Research On Intercropping Pattern And Technique In Young Walnut Orchard

Seven intercrops of different uses were planted in 2-5-year-old walnut orchards in this research. And four aspects were studied, including tree appearance index, soil nutrients content, economic benefit of intercrops and situation of main walnut producing areas in Shanxi Province. Results are as follows.1. Through research on correlation between different intercrops and young walnut tree appearance index (including trunk girth, tree height, crown diameter, shoot amount and shoot length), it showed that young walnut orchard intercropped with soybean had higher values of trunk girth, crown diameter and shoot length than thoses of the CK, while values of tree height and shoot amount almost the same as that of the CK. While intercropped with sweet potato, value of shoot length is higher than that of the CK, and values of trunk girth, tree height, crown diameter and shoot amount are basically the same as those of the CK. While intercropped with walnut seedlings, value of shoot length is higher than that of the CK, and values of trunk girth, tree height, crown diameter and shoot amount are basically the same as those of the CK. While intercropped with corn, the entire appearance index is lower than that of the CK. It indicates that low crops such as soybean and sweet potato are more suitable for intercropping in young walnut orchard than high crops such as corn.2. Through test and analysis on vertical and horizontal distribution of soil nutrient content, content of total nitrogen, valid K and valid P at different soil depths were determined. Results showed that at depths of 0-20 cm and 20-40 cm, significant difference of total nitrogen and valid P content exists for the 3 intercropping patterns. At depth of 40～60 cm, no significant difference of total nitrogen and valid P content exists. For the 3 intercropping patterns and the 3 depths of soil, valid K content has no significant difference. For horizontal distribution of soil nutrients, the closer to walnut rows, the less of the nutrients; while the farer to walnut rows, the more of the nutrients. It indicates that roots of walnut trees and intercrops have the largest niche overlap value at the soil depth of 0～40cm. At the depth of 40～60 cm, there was almost no overlap for the roots of walnut trees and shallow root crops, which showed that pattern of young walnut trees intercropped with shallow root crops can make best use of deep soil nutrients and accelerate the growth of walnut trees.3. Through test and analysis on yield and benefit of different inter-row crops in different row spaces, results showed that row space has a low effect on yield and benefit of inter-row crops. The economic benefit of inter-row crops from high to low is sweet potato, chrysanthemum, corn, pepper, peanut, soybean and winter wheat. Sweet potato and chrysanthemum have higher economic benefit, yet they have no promotion on growth of walnut trees; while soybean has low economic benefit, yet it can promote growth of walnut trees. Corn is not suitable for intercropping because of its high stalk.4. Investigation of newly-planted walnut orchards was carried out in four walnut producing areas of Shanxi Province. Results showed that walnut industry in Yuanqu County developed better because of high guiding strength of government, closely working with scientific research institutes and high enthusiasm of growers, which effectively promotes healthy, orderly and stable development of the local walnut industry.