Study On Effects Of Continuous Cropping Obstacle On Growth Of The Sugarcane And The Rhizosphere Soil Properties

The experiment explored the correlation of the soil physical and chemical properties and sugarcane continuous cropping obstacle, by the means of analyzing the agronomic traits, leaf nutrients, yield, quality of sugarcane and rhizosphere soil nutrients, enzyme activities, organic acids when was new plant in idle land, new plant in sugarcane field and the first, second, third year perennial root sugarcane.The results show that:(1) The germination rate, efficacious stem rate, growth rate, sucrose content and leaf chlorophyll content, nitrogen content, potassium content of the continuous new planting sugarcane is lower than the not continuous new planting sugarcane, when tillering rate, plant height, single stem weight, efficacious stem number, yield, sugar yield and leaf phosphorus content is higher than the not continuous new planting sugarcane. The yield of perennial root sugarcane is lower than the not continuous new planting sugarcane. Germination rate and sugarcane sucrose content is increased gradually with the increase perennial root planting years, when efficacious stem rate, growth rate, plant height, stem diameter, stem weight, efficacious stem number, yield, sugar yield and leaf nitrogen content and potassium content is showed decline trend, especially yield of the third year perennial root sugarcane decreased significantly. (2)The nitrate nitrogen, effective copper, effective zinc, effective iron content is decreased by continuous cropping, when organic content, available phosphorus and ammonium nitrogen content is increased. Alkaline hydrolysis nitrogen and available potassium content is decreased by perennial root planting, when is increased by continuous new planting. (3) Soil total organic acids content and total phenolic acid content is positively related to relationship significantly. Soil total organic acids and phenolic acid content of the continuous new planting sugarcane is higher than the not continuous new planting sugarcane. Soil total organic acids and phenolic acid content of the continuous new planting sugarcane is increased gradually with the increase perennial root planting years. Phenolic acid occupies adout 1‰-2‰ of organic acids content.The main conclusion: there is cultivated advantage for continuous new planting sugarcane. Perennial root planting is prone to lead to continuous cropping obstacle. Sugarcane continuous cropping will cause the change of soil nutrient and enzyme activity and the accumulation of soil organic acids and phenolic acids in a certain degree. It is not conducive to the normal growth of sugarcane. Soil phenolic acids content is so low. It should be further explored whether is toxic for sugarcane.