Nutrient Management Strategies for Guizhou

IPNI-1999-CHN-GZ12

12 Jan 2005

2004 Annual Interpretive Summary

Nutrient Management Strategies in Guizhou, 2004

The monitored village site in Pinba County was set up to define the site-specific nutrient management zones for this region. Initial soil testing in 2001 determined that upland soils were extremely deficient in potassium (K) and nitrogen (N), while paddy soils were largely deficient in K, phosphorus (P), and N. Balanced fertilization experiments and field demonstrations were continued in 2004 to verify soil test results.

The treatment of 152-90-150 kg N-P2O5-K2O/ha increased corn yield by 3.9 t/ha (66%) compared to the - K treatment and by 2.5 t/ha (41%) compared to the – N treatment. Similarly, application of 150-90-225 kg/ha increased rice yield by 0.8 t/ha (15%), 0.86 t/ha (15%), and 0.13 t/ha (2%) compared to the – K, - N, and – P treatments, respectively. Field trials in 2004 agreed with the previous year's results and further verified the general deficiency of K and N. However, results from 2004 failed to show a P deficiency in paddy soils.

As for the soil nutrient balances, in the uplands, N was in deficit for all treatments except for the – K and low K treatments. In the paddy soils, N was in deficit for all treatments, but K was in deficit only in the – K and low K treatments. Results suggest that distinct nutrient management strategies should be employed for upland and paddy soils. Through field demonstrations, field day activities, and technology training, farmer fertilizer use practices have been improved considerably. Guizhou-NMS05