长期施肥对河西灌漠土无机磷形态的影响

Effects of Long-term Fertilization on Inorganic Phosphorus Forms In Irrigated Desert Soil

在长期小麦和玉米轮作的基础上,通过单施化肥以及化肥与其它有机肥料的配合使用,研究不同施肥对河西灌漠土无机磷组分的影响。采用蒋柏藩、顾益初的分级体系[1],对22年有机肥与化肥定位试验中的耕层土壤无机磷组成进行分级。结果表明:供试土壤中Ca-P占无机磷绝大多数,在耕层占71.0%。无机磷各形态含量排列顺序为:Ca10-P>O-P>Fe-P>Ca8-P>Ca2-P>Al-P。与不施肥处理比较,除N处理外各处理均可增加耕层各形态无机磷含量;同时显示厩肥处理对土壤无机磷库的贡献大,可显著增加总无机磷含量。N处理的耕层土壤中,作为土壤有效磷源的Ca2-P、Ca8-P、Al-P含量比对照CK还低。比较2003年与2006年耕层数据,Ca10-P在试验各处理均略有下降,且下降幅度相近。Ca8-P、Ca2-P、Al-P含量除在CK、N处理下降外,在其余处理时均有增加;O-P除在CK处理下降外,在其余处理时也均有增加;Fe-P除在CK、N处理中下降外在M、MN处理时也有小幅度下降,在加磷的处理中均增加。

Based on long-term rotation of wheat and maize,the objective of the research is to study the effect of long-term chemical N fertilization or the mixture of chemical N fertilizer and other manures on irrigated desert soil in-organic phosphorus components.Inorganic phosphorus forms in irrigated desert soil were quantified in a 22-year fertilization trial using the method proposed by the Jiang-Gu inorganic phosphorus fractionation method.Result showed that ① Of the total Inorganic P（Pi）,Ca phosphates（Ca-P） was the dominant Pi fractions,accounted for 71.0% in 0-20cm soil layer.Pi fractions varied in the order of Ca10-P〉O-P〉Fe-P〉Ca8-P〉Ca2-P〉Al-P.②Long-term application of different fertilizers,except N treatment,could increase the content of different inorganic phosphorus fractions.Especially,the application of animal manure and chemical fertilizers in combination significantly increased the soil inorganic P content.③ In 0-20cm soil,the contents of Ca2-P,Ca8-P and Al-P in the treatment of nitrogen（N） fertilizer less than that in treatment of no fertilizer treatment（CK）.④ Compared the results obtained in 2003 and 2006,the contents of Ca10-P in all treatments tended to decline.Except N treatment,the contents of Ca8-P,Ca2-P andAl-P increased.The content of O-P tended to decline under CK treatment but increased in other treatments.The content of Fe-P increased in the treatments with Phosphorus.