Effect of Improved Nutrient Management on Potato Yield in Guizhou


15 Feb 2010

2009 Annual Interpretive Summary

Effect of Improved Nutrient Management on Potato Yield in Guizhou, 2009

Guizhou is one of the major potato producing provinces in China. It is a staple food, especially in remote areas. Nevertheless, yields have remained low for many years... a result of several limiting factors among which improper fertilization is crucial. The objective of this project was to study the effect of different fertilizer treatments on potato yield and to determine the optimal fertilizer combinations of N, P, and K. Four rates of N (0, 75, 150, and 225 kg N/ha), P (0, 52.5, 105, and 157.5 kg P2O5/ha), and K (0, 105, 210 and 315 kg K2O/ha) were used in this experiment.

Results showed that application of 75 kg N/ha produced 23 t/ha of potato tuber with the highest agronomic efficiency (AE) of 67 kg/kg N. Above this rate, yield improved marginally but AE dropped to 40 kg tuber/kg N (150 kg N/ha) and to 28 kg tuber/kg N (225 kg N/ha). The optimal rate of P appeared to be 105 kg P2O5/ha, which produced 24 t/ha and a highest AE of 82 kg tuber/kg P2O5. Below this rate, both yield and AE declined, whereas above this rate, yield increased slightly and AE decreased dramatically. For K, though application of 105 kg K2O/ha did not produce the highest yield (23.8 t/ha), it generated the highest AE (17.1 kg tuber/kg K2O). If K rate was doubled to 210 kg/ha yield only increased by 1.2%, but AE was reduced to 10 kg tuber/kg K2O.

Based on this study, the optimal rates of N, P, and K fertilizers could be 75-105-105 kg N-P2O5-K2O/ha. Verification of these results is needed through testing at more field locations. Guizhou-BFDP-2009