氮肥减量条件下间作绿豆压青对甘蔗生长及氮代谢的影响

以甘蔗单作常规施氮量为对照（CK）,设氮化肥减量20%+间作绿豆压青（A）、氮化肥减量40%+间作绿豆压青（B）和氮化肥减量60%+间作绿豆压青（C）3个处理,通过测定甘蔗农艺性状、蔗茎产量和甘蔗叶片氮代谢相关生理生化指标,研究氮肥减量条件下间作绿豆压青对甘蔗生长及氮代谢的影响。结果表明,间作绿豆影响新植蔗分蘖,分蘖率显著低于CK,但对甘蔗有效茎数影响不显著。新植蔗产量表现为A>B>CK>C。氮化肥减量条件下间作绿豆压青对宿根蔗发株率、株高、有效茎数、甘蔗茎径有促进作用。宿根蔗蔗茎产量表现为A>B>C>CK。2年的甘蔗蔗糖分含量表现为C>B>A>CK。氮化肥减少20%条件下间作绿豆压青对提高甘蔗叶片谷氨酰胺合成酶、硝酸还原酶活性和游离氨基酸、可溶性糖含量有促进作用。综合甘蔗农艺性状、蔗茎产量、氮代谢相关指标测定结果和经济效益的表现,试验以氮化肥减量20%+间作绿豆压青的A处理最优。

Effects of Intercropping Mungbean Straw Returning on Sugarcane Growth and Nitrogen Metabolism under Nitrogen Fertilizer Reduction

By setting monocropping sugarcane with conventional nitrogen application (CK) as a control, three treatments of reduced 20% nitrogen with intercropping mungbean (A), reduced 40% nitrogen with intercropping mungbean (B) and reduced 60% nitrogen application intercropping mungbean (C) with mungbean fresh straw returning were used. Sugarcane agronomic traits, yield and the nitrogen metabolism of leaves were measured to study effects of intercropping mungbean straw returning on sugarcane growth and nitrogen metabolism under nitrogen fertilizer reduction. The results showed that intercropping with mungbean affected tillering of new-planting sugarcane. Tillering rate was significantly lower than the control. But it had no significant effect on millable cane. The cane yield of new-planting sugarcane was A>B>CK>C. Intercropping mungbean straw returning with nitrogen fertilizer reduction improved shooting rate, plant height, the number of millable stalks and stalk diameter. The yield of ratoon cane was A>B>C>CK. The sugar content of cane in two years was C>B>A>CK. Reduced 20% nitrogen application with mungbean straw returning increased the activities of glutamine synthetase, nitrate reductase, and the contents of free amino acid and soluble sugar. According to sugarcane agronomic traits, cane yield, nitrogen metabolism and economic benefit in the experiment, the treatment A of reduced 20% nitrogen application with mungbean straw returning was optimal.