Research On The Influence Of Grassing Cover On Soil Properties,leaf Traits And Fruit Quality In The Pear Orchards

The Yanbian Korean Autonomous Prefecture in Jilin Province abounds with‘Pingguoli’ and ‘Yanxiangli’.However,the long-term clean tillage has decreased the orchard’s ability to keep fertilizer and water.Besides,as fruit growers devote exclusive attention to output and apply fertilizer unscientifically,soil fertility has declined intensely,which has affected the development of fruit trees,fruit quality,and the improvement of yield.This study took ‘Pingguoli’ orchard and ‘Yanxiangli’orchard as the experimental site,and took self-sown grass and clean tillage as the experimental sample points,compared the soil properties,leaf development and fruit quality of grassing area and clear plowing area,and compared different grassing varieties,aiming to reveal the influence of grassing on improving the ecological environment,leaf development and fruit quality of pear orchard,and provide theoretical basis and technical guidance for the soil management of pear orchard in Yanbian state.The main research results obtained are as follows.1.Grass cover can significantly improve soil organic matter,total nitrogen,enzyme activity,quick-acting nutrient content and soil p H.‘Pingguoli’ orchard and‘Yanxiangli’ orchard self-sown grass cover different soil layers of soil nutrients to improve the effect of different,‘Pingguoli’ orchard self-sown grass cover than clean tillage significantly improve 0-40 cm organic matter,soil fast-acting potassium,urease,sucrase,cellulase,phosphatase activity and increase 0-40 cm total nitrogen content and 20-40 cm fast-acting phosphorus content respectively.Self-sown grass in‘Yanxiangli’ orchard significantly increased p H,organic matter,total nitrogen,fast-acting phosphorus,fast-acting potassium,exchangeable calcium content and sucrase,cellulase and phosphatase activities compared with clean tillage.The effect of different grass cover on soil nutrient improvement in different soil layers was different,and the alfalfa zone significantly improved the soil total nitrogen,fast-acting phosphorus,fast-acting potassium,organic matter,sucrase,cellulase,and phosphatase activities in 0-40 cm soil layer.Bluegrass and self-sown grass had significant effect on improving soil exchangeable calcium and p H in 0-40 cm soil layer and natural grass had significant effect on improving soil urease activity in 0-40 cm soil layer.2.‘Pingguoli’ orchard and ‘Yanxiangli’ orchard after grass cover,leaf quality and chlorophyll content were increased,indicating that promoting leaf nutrient accumulation.Among them,the effect of ‘Yanxiangli’ orchard on leaf total nitrogen,total phosphorus and total potassium was obvious,and ‘Pingguoli’ orchard reduced leaf total potassium content.Bluegrass,alfalfa and self-sown grass zone had different effects on leaf quality and nutrient improvement,bluegrass zone had obvious effects on leaf area,100-leaf weight,100-leaf thickness,total phosphorus and total potassium content,alfalfa zone had obvious effects on leaf total nitrogen,total potassium,total calcium and chlorophyll content,and self-sown grass significantly increased leaf total magnesium content.3.The effect of natural grass cover on fruit quality was significant,the soluble solids,fruit hardness and vitamin C content of ‘Pingguoli’ fruit increased significantly,the soluble solids and vitamin C content of ‘Yanxiangli’ fruit increased significantly,but the titratable acid content decreased significantly,the yield and fruit weight of‘Pingguoli’ and ‘Yanxiangli’ in natural grass cover area did not change significantly compared with the clear tillage area.The effect of different grasses on fruit quality was different,alfalfa significantly reduced the content of titratable acid in fruit,but there was no significant difference in the yield and single fruit weight of three kinds of grasses: bluegrass,alfalfa and natural grass.