Nutrient management and balanced fertilization on main crops in Qinghai province
IPNI-2006-CHN-QH5
20 Feb 2010
2009 Annual Interpretive Summary
Nutrient Management and Balanced Fertilization in Qinghai, 2009
In 2009, experiments in Qinghai were mainly focused on finding the yield-limiting nutrient factors for spring wheat, rapeseed, rainfed potato, and forage grass in Xi’ning City, Huzhu County, and Chengduo County.
In spring wheat grown at Xining, N was the main nutrient limitation. Application of 150 kg N/ha produced 38% more grain yield compared to the N omission plot supplied with 90 kg P2O5/ha and 135 kg K2O/ha. Omission plots in rapeseed grown at Huzhu County also found N to be a larger yield-limiting factor compared to P. However, the balanced OPT of 125-75-135 kg N-P2O5-K2O/ha only produced 4% more yield than the farmer practice (FP) of applying 140-86-90 kg N-P2O5-K2O/ha. Agronomic efficiencies (AE) under this OPT were 6.3 kg seed increase/kg N and 3.8 kg seed increase/kg P2O5. In rainfed potato grown at Huzhu County the recommended NPK treatment of 214-86-193 kg N-P2O5-K2O/ha and the corresponding set of nutrient omission plots determined N to be most limiting followed by K, then P. The recommended treatment produced a 10% higher tuber yield compared to the farmer practice (FP) of applying 343-74-0 kg N-P2O5-K2O/ha. The AE values calculated under this recommendation were 38 kg tuber increase/kg N, 20 kg tuber increase/kg P2O5 and 28 kg tuber increase/kg K2O. Balanced use of NPK (450-210-120) in natural grassland in Chengduo County resulted in 359%, 246%, 9% more dry matter yield than the N, P, and K omission plots, respectively, and also generated an additional US$644/ha compared to the FP of zero fertilization. Data of dry matter accumulation and nutrient uptake at different crops stages were also investigated in this study. Qinghai-NMBF