Effect of Balanced Fertilization on Reviving Degraded Grasslands in Tibet

Tibet has the largest grassland area in China...67 million hectares (M ha)...a tremendous natural resource available to animal husbandry. Local government has recently advocated the development of this sector as a means to improve rural people’s income and living conditions. The severe landscape, harsh weather conditions, and a fragile grassland ecology are obstacles to overcome. Ideal pasture lands are confined to the moist, flat areas, but overstocking has caused much degradation to these regions and permanent damage to the drier regions, resulting in desertification. The study seeks solutions for protecting undamaged grasslands and the revitalization of degraded areas through balanced fertilization. Soil nutrient deficiencies, fertilizer recommendations for rates, placement methods, timing, and frequency are to be investigated.

The major nutrient limitations (in descending order) are nitrogen (N), potassium (K), and phosphorus (P). Application of 210-60-135 kg N-P₂O₅-K₂O/ha increased grass yield by 2.6 times compared to the check, which received no fertilizer and is the prevailing practice. Compared to this optimal treatment, grass yield declined from 27.8 to 10.0 t/ha (64%) without N, and to 24.0 t/ha (14%) without K. Balanced fertilization has proved to be a most promising method for rapidly revitalizing the degraded grasslands in Tibet. The residual effect of fertilizers applied to established grass stands will be studied in upcoming years. Tibet-NMS02