Effect of Balanced Fertilization on Citrus


30 Jan 2007

2006 Annual Interpretive Summary

Effect of Balanced Fertilization on Citrus Yield and Quality in Guangdong, 2006

Endowed by the favorable subtropical climate with abundant sunshine and warm temperature, Guangdong is one of the major fruit production provinces in China. Among the fruits, the high sugar content and unique taste of sweet orange is welcomed by consumers nationwide in China. Attractive profit margins have stimulated production of fruits with increased fertilizer application rates and expanded growing areas. However, this high input-output production pattern with improper fertilization has negatively impacted the soil nutrient imbalance. The objective of this project was to identify the factors affecting citrus growth and develop best fertilizer management practices for high yield and quality citrus production.

Besides N, P, and K, soil testing also showed that magnesium (Mg), manganese (Mn), and zinc (Zn) are limiting factors for sweet orange. A field experiment was designed that evaluated the recommended nutrient balance (BF) for orange production and farmers’ practice (FP). Compared to the FP of applying 705-452-543 kg N-P2O5-K2O/ha, the BF fertilizer application of 754-324-759 kg/ha significantly increased orange yield by 2,970 kg/ha (11%), and slightly lowered the acid content. Further addition at 32 kg MgO/ha increased fruit yield by 1,980 kg/ha (14%) with no negative influence on quality. Though Mn and Zn were identified as yield-limiting factors through soil testing, and deficiency symptoms were observed on tree leaves, no effect of Mn and Zn application was found. Guangdong-BFDP-06