Two split root trials were carried out in nutrient solution to evaluate nitrogen accumulation as a function of phosphorus supply applied in partial contact to maize roots. After a seven day growth period in complete nutrient solution, maize seedlings were transplanted to joint pots containing 1.6 L of nutrient solution. Roots were equally shared between the pots. In the first trial, two phosphorus levels (0.02 mmol L-1 and 0.1 mmol L-1) and phosphorus and nitrogen placement were evaluated. In the […]

The C and N mineralization potential of 20 soils from Pernambuco, Brazil (10 from the humid area and 10 from the semi-arid) was determined in a greenhouse experiment, conducted from January to October 1987. Samples of 50 g from 0-20 and 20-40 cm depth layers were incubated. The released C-CO2 and the accumulated mineral N (NO3– and NH4+) were periodically measured during 20 and 4 weeks, respectively. The mineralized amounts varied much among soils. In spite of this they were […]