【摘要】 通过田间试验研究了旋耕(RT)、深松(SS)、免耕(NT)3种耕作方式对南方旱地红壤物理特性的影响。试验采用随机区组设计,每处理重复三次,旋耕深度为20cm,深松深度为40cm。结果表明:与免耕相比,旋耕和深松降低了土壤密度和硬度,增加了土壤孔隙度。旋耕主要减少了5~10mm风干土的团聚体数量,从而降低了大团聚体的稳定性,对土壤扰动较大。深松处理在0.25~5mm粒径范围内团聚体含量最大,土壤团聚性好。不同耕作方式下土壤含水量由高到低的顺序为:免耕>深松>旋耕。深松处理可显著改善深层土壤结构,进而提高耕层土壤贮水潜力。随着土层加深,各处理土壤密度和硬度增大,孔隙度减小。收获后各处理土壤密度较播种前有不同程度的增加,孔隙度有所减小,经过一个生育期,各处理间差异呈减小趋势。结合该地区的土壤和生产条件,建议采用深松处理。更多还原

【Abstract】 The field experiment was conducted to study the effects of rotary tillage(RT),subsoiling(SS)and no-tillage(NT)on the physical characteristics of red soil of upland in southern China.The effects of tillage methods were studied in a randomized complete block design with three replications.The depth of rotary tillage was 20 cm and the depth of subsoiling was 40 cm.The results showed that RT and SS reduced the soil bulk density and penetration resistance,increased soil porosity,RT mainly reduced the content of 5~10 mm dry soil aggregate,thereby the stability of large aggregates was poor and the soil disturbance was larger;SS resulted in the highest content of 0.25~5 mm aggregates and the good soil agglomeration structure;soil moisture contents decreased in the order:NT>SS>RT;SS significantly improved the deep soil structure,and then improved the soil water storage capacity.The soil bulk density and penetration resistance increased,whilst the porosity decreased with the increase of soil depths.The soil bulk density of each treatment increased,and the porosity decreased after harvest compared with before sowing,the difference among treatments decreased after the growth period.With respect to the soil and production conditions in the study area,SS is considered to be the best way to improve soil physical characteristics.更多还原