Use of Waste Material from Seedlac Production for Producing Organic Fertilizer І. Effects of Drying Temperature and Storage period on Properties of Lac Organic Fertilizer

Abstract

The aim of this study was to evaluate the potential of utilizing waste material from seedlac processing as organic fertilizer. In this study two experiments were conducted at the Faculty of Agriculture, Chiang Mai University during May 2011-May 2012. In the first experiment, different drying temperature that ranged between 35-65^ºC were applied to fresh lac waste sediment to find an optimum temperature that affected minimum nutrients loss. Physical-chemical analysis of dried lac waste sediment, referred to as lac organic fertilizers (LOF) obtained from drying process and the fresh lac waste were performed for comparison. For the second experiment, The LOFs were stored at room temperature for six months and samples of LOF were taken at one month intervals for their properties analysis. The result showed that the optimal temperature for lac waste sediment drying was about 45-55^ºC. The loss of organic matter and nitrogen content after sediment lac drying was observed at temperature higher than 55^ºC lower than 45^ºC. Ammonium nitrogen was the main nutrient that loses 47 and 72%, respectively, but phosphorus was only slightly affected by drying. Six-months storage of the lac organic fertilizers (drying 55^ºC, 10 ±1% moisture content) resulted in a decrease in pH, 1.4-1.9 pH unit in comparison with the beginning. Results from this study indicated that the dried lac waste sediment had a high potential for agricultural utilization.