Effects of Organic Manure on Nitrate Distribution in Greenhouse Soil over Three Continuous Crop Cultivations
An experiment was conducted on a vegetable planting base in Damintun Town, Xinmin City, Liaoning Province to study the influence of different organic manure rate on nitrate distribution in vertical profile in a greenhouse soil over three continuous crop cultivations of cucumbers, beans and lettuces. The soil was treated with organic manure at five treatments. The results showed that the distribution characteristic was closely related with organic manure rate in the process of plant growth. After harvest of the cucumber and lettuce soil nitrate content of all layers was higher than before planting and the accumulation of nitrate was increased with the application rate of organic manure. When applied into the low amount of organic fertilizer (M1 and M2), no significant phenomenon of nitrate accumulation and leaching occurred. High amount of organic manure rate (M4) increased significantly (P<0.05), especially in 0~40cm soil layer. In the lower layer (60~120cm) of soil different degrees of nitrate leaching took place. The vertical distribution of nitrate before planting and harvest of beans showed that catch crops can effectively reduce the accumulation of nitrate in soil.
Yanguo Shi and Jinlong Zuo
M. F. Niu et al., "Effects of Organic Manure on Nitrate Distribution in Greenhouse Soil over Three Continuous Crop Cultivations", Advanced Materials Research, Vols. 183-185, pp. 333-337, 2011