Water movement into and out of roots depends on the water potential difference between the bulk soiland the root xylem and the total hydraulic conductance of the pathway, which can be divided into three parts,i.e. soi...Water movement into and out of roots depends on the water potential difference between the bulk soiland the root xylem and the total hydraulic conductance of the pathway, which can be divided into three parts,i.e. soil conductance, soil-root conductance and root conductance. The vaues and relative importance varywith soil water content. The general rule is that water uptake by roots is mainly limited by radial hydraulicconductance of roots in wet soils, the soil-root interfaCe becomes a major limiting factor to water uptake inmoderately dry soils, and the water uptake is limited by the rapidly decreasing soil hydraulic conductance inseriously dry soils. Meanwhile these limiting factors vary with crop variety, and these variations can be usedto evaluate the drought-resistance and water use efficiency of crops.展开更多
文摘Water movement into and out of roots depends on the water potential difference between the bulk soiland the root xylem and the total hydraulic conductance of the pathway, which can be divided into three parts,i.e. soil conductance, soil-root conductance and root conductance. The vaues and relative importance varywith soil water content. The general rule is that water uptake by roots is mainly limited by radial hydraulicconductance of roots in wet soils, the soil-root interfaCe becomes a major limiting factor to water uptake inmoderately dry soils, and the water uptake is limited by the rapidly decreasing soil hydraulic conductance inseriously dry soils. Meanwhile these limiting factors vary with crop variety, and these variations can be usedto evaluate the drought-resistance and water use efficiency of crops.
