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1.氮:在土壤中主要有氨态氮和硝态氮两种,氨态氮吸附在土壤胶粒,经过氧化即转为硝态氮,硝态氮易溶于水。氮素是维持生命力最需要的大量元素。缺乏氮素会严重影响作物的正常生育。但不同作物有所差异,一般是在作物的前半期需要总量为60％左右。据测定,在种植作物前,每百克土壤有2—3毫克即可。
1. Nitrogen: There are two types of ammonia nitrogen and nitrate nitrogen in the soil. Ammonia nitrogen is adsorbed on the soil colloids and is converted to nitrate nitrogen after oxidation. Nitrate nitrogen is easily soluble in water. Nitrogen is the most needed element to maintain vitality. Lack of nitrogen can seriously affect crop normal fertility. However, different crops are different, usually in the first half of the crop needs a total of about 60%. It is determined that before planting crops, 2-3 mg per hectare of soil can be.