Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient relea...Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release profiles of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate sodium could not improve water resistance performance and glass transition temperature Tgof coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorporation of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated controlled release fertilizer, with the 30-day cumulative nutrient release reduced to 16% and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.展开更多
A plot of 24 m × 10 m under fallow management after several years of cultivation to maize （Zea mays） was planted to tea （Camellia sinensis） cuttings at 1.0 m ×0.6 m and treated with or without fertilizer...A plot of 24 m × 10 m under fallow management after several years of cultivation to maize （Zea mays） was planted to tea （Camellia sinensis） cuttings at 1.0 m ×0.6 m and treated with or without fertilizer. The tea cuttings were applied NPK 25：5：5 （reference fertilizer）, cocoa husk, cow-dung, tea fluff and poultry droppings as manures, mixtures of the manures with urea in 3：1 ratio of N contents as organomineral and the control （no fertilizer）, monitored for growth performance for two years at Kusuku （6°50＇N; 11 °07＇E）, Nigeria. The organic based fertilizers generally outperformed NPK 25：5：5 and control in all the growth parameters. Organominerals resulted in an overall higher plant height, girth, number of leaves and branches compared to the manures in the first year of establishment, while the values were higher for manure treated plants in the second year. This trend was attributed to quicker release of nutrient by the organominerals in the first year, while the manures had undergone adequate decomposition for sufficient nutrient release to the advantage of the tea plants in the second year. However, comparative cost analysis showed that organominerals were more economical to achieve optimum tea production at minimum cost in the locality.展开更多
基金Supported by the National 12th Five-Year Science and Technology Supporting Program(2011BAD11B01)the Research & Development Projects Cooperation Project of Chinese Academy of Sciences(YDJDBNJ-2012-023)
文摘Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release profiles of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate sodium could not improve water resistance performance and glass transition temperature Tgof coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorporation of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated controlled release fertilizer, with the 30-day cumulative nutrient release reduced to 16% and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.
文摘A plot of 24 m × 10 m under fallow management after several years of cultivation to maize （Zea mays） was planted to tea （Camellia sinensis） cuttings at 1.0 m ×0.6 m and treated with or without fertilizer. The tea cuttings were applied NPK 25：5：5 （reference fertilizer）, cocoa husk, cow-dung, tea fluff and poultry droppings as manures, mixtures of the manures with urea in 3：1 ratio of N contents as organomineral and the control （no fertilizer）, monitored for growth performance for two years at Kusuku （6°50＇N; 11 °07＇E）, Nigeria. The organic based fertilizers generally outperformed NPK 25：5：5 and control in all the growth parameters. Organominerals resulted in an overall higher plant height, girth, number of leaves and branches compared to the manures in the first year of establishment, while the values were higher for manure treated plants in the second year. This trend was attributed to quicker release of nutrient by the organominerals in the first year, while the manures had undergone adequate decomposition for sufficient nutrient release to the advantage of the tea plants in the second year. However, comparative cost analysis showed that organominerals were more economical to achieve optimum tea production at minimum cost in the locality.
