The effect of compaction of the arable layer in sandy soils on the growth of maize for silage. 1. Critical matric water potentials in relation to soil aeration and mechanical impedance.

Abstract

A new approach in defining the range of soil structure for optimal maize production is proposed. The effect of different degrees of compaction of ploughed sandy soils on soil aeration and mechanical impedance and on root and shoot growth of maize was tested in 5 model field experiments in the eastern Netherlands. In this first paper the effects on soil aeration and penetration resistance are described. The narrower the range of matric water potentials which allow unimpeded root growth, the greater the potential risks for plant growth and the greater the need for a controlled supply of water. Soil structures which substantially impede root growth even at the most favourable water potential are classified as dangerous. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Soil Structural Disturbance Effects on Crop Yields and Soil Properties in a No‐Till Production System

“…The greater strength observed under NT soils is attributed to the presence of more cohesive soil, root networks, and higher density associated with the reorientation of charged surfaces favored by the absence of tillage disruption (Kay, 1990). In this study, the penetration resistance values were always smaller than reported critical levels for normal root growth and crop productivity (Greacen and Oh, 1972; Ehlers et al, 1983; Boone et al, 1986; Gupta and Allmaras, 1987). Consequently, differences in soil strength between tillage treatments do not directly explain the differences in summer crop yields where maize yields were generally greater on NT soils with the higher penetration resistance values.…”

Effects of cattle slurry and cultivation on air exchange in sandy and silty soils from northern Norway

“…The critical limit for relative diffusivity (D/D 0 ) below which crop growth is affected is in the range of 0.005-0.02 (Grable and Siemer 1968). Boone et al (1986) showed that the oxygen consumption in the soil greatly influenced the critical limits for the oxygen diffusion coefficient, and soil compaction was found to increase the oxygen consumption in the soil. At field capacity (-5 kPa) both the uncultivated and cultivated Tana soils had lower relative diffusivity than the lower limit of Grable & Siemer (1968).…”

Sistema de preparo profundo do solo e sua influência no desenvolvimento da cana-de-açúcar

“…Vasconcelos (2002a) A quantificação do crescimento do sistema radicular em campo, por qualquer método de amostragem, é um desafio em função de alguns fatores, tais como: a arquitetura geométrica complexa do sistema radicular, as diferentes atividades fisiológicas em raízes de diferentes idades, a diversidade de tipos e diâmetros das raízes, o rápido crescimento e decomposição de raízes finas, os processos microbiológicos que ocorrem na interface solo-raiz e a variabilidade do ambiente edáfico no qual as raízes se desenvolvem (LUXMOORE;STOLZY, 1987;FANTE JUNIOR, 1999). A relação entre resistência à penetração e crescimento radicular foi estudada por vários autores (BOONE et al, 1986;ROSOLEM et al, 2002), e os valores considerados restritivos ao crescimento radicular variaram de 1,34 a 3 MPa para diferentes espécies. Pfeffer (1983), citado por Bennie (1996), fez as primeiras medidas diretas da máxima pressão de crescimento radicular, encontrando valores entre 0,7 e 2,5 MPa para diferentes espécies.…”