The effect of N fertilizer application in ricefield on the environmental quality of ground-water was evaluated using large undisturbedmonolith lysimeters.Soil in lysimeters wassilty-clay-loamy paddy soil(Haplaquept)wi...The effect of N fertilizer application in ricefield on the environmental quality of ground-water was evaluated using large undisturbedmonolith lysimeters.Soil in lysimeters wassilty-clay-loamy paddy soil(Haplaquept)with apH of 6.5,15.4g/kg organic C,1.55g/kg to-tal N,88 mg/kg available N,399 mg/kg A1-abbas-P,67.5 mg/kg exchangeable K,and14.1 cmol/kg CEC.The lysimetry experiment was laid out atHangzhou during the early-rice season(ER,May-Jul)and late-rice season(LR,Jul-Oct)in 1991-1994.Three plot treatments were es-tablished,i.e.,urea plot(UN,applied urea150 kgN/ha per cropping season),ammoniumbicarbonate plot(CN,applied ammonium bi-carbonate 150 kgN/ha per cropping season),and control plot(CK,no N application).Allof the plots also received single superphosphateat 45 kg P/ha and KC1 at 75 kg K/ha.The展开更多
In order to study the law of nitrogen leaching losses from the paddy field under the condition of drainage, based on the theories of potential energy and solute transport, a water nitrogen dynamic mixed model by comb...In order to study the law of nitrogen leaching losses from the paddy field under the condition of drainage, based on the theories of potential energy and solute transport, a water nitrogen dynamic mixed model by combining the flow net with dynamic method was established. In the computation of buried pipe drainage, the superposition principle was used to simplify the complex solving of the two dimensional problem about water nitrogen transportation in Soil Plant Air Continuous (SPAC) system into several one dimensional problems. The presented method is simple and practical. Some field experiments were carried out to demonstrate the validity of the model.展开更多
文摘The effect of N fertilizer application in ricefield on the environmental quality of ground-water was evaluated using large undisturbedmonolith lysimeters.Soil in lysimeters wassilty-clay-loamy paddy soil(Haplaquept)with apH of 6.5,15.4g/kg organic C,1.55g/kg to-tal N,88 mg/kg available N,399 mg/kg A1-abbas-P,67.5 mg/kg exchangeable K,and14.1 cmol/kg CEC.The lysimetry experiment was laid out atHangzhou during the early-rice season(ER,May-Jul)and late-rice season(LR,Jul-Oct)in 1991-1994.Three plot treatments were es-tablished,i.e.,urea plot(UN,applied urea150 kgN/ha per cropping season),ammoniumbicarbonate plot(CN,applied ammonium bi-carbonate 150 kgN/ha per cropping season),and control plot(CK,no N application).Allof the plots also received single superphosphateat 45 kg P/ha and KC1 at 75 kg K/ha.The
文摘In order to study the law of nitrogen leaching losses from the paddy field under the condition of drainage, based on the theories of potential energy and solute transport, a water nitrogen dynamic mixed model by combining the flow net with dynamic method was established. In the computation of buried pipe drainage, the superposition principle was used to simplify the complex solving of the two dimensional problem about water nitrogen transportation in Soil Plant Air Continuous (SPAC) system into several one dimensional problems. The presented method is simple and practical. Some field experiments were carried out to demonstrate the validity of the model.
