CSIR - Central Institute of Medicinal and Aromatic Plants, Picnic Spot Road, Lucknow 221615, Uttar Pradesh, India.
CSIR - Central Institute of Medicinal and Aromatic Plants, Picnic Spot Road, Lucknow 221615, Uttar Pradesh, India.
J Environ Manage. 2014 Mar 15;135:118-25. doi: 10.1016/j.jenvman.2014.01.027. Epub 2014 Feb 14.
Soil organic carbon (SOC) is accumulated or depleted as a result of cropping and management strategies. It plays a significant role in maintaining soil quality, plant productivity and mitigating greenhouse gas emission. We studied the long-term (20 years) influence of a wheat-mint-Sesbania cropping system on the SOC stock. Estimates of stabilization of SOC in different pools and a tentative C budget were also developed. Twenty years of cultivation caused a decrease in SOC only in control soils, which received no manure and fertilizer. However, it increased with balanced use of NPK inputs. Soil C stock decreased significantly with increased in soil depth 0-15 cm to 15-30 and 30-45 cm. About 6% (-2 to+14) of the C added in crop residues and green manure were stabilized in the soil. On an average 12%, 14%, 59%, 15% of the water stable aggregates were in the >2 mm, 2.0-0.25 mm, 0.25-0.05 mm, and <0-0.5 size fractions, respectively. Significant improvements in structural stability and nitrogen availability were detected in all the treatments compared to the control. The amount of organic C oxidizable by a modified Walkley and Black method, which involves using only half of the amount of sulphuric acid, is a more sensitive indicator of the improvement in soil quality parameters under investigation, namely SOC, and increases in mineralizable N and water stable aggregation than the standard method.
土壤有机碳（SOC）是由于耕作和管理策略而积累或消耗的。它在维持土壤质量、植物生产力和减少温室气体排放方面起着重要作用。我们研究了小麦-薄荷-田菁轮作系统对 SOC 储量的长期（20 年）影响。还估计了不同库中 SOC 的稳定性和暂定的 C 预算。20 年的耕作仅在未施有机肥和化肥的对照土壤中导致 SOC 减少。然而，随着 NPK 投入的平衡使用，SOC 增加了。土壤 C 储量随 0-15cm 土壤深度的增加而显著减少，至 15-30cm 和 30-45cm。大约 6%（-2 至+14）的作物残茬和绿肥中的 C 被稳定在土壤中。平均而言，12%、14%、59%和 15%的水稳性团聚体分别存在于>2mm、2.0-0.25mm、0.25-0.05mm 和<0-0.5mm 粒径级分中。与对照相比，所有处理都显著提高了结构稳定性和氮素有效性。使用改良的沃克-布莱克法（仅使用一半硫酸量）可氧化的有机碳量是对所研究的土壤质量参数（即 SOC）以及矿化氮和水稳性团聚体增加的更敏感的指标，比标准方法更能提高土壤质量参数。
