a previous history of pressures associated to intensive traffic of agricultural machineries. The purpose of this study was to investigate changes in soil physical properties of a red Oxisol with clayey texture (450 g kg-1) and soybean yield, caused by two site-specific chisels and conventional (random) chisel […]

Nowadays no-tillage soybean is widely used in crop-livestock farming systems in Brazil. The yield of no-tillage soybean was analysed in the county of Selvíria (latitudes from 20 ° 18 ‘ 05 ” S and 20 ° 18 ‘ 28 ” S and the longitudes de 52 ° 39 ‘ 02 ” W and 52 ° 40 ‘ 28 ” W (Mato Grosso do Sul State – Brazil), in the 2006/07 growing season, as affected by some physical properties of a local Typic Acrustox. The objective was to determine the soil property that could best explain the variability in the agricultural productivity. For this purpose, […]