混播比例和刈割茬次对一年生禾豆混播草地根系形态、土壤养分的影响

Effect of mixed sowing ratio and cutting time on root morphology,soil nutrientsin annual ryegrass and common vetch mixture grassland

为探讨混播比例和刈割茬次对一年生禾豆混播草地根系形态、土壤速效养分及土壤酶活性的影响,设100%多花黑麦草(H)、75%多花黑麦草+25%箭筈豌豆(HJ_1)、50%多花黑麦草+50%箭筈豌豆(HJ_2)、25%多花黑麦草+75%箭筈豌豆(HJ_3)、100%箭筈豌豆(J)5个处理。结果表明,与多花黑麦草单播相比,混播模式下根干重、根直径和根体积分别降低了11.48%~46.13%、8.49%~27.36%和11.23%~38.93%;与箭筈豌豆单播相比,混播模式下的根干重和根体积分别增加了422.73%~759.09%、617.95%~943.59%。土壤有机质含量、碱解氮含量和速效磷含量随着混播中箭筈豌豆比例的增加而增加,HJ_3土壤养分持有量最好。土壤脲酶活性呈先增加后减小的趋势,土壤硝酸还原酶活性也呈先增加后减小的趋势,土壤酸性蛋白酶活性呈逐渐减小的趋势。

To discuss the effects of mixed sowing ratio and cutting time on root morphology,soil available nutrients and soil enzyme activity in annual ryegrass(Lolium multiflorum,‘Changjiang No.2’)and common vetch(Vicia sativa,‘Chuanbei’)mixture grassland,five treatments(100%annual ryegrass(H),75%annual ryegrass+25%common vetch(HJ1),50%annual ryegrass+50%common vetch(HJ2),25%annual ryegrass+75%common vetch(HJ3)and 100%common vetch(J))were set up in this study.Compared with the single sowing with annual ryegrass,the results showed that the root dry weight and root volume of mixed sowing pattern decreased by 11.48%to 46.13%and 11.23%to 38.93%respectively;compared with single sowing with common vetch,the root dry weight and root volume of mixed sowing pattern increased by 422.73%to 759.09%and 617.95%to 943.59%respectively.The content of organic matter,available nitrogen,and available phosphorus from soils samples in mixed sowing grassland with annual ryegrass and common vetch increased following the increase of legume ratios,and soil nutrient holding capacity in HJ3 was the best.The activity of soil urease and soil nitric acid reductase firstly increased and then decreased following the increase of cut times,while the soil acid protease activity gradually decreased.