【作者】 张雪梅；

【导师】 苏友波； 付利波；

【作者基本信息】 云南农业大学 ， 水土保持与荒漠化防治， 2025， 硕士

【摘要】 绿肥作为一种有机的清洁肥源,在提升后茬作物产质量、改良土壤肥力等方面效果显著,在促进农业健康可持续发展,保障粮食安全与生态和谐方面扮演着重要角色。本研究主要针对西南地区由于连作障碍、氮肥过施所导致土壤肥力和生产力下降等问题,依托云南省昆明市嵩明县8年的绿肥-玉米轮作地的田间定位试验,探究绿肥还田条件下氮肥减施对土壤理化性质、酶活性、微生物群落结构及玉米产量的影响,为西南地区的绿肥种植和科学施肥提供理论依据。主要结论如下:（1）绿肥还田及氮肥减施有助于土壤养分的提升,与CK相比,翻压绿肥及氮肥减施使土壤的全氮含量显著提升了10%～49%,其中提升效果最好的是GN70处理,其次是GN85处理,全磷显著提升了1%～17.9%,全钾含量显著提升了0.8%～21.2%,碱解氮显著提升了4.4%～41%,pH值上升了0.07～0.24个单位,有机质显著提升了3.7%～23.36%,有机碳含量显著提升了3.7%～23.35%,容重降低了6.77%～10.53%,含水量提升了33.1%～60.94%,团聚体的质量分数都得到显著增加,其中最高的是GN100处理,其次是GN85处理,土壤团聚体稳定性GMW、MWD和R_0.25变化趋势一致,GN100>GN85>GN70>GN55>GN0>CK,团聚体各粒级有机碳含量和有机碳的固碳能力均得到提升。（2）绿肥还田及氮肥减施对土壤酶活有显著影响。与CK相比,脲酶提升了2.8%～56.13%,过氧化氢酶提升了74.09%～237.82%,纤维素酶提升了1.52%～36.2%,中性蛋白酶提升了19.72%～203.4%,中性磷酸酶提升了59.35%～126.84%,蔗糖酶提升了2.76%～56.02%。单独翻压绿肥的土壤酶活含量上升不是特别明显,而氮肥量施用完全土壤酶活的表现也不是最好的,在翻压绿肥及减氮处理下,土壤各酶活达到最高值,其中脲酶、过氧化氢酶、纤维素酶、表现最好的是GN85处理。（3）绿肥还田及氮肥减施影响土壤微生物群落结构及物种分布。与CK相比,GN70、GN85处理显著提升了细菌和真菌的丰度及多样性,提升土壤细菌和真菌优势门、属的占比丰度。此外,翻压绿肥及氮肥减施处理下土壤微生物与理化性质表现出密切的相关性,Mantel-test交互性分析表明,土壤细菌、真菌与pH、AN、AHN、AP、TK、SOM、S-CAT、S-NP、S-UE、S-SC、NPA呈极显著的正相关。（4）绿肥还田及氮肥减施处理显著影响玉米的生物学性状和产量。与CK相比,株高、穗位长、行粒数、提升效果最显著的是GN85处理,分别提升了1.1%～6.8%、4.7%～15.3%、2.9%～5.9%,鲜重提升效果最高的是GN70处理,比CK提高了45.76%,GN100处理提高了玉米的穗粗,比CK提高了12.27%。翻压绿肥氮不施肥处理的玉米产量下降了1.9%,翻压绿肥及氮肥减施的各处理玉米产量得到显著提升,提升了2%～11.74%,提升效果最显著的是GN85处理。综上所述,在西南地区玉米种植系统中,推荐使用GN85处理的绿肥翻压量和氮肥施用量,更好地帮助土壤培肥,助力玉米产量的稳产高产。更多还原

【Abstract】 Green manure,as an organic clean fertilizer source,has remarkable effects in improving the yield and quality of subsequent crops and soil fertility,and plays an important role in promoting the healthy and sustainable development of agriculture and ensuring food security and ecological harmony.Aiming at the problems of soil fertility and productivity decline caused by continuous cropping obstacles and excessive application of nitrogen fertilizer in southwest China,this study explored the effects of reduced application of nitrogen fertilizer on soil physical and chemical properties,enzyme activities,microbial community structure and corn yield under the condition of returning green manure to the field,Based on the eight-year field experiment of green manure-corn rotation field in Songming County,Kunming City,Yunnan Province,,and provided theoretical basis for green manure planting and scientific fertilization in southwest China.The main conclusions are as follows:(1)Returning green manure to field and reducing application of nitrogen fertilizer are helpful to improve soil nutrients.Compared with CK,turning green manure and reducing application of nitrogen fertilizer significantly increased the total nitrogen content of soil by10%～49%,among which treatment GN70 had the best improvement effect,followed by treatment GN85,and the total phosphorus increased by 1%～17.9%,and the total potassium content increased by 0.8%～21.2%.The pH value increased by 0.07～0.24 units,the organic matter increased by 3.7%～23.36%,the organic carbon content increased by 3.7%～23.35%,the bulk density decreased by 6.77%～10.53%,the water content increased by33.1%～60.94%,GN85 the mass fraction of aggregates increased significantly,the highest of which was The change trends of soil aggregate stability GMW,MWD and R0.25 are consistent,with GN 100>GN 85>GN 70>GN 55>GN 0>CK,and the organic carbon content and carbon sequestration capacity of each particle size of soil aggregate are improved.(2)Returning green manure to field and reducing application of nitrogen fertilizer have significant effects on soil enzyme activity.Compared with CK,urease increased by2.8%～56.13%,catalase by 74.09%～237.82%,cellulase by 1.52%～36.2%,neutral protease by 19.72%～203.4%,neutral phosphatase by 59.35%～126.84%.The increase of soil enzyme activity by turning green manure alone is not particularly obvious,and the performance of soil enzyme activity by applying nitrogen fertilizer completely is not the best.Under turning green manure and reducing nitrogen,soil enzyme activities reach the highest value,among which urease,catalase and cellulase are the best.(3)Returning green manure to the field and reducing nitrogen fertilizer application affected soil microbial community structure and species distribution.Compared with CK,GN70 and GN85 treatments significantly increased the abundance and diversity of bacteria and fungi,and increased the abundance of dominant phylum and genus of soil bacteria and fungi.In addition,soil microorganisms showed close correlation with physical and chemical properties under the treatment of turning green manure and reducing nitrogen fertilizer application.Mantel-test interactive analysis showed that soil bacteria and fungi were positively correlated with pH,AN,AHN,AP,TK,SOM,S-CAT,S-NP,S-UE,S-SC and NPA.(4)The treatment of returning green manure to the field and reducing nitrogen application significantly affected the biological characteristics and yield of maize.Compared with CK,the plant height,ear length,number of grains per row and the improvement effect are the most remarkable in GN85 treatment,which are increased by1.1%～6.8%,4.7%～15.3%and 2.9%～5.9%respectively.The fresh weight is the highest in GN70 treatment,which is 45.76%higher than CK,and GN100 treatment improves the ear diameter of corn.The maize yield of the treatments of turning green manure and nitrogen fertilizer without fertilization decreased by 1.9%,while the maize yield of the treatments of turning green manure and reducing nitrogen fertilizer was significantly increased by2%～11.74%,and the most significant improvement effect was GN85 treatment.To sum up,in the corn planting system in southwest China,it is recommended to use the amount of green manure and nitrogen fertilizer treated by GN85,which can better help improve soil fertility and help the stable and high yield of corn.更多还原