Strategic tillage in conservation agricultural systems of north-eastern Australia: why, where, when and how?
- 1.3k Downloads
Farmers often resort to an occasional tillage (strategic tillage (ST)) operation to combat constraints of no-tillage (NT) farming systems. There are conflicting reports regarding impacts of ST and a lack of knowledge around when, where and how ST is implemented to maximise its benefits without impacting negatively on soil and environment. We established 14 experiments during 2012–2015 on farms with long-term history of continuous NT to (i) quantify the associated risks and benefits to crop productivity, soil and environmental health and (ii) explore key factors that need to be considered in decisions to implement ST in an otherwise NT system. Results showed that introduction of ST reduced weed populations and improved crop productivity and profitability in the first year after tillage, with no impact in subsequent 4 years. Soil properties were not impacted in Vertosols; however, Sodosols and Dermosols suffered short-term negative soil health impacts (e.g. increased bulk density). A Sodosol and a Dermosol also posed higher risks of runoff and associated loss of nutrients and sediment during intense rainfall after ST. The ST reduced plant available water in the short term, which could result in unreliable sowing opportunities for the following crop especially in semi-arid climate that prevails in north-eastern Australia. The results show that generally, there were no significant differences in crop productivity and soil health between tillage implements and tillage frequencies between ST and NT. The study suggests that ST can be a viable strategy to manage constraints of NT systems, with few short-term soil and environmental costs and some benefits such as short-term farm productivity and profitability and reduced reliance on herbicides.
KeywordsCrop productivity Environmental impact No tillage Soil health Strategic tillage Conservation agriculture
The authors would like to thank Grains Research & Development Corporation (Project no. ERM00003) for partial funding. We are also indebted to our collaborative growers, Nev and Ron Boland, Darren and Tanya Jensen, Rod and Sam Hamilton, Paul and Samantha Fulbohm, Brian and Val Gregg, Geoff Manchee, Warakirri Farming Co. and Ken and John Stump, for providing field sites, managing the trials and providing their generous support. Thanks are also due to Paul McNaulty, Paul Caster and Stuart Thorn for their support. The authors would like to thank the DSITI Ecoscience Precinct soil laboratory for their skilful soil analysis and Suzette Argent, Don Browne, Ram Dalal, Maria Harris, Tony King, Phil Moody, Clement Ng, Rod Obels and Micheal Widderick for their substantial contributions to the design, setup, acquisition, analysis or interpretation of data and continuing support of the Strategic Tillage project.
Compliance with ethical standards
Conflict of interest
The authors declare they have no conflict of interest.
- Argent S, Wixon A, Dang Y (2013) Farmers thoughts about CTF in Australia’s northern grain growing region, First International Controlled Traffic Farming Conference, Toowoomba, 25–27 February 2013 http://www.actfa.net/conferences/ctf2013/CTF2013%20papers%20pdfs/Argent,%20Suzette.pdf
- Bell M, Lester D, Smith L, Want P (2012) Increasing complexity in nutrient management on clay soils in the northern grain belt—nutrient stratification and multiple nutrient limitations. In: Yunusa I (Hrsg.) Capturing opportunities and overcoming obstacles in Australian Agronomy. Proceedings of 16th Australian Agronomy Conference 2012, 14–18 October 2012, Armidale, NSW. http://www.regional.org.au/au/asa/2012/nutrition/8045_bellm.htm#TopOfPage
- Dang Y, Balzer A, Bell M (2016) Does strategic tillage undo long term improvement in soils under no-till?, ERM00003 Final Technical Report. Grains Research & Development Corporation, Canberra, AustraliaGoogle Scholar
- FAO (2016) What is Conservation Agriculture? http://www.fao.org/ag/ca/1a.html
- Freebairn DM, Littleboy M, Smith GD, Coughlan KJ (1991) Optimising soil surface management in response to climatic risk. In: Muchow RC, Bellamy JA (eds) Climatic risk in crop production: models and management for semiarid tropics and subtropics. CAB International, Wallingford, pp 283–305Google Scholar
- Freebairn DM, Loch RJ, Silburn DM (1996) Soil erosion and soil conservation for vertisols. Dev Soil Sci 24:303–362Google Scholar
- Haak MI, Peck DM, Thompson JP (1993) Numbers of Pratylenchus thornei and P. neglectus are altered by frequent tillage and stubble retention. In: Vanstone VA, Taylor SP, Nicol JM (Hrsg.) Proceedings of the 9th Pratylenchus workshop. APPS conference, Hobart, pp. 69–73Google Scholar
- Jalota SK, Prihar SS (1990) Bare soil evaporation in relation to tillage. Adv Soil Sci 12:187–216Google Scholar
- McGarity JW (1975) Soils of the Australian wheat-growing areas. In: Lazenby A, Matheson E (eds) Australian field crops, Volume 1: wheat and other temperate cereals. Angus and Robertson, Sydney, pp 227–255Google Scholar
- McGillion T, Storrie A (2006) Integrated weed management in Australian cropping systems: a training resource for farm advisors. Cooperative Research Centre for Australian Weed Management, Adelaide, AustraliaGoogle Scholar
- Pratley JE (2000) Tillage and other physical management methods. In: Sindel BM (ed) Australian weed management systems, MelbourneGoogle Scholar
- Rayment GE, Lyons DJ (2011) Soil chemical methods—Australasia. CSIRO Publishing, Collingwood, VictoriaGoogle Scholar
- Scott BJ, Eberbach P, Evans J, Wade L (2010) Stubble retention in cropping systems in Southern Australia: benefits and challenges. EH Graham Centre Monograph No. 1, Industry and Investment NSW, AustraliaGoogle Scholar
- Thomas GA, Felton WL, Radford BJ (1997) Tillage and crop residue management. In: Clarke AL, Wylie PB (eds) Sustainable crop production in the sub-tropics: an Australian perspective. Queensland Department of Primary Industries, Brisbane, pp 195–213Google Scholar
- Webb AA, Grundy MJ, Powell B, Littleboy M (1997) The Australian sub-tropical cereal belt: soils, climate and agriculture. In: Clarke AL, Wylie PB (eds) Sustainable crop production in the sub-tropics: an Australian perspective. Queensland Department of Primary Industries, Brisbane, pp 8–23Google Scholar
- Wildermuth GB, Thompson JP, Robertson LN (1997b) Biological change: diseases, insects and beneficial organisms. In: Clarke AL, Wylie PB (eds) Sustainable crop production in the sub-tropics: an Australian perspective. Queensland Department of Primary Industries, Brisbane, pp 112–130Google Scholar