Comportamento físico-hídrico de solos submetidos ao preparo e manejo sob lavoura cafeeira

Abstract

In Brazil, coffee cultivation is an activity of great expressiveness. This occurs because the coffee production chain is directly responsible for the socio-economic development of many Brazilian regions, ensuring the production and distribution of wealth, and job generation. Among the Brazilian states, Minas Gerais and Espírito Santo are the largest coffee producers. However, the expansion of productive activities depends on the incorporation of new areas for coffee cultivation. Thus, competition with other crops of aggregate economic value compels producers to introduce coffee crops into areas with more physically restrictive soils, due to its genesis, as in the case of condensed soils. Therefore, the use of techniques that enable coffee production in these areas is fundamental for the adequate development of coffee, especially in regions where Indian summer occurs or rainfall is scarce. In this context, the objectives of the study were: i) to establish the physical-hydric conditions of cohesive Latosols that can affect irrigation management and consequence prediction, subsidizing the management of the irrigated coffee crop established in these soils of northern Espírito Santo; ii) to study the dynamics of water in Cambisol profiles subjected to different preparation systems associated to the use of brachiaria in the coffee row spacing. In experiment 1, located in the municipalities of São Mateus and Jaguaré, in northern Espírito Santo, two classes of soils under irrigated coffee crop were studied: Dystrocohesive Yellow Latosol in spray irrigation and Dystrophic Red-Yellow Latosol in drip irrigation. In this case, the evaluated variables were: soil density, water retention, resistance to root penetration and least limiting water range (LLWR). Experiment 2 was conducted in a Cambisol located in the municipality of Nazareno, state of Minas Gerais. Five treatments were evaluated, arranged as follows: coffee furrow revolved at 0.40 m of depth (PS40); coffee furrow revolved at 0.60 m of depth (PS60); coffee furrow revolved at 0.80 m of depth (PS80); row spacing with brachiaria cover (EL,) and the native Cerrado (CN), which represents the balance condition. Water infiltration at different tensions, water conductivity in saturated soil, water conductivity in unsaturated soil and water retention were evaluated. The results show that, in cohesive Latosol, the use of LLWR allowed the identification the range of moisture in which irrigation should be managed for the plant to express its maximum productive potential. In Cambisol, the planting furrow revolving done using rotary tiller associated to the subsoiling at the depths of 0.60 m and 0.80 m improved infiltration, storage and water movement up to 0.50 m of depth.