Effect of Improved Fertilization on potato Yields in Tibet

IPNI-2007-CHN-XZ7

15 Feb 2008

2007 Annual Interpretive Summary

Effect of Improved Fertilization on Potato Yields in Tibet, 2007

Potato is a very important and traditional food crop in Tibet where people rely on the tuber as a vegetable. Because of its good adaptability to poor soil conditions and harsh weather, it is scattered from mountains to river valleys on the plateau where it can grow and be harvested. Though it has a long history of cultivation in Tibet, balanced fertilization programs for this crop were just initiated in 2007. Therefore, the objective of this project was to determine the optimal rates of N, P, and K fertilizers for potato production and provide scientific fertilizer recommendations for the region.

The field experiment was conducted in a river valley in the Shannan region, an area representative of more than half of the potato growing conditions in Tibet. Results showed that different fertilizer treatments caused tremendous yield variation, particularly for N and K application. The optimal treatment was identified to be 105-75-120 kg N-P2O5-K2O/ha, which produced the highest potato yield of 64.2 t/ha or 15.5% higher than yields obtained with the government recommendation of 150-75-0 kg/ha.

By reducing N and adding K, potato yields have been boosted to record levels. This will be a real incentive for the local potato farmers to follow, and for local leaders to disseminate to a wider area. The preliminary results have been used for fertilizer recommendations in the surrounding potato areas in Tibet, but further field validation and demonstrations will be continued in 2008. Tibet-BFDP-07