Clea Anne E. Vallejera1, Anabella B. Tulin1,2, Victor B. Asio 1 and Chris G. Dorahy3
Farmers are increasingly using alternative fertilizer inputs such as manures and composts due to the high cost of inorganic fertilizers. However, different organic amendments have varied characteristics and thus also their effects on soil properties and the growth and yield of crops. The study was conducted to determine the characteristics and nutrient content of organic amendments, evaluate the decomposition rate and nitrogen mineralization rate of the various organic amendments, and examine the effects of different organic amendments on pechay. Four organic amendments used include swine manure, chicken dung, mudpress, and vermicast. These were analyzed for total elemental analysis, microbial decomposition, and nitrogen mineralization rate. A pot experiment was carried out to test the effects of these amendments on the growth and yield of pechay. Results showed that organic amended soil significantly increased the rates of microbial decomposition and nitrogen mineralization, organic material content, and the growth and yield of pechay. In terms of total elemental analysis, chicken dung had the highest content of essential nutrients such as P, K, Ca, and Cl as compared to mudpress, vermicast, swine manure, hence, has good potential as source of organic fertilizer for vegetable production. High amounts of heavy metals such as lead, strontium, nickel, copper, and zinc were detected in the swine manure.
Keywords: amendments, total elemental analysis, nitrogen mineralization, pechay