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3 mai 2021 14:25

3 mai 2021 14:28

Successful synergy between organic management and conservation tillage could provide the best agroecological benefits by minimizing the negative effects of both synthetic chemicals and intensive tillage on soils. We studied the long-term impacts of conventional and organic crop management under different tillage regimes on soil organic carbon (SOC) and soil aggregation, leveraging Rodale Institute's long-term Farming Systems Trial. The experiment was initiated in 1981 with three cropping systems under intensive tillage management: (i) conventional (3-yr rotation of corn-corn-soybean) with synthetic fertilizer application, (ii) organic-legume (4-yr rotation of corn-oats-soybean/wheat-wheat) organic system with legume as sole nitrogen source, and (iii) organic-manure (8-yr rotation of soybean/wheat-wheat/hay-hay-hay-corn silage/wheat-wheat-corn-oats) organic system with composted manure and legumes as nitrogen sources. There were 8 replications for each of these cropping systems when the trial was initiated in 1981. In 2008, four replicates of each cropping system treatment were placed under conservation tillage management. Soils were collected from 0–10, 10–20, and 20–30 cm depths in 2018 and measured for total SOC, active SOC fractions (microbial biomass C, water extractable C, permanganate-oxidizable C), aggregate size distribution, and wet aggregate stability. Overall, total and active SOC increased by 16–132% under organic management compared to conventional management and the increase was more pronounced under organic-manure treatment than organic-legume treatment. Results also showed that 10 years of tillage treatments did not influence active and total SOC concentrations, but influenced dry aggregate size distribution and wet aggregate stability. This study suggests that in long-term organic cropping systems, incorporated composted manure and perennial hay versus legumes alone accumulated the greatest amount of SOC compared to conventional systems. Conservation tillage in organic systems improved aggregation; however, beyond 10 years, is necessary to reflect tillage effects on SOC. This article is protected by copyright. All rights reserved

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• AB - Spécifique
• FREDO biologie et travail du sol
• GEO Etats-Unis
• carbon
• labour
• manure
• tillage

Soil Science Society of America Journal

n/a

24/04/2021

24 avril 2021

https://doi.org/10.1002/saj2.20259 Le DOI est une URL unique de référencement d'une publication. Il est donc plus fiable et permanent qu'une URL classique

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