Nutrient management and balanced fertilization on main crops in Qinghai province


23 Jan 2009

2008 Annual Interpretive Summary

Nutrient Management and Balanced Fertilization in Qinghai, 2008

In 2008, work mainly focused on nutrient management and balanced N, P, and K fertilization studies in important crops in Xi’ning City, Huzhu County, and Huangzhong County of Qinghai Province. The main cash crops included rapeseed, potato, and rainfed faba bean. The main forage crop in Qinghai is oats.

An irrigated potato trial in Xi’ning found 150-60-135 kg N-P2O5-K2O/ha to be the most profitable NPK treatment. Yields under this improved treatment were only 3% higher than common farm practice, which omits K (240-52 kg N-P2O5/ha), but an additional US$108/ha was generated. In Huzhu, the optimal P rate for rapeseed was 56 kg P2O5, which delivered 10% more yield and US$272 more profit than the P omission treatment. A K rate study on faba bean tested 45 to 180 kg K2O/ha co-applied with 110-104 kg N-P2O5/ha. Yields were raised by 14 to 40% compared to K omission treatment and 90 kg K2O/ha produced the highest yield of 4,210 kg/ha and the best income of US$528/ha. Oat fodder experiments in Huangzhong found yield improvements with increased N and K rates up to 100 kg N/ha, which produced 8,430 kg/ha (20%) more fodder than the N omission treatment, and 135 kg K2O/ha which produced 4,585 kg/ha or 11% more than the K omission treatment. Qinghai-NMBF