In southern Chile, there are over 1.3 million ha of pastures on volcanic ash soils. The climate change scenario and the need to increase yields are forcing farmers to increase irrigated surface areas. This implies an intensified soil use that must be analyzed to prevent soil degradation. Therefore, this study analyzed the impact of initial pasture defoliation (mowing and grazing) and short-term irrigation managements on soil structure dependent properties of a volcanic ash soil under different types of pastures. Field penetration resistance (PR) profiles (0–80 cm), soil water content measurements (0–10 cm) and undisturbed soil samples (0–3 cm) displayed the impact of animal trampling due to repeated loading events. Though this experiment did not determine significant interactions such as pasture x defoliation method x applied load, the early developmental stage of this experiment provided a basis for better understanding deformation processes due to animal trampling when different types of pastures are irrigated in the short-term. The plastic deformation caused by loads higher than precompression stress induced an increase in soil mechanical strength (e.g. Pc increased after the first grazing, but not after mowing), affecting the macropore volume and air permeability. The short-term effects (<2 years) showed the incipient consequences of grazing and irrigation: PR increased due to animal trampling (data dispersion: grazed> mowed plots, showing footprint formation after 8 grazing events) and the higher sum of PR in non-irrigated pastures evidenced the increase of the cohesion between particles/aggregates after drying events. Therefore, it can be expected that in the medium-term (3-4 years), animal trampling could lead to significant soil deformation and a progressive increase in soil mechanical strength near the soil surface.

在智利南部，火山灰土壤上有超过 130 万公顷的牧场。气候变化情景和提高产量的需要迫使农民增加灌溉面积。这意味着必须进行分析以防止土壤退化的强化土壤使用。因此，本研究分析了初始牧场落叶（割草和放牧）和短期灌溉管理对不同类型牧场下火山灰土壤土壤结构依赖性的影响。田间穿透阻力 (PR) 剖面 (0–80 cm)、土壤含水量测量 (0–10 cm) 和未受干扰的土壤样品 (0–3 cm) 显示了由于重复加载事件造成的动物践踏的影响。虽然这个实验没有确定显着的相互作用，例如牧场 x 落叶方法 x 施加的负载，该实验的早期发展阶段为更好地理解短期灌溉不同类型牧场时动物践踏造成的变形过程提供了基础。由高于预压应力的载荷引起的塑性变形导致土壤机械强度增加（例如第一次放牧后 Pc 增加，但割草后不增加），影响大孔隙体积和透气性。短期影响（<2 年）显示了放牧和灌溉的初期后果：PR 因动物践踏而增加（数据分散：放牧 > 割草地块，显示 8 次放牧事件后形成足迹）和非-灌溉牧场证明干燥事件后颗粒/聚集体之间的凝聚力增加。所以，