Brachiaria species, particularly B. humidicola, can synthesize and release compounds from their roots that inhibit nitrification, which can lead to changes in soil nitrogen (N) dynamics, mainly in N-poor soils. This may be important in crop-livestock integration systems, where brachiarias are grown together with or in rotation with grain crops. The objective of the present study was to determine whether this holds true in N-rich environments and if other Brachiaria species have the same effect. The soil N dynamics were […]

The N mineralization rate varies from one organic residue to another, and depends on the chemical composition of a residue and its interaction with the soil. This study assessed the dynamics of N mineralization of organic residues incubated in Oxisols. The experiment was carried out from July 2007 to April 2008. Samples of manures, sludges, composts, peat, and substrate were incubated in washed sand, in a Red Yellow Latosol (RYL), and in a Red Latosol (RL), with 240 and 670 […]

Rice is classified as an ammonium (NH4+)- tolerant plant due the predominance of this ion in flooded soils. However, in the oxygenated zones of flooded soil and in the rice rhizosphere, nitrate (NO3–) can be formed and become an important nitrogen (N) source for the crop. This experiment was carried out to evaluate the effect of different ammonium:nitrate proportions on rice development in nutrient solution. The experiment was carried out in a greenhouse, from January until February 2008 in a […]

The semi-arid region of Chiapas is dominated by N2 -fixing shrubs, e.g., Acacia angustissima. Urea-fertilized soil samples under maize were collected from areas covered and uncovered by A. angustissima in different seasons and N2O and CO2 emissions were monitored. The objective of this study was to determine the effects of urea and of the rainy and dry season on gas emissions from semi-arid soil under laboratory conditions. Urea and soil use had no effect on CO2 production. Nitrons oxide emission […]