Study On The Effect Of Application Phosphate To Cotton-Field Soil Phosphorus Available

In order to increase the utilization efficiency of soil phosphorus at the cotton fields in Xinjiang, the activation of phosphorus in the soil, reduce fertilizer usage, apply fertilizer to provide a theories basis for cotton-field in Xinjiang, choice three different soil texture in northern Xinjing, through field experiment and pilot experiment study different levels phosphorus fertilizer applied after the soil the changes of soil phosphorus, different types of phosphorus fertilizer effects. The main results are as follows:1. Pot experimentTo different Soil texture applied phosphorus can significant increase soil available phosphorus content, but different amount of phosphorus can significant increase soil available phosphorus only in the short time . with time prolong, applied phosphorus fertilizer only more than 300 kg/hm~2 can significant increase soil available phosphorus content. Each different amount of applied phosphorus soil available phosphorus content were no significant differences, more applied phosphorus the soil available phosphorus more decline. The fertilizer effect same to applied fertilizer 300 kg/hm~2 and more. Applied phosphorus to the three texture increase the effectiveness of available phosphorus showed that general level of applied phosphorus of soil available phosphorus largest increase at the Fine sand loamy soil, the lowest increase is Fine sand clay soil . High level of applied phosphorus to three texture soil available phosphorus increase same. ultra-high levels of applied phosphorus of soil available phosphorus largest increase at the Fine sand clay loamy , the lowest increase is Fine sand clay loamy.2.Field experiment(1)Applied phosphate to soil available phosphorus and total phosphorus effect Applied phosphorus fertilizer can increase the soil available in fine sand loamy soil and fine sand clay loamy soil , but the low level applied phosphorus fertilizer (below 300 kg/hm~2) not to be able obviously to increase the soil available phosphorus, high level applied phosphorus fertilizer (above 600 kg/hm~2) can only obviously increases the soil available phosphorus content in the cotton birth earlier period (seedling stage and flower bud time), later period (flowered bell time, boll opening time) the soil available phosphorus content no difference to applied phosphorous fertilizer and not only the most level can increase the soil available phosphorus content in the cotton growth season .Applied phosphorus fertilizer 150-600 kg/hm~2 soil available phosphorus no difference. So in the cotton field phosphorus. fertilizer should keep the level 150-300 kg/hm~2.Applied phosphorus fertilizer can increase the soil total phosphorus content but not significant. excessive applied phosphorus fertilizer can not significant increase soil total phosphorus content.(2)Different phosphate fertilizer to soil available phosphorus and total phosphorus effectThe soil available phosphorus no significant difference to fertilizer DAP and TSP applied level at 150 kg/hm~2, phosphorus fertilizer level at 300 kg/hm~2 in the cotton seedling-stage and budded-stage the soil of application TSP significantly more than DAP at soil available phosphorus. Applied phosphorus effect TSP than DAP.(3) Effects of Phosphate Fertilizer To the Cotton yieldApplied phosphorous fertilizer can significant increase cotton yield, high and low of fertilizer application levels small effect to cotton yield. Applied phosphorous fertilizer at cotton fields should control 150 kg/hm~2-300 kg/hm~2 from cotton yield and costs. The soil of application TSP more than DAP at cotton yield but no significant difference..