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目前增加农田生态系统的碳储量的措施主要有:减少碳损失,包括提高能源利用率,减少水土流失和提高水肥利用率;增加土壤有机碳,包括调整耕作制度,使用有机肥料,应用深根作物和增加土壤中微团聚体的含量。在分析各种策略与措施的基础上,笔者认为以下几种农田碳汇管理措施有效且较容易推广。①实施土地用途转换管理:把低产及土壤退化严重的农田变成草地或森林;集约管理农田,实行农林复合、林草复合经营方式;在区域或地区尺度变单一土地利用方式为承担不同人类需要的多种土地利用方式等。②调整耕作制度:免耕不仅使土壤团聚体的数量和稳定性增加,从而减少了团聚体内部有机质的分解作用;还能有效地抑制土壤的过度通气,减少有机碳的氧化降解,防止土壤侵蚀;此外,免耕土壤有机碳的平均滞留时间比常规耕作土壤增加了约1倍。轮作能提高土壤固碳效率,在轮作中加入豆科作物或豆科牧草更可增加土壤有机质汇集,是实现土壤蓄存碳潜力的重要途径。提高复种指数,降低休耕频率可以提高作物产量并增加土壤作物残茬和根的有机质输入,从而增加土壤中有机碳的含量。③改善经营与管理:有机肥或有机肥和化肥配合施用,能显著提高土壤有机碳含量,应当优先选择;人为改变土壤的水分条件可以调节土壤排放温室气体的总量、组成及其产生的潜在温室效应;残茬和土壤有机质库的增加,可以改善植物的水分利用效率和营养再循环能力,减少养分流失,加强碳汇集。④依托技术进步:如改良作物品种,有计划地抓紧培育具有对高温、干旱等极端气候及病虫害有抗性的品种,确保在新的生态环境中产量不断提高,扩大碳的吸收存储。此外,采用新型节能的农机部件对拖拉机等农业动力机械进行改装,也可减少农田碳排放,增加农田碳汇的潜力。
The current measures to increase carbon storage in farmland ecosystems include: reducing carbon loss, including increasing energy efficiency, reducing soil erosion and water and fertilizer use efficiency; increasing soil organic carbon, including adjusting cropping system, using organic fertilizers, applying deep root crops And increase soil microaggregate content. Based on the analysis of various strategies and measures, the author believes that the following measures to manage carbon sequestration in farmland are effective and easy to popularize. (1) Implement land conversion management: turn low-yielding and seriously degraded farmland into grassland or forest; intensively manage farmland and implement agroforestry and grass-forestry complex management; change single-site land use at regional or regional scales to meet different human needs A variety of land use patterns. (2) Tillage system adjustment: No-tillage not only increased the amount and stability of soil aggregates, thus reducing the decomposition of organic matter in the aggregates; but also effectively inhibited the hyperventilation of the soil, reduced the oxidative degradation of organic carbon, and prevented soil erosion In addition, the average residence time of no-tillage soil organic carbon increased by about 1 times than that of conventional tillage. Rotation can increase soil carbon sequestration efficiency. Adding leguminous crops or leguminous pasture to the crop rotation can increase the accumulation of soil organic matter, which is an important way to realize the carbon potential of soil. Increasing the multiple cropping index and reducing the frequency of fallow can increase the crop yield and increase the input of organic matter in the stubble and root of soil crop so as to increase the content of organic carbon in the soil. ③ improve management and management: organic manure or organic manure and chemical fertilizer application, can significantly increase soil organic carbon content, should be given priority; man-made changes in soil moisture conditions can regulate the total amount of greenhouse gas emissions, composition and potential Greenhouse effect; Increase in stubble and soil organic matter stocks can improve plant water use efficiency and nutrient recirculation capacity, reduce nutrient loss and enhance carbon sinks. (4) Relying on technological progress: For example, to improve crop varieties, cultivate cultivars with resistance to extreme weather and pests such as high temperature, drought and so on in a planned way, and ensure that the yield in new ecological environment will be continuously increased and carbon storage and absorption will be expanded. In addition, the use of new and energy-saving farm machinery components to retrofit agricultural power machinery such as tractors will also reduce the carbon emissions from farmland and increase the potential for carbon sequestration in farmland.