腐植酸对灰漠土棉田土壤无机磷形态的影响

石灰性土壤上常规施用磷肥,土壤有效磷固定严重,磷肥利用率较低.试验为新疆典型灰漠土棉田田间试验,通过常规施肥基础上施用不同量腐植酸,研究棉花不同生育期距地表不同深度及距棉株不同距离土壤有效磷及无机磷含量变化、各形态无机磷间动态转化以及施用腐植酸对棉花产量的影响.结果表明:对于典型灰漠土棉田,施用腐植酸能增加耕层土壤速效磷含量,并且随腐植酸用量的增加而增加,腐植酸能起到使土壤稳定持续供应土壤速效磷作用;施用腐植酸增加土壤有效磷含量的贡献依次主要是Ca2-P、Ca8-P和O-P增加的作用;腐植酸施用量必须达到一定水平才能有明显的激活土壤固定态磷、增加棉花产量的作用.

Effects of Humic Acids on Inorganic Phosphorus Forms in Gray Desert Soil and Soil of Cotton Field

The available phosphorus of the soil was fixed seriously and utilization ratio of phosphate fertilizer was lower when phosphate fertilizer was used on calcareous soil with conventional employment. This experiment is field test of the typical gray desert cotton soil in Xinjiang, through using different quantity of humic acids in the foundation of the convention applying fertilizer. The investigation on the transformation of the soil available phosphorus and the inorganic phosphorus content with different cotton growth period in different depths and different distances from the cotton plant, the dynamic transformation of various shapes inorganic phosphorus as well as the influence of humie acids on the cotton yield was conducted. The results indicated that, regarding the typical gray desert soil cotton field, the available phosphorus content of the topsoil can be increased by using humic acids, and it was increased along with the amount of humic acids increase. The available phosphorus of the soil can be applied continually and stably by using humic acids; The contribution of the available phosphorus content of the soil increased by using humic acids mainly was the increasing function of Ca2 - P, Ca8 - P and O - P in turn; The amount of humic acids must be used in a certain level if the soil fixed phosphorus would be activated obviously and the cotton yield would be increased.