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长期以来,我省不少地区由于耕作制度和施肥制度不够合理,有机肥料施得少、质量差,加上单一大量增施氮肥,已造成土壤严重缺磷和氮磷比例失调。如聊城县1980年土壤普查结果是:耕层土壤速效养分氮:磷:钾=9:1:12(作物对氮、磷、钾的吸收比例为1:0.43:1),氮磷比例严重失调;土壤速效磷含量在5ppm以下严重缺磷的耕地面积占全县总耕地面积的70.8%。随着粮棉产量的提高,对磷素吸收量相应增加,土壤缺磷已成为进一步提高产量的限制因素,亟待加以解决。
For a long time, due to the unreasonable farming system and fertilization system in many areas of our province, the lack of organic fertilizers and the poor quality, together with the single application of large amounts of nitrogen fertilizer, has resulted in the serious imbalance of phosphorus and nitrogen and phosphorus in soils. For example, in Liaocheng County, the results of the soil census in 1980 were: available nutrient N (P: K = 9: 1: 12) in the topsoil, and the ratio of nitrogen to phosphorus was 1: 0.43: 1. ; Available phosphorus content of soil below 5ppm serious shortage of phosphorus in cultivated land area accounted for 70.8% of the total cultivated land area. With the increase of output of grain and cotton, the amount of phosphorus absorption increased correspondingly, and the lack of phosphorus in soil has become the limiting factor to further increase the yield, which needs to be solved urgently.