Conservation tillage increases in soil water storage, soil animal populations, grain yield, and response to fertiliser in the semi-arid subtropics

Abstract

We compared 4 tillage practices (traditional, stubble mulch, reduced, no tillage) during 10 years under rainfed conditions on an alluvial soil in the semi-arid subtropics of central Queensland. In the final 4 years, responses to applied fertiliser nitrogen (N), sulfur (S), and zinc (Zn) were determined. We measured soil water storage, soil nitrate accumulation, grain yield (sorghum, wheat), grain protein content, and populations of soil macrofauna, with the aim of identifying soil-conserving practices that also produce high yields of high quality grain. Stubble mulch, reduced tillage, and no tillage all outyielded traditional tillage when soil fertility was adequate. With applied N, S, and Zn, the mean wheat yields from traditional, stubble mulch, reduced, and no tillage were 2.44, 3.32, 3.46, and 3.64 t/ha, respectively. The yield responses to tillage practices were due to increases in storage of soil water or efficiency of crop water use or both. Populations of soil macrofauna averaged (per m2) 19 (traditional tillage), 21 (stubble mulch), 33 (reduced tillage), and 44 (no tillage). The effect of the tillage practices on soil animal populations may be a factor contributing to the measured differences in soil water storage and water use efficiency. We conclude that conservation tillage practices can greatly increase grain yields, provided crop and fallow management practices are appropriate. Potential yield advantages are realised if crop establishment, crop nutrition; and control of weeds, bests, and diseases ark adequate.

Impacts of management on soil biota in Vertosols supporting the broadacre grains industry in northern Australia

“…More detailed descriptions of the tillage trials at Warwick (Hermitage) and Biloela are available in Thomas et al (2003) and Radford et al (1995), respectively, while descriptions of the Tulloona fertiliser trial appear in Lester and Dowling (2001) and Lester et al (2003). The Toowoomba (Wellcamp) tillage trial site had been sown to annual crops of winter wheat, with similar combinations of stubble management and tillage as Hermitage, but had only run for 9 consecutive seasons at the time of sampling, compared with the 35 years of predominantly annual wheat cropping at Hermitage (Thomas et al 2003).…”

“…Duczek and Wildermuth 1991). Similarly, there has been extensive research to investigate the interactions between cropping systems and the beneficial impact of soil macrofauna (Radford et al 1995;Wilson-Rummenie et al 1999) and mycorrhizae, (Thompson 1987), but other beneficial components of the soil biota have received limited (Roper et al 1994) or no attention. In particular, there has been little concerted effort to explore the broader impact of crops and cropping systems on the constituents and relative activities of biota constituting the detritus food web, and the impact of any changes on subsequent crop productivity.…”

“…Improved efficiency of water capture and use by crops as a result of conservation tillage and direct drill practices have been credited with increasing system productivity (e.g. Felton et al 1995;Radford et al 1995). In addition, simulation studies consistently suggest increased cropping frequency is possible with an opportunity cropping strategy combined with direct drill, controlled traffic systems (Chudleigh et al 2002) The main cropping areas (Webb et al 1997) are centred on grey, brown, or black Vertosols; red or brown Sodosols; and red or brown Chromosols (Isbell 1993).…”

A survey of dairy farmers' practices and attitudes towards some aspects of arable-land management in the Darling Downs and South Burnett regions of Queensland

“…Minimal-and zero-tillage farming has been demonstrated to have both economic and soil conservation benefits in the subtropical cereal belt (Freebairn and Wockner 1986;Radford et al 1995).…”

Soil physical properties and infiltration after long‐term no‐tillage and ploughing on the Chinese Loess Plateau

“…Benjamin (1993) and Baumhart & Lescano (1996) indicated that soils under no-tillage treatment have greater infiltration rates and water storage capacities than tilled soils. Conservation tillage was also shown to improve soil water content and crop yields in many environments (Radford et al 1995;Hemmat & Eskandari 2004;Munoz et al 2007), but Wilhelm et al (1987) and Hammel (1995) observed negative effects of no-tillage on crop yields in arid areas of the United States.…”