玉米//马铃薯间作根系特征及其与土壤水稳性团聚体关系

Root System Characteristics and Their Relationships with Soil Water-Stable Aggregates under Maize and Potato Intercropping Mode

农作物根系可以固结土壤,提高土壤团聚体的稳定性,测定农作物根系对土壤水稳性团聚体的影响,可以从侧面评价不同种植模式的水土保持作用。本试验以玉米、马铃薯为试验作物,研究不同种植模式下农作物的根系特征和土壤水稳性团聚体的组成及稳定性。结果表明:3种种植模式下5个处理(MP:玉米间作;PM:马铃薯间作;MM:玉米单作;PP:马铃薯单作;CK:裸地)的土壤水稳性团聚体含量都以0. 5~0. 25 mm粒级为主,> 0. 25 mm粒级的水稳性团聚体中MP处理含量最高;MP处理的团聚体破坏率最小,0~10 cm土层中,MP、PM处理较CK的团聚体破坏率减少35. 70%、25. 54%;5个处理中,MP、PM处理的土壤团聚体平均重量直径都大于其它3个处理,MP处理最大,CK最小;MP处理的分形维数最小,CK的分形维数最大。相同土层内,PM处理的玉米含根量、根长、根尖数、根表面积、根体积都高于MM处理;PM处理的马铃薯含根量、根长、根尖数、根表面积、根体积也都高于PP处理。MP、PM、PP、MM处理的根系特征与> 0. 25 mm土壤水稳性团聚体、团聚体平均重量直径之间都呈正相关关系,与土壤水稳性团聚体破坏率和水稳性团聚体分形维数之间都呈负相关关系。说明农作物间作可以促进根系生长和土壤团粒结构的形成,有利于提高土壤抗蚀性。

The root system of crop can consolidate soil and improve the stability of soil aggregates.Therefore the soil and water conservation effects under different planting patterns can be laterally evaluated by determining the effect of crop root system on soil water-stable aggregates.In the study,maize and potato were used as experimental crops,and five treatments including maize intercropping mode(MP),potato intercropping mode(PM),maize monoculture mode(MM),potato monoculture mode(PP)and nudation mode(CK)were set.The root system characteristics of crops and the compositions and stability of soil water-stable aggregates were studied under different treatments.The results showed that the aggregates of 0.5~0.25 mm particle sizes were the main compositions of soil water-stable aggregates under different treatments,and the content of water-stable aggregates of>0.25 mm particle sizes was the highest in MP treatment.The destruction rate of aggregates was the minimum in MP treatment,and that of MP and PM treatments in 0~10-cm soil layer reduced by 35.70%and 25.54%respectively compared with CK.The mean weight diameter of soil aggregates in MP and PM treatments were larger than that of the other treatments,and that in MP treatment was the maximum while that in CK was the minimum.The fractal dimension of soil aggregates in MP treatment was the minimum white that of CK was the maximum.In the same soil layer,the root mass,root length,root tip number,root surface area and root volume of maize in PM treatment were all higher than those in MM treatment.Similarly,the root mass,root length,root tip number,root surface area and root volume of potato in PM treatment were all higher than those in PP treatment.In MP,PM,PP and MM treatments,the root system characteristics were positively correlated with the soil water-stable aggregates of>0.25 mm particle sizes and the mean weight diameter of soil aggregates,and negatively correlated with the destruction rate and fractal dimension of soil water-stable aggregates.The above results indicated that the intercropping planting pattern could promote root growth and the formation of soil aggregate structure,which was conducive to improving soil erosion resistance.