ABSTRACT Potato (Solanum tuberosum L.) cultivation has a high demand for management and treatments during the vegetative cycle in the field. Among these requirements, water management is a limiting factor of tuber productivity and quality. This study aimed to determine the most appropriate soil water depletion depth for irrigation management in potato crops of Ágata cultivar, under the edaphoclimatic conditions of Guarapuava-PR, considering its influence on crop vegetative development. The study was conducted using four water depletion depths in the soil (12, 24, 36, and 48 mm). The different irrigation treatments promoted differences in shoot dry mass, leaf area index (LAI), number of tubers per plant, and productivity. The highest yield was observed for 27.62 mm depletion. When irrigation depth was increased to 48 mm, tubers showed individual mass reduction and hence productivity, affecting commercial classification. A cumulative depletion of about 27 mm between irrigations proved to be the most adequate management to supply the water demand of Ágata potato cultivar.

RESUMO Objetivou-se analisar a qualidade física em uma área de floresta em regeneração (FS) há 20 anos quando comparada à área que, neste período, permaneceu sendo manejada com sistema silvipastoril, com espécies arbóreas nativas em espaçamento aleatório (SSP). Foram realizadas coletas até 60 cm de profundidade para obtenção das curvas de retenção de água no solo, a densidade, a porosidade total, a macro e a microporosidade, a resistência mecânica à penetração (RMP) e sua respectiva umidade do solo, no momento da coleta. Houve similaridade entre os sistemas de manejo para as variáveis: densidade do solo, resistência mecânica à penetração e porosidade total. A microporosidade foi maior na FS em relação ao SSP, fazendo com que o sistema silvipastoril apresentasse menor capacidade de armazenamento de água. O isolamento do sistema silvipastoril no período de 20 anos apresentou capacidade de alterar o armazenamento de água no solo devido à modificação na porosidade, tornando-a similar à floresta natural.

ABSTRACT This study aimed to analyze the soil physical quality in a 20-year regenerating forest area (FS) in relation to an area under silvopastoral management during the same period with randomly spaced (SSP) native tree species. Samples were collected up to 60 cm deep to obtain soil water retention curves, density, total porosity, macroporosity, microporosity, mechanical penetration resistance (MPR) and the respective soil moisture at the time of collection. Soil density, mechanical resistance to penetration and total porosity were similar between the management systems. Microporosity was higher in FS than in SSP, leading to lower water storage capacity in the silvopastural system. The 20-year isolation of the silvopastoral system proved to be able to affect the soil water storage capacity due to changes in porosity, making its soils to reach similar values to natural forest.