【摘要】 采用尼龙网袋法对种还分离模式下的玉米秸秆还田进行田间原位模拟,比较不同秸秆还田量在不同还田深度下对土壤全磷、速效磷和不同形态有机磷的影响。试验设置4个水平秸秆添加比例R0(0%)、R1(0.44%)、R2(0.88%)、R3(1.32%)和3个不同还田深度0—15,15—30,30—45cm交叉处理。结果表明,秸杆还田1a后,各土层中土壤全磷含量随秸秆还田量的增加均无显著改变;在0—15cm土层中,与R0相比,R1、R2、R3处理下的土壤速效磷分别增加了27.0%,49.3%,64.1%,在15—30cm和30—45cm土层速效磷随着秸秆还田量的增加也呈显著增加,增加量大小依次为0—15cm>15—30cm>30—45cm;有机磷组分在0—15cm土层中表现为,相比于R0,R1、R2、R3处理的活性有机磷和高稳定性有机磷含量无显著差异,中等活性有机磷分别减少了12.8%,26.2%,36.3%,中稳定性有机磷分别增加了25.1%,53.5%,61.6%,15—30cm和30—45cm土层各有机磷组分含量变化也均表现为随着秸秆还田量的增加,中等活性有机磷含量升高,中稳定性有机磷含量降低,活性有机磷和高稳定性有机磷无显著差异。研究表明,种还分离模式下的玉米秸秆还田主要通过促进土壤其它形态的磷转化为速效磷而增加土壤速效磷含量,为下季作物提供可以直接吸收利用的磷源,同时提高了土壤中稳定性有机磷的含量,降低了中等活性有机磷的含量。更多还原

【Abstract】 In situ simulation was performed on the corn stalks under the mode of planting and returning by nylon bag method.The experiment was conducted to compare the effects of different amounts of straw returning to field on soil total phosphorus,available phosphorus and different forms of organic phosphate.In the experiment,four levels of R0(0%),R1(0.44%),R2(0.88%),R3(1.32%)and three different returning depths of 0-15 cm,15-30 cm and 30-45 cm were carried out.The results showed that the soil total phosphorus content did not change significantly with the increase of the amount of straw returning to field after 1year.Compared with R0,the soil available phosphorus in R1,R2 and R3increased by 27.0%,49.3% and64.1%respectively in 0-15 cm soil layer.The available phosphorus in 15-30 cm and 30-45 cm soil layers also showed a significant increase with increasing amount of straw returning to soil,and the increasing amount followed by the trend:0-15cm>15-30cm>30-45 cm.Compared with R0,the contents of active organic phosphorus and high-stable organic phosphorus of R1,R2 and R3in 0-15 cm soil layer showed no significant difference,and the middle active organic phosphorus decreased by 12.8%,26.2% and 36.3%respectively,and the content of stable organic phosphorus increased by 25.1%,53.5%and 61.6%.In 15-30 cm and 30-45 cm soil layers,soil moderate organic phosphorus increased respectively with the amount of straw returning and the content of moderate active organic phosphorus increased and the content of moderate stable organic phosphorus decreased,while there was no significant difference between active organic phosphorus and high stable organic phosphorus.The results showed that maize straw returning to field couldincrease the content of available phosphorus in soil by promoting the conversion of phosphorus from other forms of soil to available phosphorus.Maize straw returning could supply phosphorus source for direct use in the next season.Meanwhile,it could improve the moderate stability organic phosphorus content and reduce the moderate active organic phosphorus content in the soil.更多还原