With world population growth arable land area is decreasing. Saline soil is an important naturalresource. However it has not been well reclaimed owing to adverse conditions. Forestation is one way of saltysoil utiliza...With world population growth arable land area is decreasing. Saline soil is an important naturalresource. However it has not been well reclaimed owing to adverse conditions. Forestation is one way of saltysoil utilization; on the other hand, it can improve soil quality as well. The mechanism of salinity tolerance isthe basis for tree species selection when planting in salt affected soil. Different plants have various way ofsalinity tolerance, some are salt-exclusion, e.g. Elaeagnus angustifolia; some are salt-secretion, e.g. Tamarixspp.; some are salt-dilution, e.g. Hordeum vulgare; some are salt-avoidance, e.g. Rhizophora apiculata. Treesare favorable, which are salt tolerant and drought or waterlogging tolerant, as well as grow fast. After treespecies have been decided, site preparation including change or exchange of soil is necessary. Meanwhilesuitable density of trees and planting time must be carefully considered in terms of soil conditions andclimatic characteristics. Now a large scale of forests has been established in salt-affected soil in China by themeans discussed in the paper, and protect forest system along coast plays important roles in socio-economicsustainable development and improvement of eco-environment.展开更多
In this research, five Nitraria sibirica provenances such as Dayilu were selected to do experiment of salt-resistance, combining fixed plots test with typical plot investigation, measuring survival rate and growth as ...In this research, five Nitraria sibirica provenances such as Dayilu were selected to do experiment of salt-resistance, combining fixed plots test with typical plot investigation, measuring survival rate and growth as main indicators. The experiments of main cultural technology were done on Nitraria sibirica in 4 types of site preparation, 3 types of planting, 3 designs for planting density. The Nitraria sibirica experiments for the effects of curbing salt and improving soil were done by testing soil nutrients, salt content, soil physical properties as focal points in typical site of 3-4 years woods. The experiment results showed that the Nitraria sibirica could survive well with soil salt content of 0.6%, and that survival rate declined distinctively as soil salt content exceeded 0.8%. However, high soil salt content did not influence growth in the year of planting. There were obvious differences in salt-tolerance among Nitraria sibirica provenances; Dayilu was the best on salt-tolerance, the other 4 provenances had no differences, and obviously inferior to Dayilu. The different types of site preparation clearly influenced planting survival rate, conserving rate and growth. The method of two-ploughing-two-harrowing was the best among all 4 types of site preparation. Seed forestation was largely limited, bared-rooted seedling forestation may be popularised when soil salt content was less than 1% and soil moisture content was better in spring. Forestation with container seedling was suited to coastal saline soil in rainy season. The optimum planting density of Nitraria sibirica was 2 505/ha in the Yellow River Delta area in view of coverage rate, yield of fruits and cost of planting. Generally speaking,Nitraria sibirica could effectively refrain soil from accumulation of salt in the surface soil, decrease salt content and increase soil nutrient, and heighten soil capillary pore rate.展开更多
文摘With world population growth arable land area is decreasing. Saline soil is an important naturalresource. However it has not been well reclaimed owing to adverse conditions. Forestation is one way of saltysoil utilization; on the other hand, it can improve soil quality as well. The mechanism of salinity tolerance isthe basis for tree species selection when planting in salt affected soil. Different plants have various way ofsalinity tolerance, some are salt-exclusion, e.g. Elaeagnus angustifolia; some are salt-secretion, e.g. Tamarixspp.; some are salt-dilution, e.g. Hordeum vulgare; some are salt-avoidance, e.g. Rhizophora apiculata. Treesare favorable, which are salt tolerant and drought or waterlogging tolerant, as well as grow fast. After treespecies have been decided, site preparation including change or exchange of soil is necessary. Meanwhilesuitable density of trees and planting time must be carefully considered in terms of soil conditions andclimatic characteristics. Now a large scale of forests has been established in salt-affected soil in China by themeans discussed in the paper, and protect forest system along coast plays important roles in socio-economicsustainable development and improvement of eco-environment.
文摘In this research, five Nitraria sibirica provenances such as Dayilu were selected to do experiment of salt-resistance, combining fixed plots test with typical plot investigation, measuring survival rate and growth as main indicators. The experiments of main cultural technology were done on Nitraria sibirica in 4 types of site preparation, 3 types of planting, 3 designs for planting density. The Nitraria sibirica experiments for the effects of curbing salt and improving soil were done by testing soil nutrients, salt content, soil physical properties as focal points in typical site of 3-4 years woods. The experiment results showed that the Nitraria sibirica could survive well with soil salt content of 0.6%, and that survival rate declined distinctively as soil salt content exceeded 0.8%. However, high soil salt content did not influence growth in the year of planting. There were obvious differences in salt-tolerance among Nitraria sibirica provenances; Dayilu was the best on salt-tolerance, the other 4 provenances had no differences, and obviously inferior to Dayilu. The different types of site preparation clearly influenced planting survival rate, conserving rate and growth. The method of two-ploughing-two-harrowing was the best among all 4 types of site preparation. Seed forestation was largely limited, bared-rooted seedling forestation may be popularised when soil salt content was less than 1% and soil moisture content was better in spring. Forestation with container seedling was suited to coastal saline soil in rainy season. The optimum planting density of Nitraria sibirica was 2 505/ha in the Yellow River Delta area in view of coverage rate, yield of fruits and cost of planting. Generally speaking,Nitraria sibirica could effectively refrain soil from accumulation of salt in the surface soil, decrease salt content and increase soil nutrient, and heighten soil capillary pore rate.
