肥际微域土壤的室内培养法研究磷对石灰性潮土的影响

Effects of Phosphorus Fertilization on the Microzone Characteristics of a Calcareous Alluvial Soil Using Incubation Method

采用室内恒温培养试验法对施入不同量磷(P)肥的石灰性潮土的各种理化特性进行为期180d的模拟研究,结果表明,磷肥的加入使土壤pH值发生了显著的变化,由原来的8.76下降到最小值7.36。高施P量处理F1、F2、F3、F4和F5的Olsen-P浓度分别为2338.5、1576.7、713.6和316.9mgkg-1,0.01molL-1 KCl溶液提取P浓度分别为1226.3、1189.2、880.2和382.9mgkg-1。各处理Olsen-P和0.01molL-1KCl溶液提取P浓度在同一培养时间随施P量的增加而增大,而对同一施P量处理而言,随着培养时间的延长其值呈下降趋势,且随施P量增大下降幅度加大。培养土中有机磷含量随培养时间延长而增加。各处理的无机磷分级体系中,钙磷在无机磷中占绝对优势,Ca2-P、Ca8-P和Al-P含量随P肥加入量的增加而增大,Fe-P含量很小,O-P含量和Ca10-P含量变化不大,随着培养时间的延长,Ca2-P含量减少较多,而Ca8-P含量大量增加,且Ca8-P含量均大于Ca2-P含量。

A study on the changes of the physical and chemical properties of calcareous soils receiving different rates of phosphorus fertilizer were carried out using incubation method for 180 days.The main results showed that soil pH decreased from 8.76 to 7.36 due to the application of P fertilizer.The content of Olsen-P and 0.01 mol L-1 KCl extracted P（KCl-P） were very high for the treatments receiving high phosphorus rates.For the F1,F2,F3 and F4 treatments,the contents of Olsen-P were 2338.5 mg kg-1,1576.7 mg kg-1,713.6 mg kg-1,and 316.9 mg kg-1,respectively;the contents of KCl-P were 1226.3 mg kg-1,1189.2 mg kg-1,880.2 mg kg-1,and 382.9 mg kg-1,respectively.For samples collected at the same incubation time,the contents of Olsen-P and KCl-P increased with the higher P rates.However,as for the treatments of same phosphorus rates,the contents of Olsen-P and KCl-P decreased as the incubation time prolonged,the higher P rate the larger decrease range.The content of organic phosphorus increased with the increased incubation time.For the inorganic P fractions,the Ca-P was predominant.The contents of Ca2-P,Ca8-P and Al-P increased with the fertilization rates,while the contents of O-P and Ca10-P did not change very much.The content of Fe-P was very small during the whole incubation period.As the incubation time increased,the content of Ca2-P decreased,while the Ca8-P increased largely.