The depletion rate of phosphate in the soil-root interface zone increased along with growth and phosphateuptake of wheat or maize, which indicated that the phosphate distribution in soil near the root surfaceagreed we...The depletion rate of phosphate in the soil-root interface zone increased along with growth and phosphateuptake of wheat or maize, which indicated that the phosphate distribution in soil near the root surfaceagreed well with the phosphate movement in rhizosphere and phosphate uptake by plant. The relativeaccumulation zone of phosphate within 0.5 mm apart from the root surface developed at the 15th day or soafter cultivating wheat or maize since the root phosphate secretion increased gradually in this stage. Thephosphate distribution in the soil-root interface zone against the growing time (t) and the distance from theroot plane (x) could be described by the non-linear regression equation with the third powers of x and t.展开更多
The experiments were conducted in the artificial climate laboratory using ￣(32)P labelled soil and soil-rootplane system to investigate phosphate distribution and its movement in the soil-root interface zone andtheir...The experiments were conducted in the artificial climate laboratory using ￣(32)P labelled soil and soil-rootplane system to investigate phosphate distribution and its movement in the soil-root interface zone andtheir relations with phosphate uptake by plant as well as transpiration rate (atmosphere humidity). It wasfound that although the phosphate in the soilroot interface zone was of depletive distribution as a functionC/Co = ax￣b(C/Co is the relative content of fertilizer phosphate in a distance from the root surface x, aand b are the regression constants), and a relative accumulation zone of phosphate within 0.5 mm near theroot surface was often observed especially in the heavier texture soils because of root phosphate secretion.The depletion intensity of phosphate in the soil-root interface zone was in agreement with the phosphateuptake by plants under two humidities very well. However, the effects of air humidity on characteristics ofthe phosphate distribution near wheat or maize root surface were different. Wheat grew better under loweratmosphere humidity while maize, under higher humidity, which caused a more intensive uptake and thusa stronger depletion of phosphate in the rhizosphere. Moreover, the depletion intensity was greater by thebottom or the middle part of wheat roots and by the top or the middle part of maize roots. The depletivedistribution of phosphate in the rhizosphere soil and the relative contribution of phosphate diffusion to plant,which was more than 98% in the cultural experiments, indicated that diffusion was a major process forphosphorus supply to plants.展开更多
文摘The depletion rate of phosphate in the soil-root interface zone increased along with growth and phosphateuptake of wheat or maize, which indicated that the phosphate distribution in soil near the root surfaceagreed well with the phosphate movement in rhizosphere and phosphate uptake by plant. The relativeaccumulation zone of phosphate within 0.5 mm apart from the root surface developed at the 15th day or soafter cultivating wheat or maize since the root phosphate secretion increased gradually in this stage. Thephosphate distribution in the soil-root interface zone against the growing time (t) and the distance from theroot plane (x) could be described by the non-linear regression equation with the third powers of x and t.
文摘The experiments were conducted in the artificial climate laboratory using ￣(32)P labelled soil and soil-rootplane system to investigate phosphate distribution and its movement in the soil-root interface zone andtheir relations with phosphate uptake by plant as well as transpiration rate (atmosphere humidity). It wasfound that although the phosphate in the soilroot interface zone was of depletive distribution as a functionC/Co = ax￣b(C/Co is the relative content of fertilizer phosphate in a distance from the root surface x, aand b are the regression constants), and a relative accumulation zone of phosphate within 0.5 mm near theroot surface was often observed especially in the heavier texture soils because of root phosphate secretion.The depletion intensity of phosphate in the soil-root interface zone was in agreement with the phosphateuptake by plants under two humidities very well. However, the effects of air humidity on characteristics ofthe phosphate distribution near wheat or maize root surface were different. Wheat grew better under loweratmosphere humidity while maize, under higher humidity, which caused a more intensive uptake and thusa stronger depletion of phosphate in the rhizosphere. Moreover, the depletion intensity was greater by thebottom or the middle part of wheat roots and by the top or the middle part of maize roots. The depletivedistribution of phosphate in the rhizosphere soil and the relative contribution of phosphate diffusion to plant,which was more than 98% in the cultural experiments, indicated that diffusion was a major process forphosphorus supply to plants.
