| 摘要: |
| 【目的】探究褐煤腐植酸不同施用量对科尔沁沙地风沙土土壤特性和荞麦产量的影响，为风沙土改良提供科学依据。【方法】于2020-2022年，以科尔沁沙地风沙土为改良对象，通过田间定位试验，以不施用褐煤腐植酸为对照（CK），设置3个褐煤腐植酸用量处理：2 t/hm2（低量，H1）、4 t/hm2（中量，H2）和6 t/hm2（高量，H3），研究2020年褐煤腐植酸一次性施用后0~40 cm土层土壤贮水量（SWS）、养分含量、微生物生物量碳氮（SMC、SMN）含量及荞麦产量的变化。采用主成分分析（PCA）研究土壤贮水量、养分、微生物生物量碳氮含量和荞麦产量的关系；在此基础上，通过随机森林分析探讨了以上土壤指标对荞麦产量的贡献率。【结果】与CK相比，施用褐煤腐植酸总体上提高了风沙土0~40 cm土层的贮水量，但不同褐煤腐植酸施用量对土壤贮水量的提升幅度不同。在2020-2022年，无论是在播种前、开花期还是在成熟期，4个处理中，H3处理0~40 cm土层的土壤贮水量均最高。与CK相比，施用褐煤腐植酸影响了风沙土土壤养分含量，且褐煤腐植酸不同施用量对不同土层土壤养分含量的影响程度存在较大差异。褐煤腐植酸一次性施用3年后（2022年），H3处理的的土壤有机质、全氮、铵态氮、速效磷和速效钾含量总体高于其他处理。无论是在开花期还是在成熟期，与CK相比，施用褐煤腐植酸总体提高了土壤微生物生物量碳和氮含量，且在0～10，10~20和20～40 cm土层，H3处理SMC和SMN含量总体均最高。2020-2022年，与CK相比，施用褐煤腐植酸均提高了荞麦干物质量和产量，其中H3处理的增幅最大。主成分分析和随机森林分析结果显示，土壤速效钾、贮水量、微生物生物量碳和铵态氮与荞麦产量关系密切，其对荞麦产量的贡献率分别为11.00%，8.60%，7.85%和6.29%。【结论】在科尔沁沙地，当施用量为4~6 t/hm2时，褐煤腐植酸对风沙土保水增肥增产的改土作用明显，其中当褐煤腐植酸施用量为6 t/hm2时效果最佳。 |
| 关键词: 科尔沁沙地 风沙土 褐煤腐植酸 土壤特性 荞麦产量 |
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| 基金项目:现代农业产业技术体系建设专项（CARS-07）；内蒙古自治区自然科学基金项目（2020BS03027）；内蒙古民族大学博士科研启动基金项目（BS557） |
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| Effects of lignite humic acid on soil properties and buckwheat yield in Horqin aeolian sandy soil |
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ZHOU Lei,XIN Zhijie,DU Pinting,et al
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| Abstract: |
| 【Objective】This study investigated the effect of different application rates of lignite humic acid on soil properties and buckwheat yield in Horqin aeolian sandy soil.【Method】A field positioning experiment (2020-2022) was established for Horqin aeolian sandy soil with four treatments including CK (without lignite humic acid) and three lignite humic acid application rates of low (H1,2 t/hm2),medium (H2,4 t/ hm2) and high (H3,6 t/hm2) rates.The changes in soil water storage (SWS),nutrients,microbial biomass carbon (SMC) and nitrogen (SMN) at 0-40 cm soil depth and buckwheat yield after one-time lignite humic acid application in 2020 were studied.Principal component analysis (PCA) was used to analyze the relationship between SWS,nutrients content,SMC,SMN and buckwheat grain yield,and the random forest analysis was applied to study the contributions of above indicators to buckwheat grain yield.【Result】The application of lignite humic acid improved SWS in 0-40 cm soil layer,with varying effects of different humic acid application rates.During 2020-2021,H3 had the highest SWS content in 0-40 cm soil layer regardless of before sowing,flowering and mature stages.Addition of lignite humic acid changed soil nutrients contents,and different application rates showed greatly differences at different soil layers.Soil organic matter,total nitrogen,available phosphorus and potassium contents in H3 were higher than other treatments three years after lignite humic acid addition in 2022.Regardless of flowering and mature stages,addition of lignite humic acid overall increased SMC and SMN contents and H3 had the highest SMC and SMN values in soil depths of 0-10,10-20 and 20-40 cm.Application of lignite humic acid enhanced buckwheat dry matter and grain yield,and H3 had the highest increase.The principal component analysis and correlation analysis showed contents of soil available potassium,SWS,SMC and ammonium nitrogen were closely related with buckwheat grain yield,and the random forest analysis showed that their contribution rates to the yield was 11.00%,8.60%,7.85% and 6.29%,respectively.【Conclusion】The lignite humic acid application at the rates of 4-6 t/hm2 had considerable improvement on soil water retention,fertility and production in Horqin aeolian sandy soil,and the best rate was 6 t/hm2. |
| Key words: Horqin sandy land aeolian sandy soil lignite humic acid soil properties buckwheat yield |
