Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth...Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth process table. The Chapman-Richards equation is the best model used as the guide curve to form the site index table for dahurian larch plantations.展开更多
In order to utilize the wasted saline-sodic soils under shallow groundwater condition, a 3-year field study was carried in a field cropped with Lycium barbarum L. and irrigated by drip irrigation with saline groundwat...In order to utilize the wasted saline-sodic soils under shallow groundwater condition, a 3-year field study was carried in a field cropped with Lycium barbarum L. and irrigated by drip irrigation with saline groundwater under the water table depth of 30-40 cm in the northern Yinchuan Plain, China. Effects of cropping duration （one, two, and three years） on soil salinity, soil solution composition, and pH in three adjacent plots were investigated in 2008. Results showed that a high irrigation frequency maintained high soil water potential and subsequently facilitated infiltration and downward movement of water and salt in the crop root zone. Salt accumulated on the edges of the ridges, and soil saturated-paste electrical conductivity （ECe） was higher in the edge. Concentrations of Na^＋, Ca^2＋, Mg^2＋, Cl^-, and SO24^- in the soil increased with the soil depth as did the ECe, while HCO3 and pH had a relative uniform distribution in soil profile. As planting year increased, the ECe and soil salts in the field had a decreasing tendency, while in the root zone they decreased immediately after irrigation and then remained relatively stable in the following growing seasons. HCO3 and pH had little change with the planting year. Results suggested that the application of drip irrigation with saline water could ameliorate saline-sodic soil and provide a relatively feasible soil environment for saline-sodic soils with shallow groundwater.展开更多
文摘Several growth models were selected to fit data of dahurian larch plantations using nonlinear regression analysis. The best models were used to construct the site index table' the 2-way volume table and the growth process table. The Chapman-Richards equation is the best model used as the guide curve to form the site index table for dahurian larch plantations.
基金Supported by the Chinese Academy of Sciences Action Plan for the Development of Western China (No. KZCX2-XB2-13)the Chinese Academy of Sciences Knowledge Innovation Program (No. KSCX2-YW-N-003)the 100 Talents Program of Chinese Academy of Sciences
文摘In order to utilize the wasted saline-sodic soils under shallow groundwater condition, a 3-year field study was carried in a field cropped with Lycium barbarum L. and irrigated by drip irrigation with saline groundwater under the water table depth of 30-40 cm in the northern Yinchuan Plain, China. Effects of cropping duration （one, two, and three years） on soil salinity, soil solution composition, and pH in three adjacent plots were investigated in 2008. Results showed that a high irrigation frequency maintained high soil water potential and subsequently facilitated infiltration and downward movement of water and salt in the crop root zone. Salt accumulated on the edges of the ridges, and soil saturated-paste electrical conductivity （ECe） was higher in the edge. Concentrations of Na^＋, Ca^2＋, Mg^2＋, Cl^-, and SO24^- in the soil increased with the soil depth as did the ECe, while HCO3 and pH had a relative uniform distribution in soil profile. As planting year increased, the ECe and soil salts in the field had a decreasing tendency, while in the root zone they decreased immediately after irrigation and then remained relatively stable in the following growing seasons. HCO3 and pH had little change with the planting year. Results suggested that the application of drip irrigation with saline water could ameliorate saline-sodic soil and provide a relatively feasible soil environment for saline-sodic soils with shallow groundwater.
