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Assessing the effectiveness of agricultural conservation practices in maintaining soil organic carbon under contrasting agroecosystems and a changing climate
Author(s) -
Gollany Hero T.,
DelGrosso Stephen J.,
Dell Curtis J.,
Adler Paul R.,
Polumsky Robert W.
Publication year - 2021
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.1002/saj2.20232
Subject(s) - agroecosystem , agronomy , cover crop , soil carbon , stover , environmental science , tillage , sativum , manure , crop rotation , forage , conventional tillage , crop , biology , agriculture , soil water , soil science , ecology
The potential of conservation practices to maintain soil organic C (SOC) and reduce climate change impacts on yields is unknown. This study aimed to validate the DayCent model with observed yield data and the CQESTR model with measured SOC in two agroecosystems, and predict the best practices to sustain SOC under projected climate change. Data were from a conventional tillage (CT) wheat ( Triticum aestivum L.)–fallow rotation without N or with 135 kg N ha –1 fertilizer, and no‐till (NT) experiments, NT A (NT A0 W‐F and NT A135 W‐F) and NT B with a wheat–pea ( Pisum sativum L.) cover crop (NT B0 W‐P and NT B135 W‐P) in Oregon; and crop rotations with CT and NT silage or grain corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–alfalfa ( Medicago sativa L.) with or without manure or stover removal or a cover crop in Pennsylvania. Measured and CQESTR‐simulated SOC were significantly ( p < .0001) correlated ( r = .90). In Oregon, predicted SOC to 60 cm increased under NT A135 W‐F and NT B135 W‐P at 0.05 and 0.08 Mg ha –1 yr –1 under projected climate change, respectively. The NT management under dryland production provided a limited SOC increase. In Pennsylvania, predicted SOC to 1 m decreased at 0.07 Mg ha –1 yr –1 in corn–soybean under CT or NT with stover removal, but increased by 0.71 Mg ha –1 yr –1 in dairy forage NT and manure added under climate change. The responses of SOC to climate change were affected by management, biomass type, edaphic properties, local climate, and agroecosystem.