Effect of Balanced fertilization on Reviving Degraded Grasslands in Sichuan
IPNI-2003-CHN-SC19
12 Jan 2005
2004 Annual Interpretive Summary
Effect of Balanced Fertilization on Reviving Degraded Grasslands in Sichuan, 2004
This project is investigating the nutrient limitations for the soils in the Aba Tibetan Autonomous Prefecture...typical of the natural grasslands in Sichuan...and is examining balanced fertilization (BF) technology and methods for reviving degraded grasslands. In 2003, the nutrient limitations of the soils were identified as nitrogen (N), phosphorus (P), and potassium (K), and the effect of fertilizer application on grass growth was evaluated. In 2004, the field plots were split to examine the relative effects of different fertilizer nutrient combinations on yield as well as the residual effect of fertilizer nutrients on established grass stands.
Compared to the unfertilized check, grass yields were double, nearly triple, and 3.7 times higher with PK, NK, and NP, respectively. Application of NPK at 90-30-60 kg N-P2O5-K2O/ha produced 2.6 times more grass (2,019 kg/ha) than the check. In the residual fertilization experiment, residual (2003) PK increased yield by 114 kg/ha (15%), NK by 436 kg/ha (56%), NP by 874 kg/ha (112%), and NPK by 597 kg/ha (77%) compared to the check with no fertilizer in either 2003 or 2004. Results suggest that N is the most limiting nutrient, followed by P and K. Crude protein in grass was positively correlated with N fertilization, but the opposite was true for crude fiber content. Currently, the best fertilizer recommendation for the region is 90-30 kg N-P2O5/ha. These degraded grasslands can be fully recovered within a single season; however, the residual effects of any fertilization needs further study. Sichuan-NMS02