Effects of organic manure application on growth and senescence of root in winter wheat

Organic manure not only has the function of nutrient supplication and soil improvement, but also is an essential way with full use of source and decreasing pollution. Most researches focused on the effects of organic manure on plant yield, soil physical and chemical property, soil fertility, and soil nutrient balance, however few literatures on the effects of organic manure on plant root growth, especially root senescence, were reported. An earth pyramid culture (experiment) were carried out to explore the regulating mechanism of organic manure application on the accumulation, distribution and fresh weight of root, especial root activity in soil layer, root senescence in winter wheat at experiment plot of Shandong Agriculture University from 2000 to 2001. The results showed that application of organic manure could promote the growth of root and increase fresh weight and ratio of root in deep layer. It could increase activity of root, especially that distributed deeper than 20cm soil layer, which is favor for plant keeping higher ability of root absorption in later growing stage of winter wheat. It also could promote the root uptake of N, P and K and translocation to grain as the (result,) the nutrient quantum in grains increased. Organic manure also could increase superoxide dismutase (SOD) activity and decrease MDA content in roots in different soil layers, especially in 40cm soil layer, retard the senescence rate of roots.