硫包膜控释尿素和树脂包膜控释尿素混施对番茄生长及氮代谢酶活性的影响

Effects of Mixed Application of Sulfur-coated and Resin-coated Controlled Release Urea Fertilizer on Growth and Nitrogen Metabolism-related Enzyme Activities of Tomato

在日光温室盆栽条件下,研究了尿素(U)、硫包膜控释尿素(SCU,控释期4个月)和树脂包膜控释尿素(RCU,控释期6个月)混施(各提供50%氮素)在同等氮素及减氮30%、50%条件下,对番茄生长、光合作用及氮代谢相关酶活性的影响。结果表明,所有取样时期,番茄叶片中叶绿素a(Chla)、叶绿素b(Chlb)和类胡萝卜素(Car)含量、净光合速率(Pn)及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和谷氨酸合成酶(GOGAT)活性均随氮素用量减少而下降,进而表现为番茄株高和茎粗随之降低。同等氮素条件下定植30 d后,硫包膜控释尿素和树脂包膜控释尿素混施处理其NR、GS和GOGAT活性均低于尿素处理,Chla、Chlb、Car含量和Pn无显著差异;定植60 d和90 d后,硫包膜控释尿素和树脂包膜控释尿素混施处理所有指标均高于尿素,且定植60 d后,在减氮30%条件下,其叶片中Chla、Chlb、Car含量、Pn及NR、GS和GOGAT活性与100%尿素处理差异不显著,番茄株高和茎粗长势良好。综上所述,硫包膜控释尿素和树脂包膜控释尿素混施在番茄生长中后期养分释放规律与番茄需肥规律基本一致,能促进光合色素合成和氮代谢相关酶活性,延缓叶片衰老,更有利于番茄产量的提高。

In the condition of pot planting in greenhouse, the mixed application of sulfur - coated （ SCU, controlled release period as four months） and resin - coated （ RCU, controlled release period as six months） controlled release urea fertilizer with each providing 50% nitrogen respecetively was studied, and its effects under the same nitrogen, 30% and 50% nitrogen reduced level on the growth, photosynthetic rate and nitro- gen metabolism - related enzyme activities of tomato were compared with urea. The results showed that in all sampling periods, the content of Chla, Chlb and Car, Pn, as well as the activity of NR, GS and GOGAT de- creased with the reduction of nitrogen amount, following with the decrease of tomato plant height and stem di-ameter. Under the same nitrogen level, the activities of NR, GS and GOGAT of SCU and RCU treatment were lower than those of urea treatment after planted for 30 days, while there were no significant differences in the content of Chla,Chlb,Car and Pn. After planted for 60 and 90 days, all the indexes of SCU and RCU treat- ment were higher than those of urea treatment. Besides, after planted for 60 days and under 30% nitrogen re- duced level, the contents of Chla, Chlb and Car, Pn, as well as the activities of NR, GS and GOGAT of SCU and RCU treatments had no significant difference with those of 100% urea treatment, and the tomato plant height and stem grew well. In summary, the nutrient release rules of SCU and RCU controlled -retease fertil- izer was consistent with tomato requirement rules in the late of tomato growth, which promoted the synthesis of photosynthetic pigments and nitrogen metabolism - related enzyme activities, delayed leaf senescence and had much help for the formation of tomato production.