Bulk density and water tensions in the soil on corn root production

Abstract

Inadequate management of soil and water can cause changes in soil physical characteristics, resulting in lower root development. Thus the objective of the present study was to evaluate the dry matter production of corn roots under combinations of levels of bulk density and water tension in the soil. The experiment was conducted in a greenhouse in a randomized block design, based on a modified central composite design of a 52 fractional factorial scheme, of combinations of bulk densities (1.0, 1.2, 1.4, 1.6 and 1.8 Mg m-3) and water tensions in the soil (10, 20, 30 40 and 50 kPa), resulting in 13 treatments with four replicates. An Oxisol collected in the layer of 0-0.2 m was used. The pots were made of PVC (polyvinyl chloride) tube with compacted soil in the middle layer. The tensiometers were installed at a depth of 0.15 m, remaining in the central region of the compacted layer. The experiment was collected 104 days after sowing. Root dry matter production of corn was limited by increased water stress and bulk density.

Density of soil and nitrogen in production and nutrition of safflower (Carthamus tinctorius L.)

“…As the soil density increased, the porosity decreased causing greater resistance to penetration, limiting the soil volume that could be exploited and the water and nutrients available from the roots. This resulted in an increase in the energy expenditure of the root system to overcome the physical barrier caused by the subsurface compaction (Gao et al, 2016, Nunes et al, 2016. Under such conditions, the roots may act as drains during the vegetative growth, because the plants can be directed to assimilate from the root system, resulting in a lesser accumulation of carbohydrates in the dry mass of shoots, with increased soil density (Bonelli et al, 2011).…”

“…As the soil density increased, a correpsonding drop in nitrogen accumulation by the plant was observed. The soil density increase caused a reduction in the total porosity; while the irrigation experiment was predominantly subsurface in nature, it could have decreased the water availability in the surface layer (Nunes et al, 2016). These conditions induced those nutrients with an ion-root contact for mass flow, like nitrogen, for instance, to become more limited in plant uptake (Cabral et al, 2012).…”

“…The upper and lower rings were filled with soil, with a density of 1.0 Mg m -3 (soil without being compressed), while the central ring was filled with the compacted soil at different ground densities (1.0, 1, 2; 1.4; 1.6; 1.8 Mg m -3 ) to simulate the subsurface compaction. To assess the dry mass of the compacted soil layer, the density was considered as a ratio between the dry soil mass and the total ring volume (Equation 1) (Nunes et al, 2016). SD = DSM .…”

Reproductive Components of Safflower Genotypes Submitted of Bulk Density Levels in the Brazilian Cerrado

“…The development of cover crops under soil densities and resistance to penetration, provides significant reductions in dry mass production of rapeseed (Raphanus sativus) and black oats (Avena strigosa) at soil density of 1.34 Mg•m −3 in Oxisol [29]. For maize (Zea mays L.) under different bulk density levels of the Oxisol, bulk densities greater than 1.21 Mg•m −3 were found to be limiting to the growth [3]. Soil penetration resistance was pointed out as the main responsible for the lower plant development, even in comparison to the availability of water and nutrients [30].…”

“…Soil compaction can hinder the water and nutrient uptake in plants, thus inhibiting their development [2] [3] [4], besides undermining the root system aeration and obstructing the suiting development. Intensification of bulk density can curtail the macro-porosity, lower the infiltration rate and minimize the morphological changes in the roots of the cultivated plants [3] [5].…”