Shallow mechanical loosening of a soil under dairy cattle grazing: Effects on soil and pasture

Abstract

Shallow mechanical loosening of soil to 22 cm deep (aeration) was investigated as a method for ameliorating soil compaction caused by dairy cattle treading. Soil physical and pasture measurements taken over 46 weeks compared plots grazed under normal grazing practice (non-aerated) with plots under normal grazing practice where soil was mechanically loosened (aerated). Aerated soil initially showed reduced (P < 0.05) penetration resistance, degree of packing, and bulk density, and increased (P < 0.05) hydraulic conductivity, total porosity, macroporosity, and proportion of small aggregates, compared with non-aerated soil. However, after 40 weeks aerated soil showed some reversion back to a non-aerated state, and only the most sensitive measurements (penetration resistance, degree of packing, soil structure, and *Author for correspondence A99038 Received 6 August 1999; accepted 13 April 2000 macroporosity) showed significant (P < 0.05) treatment differences. Pasture herbage yield, botanical composition, and root length were unaffected (P < 0.05) by aeration, but aeration increased (P < 0.05) root dry weight and decreased bare ground. This work suggests that timing of aeration with regard to soil moisture and atmospheric conditions is vital for optimal soil and pasture responses. The need to use methods which sample large volumes of soil and pasture to detect soil physical and pasture changes due to loosening is also stressed.

Impact of soil aeration on runoff characteristics in dual-purpose no-till wheat systems

“…Bulk density measurements were collected approximately 9 months after tillage operations. Burgess et al (2000) found bulk density from aerated plots in pastures were the same as undisturbed plots within 10 months. Another study evaluating soil aeration on a pasture found that bulk density between aerated and control treatments were not different within 6 months without cattle grazing and from 7 months onwards with grazing (Cournane et al 2011).…”

“…Several researchers have also reported decreased runoff volumes and nutrient losses as a result of soil aeration (deKoff et al 2011;Shah et al 2004;Franklin et al 2007Franklin et al , 2011. However, the effect of aeration on soil physical properties and runoff characteristics have been shown to be effective only in the short term, with these characteristics reverting back to nonaerated plots within 3 to 10 months (deKoff et al 2011;Burgess et al 2000;Houlbrooke 1996;Acock et al 2007;Cournane et al 2011). Furthermore, Franklin et al (2007) found that the impact of soil aeration on runoff parameters may be soil dependent, as aeration increased nutrient losses and runoff volume on poorly drained soils.…”

“…Baumhardt et al (2011) recommended stubble-mulch tillage after wheat harvest to disrupt soil compaction and restore grazed soil productivity. Mechanical soil aeration has been shown to increase macroporosity, saturated hydraulic conductivity, and air permeability and to decrease bulk density in grazing lands (Burgess et al 2000;Drewry et al 2000). Several researchers have also reported decreased runoff volumes and nutrient losses as a result of soil aeration (deKoff et al 2011;Shah et al 2004;Franklin et al 2007Franklin et al , 2011.…”

Building resilience to climate change in rain-fed agricultural enterprises: An integrated property planning tool

“…Strategies to improve rainfall infiltration rates include: improving ground cover through control of grazing pressure, correcting dispersive factors such as sodicity, soil conditioning such as spike aeration (Taddese et al 2002;Steed et al 1987;Burgess et al 2000), and improving soil structure by raising the percentage of soil organic carbon. Improving infiltration rates has the most effect on slopes where clay content is high in areas mapped as 2A and 2B.…”

Effects of Pasture Renovation on Hydrology, Nutrient Runoff, and Forage Yield

“…Gordon et al (2000) observed significantly reduced forage yields in nine out of 11 trials on renovated, manured plots containing sandy loam to sandy soil textures vs. manured plots. No significant differences were determined for forage growth and root length between renovated and nonrenovated plots grown on a silt loam that was intensively grazed both before and during the study (Burgess et al, 2000). There was, however, greater root weight associated with renovated plots at a depth of 0 to 5 cm 1 wk after renovation, which was negatively correlated with penetration resistance.…”