Biochar-based nitrogen fertilizers: Greenhouse gas emissions, use efficiency, and maize yield in tropical soils.

The sustainable development of agriculture depends on increasing N use efficiency (NUE) and consequently reducing N losses from different sources, such as NH volatilization, NO leaching, and NO emissions. While the chemical and physical properties of biochar (BC) in fertilizers have been evaluated to increase NUE, a lack of information exists regarding the effects of BC amendments in tropical soils. We performed a one-year field experiment with tropical soil to evaluate the effects of BC-based N fertilizers (BN) on maize yield and on greenhouse gas (GHG) emissions.

Ion leaching and soil solution acidification in a vadose zone under soil treated with sewage sludge for agriculture.

In this study, we performed monitoring of the soil solution (SS) over 10 years on a loamy/clayey-textured Dark Red Dystroferric Oxisol that received sewage sludge for agricultural purposes. The SS was obtained by lysimeters installed along the walls of a well at 1 m, 2 m, 3 m, 4 m and 5 m in depth. The major ions found in the SS were NO, SO, Cl, Ca, Mg, Al, Pb, Cd and Zn, and the pH level ranged from 4 to 6.