Nutrient Content in Rhizospheric Soil of Three Weed Species(Veronica agrestis L.,Erysimum cheiranthoides L.,and Chorispora tenella(pall).)in Winter Wheat Field under Different Fertilization Treatments

Veronica agrestis L.,Erysimum cheiranthoides L.,and Chorispora tenella(pall).are three important weed species in winter wheat field.In our previous study,The three weed species were found to become dominant under different fertilization in weed community,respectively.Such as,V.agrestis was the most dominant weed species when no N fertilizer was applied,however,it was C.tenella(pall) when no P fertilizer was applied,and C.tenella(pall) and E.cheiranthoides became more abundant than V.agrestis in the field with no K fertilizer applied.To elucidate their happening in the field,the available N,P,and K in rhizospheric and non-rhizospheric soil of V.agrestis,C.tenella(pall).and E.cheiranthoides were studied with pot trials in green house.The result showed V.agrestis absorbed more available N from non-rhizospheric soil than C.tenella(pall).and E.cheiranthoides with or without N fertilizer applying;the available P in rhizosphere of C.tenella(pall).was higher than that of the other two weed species when no P was applied;and the available K in rhizosphere of C.tenella(pall.) and E.cheiranthoides was more abundant than that of V.agrestis in K fertilization or no K fertilization treatments.So,it suggested V.agrestis had the best advantage to grow in soil with low available N content among the three weed species,but it was C.tenella(pall.) in P-deficient soil,and C.tenella(pall.) and E.cheiranthoides in K-deficient soil.