Nutrient management and balanced fertilization in Shaanxi province

IPNI-2006-CHN-SN4

23 Jan 2009

2008 Annual Interpretive Summary

Nutrient Management and Balanced Fertilization for Major Crops in Shaanxi, 2008

Imbalanced use of nutrients in Shaanxi Province has restricted crop yield and quality of apple, kiwi, chili pepper, and corn — all major crops in the province. A series of field experiments were arranged to determine the nutrient limitations and best application rates and timings for high nutrient use efficiency.

Balanced use of N, P, and K in apple at Heyang County was determined to be 0.4-0.24-0.6 kg N-P2O5-K2O/tree (2,222 trees/ha). Half of the N and K treatment was applied basally and the remainder was topdressed. Yield was most impacted by N omission followed by P, then K. The balanced NPK treatment produced 10.6 t/ha (+33%) more than common farm practice (1.28-0.46-0 kg/tree) and generated an additional US$5,720/ha. Research in other crops included chili pepper in Fengxiang County where 240-175-200 kg/ha was found to be most profitable. Yield under this treatment was 3,330 kg/ha (+18%) higher than the K omission treatment and income was improved by US$440/ha.

A study on nutrient uptake and accumulation by kiwi trees found rapid N accumulation between early July to early September after which N was redistributed to the developing aboveground tree parts. Total N uptake was 217 kg/ha annually. Total N removal by leaves, trunks, and fruits was 20, 26, and 113 kg/ha, respectively, accounting for 9%, 12%, and 52% of total N uptake. The appropriate N rate was 278 kg/ha which should be split between periods immediately following harvest, late May, and early July.

Researchers also examined the integration of nutrient management and planting density in summer corn grown near Yangling City. Base grain yields were 13.5 t/ha under 67,500 plants/ha and NPK applied at 225-67-0 kg/ha. Yields improved to 17 t/ha under 82,500 plants/ha and 300-90-60 kg/ha plus 15 kg zinc (Zn) + 15 kg boron (B)/ha and improved even further to 18.6 t/ha under 97,500 plants/ha and 375-112-75 kg/ha plus 15 kg Zn + 15 kg B/ha. In all these cases, N was split between seedling (40%), stem elongation (30%), and tassel emergence (30%). Shaanxi-NMBF