不同水土保持措施对红壤坡耕地土壤物理性质的影响

【目的】针对红壤坡耕地土壤结构差、水土流失严重等问题,研究不同水土保持措施对土壤容重、孔隙度等土壤物理性质的影响,为实现红壤坡耕地的持续、高效利用提供参考。【方法】以等高花生常规耕作为对照(CK),探析表施聚丙烯酰胺(PAM)、香根草篱和PAM+香根草篱等3种水土保持措施对土壤容重、孔隙度、持水量的影响,综合评价不同措施对土壤物理性质的改良效果。【结果】不同水土保持措施处理下0~20 cm土层土壤容重差异显著(P0.05),3种水土保持措施主要对红壤坡耕地0~20 cm土壤容重改善效果明显;不同处理下0~40 cm土层土壤孔隙度和持水量差异不显著(P0.05),不同水土保持措施对0~10 cm土层土壤孔隙度和持水量的提升效果较好。土壤容重与其他土壤物理指标呈负相关,且作为主成分评价不同水土保持措施对土壤物理性质的改良效果的贡献率较高(76.517%)。【结论】土壤容重是评价不同水土保持措施对土壤物理性质改良效果的重要因子,影响着土壤孔隙度和持水量等物理性质;不同水土保持措施对0~10 cm土层土壤物理性质的综合改良效果较好,且以表施PAM+香根草篱效果最佳,是值得推广应用的红壤坡耕地水土保持措施。

Effects of different soil and water conservation measures on soil physical properties in red soil slope field

Objective]In order to realize efficient and sustainable utilization of red soil slope field , effects of different soil and water conservation measures on soil physical properties were studied in view of the poor soil structure and soil erosion in red soil slope field. Method]Taking ordinary peanut fields at equal altitude as control, effects of three soil and water conservation measures, polyacrylamide (PAM), hedgerows of Vetiveria zizanioides and PAM+V. zizanioides, on soil bulk density, porosity and water holding capacity were studied. Effects of different measures on soil physical properties were evaluated comprehensively. Result]Soil bulk density at 0-20 cm soil layer showed significant difference under dif-ferent treatments(P<0.05), improvement effects of three soil and water conservation measures on soil bulk density in 0-20 cm soil layer was obvious. There was no significant difference in soil porosity and water holding capacity in soil layer of 0-40 cm under different treatments(P>0.05). Different soil and water conservation measures posed sound effects on soil porosity and water holding capacity in 0-10 cm soil layer. Soil bulk density was negatively correlated with other physical properties , and made a high contribution rate ( 76 . 517%) in evaluating different soil and water conservation mea sures ’ effects on soil physical properties as a principal component. Conclusion]Soil bulk density is an important factor to eval-uate improvement effects of different soil and water conservation measures on soil physical properties. It affects soil physi-cal properties such as porosity and water holding capacity. The comprehensive improvement effect of soil physical proper-ties is better in 0-10 cm soil layer under different soil and water conservation measures compared with that in other layers. The most effective treatment is PAM+V. zizanioides, which can be recommended as a soil and water conservation measure in red soil slope field.