磷与富啡酸配施对潮土中磷锌有效性及锌形态转化的影响

采用室内培养方法,研究了磷与富啡酸(fulvic acid,FA)配施对石灰性潮土中磷锌有效性及锌形态转化的影响。结果表明:潮土中速效磷含量随外加磷量的增加而显著增加,且随着培养时间的延长发生了明显的固定,而且外加磷越高,土壤对其的固定越明显。土壤速效磷含量随添加FA量的增加而增加,即FA提高了磷有效性,但在低磷处理下,FA对磷的活化作用很小,而在高磷处理下作用明显;土壤速效磷含量随添加锌量的增加而降低,即高锌降低了速效磷的含量。土壤DTPA-Zn含量随锌添加量的增加显著增加,且随培养时间的延长而显著降低;低量磷可提高DTPA-Zn含量,但当土壤磷添加量太高时(高于120 mg kg-1或160 mg kg-1)则降低DTPA-Zn含量。土壤DTPA-Zn含量随FA添加量的增加而增加,但FA对长时间培养土壤锌的活化作用不明显。对土壤锌分级表明,土壤锌主要以残渣态(RES)形式存在,而交换态和有机质结合态锌在石灰性土壤中含量极低。同时,外源可溶性锌明显提高了土壤中RES-Zn、CAB-Zn、OFe-Mn-Zn和EX-Zn含量,但OM-Zn增加趋势不明显,且随着培养时间的延长,土壤中有效性较高的EX-Zn和OM-Zn逐渐向无效态RES转化,FA对土壤锌形态转化作用不明显。

Effect of Phosphorus and Fulvic Acid (FA) Combined Application on P & Zn Availability and Zn Transformation in Calcareous Chao Soil

The effect of phosphorus and fulvic acid(FA)combined application on P&Znavailability and Zntransform ation in calcareous Chao soil by incubated method.The results showed that,the available P content in Chao soil was significantly increased with P added amount increased,and the P was fixed with incubated time extend,and the phenomenon of fixed was evidence.The available P content was increased with FA added amount increased,it could say that FA improved the availability of P,but the P activate foundation by FA was very feebleness when under the low P content treatment,and the activated foundation was very evident under the more P content treatment.The soil DTPA-Zn content was significantly increased with Zn added amount increased,and the DTPA-Zn content was significantly decreased with incubated time extend.The added P amount was low could increased DTPA-Zn content,but when P added amount was too much(more than 120 mg kg-1 or 160 mg kg-1) P added could decreased DTPA-Zn content.The content of DTPA-Zn was increased with FA added amount increased,but it was decreased with incubation time extended.The forms of Zn in soil was main residue form Zn(RES-Zn),but the exchange form Zn(EX-Zn) and organic bound form Zn(OM-Zn) content was very little.Added dissoluble Zn could increased the content of residual form Zn(RES-Zn),carbonate form Zn(CAB-Zn),Fe-oxide and Mn-oxide bound form Zn(OFe-Mn-Zn) and exchange form Zn(EX-Zn),but the EX-Zn content increased was very little,and also showed that the higher available EX-Zn and OM-Zn could transfer to RES-Zn with incubated time extend.The effect of FA on Zn forms transfer was unconspicuous.