TY - JOUR

T1 - Winter cover crops favor cereal crop in N competition against creeping thistle Cirsium arvense (L.) Scop

AU - Phan, Hong T.T.

AU - Wacker, Tomke Susanne

AU - Thorup-Kristensen, Kristian

N1 - Publisher Copyright: © 2021 Elsevier B.V.

PY - 2022

Y1 - 2022

N2 - Weed control is important to improve crop yield in organic farming. In Northern Europe, the use of mechanical weed control restricts the ability to use green manure-cover crops that could be a key source of N supply. In a two-year experiment repeated twice, the objective of this study was to compare the effect of cover crop- and autumn tillage-based systems on N uptake of the succeeding barley crop (Hordeum vulgare L.) and creeping thistle (Cirsium arvense (L.) Scop.). Each autumn, a 15NO3- tracer was applied to the topsoil, and in spring its recovery was measured in the soil, barley and thistle. The effect of cover crops on soil N distribution was significant: 66–85% of the total recovered 15NO3- was in the upper 0.5 m after the cover crop treatments, while after the autumn tillage treatment only 4–8% of the recovered 15NO3- was in this soil layer. The 15NO3- retained by cover crops in the topsoil postponed its availability to the deep-rooted thistle, while making it available to the shallow-rooted spring barley, thus strengthening the barley's ability to compete against thistle. In contrast, following autumn tillage, 15NO3- clearly leached downward; much of it leached below the barley root zone, but remained at depths where it could be taken up by thistle. Cover cropping was found to have a post-harvest control effect on perennial weeds.

AB - Weed control is important to improve crop yield in organic farming. In Northern Europe, the use of mechanical weed control restricts the ability to use green manure-cover crops that could be a key source of N supply. In a two-year experiment repeated twice, the objective of this study was to compare the effect of cover crop- and autumn tillage-based systems on N uptake of the succeeding barley crop (Hordeum vulgare L.) and creeping thistle (Cirsium arvense (L.) Scop.). Each autumn, a 15NO3- tracer was applied to the topsoil, and in spring its recovery was measured in the soil, barley and thistle. The effect of cover crops on soil N distribution was significant: 66–85% of the total recovered 15NO3- was in the upper 0.5 m after the cover crop treatments, while after the autumn tillage treatment only 4–8% of the recovered 15NO3- was in this soil layer. The 15NO3- retained by cover crops in the topsoil postponed its availability to the deep-rooted thistle, while making it available to the shallow-rooted spring barley, thus strengthening the barley's ability to compete against thistle. In contrast, following autumn tillage, 15NO3- clearly leached downward; much of it leached below the barley root zone, but remained at depths where it could be taken up by thistle. Cover cropping was found to have a post-harvest control effect on perennial weeds.

KW - N isotope

KW - Autumn tillage

KW - Cover crops

KW - Creeping thistle

KW - Inter-row hoeing

KW - Nitrogen distribution

KW - Organic farming

KW - Perennial weed control

KW - Species competition

U2 - 10.1016/j.still.2021.105261

DO - 10.1016/j.still.2021.105261

M3 - Journal article

AN - SCOPUS:85119596559

VL - 216

JO - Soil & Tillage Research

JF - Soil & Tillage Research

SN - 0167-1987

M1 - 105261

ER -