title: Strategic tillage in conservation agricultural systems of north-eastern Australia: why, where, when and how?
abstract: 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.
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia. y.dang@uq.edu.au.
authors.forename: Yash Pal
authors.initials: YP
authors.lastname: Dang
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Anna
authors.initials: A
authors.lastname: Balzer
authors.affiliation: Department of Natural Resources and Mines, Toowoomba, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Crawford
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Vivian
authors.initials: V
authors.lastname: Rincon-Florez
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liu
authors.affiliation: University of Southern Queensland, Toowoomba, Australia.
authors.forename: Alice Rowena
authors.initials: AR
authors.lastname: Melland
authors.affiliation: University of Southern Queensland, Toowoomba, Australia.
authors.forename: Diogenes
authors.initials: D
authors.lastname: Antille
authors.affiliation: University of Southern Queensland, Toowoomba, Australia.
authors.forename: Shreevatsa
authors.initials: S
authors.lastname: Kodur
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Michael John
authors.initials: MJ
authors.lastname: Bell
authors.affiliation: CSIRO, Toowoomba, Australia.
authors.forename: Jeremey Patrick Milroy
authors.initials: JPM
authors.lastname: Whish
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Yunru
authors.initials: Y
authors.lastname: Lai
authors.affiliation: Department of Agriculture and Forestry, Toowoomba, Australia.
authors.forename: Nikki
authors.initials: N
authors.lastname: Seymour
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Lilia Costa
authors.initials: LC
authors.lastname: Carvalhais
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Australia.
authors.forename: Peer
authors.initials: P
authors.lastname: Schenk
mesh_terms: D000383:Agriculture / Q000295:instrumentation / Q000379:methods*; D018556:Crops, Agricultural / Q000254:growth & development*; D004777:Environment; D009517:New South Wales; D011793:Queensland; D012987:Soil / Q000737:chemistry*; D013997:Time Factors
chemical_list: D012987:Soil
keywords: Conservation agriculture; Crop productivity; Environmental impact; No tillage; Soil health; Strategic tillage