水肥优化配施腐解剂对小麦-玉米轮作体系土壤养分含量和作物产量的影响

Effects of Optimal Water and Fertilizer Management Combined with Straw￣Decomposing Agent on Soil Nutrient Content and Crop Yield in Wheat￣Maize Rotation System

本试验以小麦‘烟农24’、玉米‘郑丹958’为材料,全量秸秆还田条件下,以农民常规水肥管理(漫灌+常规施肥)为对照(CK),设置常规水肥管理+腐解剂(CKD)、优化水肥管理Ⅰ(滴灌+缓控释肥,SS)、优化水肥管理Ⅰ+腐解剂(SSD)、优化水肥管理Ⅱ(水肥一体,SF)、优化水肥管理Ⅱ+腐解剂(SFD)5个处理,探究水肥优化配施腐解剂对小麦-玉米轮作体系土壤养分和作物产量的影响。结果表明,在玉米季,各处理土壤速效养分含量呈不规律的波动变化趋势,大喇叭口期追肥可有效缓解土壤养分下降,维持土壤肥力。小麦季,随生育期的推进,氮磷钾速效养分含量呈逐渐降低趋势。成熟期,水肥优化配施腐解剂(SSD和SFD)处理显著提高玉米季0~20 cm土层碱解氮和有效磷含量,较SS和SF分别提升27.9%、35.9%和12.5%、19.5%。CKD处理玉米产量最高,为10.0 t/hm^(2),其次为SFD、SF处理,较CK分别显著增产16.3%、11.6%、9.3%;SFD处理小麦产量最高,为8.6 t/hm^(2),其次为SS、SF处理,较CK分别显著增产19.4%、18.1%、15.3%。相关性分析表明,玉米产量与苗期0~20 cm土层和成熟期20~40 cm土层碱解氮及有效磷含量呈显著负相关,与大喇叭口期20~40 cm和灌浆期0~20 cm土层速效钾含呈显著正相关;而小麦产量主要与返青期土壤速效养分相关。综上,相同水肥管理下,配施腐解剂有助于维持土壤速效养分含量,对小麦、玉米产量有积极影响。玉米季以滴灌+缓控释肥和水肥一体配施腐解剂、小麦季以滴灌+缓控释肥配施腐解剂土壤速效养分含量较高,常规水肥管理配施腐解剂的玉米产量和水肥一体管理配施腐解剂的小麦产量较高。

The experiment was conducted under the condition of returning all the straw into the field.Wheat variety‘Yannong 24’and maize variety‘Zhengdan 958’were used as experimental materials.With farmers’conventional water and fertilizer management(flood irrigation+conventional fertilization)as control(CK),five treatments including conventional water and fertilizer management with decomposing agent(CKD),optimal water and fertilizer managementⅠ(drip irrigation+slow and controlled release fertilizer,SS),optimal water and fertilizer managementⅠwith decomposing agent(SSD),optimal water and fertilizer managementⅡ(integrated water and fertilizer,SF)and optimal water and fertilizer managementⅡwith de-composing agent(SFD)were set to study the effects of optimal water and fertilizer management combined with straw-decomposing agent on soil nutrients and crop yield in wheat-maize rotation system.The results were as follows.In maize season,the content of soil available nutrients under each treatment showed an irregular fluc-tuation trend,and topdressing at flare opening stage effectively alleviated the decline of soil nutrients and maintained soil fertility.In wheat season,the content of available nitrogen,phosphorus and potassium de-creased gradually with the advance of growth period.At maturity stage,SSD and SFD treatments significantly increased the content of alkali-hydrolyzed nitrogen and available phosphorus in 0~20-cm soil layer in corn sea-son by 27.9%and 35.9%,12.5%and 19.5%compared with SS and SF treatments,respectively.The maize yield of CKD treatment was the highest as 10.0 t/hm^(2),followed by SFD and SF treatments,which significantly increased by 16.3%,11.6%and 9.3%compared with CK,respectively.The wheat yield of SFD treatment was the highest as 8.6 t/hm^(2),followed by SS and SF treatments,which significantly increased by 19.4%,18.1%and 15.3%compared with CK,respectively.Correlation analysis showed that the maize yield was significantly negatively correlated with the contents of alkali-hydrolyzed nitrogen and available phosphorus in 0~20-cm soil layer at seedling stage and 20~40-cm soil layer at maturity stage,but significantly positively correlated with the content of available potassium in 20~40-cm soil layer at flare opening stage and 0~20-cm soil layer at filling stage.The wheat yield was mainly correlated with the soil available nutrients at reviving stage.In sum-mary,under the same water and fertilizer management,combined application of decomposing agent could help maintain the content of soil available nutrients,and had positive effects on the yield of wheat and maize.In maize season,the content of soil available nutrients was higher under SS and SFD treatments.In wheat season,the content of soil available nutrients was higher under SSD treatment.The yield of maize under CKD treat-ment,and that of wheat under SFD treatment were higher.