Morfologia do sistema radicular de cafeeiro com uso de mulching

Abstract

One of the major concerns in coffee cultivation, mainly in the formation phase of the crop, is the control of weeds and the availability of water responsible for promoting the establishment of seedlings and all the initial development of the plant. Aiming to advance root development, the use of polyethylene mulching can be an alternative to improve the chemical and biological properties of the soil. The objective of this study was to evaluate the morphology of the root system of coffee trees and the soil resistance to penetration using polyethylene mulching of different widths and colors. The planting of the crop, with the cultivar Topaz MG-1190, was carried out in December 2016, using a spacing of 3,5 m between rows and 0,6 m between plants. The experimental design used was in randomized blocks, with four blocks and five treatments, as follows: 1- white/black double-sided mulching with 1,20 m width; 2 - white/black mulching with 1,40 m width; 3 - silver/black mulching with 1,20 m width; 4 - silver/black mulching with 1,40 m width and 5 - no mulching. Each plot consisted of 10 plants, considering the eight central plants as useful. The following morphological parameters associated with coffee root morphology were estimated: total root dry matter mass per soil volume (MST), in mg cm-3; total length of roots per soil volume (TC), in cm cm-3; total root volume per soil volume (VT), in mm3 cm-3; total area of roots per soil volume (AT), in mm2 cm-3; root specific surface (SE), obtained by the relationship between AT and MST, in m2 kg-1; specific length of roots, obtained from the relationship between TC and MST, in m g-1; and the roots mean diameter (DM), in millimeters. With the use of a penetrometer, the soil resistance to penetration was evaluated. Roots with smaller diameters are more concentrated in the 0 to 20 cm deep layer, while roots with larger diameters are found in the 20 to 40 cm layer. The treatment plants with mulching with 1,20 m width had greater surface and specific length of the roots, in addition to presenting lower soil resistance to penetration.