Absorption of primary macronutrients and soybean growth at different compactation densities and moisture levels in a silt loam soil

Abstract

RESUMOAbsorption of primary macronutrients and soybean growth at different compactation densities and moisture levels in a silt loam soil 1 Soybean cultivation is increasing rapidly in the region of Alto Vale do Itajaí, State of Santa Catarina, where there is a predominance of silt soils. The objective of this work was to evaluate the content of primary macronutrients in shoots and shoot and root vegetative growth of soybean (Glicine max L. Merrill) grown in a silt-loam soil under different compactation densities and moisture levels. A randomized block design in a 4x4 factorial arrangement was used, with four compactation densities: 1.00; 1.20; 1.40 and 1.60 Mg m -3, and four soil moisture levels: 0.130; 0.160; 0.190 and 0.220 kg kg -1 and four replications. Each pot consisted of the overlapping of three 150-mm PVC rings, where soil was maintained in the higher and lower part of the pot with a density of 1.00 Mg m -3 and in the intermediate ring, the compactation densities were increased. Values of soil density higher than 120 Mg m -3 negatively affected N, P and K uptake by soybean plants, as well as the plant mass of the shoots and roots. The higher levels of soil moisture reduced the compaction effect and promoted better absorption of P and K.Key words: compactation density, nutrients uptake, root density, shoot system. , e no intermediário, implementados os níveis de compactação. Valores de densidade do solo superiores a 1,20 Mg m -3 afetam de forma negativa a absorção de N, de P e de K, e a produção de biomassa de parte aérea e sistema radicular da soja. Níveis mais elevados de umidade do solo reduzem o efeito da compactação e favorecem a absorção de P e a de K. Romano RobertoPalavras-chave: densidade do solo; densidade de raízes; parte aérea; absorção de nutrientes.

Shoot and root development of brachiaria grass (Urochloa ruziziensis) under different levels of soil density

“…Reduction in absorption of water and essential nutrients by plant roots may occur as a result of less volume of explored soil (Sá & Santos Junior, 2005). The other factors that may contribute to reduction of water and nutrients absorption by plant roots is the modification of the structural arrangement of the soil, by reducing the amount of macropores, oxygenation and soil water availability (Cardoso et al, 2006;Valicheski et al, 2016). These effects can also be observed as a significant reduction in crop yield (Homma, 2005).…”

Influence of biological fertilizer and plant cover in the physical properties of soil

“…According to Silva et al (2004), even with macropores' critical values of the soil (0.10 cm 3 cm -3 ), the plant can still develop, however, with restriction to root growth. In the Valicheski et al (2016) study, was observed a reduction in the grain yield, it is because of the physical restriction, poor aeration of the soil and low soil macroporosity. The soil macroporosity is agreement correlated with soybean grain yield, where low soil microporosity results in crop yield loss (Queiroz et al, 2011).…”