Nitrous oxide (N2O) is the most important greenhouse gas produced by agricultural soils and is a byproduct of microbial nitrification and denitrification processes. The N2O emission rates depend on soil, climatic and management factors. The objectives of this study were i) to evaluate N2O emissions during a barley crop period and its subsequent barley-maize interperiod, under two management systems, and ii) to relate the N2O flux rates with soil mineral N content, waterfilled pore space (WFPS) and soil temperature.
The no-tillage system combining winter cover crops and crop rotation may increase the efficiency use of soil P and phosphate fertilizer. The objective of this study was to evaluate the effect of three decades of different soil management systems and winter cover crops on the fractions of P in a clayey Oxisol of Paraná State, Brazil. The bi-factorial experiment with three replicates was established in 1986. The main plots consisted of seven winter cover crops. In the subplots, two tillage systems were used: no-tillage and conventional tillage.
