The Relationship Between The Continous Cropping Obstacle And Physical And Chemical Properties Of Cassava Rhizosphere Soil

This research as the Xinxuan048,Huanan205,Nanzhi199 and FuxuanOlfour cassava varieties for experimental material,through the comparison research of rotation and continuous cropping of cassava rhizosphere physical and chemical properties,physiological and biochemical,and yield,To discuss the relationship between the continuous cropping obstacle and and physical and chemical properties of soil,the results show that:(1)Continuous cropping obstacle have a certain influence on cassava physical and chemical properties of soil,physiological and biochemical and the agronomic traits;For the purpose of this test of four varieties of cassava,comprehensive analysis it is concluded that the best cassava varieties resistance to continuous cropping obstacle for the Xinxuan048,followed by the Nanzhi199,finally the Huanan205 and the Fuxuan01.(2)For the physical properties of cassava rhizosphere soil,continuous cropping make the solid phase volume and porosity decreases of rhizosphere soil to be smaller,bulk density of rhizosphere soil to be larger,it can also lead to these three traits of rhizosphere soil had adverse changes.(3)For the chemical properties of cassava rhizosphere,continuous cropping can reduce PH of rhizosphere soil and the phenolic acids content of rhizosphere soil had increased,continuous cropping also inhibit catalase activity of rhizosphere soil.(4)For the available nutrients of cassava rhizosphere soil,It is presents the fluctuation condition of rotation and continuous cropping of cassava rhizosphere soil available nitrogen content,on the whole continuous cropping can reduce the available nitrogen content of rhizosphere soil.Continuous cropping available p and k of rhizosphere soil whether there exists inhibitory effect remains to be verified;Continuous cropping to cause a decline in organic matter content of cassava rhizosphere soil.(5)For cassava leaves of nutrient elements,continuous cropping inhibits the accumulation of leaf nitrogen content;Continuous cropping for blade phosphorus of leaf accumulation content has certain inhibitory effect;In seedling and root formation,continuous cropping may affect the total potassium accumulation of leaf,in the expanding and mature of root period,whether continuous cropping in the two periods of cassava leaf potassium accumulation remains to be studied.(6)For cassava leaf physiological factor,continuous cropping for the accumulation of cassava leaf chlorophyll have inhibition;Continuous cropping for the soluble sugar content of cassava leaf chlorophyll had inhibition.(7)For cassava root characters and yield,continuous cropping can make cassava root,stem length and the number of stem diameter to be smaller and plant root yield decline.Among them,the yield of Xinxuan048 continuous cropping was low 5.65%then the rotation,the yield of Huannan205 continuous cropping was low6.14%then the rotation,the yield of Nanzhi199 continuous cropping was low 9.55%then the rotation,the yield of Fuxyan01 continuous cropping was low 7.26%then the rotation.