内蒙古砒砂岩不同类型区土壤水分、养分特征研究

目的]探究砒砂岩不同类型区及不同土地利用方式对土壤水分、有机碳和全氮含量的影响，对于砒砂岩区进一步发展具有重要指导作用。方法]以内蒙古准格尔旗砒砂岩覆土区的13年生沙棘林地、6年生沙棘林地、天然草地及砒砂岩裸露区草地和砒砂岩覆沙区的天然草地、柠条林地、农地、退耕5年地共8个样地为研究对象，通过测定0—100 cm深度不同土层土壤含水量、有机碳和全氮含量，研究和比较了不同土层土壤水分、有机碳和全氮含量与变化规律。结果](1)覆土区(13年生沙棘林地152.36 mm、6年生沙棘林地165.16 mm、天然草地160.97 mm)0—100 cm土层土壤储水量均高于覆沙区(天然草地73.03 mm、柠条林地66.56 mm、农地79.70 mm、退耕5年地107.03 mm)。(2)裸露区草地土壤有机碳含量均低于覆土区和覆沙区，0—100 cm土壤有机碳储量(1.97 kg/m²)分别比覆土区天然草地、6年生沙棘林地、13年生沙棘林地和覆沙区天然草地、柠条林地、农地、退耕5年地分别低了2.24 kg/m²,2.36 kg/m²

Characteristics of Soil Water and Nutrients in Different Types Area of Pisha Sandstone in Inner Mongolia

Objective] Exploring the effects of different types of Pisha Sandstone and different land use patterns on soil water, organic carbon and total nitrogen content plays an important guiding role in the further development of Pisha Sandstone area. Methods] 13-year-old Seabuckthorn(Hippophae rhamnoides)woodland, 6-year-old Seabuckthorn woodland, natural grassland in the soil-covered Pisha Sandstone area of Jungar banner of Inner Mongolia, natural grassland in the exposed Pisha Sandstone area, and natural grassland, Caragana korshinskii woodland, farmland and 5-year-old abandoned farmland in the sand-covered Pisha Sandstone area, a total of eight sample plots were used as the research objects. By measuring the soil water content, organic carbon and total nitrogen content of different soil layer at a depth of 0—100 cm, the contents and variation of soil water, organic carbon and total nitrogen in different soil layers were studied and compared. Results](1)The soil water storage in 0—100 cm soil layer in the soil-covered Pisha Sandstone area(13-year-old Seabuckthorn woodland(152.36 mm), 6-year-old Seabuckthorn woodland(165.16 mm), natural grassland(160.97 mm))was higher than that of the sand-covered Pisha Sandstone area(natural grassland(73.03 mm)and Caragana korshinskii woodland(66.56)mm), farmland(79.70 mm), and 5-year-old abandoned farmland(107.03 mm)).(2)Soil organic carbon content of grassland in the exposed Pisha Sandstone area was lower than that in the soil-covered and sand-covered Pisha Sandstone area. Soil organic carbon storage in the 0—100 cm soil layer(1.97 kg/m²)was lower than that of the natural grassland, 6-year-old and 13-year-old Seabuckthorn woodland in the soil-covered Pisha Sandstone area, natural grassland, Caragana korshinskii woodland, farmland and 5-year-old abandoned farmland in the sand-covered Pisha Sandstone area by 2.24 kg/m², 2.36 kg/m², 1.74 kg/m², 1.23 kg/m², 0.66 kg/m², 2.58 kg/m² and 1.21 kg/m², respectively.(3)Compared with each type of Pisha Sandstone area, the total nitrogen storage of the grassland in the exposed Pisha Sandstone area was the lowest(0.18 kg/m²), which was lower than that of the natural grassland in the soil-covered Pisha Sandstone area and the natural grassland in the sand-covered Pisha Sandstone area by 0.22 kg/m². Conclusion] To sum up, the soil water storage, organic carbon and total nitrogen storage in the 0—100 cm soil layer of the 13-year-old Seabuckthorn woodland in the soil-covered Pisha Sandstone area and the Caragana korshinskii woodland in the sand-covered Pisha Sandstone area were all lower than those of the natural grassland in the same type of area. Caragana korshinskii and Seabuckthorn planting after a certain period of years, comprehensively considering the benefits of water conservation, it should be thinned to reduce the competition with understory herbss, thereby accelerating the natural succession of the understory vegetation and ensuring the sustainable development of the ecological environment in the Pisha Sandstone area.