控释氮肥对棉花叶片生理特性和产量的影响

Effects of Controlled Release Nitrogen Fertilizers on Leaf Physiological Characteristics and Yield of Cotton

通过大田试验,研究树脂包膜尿素和硫加树脂包膜尿素2种控释氮肥对棉花叶片生理特性、土壤氮素及产量和品质的影响,并以普通尿素为对照。结果表明,一次基施控释氮肥较尿素处理,显著提高了叶片光合速率,增加了叶绿素和可溶性蛋白含量,增强了硝酸还原酶和谷氨酰胺合成酶的活性;增强了叶片超氧化物歧化酶和过氧化物酶活性,减少了丙二醛含量,延缓了叶片衰老。基施树脂包膜尿素和硫加树脂包膜尿素较普通尿素处理显著提高了初花期以后土壤中的硝态氮和铵态氮含量,且氮肥利用率分别提高了25.18%和52.69%,皮棉产量分别增加了9.26%和11.67%。同时,控释氮肥显著提高了纤维长度及伸长率,但对衣分、整齐度指数和马克隆值无显著影响。因此,施用控释氮肥保证了土壤氮素的供应,显著改善了棉花叶片光合特性,增强了氮素同化关键酶和保护性酶活性,在获得高产的前提下改善了纤维品质。

A field experiment was conducted to investigate the effects of controlled release nitrogen fertilizers（CRNF）including polymer coated urea（PCU）and polymer coating sulfur-coated urea（PSCU）on leaf physiological characteristics,soil nitrogen content（N）,yield and fiber quality of cotton in 2013.The common urea was used as control in this experiment.The results showed that compared to common urea treatments,CRNF treatments significantly increased the photosynthetic rate（Pn）,contents of chlorophyll and soluble protein,and the activities of nitrate reductase（NR）,glutamine synthetase（GS）,superoxide dismutase（SOD）and peroxidase（POD）in cotton leaves,but decreased the content of malonyldialdehyde（MDA）,delaying senescence of leaves.Moreover,compared to common urea treatments,both PCU and PSCU treatments greatly increased the contents of nitrate nitrogen and ammonium nitrogen in 0—20cm soil layer after initial bloom stage,and increased nitrogen use efficiency by 25.18% and 52.69%,respectively,due to the sufficient supply of nitrogen.Meanwhile,the lint yields of cotton in PCU and PSCU treatments were 9.26% and 11.67% higher than those in control treatments,respectively.The fiber elongation and length were also improved by CRNF treatments.However,the lint percentage,fiber uniformity and micronaire value were not influenced by the type of nitrogen fertilizer.In conclusion,application of CRNF could meet the demand of nitrogen in soil during the whole growth period of cotton significantly improved the photosynthetic characteristics of cotton leaves and enhance the activities of key enzymes and protective enzyme of nitrogen metabolism.Therefore,the yield of cotton was increased and fiber quality was improved by CRNF.