ADUBAÇÃO FOSFATADA E COMPACTAÇÃO DO SOLO: SISTEMA RADICULAR DA SOJA E DO MILHO E ATRIBUTOS FÍSICOS DO SOLO

By Franciele Caroline de Assis Valadão, O. Weber, Daniel Dias Valadão Júnior, Alex Scapinelli, Filipe Rafaeli Deina, Aloísio Bianchini. 2015

57 citations recorded by the source corpus.

Associated with the benefits of the no-till system for the soil, there may be the formation of a vertical gradient of fertility and a compacted layer caused by heavy farm machine traffic, which may modify the root growth of crops. The aim of this study was to evaluate the effect of rates and forms of phosphate fertilizer application and soil compaction by machine traffic on the physical properties and root system of soybeans and maize. The study was conducted in Campo Novo do Parecis, MT, Brazil, in a clayey Latossolo Vermelho-Amarelo distrofico (Oxisol) in a randomized block experimental design with three replications. A 2 × 4 × 4 factorial arrangement was used, consisting of two forms of phosphate fertilization (broadcast and in the furrow), four rates of P2O5 (0, 50, 100, and 150 kg ha- 1), and four levels of compaction (PT0, PT2, PT4, and PT8 - no-tillage with compaction induced by tractor traffic at zero, two, four, and eight passes, respectively). Machine traffic causes soil compaction in no-tillage, increasing soil bulk density (Bd) and soil resistance to penetration (SRP) and reducing macroporosity and total porosity, without effect from P fertilization. The response of the species to the form of P fertilization was differentiated. There was no significant influence on root growth in soybean, but in maize, broadcast fertilization provided for greater root area in the root zone in the 0.00-0.05 m layer, and fertilization in the furrow led to smaller differences in root area between the layer. The SRP values of 1.48 and 1.84 MPa (Us = 0.28 m3 m-3) and Bd values of 1.32 and 1.35 kg dm- 3 in the 0.05-0.10 and 0.10-0.20 m layers, respectively, resulted in a reduction of 19 and 27 % in the average diameter of corn roots, and an increase of 110 and 49 % in the diameter of soybean roots.

Subfields: Civil and Structural Engineering, Plant Science, Soil Science

View Paper: https://www.semanticscholar.org/paper/baf8705f67ca2d859ad39adabb8cf145e6ca93cb