Studies On The Effects Of Water And Fertilizer Coupling At The Elongation Stage In Sugarcane

Sugarcane variety Roc22 was as material in this experiment.Irrigation norm of 20mm/ten days(A₁),40mm/ten days(A₂)and 60mm/ten days(A₃) were planned at the period of elongation.Nitrogen rate of 12kg/666.7m²(B₁), 24kg/666.7m²(B₂)and 36kg/666.7m²(B₃)were designed in growth period. The effects of water supply treatment and Nitrogen rate treatment on agronomic traits,drought-resistant physiology,physiology biochemistry of growth,yield,technical traits,mineral nutrient in sugarcane were studied. Results were as follows.1.Chlorophyllous concentration,soluble sugar concentration,nitrate reductase activity,and soil water content,fresh leaves water concentration and the third leaf NP and K concentration were increased,but dead leaves K content were decreased in 40mm/ten days treatment.Plant height,sugarcane stem growth rate and leaf area index were big,and yield was highest,and dead leaves N,P concentration were decreased,membrane permeability was reduced,peroxidase activity was increased.2.Chlorophyllous concentration was higher,and fresh leaves water content and the third leaf N,P and K were enhanced,and N,P and K concentration of dead leaves were reduced,and sugarcane stem sugar concentration was highest in 24kg/666.7m² treatment.Soil water content was increased,and leaf area index was bigger,and Polyphenoloxidase activity was bigger,and soluble sugar concentration and nitrate reductase activity were higher,and yield was highest.3.According to interactions experiment of water and fertilizer,the results were as follows:A.according to interactions of water and nitrogen,chlorophyllous concentration was higher in the lower nitrogen and lower water treatment, chlorophyllous concentration was higher in the higher nitrogen and higher water treatment,and polyphenoloxidase activity was not effected by water in the lower nitrogen treatments.Soluble sugar content of the third leave was higher in the condition of water and nitrogen together increasing,and nitrate reductase activity was not effected by water in the higher nitrogen treatment,and phosphorus concentration was increased in the high water and lower nitrogen treatment and in the middle water and higher nitrogen treatment.Plant height and elongation speed was positively effected by nitrogen increasing in the condition of lower water.Under the condition of high water,yield(up to9 647kg/666.7m²)and sugar concentration(up tol 350kg/666.7m²)was high in 24kg/666.7m² treatment.B.according to interactions of nitrogen and water,polyphenoloxidase activity was not effected by nitrogen addition.In the 20mm/ten days treatment,soluble sugar content was higher in any nitrogen addition. Potassium concentration was enhanced in low water and any nitrogen addition.Potassium concentration of dead leaves and sheath were decreased to enhance potassium recycle rate in 40mm/ten days treatment and any nitrogen addition.Plant height and growth speed were positively effected in interactions of water and fertilizer.Yield and sugar concentration were highest in high water and middle nitrogen treatment.