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A Comparison of Reduced Tillage Implements for Organic Wheat Production in Western Canada
Author(s) -
Podolsky Kristen,
Blackshaw Robert E.,
Entz Martin H.
Publication year - 2016
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2016.01.0032
Subject(s) - agronomy , tillage , cover crop , mulch till , weed , weed control , no till farming , minimum tillage , seedbed , hordeum vulgare , environmental science , perennial plant , conventional tillage , biology , sowing , soil fertility , poaceae , soil water , soil science
Low‐tillage systems are needed to improve soil conservation in organic farming. This study evaluated three no‐till/low‐till cover crop termination strategies on the basis of weeds, N dynamics and growth and yield of a wheat ( Triticum aestivum L.) test crop. Field experiments were conducted in two different Canadian provinces. The blade roller, flail mower, and undercutter cultivator were comparable with standard tillage for controlling a full‐season barley ( Hordeum vulgare L.)–pea ( Pisum sativum L.) cover crop. Reduced tillage implements resulted in some depression of soil temperature the following spring and some delay in spring wheat development. Yield differences between treatments were related to weed and N consequences not seedbed quality or wheat development. Undercutting sometimes resulted in better perennial weed control than blade rolling. Blade roll plus late‐season tillage treatment improved perennial weed control but provides less residue for soil protection. Flail mowing resulted in more rapid cover crop biomass mulch decomposition, allowing weeds to establish. Reducing tillage reduced N availability to the following wheat crop relative to tillage, and reduced N leaching. Poor weed suppression in low‐till treatments meant that a higher proportion of available N was sometimes captured by weeds compared with the wheat crop. Future studies should test combinations of alternative tillage and crop termination approaches aimed at specific weed and nutrient challenges. Core Ideas Alternative tillage tools were tested for control of cover crops preseeding spring wheat. Perennial weeds meant low tillage options were not feasible when wheat seeding was delayed. Undercutting liberated more cover crop N than blade roll but weeds sometimes captured this N.