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Fertilizer...beneficial or harmful Most farmers in Thailand lack of sufficient knowledge on soil and fertilizer. Even there is a lot of related knowledge developed to assist them, but the knowledge distribution was limited only among scholars and farmer leaders. One reason is the difficulty of knowledge transfer. The composition of soil, which is comprised of organic matter, minerals, water, and air, is so complicated and inconstant. Moreover, there are many types of fertilizers and several formulas, especially commercial chemical fertilizers which there are nearly 800 formulas in the market. Meanwhile soil fertility depends on various factors such as land use characteristic, behavior of fertilizers using, and natural disasters that is able to affect to soil conditions. Therefore, farmers should analyze soil before using fertilizers every two years. Type of fertilizer There are two main types of fertilizer: organic fertilizer and inorganic fertilizer, as following details. 1. Organic fertilizers derived from a living plant or animal source which includes well-rotted animal and animal waste, for example manure, compost manure, green manure. Though humans have used organic fertilizer since ancient times, the initiated concept of natural nutrients efficiency improvement has stimulated the development of inorganic fertilizer or chemical fertilizer that has higher concentrations of nutrients than organic fertilizer. Consequently, some farmers have reduced using or even have not used organic fertilizers or organic materials anymore. Organic fertilizer was classified into different types as follows. • Manure derived from feces and urine of human and animals which are the rest of farm product. To use manure, we have to be careful because the new manure can harm plants, due to the saltiness and heat that occurred during the decomposition process. In addition, it may have problems of weeds, disease or insect contaminated in manure. Therefore, it should be well fermented and decomposed before using. • Compost derived from the fermentation of plant remains by regularly watering and turning over from time to time. Animal manure, chemical fertilizers and booster may be added as a mixture to increase the quality of compost fertilizer and shorten the fermentation period. The high standard quality compose should have the following characteristics: 1. Fertilizer grade should be not less than 1:1:0.5 (nitrogen: phosphorus: potassium). 2. Moisture and volatile matter should be not more than 35-40% by weight. PAGE 10ปีที่ 3 ฉบับที่ 7 ประจำเดือนกรกฎคม 2554 Center of Excellence for Environmental and Hazardous Waste Management สาระน่ารู้
3. pH should be between 6.0 - 7.5. 4. Well-composted fertilizer should not have contaminations. 5. Well-composted fertilizer must not have heat remains. 6. The amount of organic matter must be between 25-50%. 7. ratio of carbon to nitrogen must be less than 20 to 1. สาระน่ารู้ • Liquid Organic Fertilizer or liquid bio-fertilizer made by using sugar or molasses to extract nutrient from plant and animal cells. Anaerobic microorganisms are used for decomposing in fermentation process until the liquid turn to be brown color. Useful or beneficial microbial will control harmful microbial, keep nitrogen in the soil and produce plant hormones to stimulate the growth of root and create immunization. Therefore, the plants grow up strongly with good quality. Most of all, organic fertilizer is an alternative to reduce chemical using as well as provide safety for both farmers and consumers. • Green manure made by ploughing up and over the fiber and stubble of plants after harvesting. The debris will let to decompose, before planting, for 1-2 months until it releases the nutrients. Legumes are often used as green manure crops for their easy growth and nitrogen fixing abilities. For good benefit in producing green manure, chopping and ploughing the plants when they are half-blooming to get good quality and high weight per hectare. Other advantage of green manure is that raw materials can be available at the farm, so there is no transportation costs. 2. Inorganic fertilizers came from non-organic sources which was regularly found in nature. They are also known as chemical fertilizer. Inorganic fertilizers were divided into 2 types according to the component of primary nutrients (N-P-K) as follows. • Single fertilizers are chemical fertilizers that contain only 1 kind of primary nutrients, such as Ammonium Sulfate Fertilizer (21-0-0) contains Nitrogen (N) 21%, Potassium Nitrate Fertilizer (13-0-0) contains Nitrogen (N) 13%, Potassium Chloride Fertilizer (0-0-60) contains Potassium (K) 60%, Potassium Sulfate Fertilizer (0-0-50) contains Potassium (K) 50%, etc. • Mixed Fertilizers or bulk blending fertilizers are from the mixing of single fertilizers to increase nutrients under appropriate N, P and K for each specific fertilizer. Mixed fertilizers are generally found in the markets due to its popularity. In addition, with today’s technological advances, the elements of mixed fertilizers are blended homogeneously. The fertilizer content is not compacted or agglomerated during long-term storage and very easy to use. Fertilizers Act of 1975 indicated that chemical fertilizer manufacturers had to specify the amount of fertilizer nutrients on the label which meant as follows. • The first number of fertilizer formula refers to the amount of total nitrogen (% N). • The second number of fertilizer formulation refers to the amount of useful phosphorus. (% P 2 O 5) จดหมายข่าวPAGE 11 Center of Excellence for Environmental and Hazardous Waste Management
Page 1 and 2: CONTENT ÈÊÍ. ÈÙ¹Â¤ÇÒÁà
Page 3 and 4: From the Editor For this month of o
Page 5 and 6: นานางานวิจั
Page 7 and 8: สาระน่ารู้ •
Page 9: สาระน่ารู้ ผ
Page 13 and 14: สาระน่ารู้ Non-
Page 15 and 16: ศสอ. และผู้บร

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