有机酸添加对不同磷肥用量棉田磷素状况和产量的影响

【目的】 研究有机酸添加对不同磷肥用量棉田磷素状况和产量的影响。【方法】 采用大田试验方法，在不同磷肥P₂O₅用量处理（0、50、100和150 kg/hm²）的基础上，设置对照（CK）和有机酸添加（OA）处理，测定棉花不同生育期土壤速效磷、植株生物量和吸磷量、籽棉产量、计算棉田磷肥利用率及磷平衡。【结果】 （1）随磷肥用量增加，土壤速效磷表现出先增加后略有降低趋势；在对照处理，土壤速效磷（花铃期和吐絮期）在MAP₁₀₀处理达到最大值，而在有机酸添加处理，土壤速效磷在MAP₅₀处理最高。（2）植株累积吸磷量表现出随施磷量增加而先增加后略有降低趋势；在对照处理，植株累积吸磷量在MAP₁₀₀处理达到最高，而在有机酸添加处理时，在MAP₅₀处理即达到最高；有机酸添加也提高了磷素向生殖器官的分配比例。（3）在对照处理，籽棉产量表现出随施磷量增加而增加趋势，在MAP₁₅₀处理产量最高（5 220 kg/hm²）；而在有机酸添加处理，籽棉产量表现出随施磷量增加而先增加后降低趋势，在MAP₁₀₀处理最高（5 194 kg/hm²）。（4）在不添加有机酸时，磷肥利用率表现出随施磷量增加而先升高后降低趋势，在MAP₁₀₀处理磷肥利用率最高（32.97%）；而在添加有机酸时，磷肥利用率表现出随施磷量增加而降低趋势，在MAP₅₀处理最高（32.92%）。【结论】 有机酸添加可在较低化学磷肥P₂O₅用量时（推荐用量：45 kg 有机酸+ 100 kg/hm²），提高土壤磷素有效性、植株吸磷量，促进磷素向生殖器官分配，提高籽棉产量和棉田磷肥利用率。

Effects of Organic acid Addition on Field Phosphorus Status and Yield in Cotton Field with Different Phosphorus Fertilization Rates in Xinjiang

【Objective】 Effects of organic acid addition on field phosphorus status and yield in cotton field with different phosphorus fertilization rates in Xinjiang. 【Method】 In order to reduce the chemical phosphorus fertilization rate and improve phosphorus fertilizer use efficiency in cotton field in Xinjiang， different treatments of phosphorus fertilization rates （0，50，100 and 150 kg P₂O₅/hm²， MAP0， MAP50， MAP100 and MAP150）， with and without organic acid addition （organic acid 45 kg/hm²， OA and control， CK） were set under the field conditions. The characteristics of soil available phosphorus， plant uptake and distribution and yield were measured， and phosphate fertilizer use efficiency and field phosphorus balance were calculated. 【Result】 （1） With the increase of P fertilization rate， soil Olsen-P showed a first increase and then slightly decrease trend； under CK treatment， Olsen-P （at flowering and bolling stage） reached the maximum value under MAP100 treatment， while under OA treatment， Olsen-P reached the maximum value under MAP50 treatment. （2） The plant P uptake showed a trend of first increase and then slightly decrease with the increase of P fertilization rate. In CK treatment， the plant P phosphorus uptake reached the highest level at MAP100 treatment， and reached the highest in MAP50 treatment when organic acids were added. The addition of organic acids also increased the proportion of phosphorus distribution to reproductive organs. （3） UnderCK treatment， the yield of seed cotton increased with the increase of P fertilization rate， and the highest yield was 5，220 kg/hm² under MAP150 treatment. However， under OA treatment， the yield of seed cotton showed a first increase and then decrease trend with the increase of P fertilization rate， and reached the highest value under MAP100 treatment （5，194 kg/hm²）. （4） Under CK treatment， the P fertilizer use efficiency increased first and then decreased with the increase of P fertilization rate， and the P fertilizer use efficiency in MAP100 treatment was the highest （32.97%）； 【Conclusion】 however， under OA treatment（proposed dosage：45 kg OA+ 100 kg P₂O₅/hm²）， the P fertilizer use efficiency decreased with the increase of P fertilization rate， and the maximum P fertilizer use efficiency was 32.92% in MAP50 treatment. In conclusion， organic acid addition could improve soil phosphorus availability， plant phosphorus uptake， and distribution of phosphorus to reproductive organs at a lower chemical P fertilizer application rate， thus increasing seed cotton yield and P fertilizer use efficiency in cotton field.