平茬方式对宁夏荒漠草原人工柠条林土壤物理性质及持水能力的影响

Effects of stubble on soil physical properties and water holding capacity of artificial Caragana in Ningxia desert steppe

人工种植柠条是宁夏荒漠草原植被恢复的重要措施之一,平茬利用既是生态需求也是生产需求。设4种不同平茬方式即隔一带平茬一带(G1P1)、隔两带平茬两带(G2P2)、隔三带平茬三带(G3P3)和隔五带平茬五带(G5P5)的人工柠条林带为研究对象,对样带的土壤持水量、孔隙度、容重等指标进行测定。结果表明:(1)平茬处理的毛管持水量较WP不同程度提高,而非毛管持水量减少;0~200 cm土层中毛管持水量为G3P3>G5P5>G2P2>G1P1>WP;非毛管持水量WP最大,G3P3最小。(2)平茬处理能有效改善土壤物理结构,在0~20 cm土层下,G3P3的粉粒、G5P5的细砂粒较WP增多,G3P3处理下粗砂粒、极粗砂粒均增多;土壤总孔隙度和毛管孔隙度均表现为G3P3>G5P5>G1P1>G2P2>WP;非毛管孔隙度和土壤容重分别表现为G2P2>G5P5>WP>G1P1>G3P3、G1P1>WP>G2P2>G5P5>G3P3。(3)综合分析得出:G3P3处理条件下,土壤持水量增高,毛管孔隙度增大,非毛管孔隙度减小,持水能力和蓄水性能增强,粉粒增多,容重减小,因此G3P3是更适宜于宁夏荒漠草原饲用柠条的平茬方式。

Artificial Caragana planting is one of the important measures for vegetation restoration in the desert steppe,Ningxia,stubble utilization is both ecological and production demand.In this study,we measured the soil water holding capacity,porosity,bulk density and physical indicators in the sample belt of five different management practices of stubble spacing,such as stubble one belt with one belt no stubble(G1 P1),stubble two belts with two belts no stubble(G2 P2),stubble three belts with three belts no stubble(G3 P3),stubble five belts with five belts no stubble(G5 P5),and no stubble(WP).The results showed that:(1)The capillary water holding capacity of stubble was higher than that of WP,the non capillary water holding capacity of stubble decreased;the capillary water holding capacity of soil in the 0~200 cm decreased in the order:G3 P3>G5 P5>G2 P2>G1 P1>WP;the non capillary water holding capacity of WP was the largest and that of G3 P3 was the smallest.(2)Stubble treatment can effectively improve the physical structure of the soil.When compared with WP treatment,the silt of G3 P3 and the fine sand of G5 P5 in soil layer of 0~20 cm were higher,the coarse sand and extremely coarse sand of G3 P3 were higher in each soil layer;the the total porosity and capillary porosity of the soil were as follows:G3 P3>G5 P5>G1 P1>G2 P2>WP;the non capillary porosity and soil bulk density were as follows,respectively:G2 P2>G5 P5>WP>G1 P1>G3 P3,G1 P1>WP>G2 P2>G5 P5>G3 P3.In conclusion,G3 P3 treatment can enhanced the soil water holding capacity and capillary porosity,reduced the non capillary porosity and bulk density.Therefore,G3 P3 was more suitable for the stubble of forage Caragana in desert steppe of Ningxia.