摘要： 为进一步加强苦荞氮肥的科学管理，研究了不同类型氮肥对不同生育时期苦荞光合特性、土壤酶活性及土壤氮素形态的影响。共设4个处理：普通尿素（U）、树脂包膜尿素（CRU）、硫包膜尿素（SU）和有机肥（ORU）。结果表明：与普通尿素相比，控释氮肥和有机肥处理可有效提高花后苦荞叶片的SPAD值、净光合速率（Pn），降低胞间CO₂浓度（Ci），SU处理的光合参数在开花期处于较好水平，而CRU和ORU处理下在灌浆中期处于较好水平；控释氮肥和有机肥对于改善土壤氮素相关酶活性有一定的促进作用，特别是有机肥对生育后期土壤酶活性的促进更为明显；控释氮肥和有机肥处理均显著提高了苦荞中后期的硝态氮和铵态氮水平，提高了后期土壤的氮素供应能力，通过相关性分析发现，硝态氮含量与各土壤酶活性均呈正相关关系（与脲酶和蛋白酶的相关性较高），铵态氮含量与土壤脲酶活性的相关系数在生育后期达到显著水平（P<0.05）。

关键词: 苦荞, 氮素营养, 光合特性, 土壤酶活性

Abstract: To strengthen the nitrogen management of tartary buckwheat,the effects of different types of nitrogen fertilizer on photosynthesis properties,soil enzyme activities and soil nitrogen forms of tartary buckwheat on different stages were investigated. In total four treatments were tested,including conventional urea(U),resin-coated urea(CRU),sulfur-coated urea(SU),organic fertilizer(ORU). The results showed:Compared with conventional urea,controlled release nitrogen fertilizer and organic fertilizer could increase the SPAD value,Pn and decrease Ci effectively;the photosynthesis parameters showed better level under SU treatment on flowering stage,and performed better under CRU and ORU treatment on middle filling stage;Controlled release nitrogen fertilizer and organic fertilizer could promote the soil nitrogen-related enzyme activities on certain degree,especially the effects of organic fertilizer on enzyme activities of late-growth stage was more obvious;Controlled release nitrogen fertilizer and organic fertilizer could increase the nitrate and ammonium nitrogen level significantly,and improve the soil nitrogen supply capacity. The relevant analysis showed,nitrate nitrogen content had positive correlation with soil enzyme activities(urease and protease);ammonium nitrogen content had significant correlation with urease activity on late-growth stage.

Key words: Tartary buckwheat, Nitrogen nutrition, Photosynthetic characters, Soil enzyme activities

中图分类号: 

• S145.6

• S143.1