ABSTRACT Experiments were conducted to evaluate the impact of 36 years of no-tillage (NT), compared to conventional-tillage (CT), on soil physical properties in a continuous grain sorghum experiment. Results revealed that long-term tillage treatments had minimal impact on bulk density (BD), total porosity (TP), air-filled porosity (AFP), water-filled pore space (WFPS), and volumetric water content (Θv). However, water-holding capacity (WHC) was 26% greater in NT, compared to CT. Irrespective of the tillage system, soil physical properties differed across soil depth. The BD was greater at the 0 to 5, and 10 to 20 cm soil depths, compared to the 5 to 10 cm depth; further, BD was positively correlated with Θv (r = 0.47) and WFPS (r = 0.49). However, the TP and AFP values were greater (52.4% and 52.2%, respectively) at the 5 to 10 cm depth. Penetration resistance (MI) was maximum (≥ 48.11 J cm–1) at the greatest depth tested (60 cm) in both tillage systems. Overall, results indicated that NT had a positive impact on WHC. High WHC associated with long-term NT systems is expected to increase available soil water content, thereby improve productivity, especially under limited moisture environments.

中文翻译：

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德克萨斯州东南部粮食高粱试验中长期（36 年）耕作方式对土壤物理性质的影响

摘要 进行了实验以评估与常规耕作 (CT) 相比，36 年免耕 (NT) 对连续谷物高粱试验中土壤物理性质的影响。结果表明，长期耕作处理对堆积密度 (BD)、总孔隙率 (TP)、充气孔隙率 (AFP)、充水孔隙空间 (WFPS) 和体积含水量 (Θv) 的影响最小。然而，与 CT 相比，NT 的持水能力 (WHC) 高 26%。不考虑耕作系统，土壤物理性质因土壤深度而异。BD 在 0 到 5 和 10 到 20 厘米的土壤深度比 5 到 10 厘米深度更大；此外，BD 与 Θv (r = 0.47) 和 WFPS (r = 0.49) 呈正相关。然而，TP 和 AFP 值在 5 至 10 厘米深度更大（分别为 52.4% 和 52.2%）。在两种耕作系统中测试的最大深度 (60 cm) 处，穿透阻力 (MI) 最大 (≥ 48.11 J cm–1)。总体而言，结果表明 NT 对 WHC 产生了积极影响。与长期 NT 系统相关的高 WHC 预计会增加可用土壤含水量，从而提高生产力，尤其是在水分有限的环境下。