Previous studies have defined compaction as an important degradation process of agricultural soils. However, there is very little information (under field conditions) on the effects of tractor and grain chaser traffic during harvest operations on soil cropped for 15 years under no‐till cultivation methods. The aim of this study was to quantify the effects of two different total loads of tractor and grain chaser traffic on soil physical properties and sunflower (Helianthus annuus L.) yields. The treatments included a control plot with no tractor or grain chaser traffic (T1), a plot with tractor and grain chaser traffic with a total load of 275.8 kN (94.35 kN km⁻¹ ha⁻¹; T2), and a plot with tractor and grain chaser traffic with a load of 332.2 kN (123 kN km⁻¹ ha⁻¹; T3). Soil physical properties and sunflower yields were analysed over three growing seasons in the western part of the Pampa region, Argentina. In the topsoil (0 to 200 mm), the results showed that after one pass of T2 and T3, infiltration decreased significantly compared with that in T1; a similar trend was observed for total topsoil porosity. Cone index values in T3 were >2.5 MPa and between 3.33 and 4.90 MPa in the subsoil (200 to 600 mm). Dry bulk density values in T3 were >1.70 Mg m⁻³ in the topsoil and in the subsoil. This study also demonstrated that as the wheel load and ground contact pressure increase, sunflower yields decrease and subsoil compaction increases, even in soils with a high bearing capacity.

中文翻译：

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向日葵（Helianthus annuus L.）收获：拖拉机和谷物追逐者交通对土壤压实和农作物产量的影响

先前的研究已将压实定义为农业土壤的重要降解过程。但是，在田间条件下，对于在免耕法下耕种了15年的土壤，在收割过程中拖拉机和谷物追逐者交通的影响所知甚少。这项研究的目的是量化两种不同的拖拉机和谷物运输车的总负荷对土壤物理性质和向日葵（向日葵）产量的影响。处理包括：没有拖拉机或谷物追踪器流量的对照地块（T1），总负载为275.8 kN（94.35 kN km ^-1  ha ^-1； T2）的带有拖拉机和谷物追踪器流量的地块，以及带有拖拉机的地块负荷为332.2 kN（123 kN km^-1 公顷^-1 ; T3）。分析了阿根廷潘帕地区西部三个生长季节的土壤物理性质和向日葵产量。结果表明，在表土（0〜200mm）中，T2和T3经过1次后，入渗量明显低于T1。表层土壤总孔隙度也有类似的趋势。T3中的锥度指数值> 2.5 MPa，并且在底土（200至600 mm）中介于3.33和4.90 MPa之间。在T3中，表层土壤和下层土壤的干容重值> 1.70 Mg m ^-3。这项研究还表明，即使在具有高承载力的土壤中，随着车轮载荷和地面接触压力的增加，向日葵的产量也会下降，地下土壤的压实度也会增加。