Long-term soil tillage trials can provide important knowledge about sustainable changes in soil physical quality and crop yield. This study evaluated soil physical quality indicators under different long-term tillage systems and examined the relationships between quality indicators and crop yield. The study was carried out on a Rhodic Ferralsol with three tillage systems established in 1989: conventional tillage (CT), strategic tillage (ST), and no-tillage (NT). All treatments had long-term crop rotation. The soil parameters evaluated were total organic carbon (TOC), bulk density (ρ_s), macro and microporosity (Mac and Mic), relative gas diffusivity (D/D₀), pore tortuosity (τ), relative field capacity (RFC), structural stability index (SSI), least-limiting water range (LLWR), and degree of compactness (DC, taking as reference the soil bulk density in which LLWR = 0). Soybean and maize yields in two consecutive summer seasons were measured. Conventional and strategic tillage provided higher ρ_s in the 0.15–0.30 m layer depth, leading to higher DC in CT. Using soil bulk density at LLWR = 0 as reference proved useful to assess soil DC and plant response. No-tillage provided lower DC in the 0–0.15 m (86 %) and 0.15–0.30 m (78 %) layers than CT (91 % and 94 %, respectively). The maize yield had a negative linear relationship to DC, with the lower values at DC > 87 %. All tillage systems affected D/D₀, even at similar porosity values. The better soil physical quality under NT provided 1211 kg ha⁻¹ higher maize yield compared with CT. The differences in soybean yield between treatments were not significant, but NT provided 381 kg ha⁻¹ more than CT. These findings indicate that NT is the best system studied. Our results strongly suggest that ST does not improve physical properties of soils under NT with crop rotation, and that a diversified crop rotation in NT was efficient to avoid soil physical degradation.

长期的土壤耕作试验可以提供有关土壤物理质量和作物产量可持续变化的重要知识。这项研究评估了不同长期耕作制度下的土壤物理质量指标，并研究了质量指标与作物产量之间的关系。这项研究是在Rhodic Ferralsol于1989年建立的三种耕作系统上进行的：常规耕作（CT），战略耕作（ST）和免耕（NT）。所有处理均长期轮作。评价的土壤参数为有机碳总量（TOC），堆积密度（ρ_小号），宏观和微孔（Mac和麦克风），相对气体扩散（d / d ₀），孔隙曲度（τ），相对场容量（RFC），结构稳定性指数（SSI），最小极限水域（LLWR）和压实度（DC，以LLWR = 0的土壤容重为参考） ）。测量了连续两个夏季的大豆和玉米单产。常规和战略耕作提供更高ρ_小号在0.15-0.30米层的深度，从而导致更高的DC在CT。以LLWR = 0时的土壤容重作为参考被证明有助于评估土壤DC和植物响应。免耕提供的0-0.15 m（86％）和0.15-0.30 m（78％）层的DC低于CT（分别为91％和94％）。玉米产量与DC呈负线性关系，在DC> 87％时较低。所有耕作系统都受影响D / D ₀，即使在相似的孔隙率值下也是如此。与CT相比，在NT下更好的土壤物理质量使玉米产量提高了1211 kg ha ^-1。不同处理之间的大豆产量差异不显着，但NT比CT提供381 kg ha ^-1。这些发现表明，NT是研究的最佳系统。我们的结果强烈表明，ST不能随着作物轮作而改善NT下土壤的物理特性，并且在NT中多样化的作物轮作能够有效避免土壤物理退化。