Nutrient Management and Optimized Fertilization on Wheat and Maize in Hebei Province

Hebei is a great production base for winter wheat, summer corn, cotton, and peanut. Research activities in 2007 continued monitoring balanced fertilization on these crops.

A long-term, fixed-site study for K use in a winter wheat/summer corn rotation system had been carried out in Xinji since 1992. Four treatments included: 1) NP: 225-90-0 kg N-P₂O₅-K₂O/ha without stalks returned; 2) NPK: 225-90-150 kg/ha without stalks; 3) NPSt: 225-90-0 kg/ha plus stalks; 4) NPKSt: 225-90-150 kg/ha plus stalks. In wheat, compared to the 5.4 t/ha yield obtained by the NP treatment, the NPK, NPSt, and NPKSt treatments produced 5%, 0.6%, and 14% more yield. In corn, the 7.2 t/ha yield obtained by NP treatment was 22%, 10%, and 26% less than the NPK, NPSt, and NPKSt treatments, respectively. Moreover, K application significantly increased available and slowly-released K in the top 20 cm of soil.

Nutrient omission treatments applied within a winter wheat field trial were carried out in Xinji. The highest yield average of 6.3 t/ha was achieved with the balanced “optimum” (OPT) of 180-100-75 kg/ha. Yields were 24% lower without N, 9% lower without P, and 2% lower without K. The farmer practice (FP) of applying 300-150-0 kg/ha produced 11% less yield, and yields under the zero fertilizer check (CK) was 38% lower than the OPT. Agronomic efficiency of N under the OPT was 8.6 kg/kg, and the apparent recover efficiency of N was 38%. In summer corn, the OPT of 270-45-120 kg/ha produced the highest yield of 8.8 t/ha. Omission of N, P, and K resulted in 12%, 9%, and 10% less yield compared to OPT. The FP of applying 160-48-72 kg/ha reduced yield by 14% and the CK reduced yield by 15%.

A winter wheat field trial conducted in Zhengding County demonstrated that balanced fertilization could increase wheat yield. Compared to NP application of 180 kg N/ha plus 40 kg P₂O₅/ha which produced 7.5 t/ha, treatments providing an additional 60, 120, 180, and 240 kg K₂O/ha improved yield by 5%, 10%, 17%, and 19%, respectively. In cotton, the OPT of 240-45-165 kg/ha achieved the highest yield of 3.8 t/ha. Omission of N, P, and K resulted in 7%, 4%, and 3% less yield, respectively, while the FP of applying 300-135-90 kg/ha was 4% lower and the CK 11% lower than the OPT. Nutrient omission treatments in a peanut field trial at Luquan County determined that yields declined from 4 t/ha produced with the OPT of 120-45-90 kg/ha to 3.7 t/ha , 3.9 t/ha, and 3.9/ha under the -N, -P, and -K treatments. The CK produced 7% less yield, and the FP of applying 105-120-60 kg/ha produced 5% more yield than the OPT. Hebei-NMBF