还田时期对绿肥用油菜腐解与养分释放规律的影响  

Effects of decomposition and nutrient release of green manure rapeseed by stages of returning to the field

作　　者：苏港 王怡针 吴锡冬 李子芳 臧凤艳 王金龙 葛均筑 SU Gang;WANG Yi-zhen;WU Xi-dong;LI Zi-fang;ZANG Feng-yan;WANG Jin-long;GE Jun-zhu(College of Agronomy&Resources and Environment,Tianjin Agricultural University,Tianjin 300384)

机构地区：[1]天津农学院农学与资源环境学院,天津300384

出　　处：《中国土壤与肥料》2022年第12期192-199,共8页Soil and Fertilizer Sciences in China

基　　金：国家重点研发计划项目(2017YFD0200808)。

摘　　要：探讨绿肥用油菜还田时期对干物质腐解与养分释放规律的影响,以期为华北地区油菜用作绿肥及后茬作物减氮增效提供理论依据。采用尼龙网袋埋田法研究了绿肥油菜初花期(G1)、盛花期(G2)和角果成熟期(G3)还田的干物质腐解与养分释放规律。结果表明,G1处理油菜还田干物质量比G2和G3处理显著减少45.43%和46.87%;G1和G2处理还田时碳含量低于G3处理,G1处理氮和磷含量最高,分别为28.17和5.21 g/kg,钾含量表现为G1>G2>G3,G1与G3处理差异显著。绿肥油菜还田后分快速、中速和慢速腐解3个阶段,持续期分别为还田后0~17、18~45和46~123 d,阶段内累积腐解率分别达44.27%~66.87%、12.56%~29.18%和4.49%~13.81%,最终累积腐解率达60.53%~91.87%;G1和G2处理间腐解率无显著差异,但显著高于G3处理。绿肥油菜还田后碳、氮、磷和钾释放率与腐解率对应亦表现为前期快速释放、中期缓慢释放、后期趋于平稳的规律,且养分累积释放率均表现为钾>碳>氮>磷。经腐解,G1处理碳、氮、磷和钾累积释放率分别为94.70%、92.97%、88.76%和93.26%,G2处理分别为84.25%、86.32%、86.51%和92.52%,G3处理分别为72.52%、59.97%、68.54%和87.67%;G2处理氮、磷和钾释放量最高,分别为125.15、22.88和50.42 kg/hm^(2),且G2处理氮、磷释放量显著高于G1和G3处理,G2处理的钾释放量与G3处理无明显差异。综上所述,华北地区绿肥油菜在盛花期还田干物质量大且氮、磷、钾释放量最高,是最适宜的还田时期,可为下茬作物减施化肥提供技术支撑与理论依据。The burying nylon mesh bag method was used to study the effects of returning green manure rapeseed to the field in the initial flowering stage(G1),full blooming stage(G2)and silique maturity stage(G3)on the dry matter decomposition and nutrient release of rapeseed,which provided a theoretical basis for rapeseed applying to reduce nitrogen and increase its efficiency for after-reap crops.The results showed that the dry matter amount returning of G1 treatment was significantly lower than that of G2 and G3 treatments,with a decrease of 45.43%and 46.87%,respectively.The carbon content of G1 and G2 treatments was lower than that of G3 treatment,while the nitrogen and phosphorus content in G1treatment was the highest,which was 28.17 and 5.21 g/kg,respectively.The potassium content ranked as G1>G2>G3 and had significant difference between G1 and G3 treatments.After returning,rapeseed decomposition was divided into fast,medium and slow stages.The according durations were 0~17,18~45 and 46~123 d after returning,and the corresponding cumulative decomposition rates were 44.27%~66.87%,12.56%~29.18%and 4.49%~13.81%,respectively,with the final cumulative decomposition rate reaching 60.53%~91.87%.There was no significant difference in decomposition rates between G1 and G2 treatments,however they were significantly higher than that of G3 treatment.The nutrient release rates of carbon,nitrogen,phosphorus and potassium corresponding to the decomposition rates of rapeseed after returning also showed a pattern of fast,slow and stable release in three stages,and the cumulative release rates of nutrients in different returning stages were shown as follows:potassium>carbon>nitrogen>phosphorus.After decomposition,the cumulative release rates of carbon,nitrogen,phosphorus and potassium were 94.70%,92.97%,88.76%and 93.26%in G1 treatment,84.25%,86.32%,86.51%and 92.52%in G2 treatment,and 72.52%,59.97%,68.54%and 87.67%in G3 treatment,respectively.The amounts of nitrogen,phosphorus,and potassium release in G2 treatment were the highest,which

关 键 词：绿肥油菜 还田时期 腐解 养分 释放特征 

分 类 号：S55[农业科学—作物学]