干旱季节不同耕作制度下红壤-作物-大气连续体水流阻力变化规律  

VARIATION OF HYDRAULIC RESISTANCES IN RED SOIL-ROP-IR CONTINUUMS IN DIFFERENT FARMING SYSTEMS IN DRY SEASON

作　　者：张斌[1] 丁献文 张桃林[1] 赵其国[1] 

机构地区：[1]中国科学院南京土壤研究所,南京210008 [2]江西省鹰潭市土地局

出　　处：《土壤学报》2001年第1期17-24,共8页Acta Pedologica Sinica

基　　金：国家自然科学基金项目!(49701008);中科院重大项目!(KT95-04-01-15);国家攻关项目!(96-004-03

摘　　要：确定水流阻力不仅有助于定量土壤栕魑飽大气连续体（SPAC）描述的水分传输过程，而且对建立减少水流阻力的节水农业措施，解决红壤区季节性干旱有重要意义。本文研究了不同耕作制度下作物气孔阻力日变化及其与蒸腾速率、土壤基质势、作物叶水势的关系，并分析了水流阻力的分布及其日变化规律。结果表明气孔阻力和蒸腾速率受作物种类和耕作制度影响，气孔阻力随着70cm土层以上土壤基质势的变化而变化；SPAC中叶气系统水流阻力为109～1010S，是作物体水流阻力的1000倍，而后者又是70cm以上土层土壤水流阻力的100倍；作物体水流阻力大小顺序为：大豆＞花生＞玉米＞甘薯，除甘薯外，其它作物体水流阻力有明显的日变化；此外，耕作制度也影响作物体水流阻力。Estimation of hydraulic resistances of soil-lant-limate continuum (SPAC) is important both for describing water movement in the continuum and for adopting practical water-aving measures in agriculture to find the solutions to seasonal drought in the area of Red Soil of China. The diurnal variation of stomatal resistance of crops in dry season was observed and its relation to transpiration rate and water potentials of crop leaf and soil in different farming systems was also studied. Results indicated that stomatal resistance and transpiration rate were different for each crop in different farming systems. Stomatal resistance was related to soil water potentials within the soil layers of 70cm. The hydraulic resistances of the leaf朼ir interface in SPACs ranged from 109 to 1010 S, which was 1000 times higher than those of crop body. The resistance of crop body was 100 times as much as that within the soil layer of 70cm. In dry season, soil resistance increased with the depletion of soil water.Resistance of crop body fell in the order: soybean＞peanut＞corn＞sweet potato, which experienced dramatically diurnal variation except that of sweet potato. Resistance of crop also varied with cropping systems.

关 键 词：水流阻力 气孔阻力 水势 红壤 耕作制度 干旱季节 作物 

分 类 号：S152.75[农业科学—土壤学]