Diagnosis and Comprehensive Evaluation of Soil Fertility of Good Agricultural Practices Base for Spatholobus suberectus Dunn. in Pingyuan of Guangdong Province / 广州中医药大学学报

ABSTRACT

Objective To investigate the status of soil fertility of Good Agricultural Practices ( GAP) base for Spatholobus suberectus Dunn. (SSD) in Pingyuan county of Guangdong province, thus to provide reference for GAP research and the subsequent fertilization for SSD. Methods The deep layer and superficial layer of GAP soil were collected for the physiochemical detection and nutrient assay. Compared with the classification standard of the second national general soil investigation, single base soil fertility index was diagnosed and the comprehensive soil fertility was evaluated with modified Nemoro Index. Results The soil pH value and the contents of exchangeable calcium and magnesium were unbalanced, and the contents of macroelements of nitrogen and phosphonium, microelements, and organic matter were low. Therefore, the measures for improving the base soil fertility should be as follows ( 1) soil amendments of bentonite, gypsum and slaked lime should be used to adjust the soil pH value; ( 2) each plant should be given 10 kg of slaked organic fertilizer as base fertilizer; ( 3) in the process of nurturing, some special micro-fertilizer solution should be used to treat the cut slips, and 5 kg of urea should be used for every 667 meter square of land; ( 4) besides compound fertilizer, every 667 meter square of land should be fertilized with 15 kg of ammonium dihydrogen phosphate for the supplement of nitrogen and phosphorus, and slaked lime and magnesium carbonate should be used for the supplement of soil moderate-quantity elements after transplantation. Conclusion The comprehensive fertility of Pingyuan GAP base for Spatholobus suberectus Dunn. is at low level, and should be improved in combination with GAP requirements.