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三、大豆的需肥特点及合理施肥(一)需肥特点有人认为大豆有根瘤,能固定空气中游离的氮,用不着施肥。其实与禾谷作物相比,大豆是需肥较多的,特别是对氮肥的需要量是禾谷类作物的5—7倍。而它本身固定的氮,只能供给它一生中的25—66%。据研究每亩要获得448斤子实产量,需要N42斤,P_2O_5 11斤,K_2O 18斤,产量再高,吸收N、P、K的量也随之增高。大豆除需要三要素外,还需要硼、铜、锌、钼、锰等微
Third, the characteristics of fertilizer and fertilization of soybean needs (A) characteristics of fertilizer Some people think that soybean nodules can be fixed in the air of free nitrogen, no fertilization. In fact, compared with cereal crops, soybean needs more fertilizer, especially for nitrogen fertilizer needs 5-7 times as much as cereal crops. And its own fixed nitrogen, it can only provide 25-66% of its lifetime. According to the study to obtain 448 pounds of acre per mu of real output, you need N42 pounds, P_2O_5 11 pounds, K_2O 18 pounds, the output is higher, the absorption of N, P, K is also increased. In addition to the three elements of soybeans, but also need boron, copper, zinc, molybdenum, manganese and other micro