Influence of tillage on soil macropore size, shape of top layer and crop development in a sub-humid environment

Abstract

Topsoil macropores of two plots under no-tillage and conventional tillage were analyzed. A leguminous-cereal rotation was applied for six cycles under dry-land farming system (crop residues were removed). The clay-loam soil shows some vertic characteristics. The main goal is to identify the relationship between the top soil macro and meso-pore distribution for the two tillage systems (at the end of sixth cycle of cultivation) with the annual crop production (rainfall in normal growing period and crop production values are included). Unaltered topsoil samples were taken from 0 to 60 mm (row and interrow positions) and from the immediate depth (60 to 110 mm) in both plots (conventional and no-tillage). The morphometric analyses of 66 polished slices were carried out with the aim to identify differences in soil macro and meso-pore organisation. Soil macropores were classified by size (area) and elongation ratio and by form factor and equivalent pore diameter. No appreciable differences were observed. Soil macro and meso-pore distributions of samples were also compared. The main difference observed between topsoil's treatments was a different macropore size distribution between topsoil positions. The presence of larger macropores was higher in conventional tillage compared to no-tillage. Samples taken from row and deeper positions of conventional tillage show a somewhat higher amount of macropores in the range between 2 to 2.3 mm equivalent pore diameter. Soil macropores contribute to increase soil aeration and soil drying when topsoil is too wet in critical periods of crop development. Conventional tillage (crop residues removed), provides to the topsoil of a larger lateral and vertical variability of macropore distribution than no-tillage topsoil.

Soil sealing and soil water content under no‐tillage and conventional tillage in irrigated corn: Effects on grain yield

“…In fact, macroporosity was significantly higher in CT (10.8%) than in NT (6.1% p < .02) and microporosity significantly lower ( p < .01), being macroporosity 25% of total porosity in CT and 14% in NT. In this respect, Josa, Gorchs, Ginovart, and Solé‐Benet () indicated higher presence of macropores in CT compared with NT. Similarly, Shipitalo and Protz () indicated that no‐till plots had approximately half the macroporosity of those of conventionally tilled plots.…”

Assessing the long-term effects of zero-tillage on the macroporosity of Brazilian soils using X-ray Computed Tomography

“…Mangalassery et al (2014) found larger differences between ZT and CT, with CT porosity 47% higher than under ZT soils in the upper 10 cm when assessed by X-ray micro Computed Tomography (μCT) at a resolution of 64 μm. An increased number of macropores in CT compared to ZT in the surface but a higher proportion of micropores in ZT soils has been reported by Josa et al (2013) and Mangalassery et al (2014). Previously, most studies have focused on agricultural land under ZT management for ten years or fewer, with long-term studies typically viewed as those with 5 years beyond conversion.…”

Estimates of Tillage and Rainfall Effects on Unsaturated Hydraulic Conductivity in a Small Central European Agricultural Catchment

“…The reason for the different outcome in our case is not clear; however, a possible explanation could lie in the specific weather conditions in 2015, which resulted in exceptionally dry topsoil conditions before the spring tillage and throughout the season. Soil moisture conditions and soil aeration affect the amount and properties of macropores [61]. Tillage of very dry soil could also lead to lower stability and differing sizes and arrangement of soil aggregates.…”