Nutrient management and balanced fertilization in Shaanxi province

IPNI-2006-CHN-SN4

03 Feb 2007

2006 Annual Interpretive Summary

Research and Extension of Balanced Fertilization Technology on Major Crops in Shaanxi, 2006

Apple, grape, kiwi, pepper, and corn are major crops in Shaanxi Province. Apple is particularly important with 430,000 ha planted and an output of 5.6 million metric tons (M t), accounting for 23% of China’s total production. Balanced fertilization experiments were arranged in Fufeng, Fengxiang, Heyang, Zhouzhi, and Yangling counties. In apple, chili, and corn, four treatments were tested including a balanced NPK optimum (OPT), and treatments omitting N, P, and K. In grape and kiwi, six treatments included a zero fertilizer check along with an NPK OPT, the OPT plus iron (Fe) + zinc (Zn), and treatments omitting N, P, and K.

In Heyang, the OPT for apple was 0.3-0.14-0.3 kg N-P2O5-K2O/tree at a planting density of 2,222 trees/ha. The OPT increased 100-leaf dry weight by 8.8 g (38%) and leaf area by 1.0 cm2 compared to the N omission treatment; 6.5 g (26%) and 3.1 cm2 compared to the P omission treatment; and 4.8 g (18%) and 2.9 cm2 compared to K omission treatment. Applied N, P, and K had similar effects on the proportion of apples with diameters over 7.0 cm. The complete NPK treatment produced 25.8 t/ha. Apple yield increased from 21.2 t/ha to 23.1 t/ha to 22.3 t/ha under the N, P, and K omission treatments, respectively. Balanced use of NPK also increased vitamin C (Vc) content, soluble sugars, and fruit rigidity.

Results from grape trials in Fufeng found the balanced OPT to be 0.2-0.1-0.2 kg/tree at a planting density of 1,800 trees/ha. The OPT produced 2.4 t/ha (US$949/ha) more than the N omission treatment, 0.5 t/ha (US$179/ha) more than the P omission treatment, and 1.2 t/ha (US$397/ha) more than the K omission treatment. Kiwi fruit research in Zhouzhi determined that K was most limiting this year. Potassium increased single kiwi fruit weight by 5.0 g and yield by 3.1 t/ha, and pure production value increased by US$77/ha. Potassium also improved fruit quality. When 0.4 kg N/tree and 0.17 kg P2O5/tree was applied, a 17.5 mg Vc/100g and 1.15% sugar content increase was attributed to K application at the rate of 0.3 kg K2O/tree.

As for corn plots in Yangling, without N, P, or K, grain yield decreased by 1.1, 0.7, and 1.0 t/ha, respectively, compared to the balanced OPT of 380-221-253 kg/ha. The chili experiment in Fengxiang showed that the balanced (OPT) increased fresh yield of chili by 2.5, 1.1, and 2.5 t/ha compared to treatments omitting N, P, and K, respectively. Shaanxi-NMBF