Nutrient Management Strategies for Forage in Yunnan

Yunnan’s provincial government is planning to develop more than 10 million hectares (M ha) of grassland over the next several years. To date, more than 150,000 ha have been planted. A Grassland Research Institute was founded and stationed in Xiaoshao County, where over 200 ha of demonstration plots are established and a number of field experiments are conducted annually. Currently, the Institute is preoccupied with the introduction and breeding of grass species from abroad and at home, while important aspects concerning forage grass nutrition are being ignored. This study is addressing the issue by investigating the yield-limiting nutrients in main soils and determining nutrient management strategies for forage grass production.

The dominant nutrient deficiency was nitrogen (N), followed by phosphorus (P), calcium (Ca), boron (B), and zinc (Zn). Field trials found improved grass yield with both P and potassium (K), although soil tests had not indicated K as a yield-limiting nutrient. Grass yield response to B and Zn was positive, but not statistically significant. Application of 210-60-135 kg N-P₂O₅-K₂O/ha is considered optimal and can be recommended to local forage growers. This treatment increased ryegrass yield by 21.2 t/ha (44%) compared to the - P treatment and by 18.3 t/ha (36%) compared to the - K treatment. In clover, yield was increased by 29.5 t/ha (59%) compared to the - P treatment and by 25.1 t/ha (46%) compared to the - K treatment. Field trials will be conducted on an expanded group of grass-types in future years. Yunnan-NMS-02