Abstract
The research aimed to evaluate machine traffic effect on soil compaction and the least limiting water range related to soybean cultivar yields, during two years, in a Haplustox soil. The six treatments were related to tractor (11 Mg weight) passes by the same place: T0, no compaction; and T1*, 1; T1, 1; T2, 2; T4, 4 and T6, 6. In the treatment T1*, the compaction occurred when soil was dried, in 2003/2004, and with a 4 Mg tractor in 2004/2005. Soybean yield was evaluated in relation to soil compaction during two agricultural years in completely randomized design (compaction levels); however, in the second year, there was a factorial scheme (compaction levels, with and without irrigation), with four replicates represented by 9 m² plots. In the first year, soybean [Glycine max (L.) Merr.] cultivar IAC Foscarim 31 was cultivated without irrigation; and in the second year, IAC Foscarim 31 and MG/BR 46 (Conquista) cultivars were cultivated with and without irrigation. Machine traffic causes compaction and reduces soybean yield for soil penetration resistance between 1.64 to 2.35 MPa, and bulk density between 1.50 to 1.53 Mg m-3. Soil bulk density from which soybean cultivar yields decrease is lower than the critical one reached at least limiting water range (LLWR =/ 0).
Highlights
Soil compaction can reduce root growth through physical processes associated with lower aeration and decreasing water and nutrients absorption, which causes significant yield decrease (Flowers & Lal, 1998; Beutler & Centurion, 2004; Czyz, 2004)
The inferior limiting range is the highest value between water content retained at the permanent wilting point (Richards & Weaver, 1944), and water content at which penetration resistance (PR) is limiting to root growth
The soybean yield was evaluated in relation to soil compaction, during two agricultural years in completely randomized design; in the second year, there was a factorial scheme, with four replicates represented by 9 m2 plots
Summary
Soil compaction can reduce root growth through physical processes associated with lower aeration and decreasing water and nutrients absorption, which causes significant yield decrease (Flowers & Lal, 1998; Beutler & Centurion, 2004; Czyz, 2004). Adequate PR to the plants development, suitable levels of available water and aeration are required; these properties affect root growth and plant yield directly (Letey, 1985). The least limiting water range has been effectively utilized in soil physics to monitor soil use and tillage systems, in three ways: to evaluate physical quality towards plant growth (Tormena et al, 1999; Wu et al, 2003); to establish relations between this indicator and the aerial part of plant growth (Silva & Kay, 1996); to investigate functional relationships between LLWR and grain yield (Benjamin et al, 2003; Lapen et al, 2004; Beutler et al, 2005; Collares et al, 2006). The research aimed to evaluate machine traffic effect on soil compaction and the least limiting water range related to soybean cultivar yield, during two years, in a Haplustox soil
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
