Características físico-hídricas das áreas irrigadas por pivô central no município de Manoel Viana, RS

Abstract

Irrigation is an ancient technique that has the purpose of making water available to plants in a way that is adequate for full productivity. The central pivot is the most used equipment in the irrigation, for being able to irrigate large areas with little labor. Its versatility and high performance are factors that make your choice easier. The infiltration of water into the soil is a physical-water parameter of total importance, its knowledge tells the irrigant the amount of water that the soil can infiltrate, and its quantitative limits on irrigation without causing physical damage to the soil. The lack of technical knowledge of irrigators in relation to their areas and how to perform irrigation management results in poor utilization of the system. However, the parameters soil density and resistance to penetration are limiting factors in the production, their values can either alter the amount of water that the soil can be able to store, or, difficult the root growth of the plants, resulting in the reduction of grain production . Therefore, the objective of this work was to evaluate the infiltration speed, soil density and resistance to penetration in irrigated areas with central pivot in the municipality of Manoel Viana, RS. It was done by the rural union of Manoel Viana and EMATER a survey of the number of irrigation equipment of the central pivot type in the municipality. Visits were performed in the areas to perform infiltration tests by the concentric ring method, where three tests were performed per equipment, each equipment will be divided into three slices, aiming at a better representativeness of the samples. Each of the three trials was done in one set and one slice of the pivot being them: one on the first throw and first slice, one on the middle and second slice throw and the third on the last throw and third slice of the equipment. The soil density was determined by sampling the samples using the rings method. Twelve samples were collected for each infiltration test, three at each depth: 0-10, 10-20, 20-30 and 30- 40. The penetration resistance was determined with the aid of a digital penetrometer, also performing three repetitions per infiltration test. At the end of the trials, the data were analyzed and related to each other, seeking to identify physical problems in the areas and solutions of soil improvement of irrigated areas by central pivot in the municipality of Manoel Viana. It was verified that the producers have little technical follow up on their irrigation equipment, the values of the analyzed parameters obtained varied values, having variations even in the same equipment. Although this work provides important data for irrigating producers, it is recommended that more parameters be studied, leaving farmers with better understanding, so that they can better understand their planting environment.