Nutrient Management and Optimized Fertilization on Maize in Heilongjiang Province

Maize experiments conducted in Shuangcheng, Bingxian, and Gannan counties indicated that N application at the rate of 50 to 200 kg/ha increased maize yield by 7 to 73% with an average increase of 31%, and an average net benefit from N application of 1,810 Yuan/ha (US$266/ha). The proper N rate for maximum economic yield at these sites ranged between 100 to 180 kg N/ha, with an expected yield increase of 24 to 73%. For maize experiments conducted in Shuangcheng, Zhaodong, Hanlun, and Gannan Counties, P application between 45 to 135 kg P₂O₅/ha increased maize yield by 8 to 34%, and the average net benefit from P application was 609 Yuan/ha (US$90/ha). Further increases in P rate did not improve maize yields.

For soybean experiments conducted in Hailun, Baoqing, Keshan, and Qingan Counties, P application between 45 to 135 kg P₂O₅/ha increased soybean yield by 5 to 32% and the average net benefit from P application was 459 Yuan/ha (US$68/ha). Further increases in P rate did not further improve soybean yields.

In rice experiments conducted in Fangzheng, Huachuan, and Qingan counties, N application between 25 to 200 kg N/ha increased rice yield by 11 to 80% and the average net benefit of N application was 2,730 Yuan/ha (US$402/ha). Rice trials in Fangzheng, Huachuan, Ningan, and Qingan counties indicated that P application between 22 to 135 kg P₂O₅/ha increased rice yield by 7 to 58% and the average net benefit of P application was 1,620 Yuan/ha (US$238/ha). Heilongjiang-NMBF