Activation Of Phosphorus In Cotton Field Soil Of Shawan City By Vinegar

Xinjiang is China’s most important cotton production area,the total cotton production has accounted for 87%of the country.The high yield of cotton is accompanied by the excessive application of P fertilizer,and the various fixation mechanisms of P fertilizer in the soil lead to the accumulation of P fertilizer in the cotton field soil,and the utilization rate of P fertilizer is generally low（10-20%）.Therefore,improving the availability of soil accumulated phosphorus is an important research content of green and sustainable development of cotton planting industry.This study based on calcareous soil p transformation form and in the process of crop root system under the condition of p stress the basic principle of secretion of organic acids,combined the technology of drip irrigation can realize the positioning of quantitative water use,discusses the three acid hydrochloric acid,acetic acid and vinegar Shawan City in Xinjiang cotton soil phosphorus activation,set up the indoor simulation test and field validation test,The changes of soil pH,calcium carbonate and available phosphorus were analyzed,and the mechanism of activated soil phosphorus by three kinds of acids was revealed.The aim was to improve the utilization rate of soil P fertilizer and to provide a basis for organic acid activation of soil P accumulation in cotton fields in Xinjiang.The main conclusions are as follows:（1）Different amounts of vinegar have different effects on the activation of soil phosphorus.With the increase of the amount of vinegar,the soil pH gradually decreases,and the content of phosphorus in the soil shows a trend of obvious increase at first and then slow decrease.Combined with the comprehensive analysis of the cost of vinegar,the reasonable and effective amount is set at 105 L/hm².（2）The laboratory test results show that:Four kinds of cotton soil were collected in the field.Through indoor simulated drip irrigation,adding reasonable amount of vinegar,hydrochloric acid and acetic acid with the same acidity to the cotton field soil with high available P（15.9-23.0 mg/kg）,acetic acid and vinegar could increase the available P by 3.1-9.6 mg/kg in 0.5 days.It was approximately equivalent to P₂O₅=4.6～14.1 kg/hm²,and the activation effect could last for 7 days,which was close to the irrigation cycle of cotton drip irrigation,in which hydrochloric acid had no obvious effect on the activation of soil phosphorus.But for low P（8.0 mg/kg）soil,the three acids had no obvious effect on the activation of P.（3）Field validation test showed that:Acetic acid and vinegar significantly reduced the soil pH and calcium carbonate content,and increased the available P content,which had a significant effect on the activation of soil P.During the cultivation process,the available P content in the 0-5 cm soil layer increased by 1.5-14.4 mg/kg and 4.9-17.1 mg/kg,respectively,in the 0-5 cm soil layer 0 cm from drip irrigation zone.The available P content in 0-5 cm soil layer 10 cm away from drip irrigation increased by 2.0～12.4mg/kg and 2.4～18.1 mg/kg,and the effect of activated soil P gradually weakened with the extension of culture time.But the activation effect of hydrochloric acid on soil phosphorus is not obvious.Overall activation effect:vinegar>acetic acid>hydrochloric acid.Therefore,long-term use of phosphate fertilizer in Xinjiang cotton fields to add 105 L/hm² vinegar,in a certain period of time can effectively reduce the soil pH and the content of calcium carbonate,ease of soil effective phosphorus holding and fixed,enhance the capacity of soil to crops for phosphorus,can activate soil p accumulation state,improve the utilization efficiency of phosphate fertilizer,promote the development of green cotton.