Nutrient Management Strategies for Guangxi

Laibin and Fushui counties continued as long-term monitored village sites. Soil nutrient limitations identified by initial soil testing in 2002 continue to be verified by field trials. This information will be used to develop reliable recommendations capable of sustaining crop yield and quality.

Peanut crops were deficient in nitrogen (N), phosphorus (P), potassium (K), and boron (B). Balanced fertilization with 242-160-380 kg N-P₂O₅-K₂O/ha plus 2.5 kg B/ha increased yield by 373 kg/ha (14%) compared to the – P treatment and by 227 kg/ha (8%) compared to the – K treatment. Peanut yield decreased by 297 kg/ha (11%) without B.

In citrus orchards, symptoms of N, P, K, and magnesium (Mg), sulfur (S), B, and zinc (Zn) deficiency were present in 2003. In 2004, Mg and B deficiency symptoms were not observed. Citrus yield decreased by 13% without S and by 8% without Zn. Our understanding of this yearly variation in citrus response to nutrient stress, which must be related to changes in climate and other environmental conditions, will be of great importance in correctly comparing and interpreting field data. Guangxi-NMS02