การใช้ของเสียจากกระบวนการผลิตครั่งเม็ดเป็นปุ๋ยอินทรีย์

Abstract

A study on potential of utilizing waste material from seed lac processing as organic fertilizer was conducted at faculty of agriculture, Chiang Mai University during May 2012 - May 2013. This study has three experiments, the first experiment, two lac organic fertilizer production processes were evaluated. Method I is drying process, different drying temperatures that ranged between 35 and 75C were applied to fresh lac waste sediment to find an optimum temperature that affect minimum nutrients loss. Physico-chemical analysis of dried lac waste sediment (10-11% moisture content), referred to as lac organic fertilizers obtained from the drying process and the fresh lac waste were performed for comparison. Method II is composting process, fresh lac sediment was composted for 8 weeks. Lac organic fertilizers samples were taken every two weeks until 8 weeks for their properties analysis. In addition, effect of storage period on lac organic fertilizer properties were also evaluated. The lac organic fertilizers obtained from drying process were stored at room temperature and analysed their properties every month untit 6 month. The second experiment, the effects of lac organic fertilizer application on N-mineralization and microbial biomass in soil were determinaed by incubation soil with lac organic fertilizer at the rate of 1, 2, and 3 tons/rai in comparison with 2 ton/rai of AG5 compost and control treatment (without organic fertilizer). Moisture of soil samples were maintained at 60% of maximum water holding capacity. Then, the samples were incubated at 25 °C for a month. Soil samples were taken weekly for inorganic N, microbial biomas analysis. The third experiment, the effect of the lac organic fertilizers on growth and yield of Chinese kale under green-house conditions was conducted at the Faculty of Agriculture, Chiang Mai University. Different rate of lac organic fertilizers were applied to Chinese kale which planted in plastic pots. The treatments used were as followings: control (no fertilizer), 50 kg/rai chemical fertilizer (16-16-16), 3 ton/rai AG5-compost, 3 ton/rai lac organic fertilizer, 3 ton/rai AG5-compost + 25% lac organic fertilizer, 3 ton/rai AG5-compost + 50% lac organic fertilizer, and 3 ton/rai AG5-compost + 75% lac organic fertilizer. The result showed that the optimum temperature of lac waste sediment drying was about 45-55ºC. The drying temperature higher than 55◦C and lower than 45◦C effect the loss of organic matter and nitrogen content particularly ammonium-nitrogen content about 47 and 72 percent, respectinely, but phosphorus contents was only slightly decreased by drying. Composting of wet lac waste sediment at 8 weeks found that lac compost was more suitable for growing plants, which is clearly shown from the increasing pH with period of composting. At six-months storage of the lac organic fertilizers (55ºC drying, 10-11 percentage moisture content) resulted in pH decreasing about 1.4-1.9 pH unit in comparison with the beginning. Soil incubating with different lac organic fertilizer rates gave the higher results on N-mineralization and microbial biomass carbon in soil compared to AG-5 compost. Besides, the application of lac organic fertilizers at the rate of 1 ton/rai increased the N-mineralization and microbial biomass carbon in soil equally 2 tons/rai of compost AG-5 usage. The lac organic fertilizers application rates were applied to Chinese kale found that the mixed organic fertilizer (AG-5 compost plus 50% of lac organic fertilizers) at the rate of 3 tons/rai gave the best result on Chinese kale productivity compared to AG-5 compost at the rate of 3 tons/rai and chemical fertilizer (16-16-16) at the rate of 50 kg/rai. However, application of lac organic fertilizer at the rate of 3 tons/rai possibly caused the plant toxicity. The results indicated that the dried lac waste sediment had a high potential for agricultural utilization. Conversely, the application rate over 3 tons/rai of lac organic fertilizer caused plant stuck growing. Therefore, the mixtures of lac organic fertilizer and compost at rate 25-50% gave the best result on plant response to the applied fertilizer.