Institute of Geography, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350007, China.
Institute of Geography, Fujian Normal University, Fuzhou 350007, China; Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, Fujian Normal University, Fuzhou 350007, China.
Sci Total Environ. 2022 Dec 10;851(Pt 2):158322. doi: 10.1016/j.scitotenv.2022.158322. Epub 2022 Aug 28.
Agronomic management practices present an opportunity to improve the sustainability of crop production, including reductions of greenhouse gas emissions through impacts on soil organic carbon (SOC) dynamics. We investigated the impacts of contrasting application rates of nitrogen (N)-enriched biochar (4 and 8 t ha) on the concentrations of total and active SOC, microbial biomass carbon (MBC), soil aggregates, and the carbon (C) pool management index (CPMI) as an indicator of soil quality in tillering and mature subtropical early and late rice in China. Soil salinity and soil bulk density increased, and soil water content generally decreased under the application of N-enriched biochar at 4 t ha. Following the application of the biochar, there were greater soil concentrations of SOC and lower concentrations of dissolved organic-C and active labile organic‑carbon, indicating reduced mineralization and enhanced stocks of stable-C. Biochar application (4 and 8 t ha) led to lower soil Ca-SOC concentrations and greater soil Fe(Al)-SOC concentrations. Concentrations of Fe(Al)-SOC were greater under the application of N-enriched biochar at 4 t ha, indicating the bonding capacity of iron‑aluminum oxide and organic carbon provided by biochar improved levels of SOC fixation. The composition of soil aggregates under each treatment was mainly micro-aggregates (<0.25 mm). The greater soil content of macro-aggregates (>0.25 mm) increased under amendment with 4 t of biochar ha and the greater SOC content led to greater soil aggregate stability. Levels of C pool activity, C pool index, and CPMI reduced following application of the biochar, while C pool activity index increased slightly, indicating an increase in soil quality. These results indicate that the application of N-enriched biochar during rice cultivation may lead to reductions in SOC mineralization and C emissions and increases in soil C sink capacity, due to greater SOC pool stability, thus improving the sustainability of paddy rice production.
农业管理措施为提高作物生产的可持续性提供了机会，包括通过影响土壤有机碳（SOC）动态来减少温室气体排放。我们研究了不同施氮量富氮生物炭（4 和 8 t ha）对分蘖期和成熟期亚热带早稻和晚稻总SOC 和活性 SOC、微生物生物量碳（MBC）、土壤团聚体和碳库管理指数（CPMI）浓度的影响，CPMI 作为土壤质量的指标。在施氮量富氮生物炭 4 t ha 的情况下，土壤盐分和土壤容重增加，土壤含水量普遍降低。生物炭施用后，SOC 土壤浓度增加，溶解有机碳和活性易分解有机碳浓度降低，表明矿化减少，稳定碳储量增加。生物炭施用（4 和 8 t ha）导致土壤 Ca-SOC 浓度降低，Fe（Al）-SOC 浓度增加。在施氮量富氮生物炭 4 t ha 的情况下，Fe（Al）-SOC 浓度更高，表明铁铝氧化物和生物炭提供的有机碳的结合能力提高了 SOC 固定水平。在每个处理下，土壤团聚体的组成主要是微团聚体（<0.25 mm）。在施用 4 t ha 生物炭的情况下，较大的土壤宏团聚体（>0.25 mm）含量增加，SOC 含量较高导致土壤团聚体稳定性增加。生物炭施用后，C 库活性、C 库指数和 CPMI 水平降低，而 C 库活性指数略有增加，表明土壤质量提高。这些结果表明，在水稻种植过程中施用富氮生物炭可能会导致 SOC 矿化和 C 排放减少，以及土壤 C 汇能力增加，这是由于 SOC 库稳定性增加，从而提高了水稻生产的可持续性。
