Nutrient management and optimized fertilization on selected crops in Liaoning province

In 2006, a range of experiments were carried out that focused on nutrient management in rice and corn. Rice yield (and profits) were maximized at 9.1 t/ha (US$2,011/ha) with the optimum (OPT) treatment of 300-120-180 kg N-P₂O₅^-K₂O/ha. This provided 11% more yield than the farmers’ practice (FP) which used 210-105-105 kg N-P₂O₅^-K₂O/ha, and 44% more than the unfertilized check. Omission of N, P, and K reduced yield by 41%, 29%, 44%, and reduced profit by 32%, 27%, and 43%, respectively. It is apparent that this region requires much greater attention to balanced fertilization on rice production. In corn, the OPT of 270-150-150 kg N-P₂O₅^-K₂O/ha produced the highest yields (and profits) of 10.1 t/ha (US$1,248/ha). This provided 6.5% more yield than the FP of 180-90-90 kg N-P₂O₅^-K₂O/ha and 28% more than the unfertilized check.

Another rice field trial evaluating K fertilization methods was conducted in Tieling County. Treatments included: 1) 100% basal K application, 2) 50% basal and 50% at tillering, and 3) 40% basal, 30% at tillering, and 30% at spike initiation. All treatments received 180 kg K₂O/ha, 300 kg N/ha, and 90 kg P₂O₅/ha with one-third of N and all of the P applied basally, and the remaining N applied at tillering. Yields were 6.7 t/ha, 8.3 t/ha, and 8.8 t/ha for treatments 1, 2, and 3, respectively. These results support the conclusion that there is ample advantage to splitting K application throughout the season. Potassium application rate had a significant effect on corn yield, which increased by 50%, 51%, 60%, and 67% with 60, 90, 120, and 180 kg K₂O/ha as compared with the check treatment without K (yield with 9.9 t/ha) based on 300 kg N/ha and 150 kg P₂O₅/ha. Liaoning-NMBF