The Effects of Long Term Different Fertilization on Community and Biodiversity of Crop Weeds

A survey was conducted in Zhengzhou on species constitution and the densities of weeds community which is under long term different fertilization.The paper gives analysis of the diffe-rence of weeds constitution and diversity index existing in the stage of wheat in both wheat-corn rotation and wheat-soybean rotation under long term different fertilization.It is due to the diffe-rent kinds of available soil nutrients which may have different impacts on the growth of different weeds.For example,the Galium aparine L.and Capsella bursa-pastoris Medic showed certain dependence on specific soil nutrient.