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引言施用可溶性锌盐、螯合态锌和氧化锌以及改善土壤中锌的可给性等办法(例如使土壤氧化或酸化等)能克服或防治湿地水稻缺锌。在这个问题开始被认识以后,人们于栽秧前在田面撒施、或与土壤混施大量锌盐,例如每公顷施100公斤ZnSO_4。实际上,为此目的所施的氧化锌,或移栽前在秧苗根部所施的氧化锌悬浮液(醮秧根),均可大大减少其实际用量,即每季作物每公顷约仅需4—8公斤锌。目前,看来成本不是施用锌肥的主要障碍。1980年菲律宾农民施4公斤锌(氧化物)的成本约为20美元,约占每公顷3.5吨谷物总值的4%,以及仅为化学或人工除草成本或主要肥料成本的一部分。
INTRODUCTION Zinc deficiency in wetland rice can be overcome or prevented by applying soluble zinc salts, chelating zinc and zinc oxide, and improving the availability of zinc in the soil (eg, oxidizing or acidifying the soil, etc.). After the problem began to be recognized, people cast their soil on the field before planting them, or they mixed a large amount of zinc with soil, for example, 100 kg of ZnSO4 per hectare. In fact, the zinc oxide applied for this purpose, or the zinc oxide suspension applied to the seedling root before transplanting (seedling rooting), can substantially reduce its actual use, ie about 4 -8 kg zinc. At the moment, it appears that cost is not a major barrier to the application of zinc fertilizer. The cost of 4 kg of zinc (oxide) applied by farmers in 1980 in the Philippines was about $ 20, accounting for about 4% of the 3.5 tons of cereal per hectare and only a fraction of the cost of chemical or artificial weeding or major fertilizer.