Cultivated soils, when submitted to agricultural practices, tend to compact due to the pressure exerted by agricultural machines and implements, a process that compromises soil quality and system sustainability. Specific properties of each soil, such as particle size and organic matter content, interfere with the process and degree of compaction and, consequently, plant growth. This study aimed to analyze the effect of different degrees of compaction (DC) on soil physical properties and black oat (Avena strigosa Schreb) growth. For this purpose, four soils were collected: Latossolo Vermelho distrófico retrático (Ferralsol LV CN), Cambissolo Húmico alumínico típico (Cambisol CH LG), Nitossolo Bruno distrófico típico (Nitisol NB PA), and Nitossolo Bruno distrófico húmico (Nitisol NB SJ). They were submitted to five degrees of compaction (bulk densities corresponding to 80, 85, 90, 95, and 100 % DC), defined by their relation to the maximum density obtained by the Normal Proctor Test. For each DC, porosity, soil water retention curve, penetration resistance, hydraulic conductivity, and aeration capacity were determined. In a greenhouse, the oats were cultivated in the four soils with five different degrees of compaction. The experiment was carried out in a completely randomized design, factorial scheme, and five replications. Crop measurements included the growth rate, shoot dry matter, and forage quality analysis. Soil compaction changed the physical properties of soils. In all tested soils, macroporosity and total porosity decreased, more intensely at LV CN. It had macroporosity below the critical level (0.10 m 3 m-3) from DC 85. Hydraulic conductivity also decreased in all soils, which is evidence of significant environmental degradation from DC 90 onwards. Microporosity increased in the four soils due to compaction effect, and it is one of the reasons why permanent wilting point has increased. It resulted in a problem at NB SJ , mainly because it reduced the available water volume at DC 90, 95, and 100. Penetration resistance has also increased from DC 80 to 100 at all soils, exceeding the limit of 2 MPa in DC 80 for NB SJ , DC 85 for NB PA and LV CN , and DC 95 for CH LG , representing a risk to root development. Regarding black oat crop, there was a reduction in shoot dry matter only in Cambisol and in the higher DC, fiber content keeps within a satisfactory amount, without affecting forage quality in all soils and DC, thus showing that black oat is tolerant to compaction.

Resumo -O objetivo deste estudo foi avaliar a presença da fauna edáfica sob diferentes manejos e tempos de descarte de resíduos animais. As áreas utilizadas para o estudo foram diferenciadas pelos seguintes manejos: mata nativa, pastagem nativa sem descarte e as áreas de uso agrícola: pastagem de azevém com 5 e 17 anos de descarte de resíduos animais, milho para silagem com 9 e 22 anos de descarte, pastagem sem pastejo com 22 anos de descarte. Em cada época de coleta foram amostrados 9 pontos por área, com espaçamento de 30 metros entre cada ponto. Foram realizadas avaliações da fauna (método do Berllese e TSBF) e atributos físicos e químicos. Utilizou-se a curva de resposta principal (CRP) para observar o comportamento das áreas ao longo do tempo e análise de redundância (ADR) para os atributos que explicaram a variabilidade dos grupos da fauna edáfica. A área de pastagem com 22 anos se mostrou mais estável em relação as demais (exceto a mata nativa) quanto ao comportamento da densidade dos organismos ao longo do tempo pela CRP. Os atributos MO e Cu foram variáveis explicativas significativas na ADR para as duas metodologias considerando todas as épocas de coleta. O descarte continuado de resíduos animais no solo ocasiona mudanças no ambiente influenciando as populações da fauna edáfica.Palavras-chave -Dejeto de suíno. Cama de aves. Análise multivariada.Abstract -The goal of this study was to evaluate the presence of soil fauna under different managements and times disposal of animal waste. The areas used for the study were differentiated by the following managements: native forest, native pasture without disposal and areas of agricultural use: ryegrass pasture with 5 and 17 years of disposal of animal waste, corn for silage with 9 and 22 years of disposal pasture without grazing with 22 years of disposal. Each season were sampled 9 points per area, with spacing of 30 meters between each point. Were performed fauna assessments (method Berllese and TSBF) and physical and chemical attributes. We used the principal response curve (PRC) to observe the behavior of the areas over time and redundancy analysis (RDA) for the attributes that explain the variability of the soil fauna groups. The pasture area with 22 years was more stable compared the others (except the native forest) how the behavior of the density of organisms over time by CRP. The OM and Cu attributes were significant explanatory variables in ADR for the two techniques considering all the collecting seasons. Continued disposal of animal waste in the soil causes changes in the environment influencing the populations of soil fauna.

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