耕作方式对砂姜黑土小麦氮代谢及氮素利用效率的影响

为探求砂姜黑土区小麦高产高效的最佳耕作方式,在大田条件下,比较分析了深松、旋耕和常规翻耕三种耕作方式下小麦氮素同化关键酶活性、中间产物含量及氮素的积累、分配、转运和利用效率的特点。结果表明,随生育进程的推进,小麦叶片谷氨酰胺合成酶活性、游离氨基酸和可溶性蛋白含量均呈先升后降的趋势,全氮含量则逐渐下降,在各时期深松处理的这些指标均显著高于旋耕和常规耕作处理,且在后期维持较高水平。深松处理通过营养器官花前贮存氮素向籽粒的高转运以及花后氮素的高吸收、高贡献,获得成熟期较高的籽粒氮素积累量和分配比例;虽然旋耕处理的转运氮对籽粒氮素的贡献率较高,但其氮素转运量、转运效率和花后吸收氮量较低,成熟期籽粒的氮积累量和分配比例在三种耕作方式中最低,茎秆和穗轴+颖壳的分配比例反而最高。深松处理较其余二处理能显著提高小麦籽粒产量和蛋白质含量、氮素吸收效率、氮肥回收效率、氮肥偏生产力和氮素产投比。因此,深松能有效促进砂姜黑土区小麦的氮素同化能力,延长叶片功能期,提高氮素利用效率,促进小麦产量与品质的形成。

Effects of Different Tillage Methods on Nitrogen Metabolism and Nitrogen Utilization Efficiency of Wheat Grown in Lime Concretion Black Soil Region

The purpose of this experiment is to find the best tillage method to realize the high efficient and high yield of wheat.Under field condition,three tillage methods (subsoiling,rotary tillage,and conventional tillage) was set to study the effects of different tillage methods on the activities of key enzymes and intermediate products in nitrogen assimilation,the accumulation,distribution,translocation of nitrogen and nitrogen use efficiency of wheat.The results showed that GS activity,free amino acid content and soluble protein content increased at first and then decreased with the advancement of reproductive period.Total nitrogen content decreased gradually.The activities of key enzymes and intermediate products in nitrogen assimilation of subsoiling were significantly higher than the other two methods at each growth period,and maintained a high level at the late stage.Subsoiling tillage had higher translocation of nitrogen from vegetative organs to grain,higher absorption of nitrogen after flowering and higher contribution from absorbed nitrogen after flowering to grain than the other two tillage methods.So the accumulation and distribution rate of nitrogen to grain were the highest.Though rotary tillage had higher contribution rate from translocation nitrogen to grain,but the amount of translocation nitrogen,translocation efficiency and absorption nitrogen after flowering were lower.So the nitrogen accumulation and distribution rate of grain were the lowest.The distribution rates of stem,spike stalk and shell were the highest.Grain yield,protein content,nitrogen uptake efficiency,nitrogen recovery efficiency,partial factor productivity from applied nitrogen and nitrogen input output ratio were enhanced by subsoiling tillage.So subsoiling tillage could promote nitrogen assimilation,extend functional period of the leaf and improve nitrogen use efficiency to realize the high efficient and high yield of wheat.