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作 者 ：王群;李潮海;郝四平;张永恩;韩锦峰

期 刊 ：应用生态学报 2008年 19卷 04期 页码：787-793

关键词：玉米；

摘 要 ：在耕层（0～20 cm）土壤容重不变情况下，采用池栽方法研究了下层（20～40 cm，40～60 cm）土壤容重变化对玉米生育后期光合特性和产量的影响.结果表明：当下层土壤容重不同时，玉米的光合速率（P_n）和产量都存在显著差异，随着下层土壤容重的增加，叶片P_n和产量降低，下层土壤容重越大，降幅越大.不同处理玉米叶片的P_n和细胞间隙CO₂浓度（C_i）的变化趋势不同，P_n早晨和傍晚较低，中午较高，且随着下层土壤容重的增加而降低, C_i的变化趋势则相反.气孔限制值（L_s）和气孔导度（G_s）也随着下层土壤容重的增加而降低. 随着玉米生育进程，P_n、L_s和G_s不断下降，而C_i不断升高.

Abstract:A pool-culture experiment was conducted to study the effects of different subsoil bulk density at the depths of 20-40 and 40-60 cm on the late growth stage photosynthetic characteristics and grain yield of maize. The results showed that there existed significant differences in the net photosynthetic rate (P_n) and grain yield when the subsoil bulk density was differed. The P_n and grain yield decreased with increasing subsoil bulk density, and the higher the bulk density, the more significant the decrement inP_n and grain yield. The diurnal changes of P_n and intercellular CO₂ concentration (C_i) were not in the same trend. P_n was high at noon and low at twilight and dusk, and decreased with increasing subsoil bulk density; while C_i was in adverse. The stomatal limitation (L_s) and stomatal conductance (G_s) also decreased with increasing subsoil bulk density. With the development of maize, the P_n,L_s and G_s decreased gradually, while C_i increased continuously.

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