蔗田农业废弃物资源化利用对土壤养分的影响

采用连续多年观察和跟踪检测的方法,对广西甘蔗研究所试验农场经过连续9年机械粉碎蔗叶还田后定点检测土壤的有机质含量及氮、磷、钾三大元素含量的变化,研究蔗叶还田对土壤肥力的影响,养分量化变化趋势,对产量的贡献。跟踪测试验结果表明,3个品种半干叶片叶茎率平均为14.6%,初步估测每公顷残留氮磷钾总量为36.60kg、3.75kg和17.25kg。土壤有机质含量平均提高了3.32g/kg,折合每年提高0.42g/kg,相当于每年每公顷蔗地净递增土壤有机质含量1245kg。氮、磷、钾三大元素中,增加幅度最大的是钾,土壤全钾提高0.408个百分点,增幅达到43.3%相对值;虽然土壤全氮绝对值含量提高不多,但速效氮含量提高了28.87mg/kg,占相对值为31.9%,说明供氮能力大大提高;全磷和速效磷变化水平都较低,速效磷只提高了5.97mg/kg,占相对值为16.7%。蔗叶还田除了当造可获得180～210元/hm2的经济效益之外,更重要的还有使土壤环境进入良性的生态循环,既可以获得增产,提高经济效益,降低生产成本,又可以减少对矿物资源的消耗,具有多重的良好社会效益。

Effects of Cane Leave Residue on the Soil Fertility

Effects of leaving cane residues to the cane field after harvested were studied as the scientific basis and technology to establish Guangxi sugarcane favorable soil ecology circle.By 9 years continuously tracking testing on content change of organic matter,nitrogen,phosphorus and potassium were determined in Guangxi Sugarcane Research Institute Farm field in where cane leave residues were put on the land by mechanical roll crush.The results showed that the average leave-stem rate with semi-dried of three va...