Organic fertilizers often contain numerous elements beside nitrogen (N) such as phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na). In general, the application rates of organic fertilizer are based on N requirement which could result in extra amount of other elements i.e. P and Na which could negatively impact on environment. This study aimed to investigate the release of P, K, Ca, Mg, and Na using a batch technique from three organic fertilizers (e.g. cow manure, compost and sunn hemp) incubated in two paddy soils at various time periods (e.g. 0, 3, 5, 7, 14, 21, 28, 42, 56, 70, 98 and 120 days). A 2×4 factorial in completely randomized experimental design with three replications was employed. A factor A was type of paddy field (an organic paddy field (SO), and non-organic paddy field (SC)) and a factor B was four different organic fertilizers application type (control, cow manure compost and sunn hemp). Soil samples were collected to analyze soil pH, electrical conductivity, available P (Bray II), exchangeable K, Ca, and Mg and extractable Na at the end of each incubation time period. Results showed that the incubation time period did not play a role on the release of P, K, Ca, Mg and Na in soils. Release of P, K, Ca, Mg, and Na in SC was higher than SO. Release of P, K, and Na were highest in cow manure, while compost gave higher release of Ca and Mg. Electrical conductivity did not exceed safety levels with all treatments less than 0.50 mS/cm.
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E-mail: sukunya.ya@kmitl.ac.th
Surin, P. ., Supsuan, P. ., & Yampracha*, S. . (2019). Release of Various Elements from Organic Fertilizers Incubated in Organic and Non-organic Paddy Soils at Various Time Periods. CURRENT APPLIED SCIENCE AND TECHNOLOGY, 276-288.
