旱地土壤氮有效度的分级指标  

Fractional Index of Nitrogen Availability for Aerated Soils

作　　者：易小琳[1] 李酉开[1] 

机构地区：[1]北京农业大学植物营养系,北京100094

出　　处：《北京农业大学学报》1993年第4期42-47,共6页

摘　　要：对几种目前较为常用的土壤有效氮测试法进行优选和改进,提出适用于旱地土壤的 NaHCO_3分级指数法。用连续矿化-栽培春小麦微钵试验进行相关研究的结果表明,0.05 mol·L^(-1)NaHCO_3-硝态氮(N_(NO_3))和-有机氮(N_(org))的二组分测定值与5期作物总吸氮量间的二元回归相关系数达0.883(n=19)。综合评价,该法优于其他所试各法,可作为评估旱地土壤供氮水平的快速常规方法,能正确地反映土壤有效氮的强度和容量因子。Estimating the status of available N in soils is important for N fertilization recommenda- tion.Organic N in aerated soils which can be mineralized during the plant growing period is also the pool available to corps besides mineral N(NO_3^- -N).This paper deals with establishment of a routine method for determining available N-fractional indexes of soils obtained by a single extractant.According to the results of correlation analysis,0.05 tool·L^(-1)NaHCO_3 extraction method is better than 0.01 mol·L^(-1)CaCl_2 ex- traction method and other methods;and the combined index of NaHCO_3-N_(No_3)and -N_(org)(nitrate N and or- ganic N)is also better than NaHCO_3-N_T(total N)single index.The multiple correlation between the com- bined index of NaHCO_3-N and the total N-uptake by spring wheat of 5 crops harvest(y)is highly signifi- cant,y=58.6+0.23N_(NO_3)+1.45No_(org),r=0. 883(n=19).Hence we willing propose the combined fractional index of 0.05 mol·L~_(-1)NaHCO_3-N as a reliable index of N availability for aerated soils.

关 键 词：土壤有效氮 分析 旱地 

分 类 号：S153.61[农业科学—土壤学]