长期施肥对菜田土壤微量元素有效性的影响

利用田间试验研究了长期定位施用有机肥和氮、磷、钾化肥对菜田土壤重要微量元素有效性的影响。结果表明,长期施用氮肥会提高土壤有效态铁、锰、锌、铜含量,随着氮肥用量增加,土壤酸化程度加重,土壤中铁、锰、锌、铜有效性亦随之增强。磷、钾化肥能够提高土壤有效铁、锰含量,对土壤锌有效性不会产生明显影响,在一定范围内可以提高土壤有效性铜含量,但效果不明显。长期施用有机肥对土壤微量元素的影响与配施的化肥种类有关。土壤有效铁、锰、铜含量与土壤pH呈极显著负相关,而有效锌含量与pH相关性不明显,而且关系比较复杂。总之,影响微量元素有效性的首要因素是土壤酸碱度。

Effects of long-term fertilization on availability of micro-elements in vegetable soil

Under field condition,a long-term trial with fixed position experiment was carried out to study long-term fertilization on the availability of microelements on a vegetable soil.The experiment started from 1988.The result showed that the micro-elements availability(Avail.Cu,Zn,Fe and Mn) of vegetable soil might be enhanced by long term N fertilization since N application exacerbated soil acidity,which in turn enhanced the availability of Fe,Mn,Zn and Cu in the soil.P and K application increased the availability of soil Fe and Mn,while it did not affect the the content of available Zn.Soil available Cu was observed to increase to certain extent with P and K application,however,there was no statistical significant.Effect of long-term manure application on the availability of micro-elements depended on the type of fertilizers combined.The contents of soil available Fe,Mn,Cu was significantly negative correlation to soil pH at 1% level,but there was no correlation between soil available Zn and soil pH.We can concluded that the soil pH was the dominant factor affecting the availability of soil micro-elements.