Effect Of Rape Plantign As Catch Crop On Soil Characteristics And Potato Yield In Potato Field

It has been more difficult for potato production to have a big breakthrough due to the soil organic matter and nutrient loss,soil physical and chemical properties deterioration of northern Shaanxi.Rape was been used as experimental materials,the study was conducted to measure changes of soil nutrients content,soil moisture,soil structure and microbial enzyme activity and the yield of potato.The results were as follow:Under the different density,compared with the CK,(1)rape planting as catch crop increased soil moisture content before next potato sowing mainly in 0-20 cm soil layer;(2)bigger soil aggregates content of A??A??A? were higher than CK;(3)A?(row spacing=20cm)could improve soil available phosphorus ? available potassium and available nitrogen of0-60 cm and soil organic matter of 0-20 cm significantly,A?(row spacing=10cm)could significantly improve the soil available phosphorus of 0-20 cm ? soil available nitrogen and organic matter of 0-20 cm and 40-60 cm and soil available potassium of 20-40 cm,A?(row spacing=15cm)could significantly improve soil available phosphorus of 0-20 cm layer ? soil available nitrogen and organic matter of 0-40 cm layer and soil available potassium of20-60 cm layer,which proved that the smaller the density of rape,in other words,the greater the row spacing was,the wider of the influence on soil nutrient were within a certain range;(4)The influence of different density treatment on soil urease activity and catalase activity had reached 0-60 cm layer;the greater the density was,the bigger the sucrase activity in the surface layer of soil was.A??A? owned larger soil alkaline phosphatase activity in 0-40 cm layer;(5)the theoretical yield of each treatment was CK>A?>A?>A?,and no significant difference between A? and CK,the tuber weight A?>A?>CK>A?;The number of potatoes weight>30g in 1m field: A?=A?>CK>A??Under different sowing date,the results were follow:(1)B?(rowing date is 7.10)?B?(rowing date is 8.10)? B?(rowing date is 9.8)could be able to improve significantly soil moisture content in topsoil,and the earlier the rape sowing time,the higher the surface soil water content after new year's,the wider influence of rape on soil moisture;(2)the soilparticle of particle size of >0.25 mm of B??B??B? were bigger compared with the CK;(3)B?was able to improve soil available nitrogen?soil available phosphorus and organic matter of0-40 cm and soil available potassium of 20-40 cm,B? could improve soil available nitrogen of0-40 cm,soil organic matter and available potassium content of 20-40 cm,and soil available phosphorus content of 0-20 cm,B?(9.8)only increased the soil available nitrogen content of0-20 cm significantly.The earlier the rape sowing time was,the more the soil nutrient content was before next potato sowing within a certain range;(4)soil urease activity and catalase activity of 0-60 cm,soil alkaline phosphatase activity and sucrase activity of 0-20 cm of B?was higher than CK;B? was more in soil catalase and sucrase activity of 0-20 cm,soil urease activity of 0-20 cm and 40-60cm;B? could significantly improve the soil urease activity and alkaline phosphatase activity of 0-60 cm,soil catalase and sucrase activity of 0-20cm;(5)Theoretical yield of potato was B?>B?>CK>B?,the single potato weight CK>B?>B?>B?,the number of potato weight>30g in 1m field: B?>B?=B?>CK.The results showed that the earlier the sowing date of potato could be conducted to increasing the single potato weight and the number of bigger potato in a certain period,contributing to achieving high yield.Thus,rape planting in potato field as catch crop could be able to decrease significantly the soil water evaporation certainly,improved soil structure and soil nutrient,furthermore,A?(rape sowing rows was 20cm)treatment and B?(rape sowing date was July10th)treatment were was more suitable for planting in northern of Shanxi.