Optimizing organic substitution: Balancing carbon sequestration and priming effects of a six-year field experiment for sustainable vegetable production

作者：Xintong Xu, Ruiyu Bi, Mengxin Song, Bingxue Wang, Yubing Dong, Qianqian Zhang, Zhengqin Xiong · 发表于：Sustainable Production and Consumption · 年份：2023 · DOI：10.1016/j.spc.2023.11.019 · 被引用次数：19 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics、Soil and Unsaturated Flow

Organic substitution has been recognized to markedly influence soil organic carbon (SOC) dynamics and carbon sequestration . However, the priming effect can alter SOC mineralization , contingent upon the varying proportions and intensities of mineralization introduced by fresh organic substrates. A comprehensive assessment to pinpoint the organic substitution level in intensive vegetable cultivation remains elusive. Thus, we carried out a 6-year field experiment, following four fertilization treatments at consistent nitrogen levels: solely mineral fertilizer ; and organic fertilizers replacing 20 %, 50 %, and 100 % of mineral nitrogen fertilizer . We assessed carbon dioxide emissions derived from various sources, soil properties, nutrient availability, enzyme activity , 13 C-phospholipid fatty acid, SOC stability, and nutrient stoichiometries via a 63-day incubation with 13 C glucose. Our results showed that different levels of organic substitution significantly affected soil mineralization and priming effect. The microbial community was the primary determinant of priming effect, accounting for 59.4 % of the variation, with gram-positive bacteria (i.e., a15: 0) being instrumental. Moreover, organic fertilizers provided a large amount of labile substrate, diminishing the microbial requirement for enzyme production in SOC decomposition. Notably, 50 % organic substitution consistently outperformed others, consistently yielding 1.17 to 1.29 times more than alternative treatments....