Abstract: This study aimed to observe the agronomic characteristics of different varieties of forage soybeans and their effects on soil improvement through return to field， as well as to analyze the fertilization effects， with the goal of identifying more green manure resources for soil improvement. The varieties used as green manure materials were ‘S001 Forage Hybrid Wild Soybean’ （S001）， ‘Inner Agricultural S002 Forage Soybean’ （S002）， ‘Mengnong S003 Forage Soybean’ （S003）， ‘Mengnong S004 Forage Soybean’ （S004）， ‘Mengnong S005 Forage Soybean’ （S005）， and ‘Mengnong S006 Forage Soybean’ （S006）. with tillage as the control （CK）. The field experiment was conducted in early May 2023 at the M-Grass Seed Industry Center Experimental Field in Hohhot. The forage soybeans were plowed into the soil during the peak flowering stage， and after the decomposition soil samples were randomly collected from the 20 cm depth to determine nutrient contents and soil enzyme activities. The results showed that the incorporation of forage soybeans significantly increased soil nutrient contents （P<0.05）， with a decrease in soil pH by 0.86 to 0.95. The activities of soil sucrase， peroxidase， phosphatase， and urease significantly increased （P<0.05）， with increases ranging from 52.9% to 67.9%， 1.3% to 6.1%， 8.1% to 42.5% and 21.0% to 56.6%， respectively. In conclusion， different varieties of forage soybeans used as green manure significantly improved soil nutrient contents and enzyme activities， with S001， S004， and S005 treatments performing particularly better in improving soil structure， reducing bulk density， and lowering pH.

Key words: Forage soybean, Agronomic traits, Incorporation, Soil physicochemical properties, Soil enzyme activity

摘要： 本研究旨在观测不同品种饲用大豆（ Glycine max （L.） Merr.）的农艺特征及其还田对耕作土壤的改良效果，分析肥田效应，以期为土壤改良寻找更多的绿肥资源。以品种‘S001草食兼用杂交野大豆’（S001）‘内农S002饲用大豆’（S002）‘蒙农S003饲用大豆’（S003）‘蒙农S004饲用大豆’（S004）‘蒙农S005饲用大豆’（S005）和‘蒙农S006饲用大豆’（S006）为绿肥材料，以清耕为对照（CK），于2023年5月上旬在呼和浩特市蒙草种业中心试验田进行小区田间种植。于盛花期翻压，待饲用大豆腐解后随机采集20 cm土层土壤样品，测定养分含量和土壤酶活性。结果表明：饲用大豆翻压处理显著提高了土壤养分含量（P<0.05），土壤pH值降低0.86~0.95；土壤蔗糖酶、过氧化氢酶、磷酸酶和脲酶活性均显著增加（P<0.05），增幅分别为52.9%~67.9%，1.3%~6.1%，8.1%~42.5%和21.0%~56.6%。综上所述，不同品种饲用大豆用作绿肥，显著改善了土壤的养分含量和酶活性，其中S001，S004和S005处理在提升土壤结构、降低容重和pH值方面表现突出。

关键词: 饲用大豆, 农艺特性, 还田, 土壤理化特性, 土壤酶活性