Physiological And Rhizosphere Soil Nutrients Changes Of Continuous Cropping In Potato

In recent years, with the reduction of global arable land, population growth and frequent natural disasters, the mankind is faced with serious challenges of hunger. The crops with high-yield and stress resistance have been the inevitable choice. Potato has been recognized as the relief and economic crop with many advantages such as the high-yield, rich-nutrient, short growth period, strong resistance and high economic benefits. As a long-term monocultures in some areas, the potato continuous cropping has been as a problem in front of growers. In this study, the physiological characteristics, biological indexes and dynamic change of soil nutrient of potato plants continuously cropped for zero, one, two, and three years were investigated. The results were as following:1.With the continuous cropping years increasing, the proline content of potato plant was significantly increased, the superoxide dismutase activity was significantly increased, while the change in MDA content was not significant. The plant height, leaf area, leaf water content and yield were reduced with the increase of continuous cropping years.The results indicated that continuous cropping as a stress environment inhibited the potato plant growth and derelopment, reduced the plant senescence.2.With the continuous cropping years increasing the content of total P and effective Mn and Zn in the soil were significantly increased, The content of effective B, Ca, Cu and Mg were enhenced to some extent, while no significant change in the content of total K, N and effective Fe. The result might represent that the absorption of total P, effective Mn and Zn in potato plants were significantly reduced, the absorption of effective B, Ca, Cu and Mg were decreased, and the absorption of K, N and Fe were no significant change.All the results showed that continuous cropping caused the increase of some elements in soil and the formation of sigle salt poison, which affecting the osmotic pressure of plant. Meanwhile, these deficiency elements resulted in the formation of deficiency elements symptom, which directly affected the photosynthesis and renpiration of potato, decreased the potato yield, qulity and resistance, caused the deterioration of soil physical and chemical properties, and also significantly reduced the valne of goods.