CAJ | 학술논문

A new site-specific nutrient management approach was developed to break the apparent attainable yield barrier of 6 t*ha-1 in the double rice cropping system of Zhejiang. On-farm experiments involving 21 rice-growing farmer families and NPK long-term experiments commenced in 1997 in the central part of Zhejiang Province to assess the status of soil fertility and productivity under intensive rice-rice cropping. A new site-specific nutrient management (SSNM) approach has been developed for this studied area. Field-specific fertilizer recommendations are calculated considering indigenous nutrient supply, reasonable grain yield targets and corresponding nutrient demand, nutrient balance and nutrient use efficiency, as well as socio-economic factors. The agronomic performance of SSNM was tested against the farmer's fertilizer practice (FFP) in four 1998-1999 cropping seasons. Across seasons and years, SSNM consistently increased plant nutrient uptake, grain yield and profit by about 10%-15% compared to the FFP. Yield levels of 7.5 t *ha-1 or more seem achievable and sustainable through introduction of SSNM and improved extension services in Zhejiang Province.