A Short-Term Assessment of Carbon Dioxide Fluxes under Contrasting Agricultural and Soil Management Practices in Zimbabwe
A Short-Term Assessment of Carbon Dioxide Fluxes under Contrasting Agricultural and Soil Management Practices in Zimbabwe
复制标题
津巴布韦农业和土壤管理实践对比二氧化碳通量的短期评估
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
S. Twomlow
中科院分区：
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作者：
J. Nyamangara;K. Nyengerai;E. Masvaya;R. Tirivavi;N. Mashingaidze;W. Mupangwa;J. Dimes;L. Hove;S. Twomlow
人类面临的两个最大问题是养活呈指数级增长的人口和防止大气温室气体的积累及其气候变化后果。改进的农业实践可以解决这两个问题。这里涉及的研究是探索替代农业实践在封存碳(C)方面的有效性。这项研究是在津巴布韦进行的，目的是(A)展示微气象方法在短期内测量地表和大气之间二氧化碳(CO2)交换的效用，以及(B)量化各种农业实践中这种交换率的差异。建立了4个波文比能量平衡(BREB)系统：(1)免耕(NT)后种植冬小麦(Triticum Aestivum)；(2)免耕后种植蓝羽扇豆(Lupinus angustifolios L.)；留在地面上；(4)玉米秸秆与耕作结合。在139天的时间里(从2013年6月15日到10月31日)，冬小麦覆盖作物产生了257克CO2-Cm-2的净累积，而没有覆盖作物的耕作地产生了197克CO2-Cm-2的净排放，而无覆盖的耕作地产生了235克CO2-Cm-2的净排放。蓝色羽扇豆覆盖作物排放58克CO2-Cm-2，表明冬季覆盖作物可以固定碳，并在非生长季节休耕的土地上减少排放。这项工作中描述的微气象方法可以在几个月的时间内检测到不同处理之间的显著差异，这一结果对于确定哪些小农土壤管理做法可以有助于缓解气候变化非常重要。
Two of the biggest problems facing humankind are feeding an exponentially growing human population and preventing the accumulation of atmospheric greenhouse gases and its climate change consequences. Refined agricultural practices could address both of these problems. The research addressed here is an exploration of the efficacy of alternative agricultural practices in sequestering carbon (C). The study was conducted in Zimbabwe with the intent to (a) demonstrate the utility of micrometeorological methods for measuring carbon dioxide (CO2) exchange between the surface and the atmosphere in the short-term, and (b) to quantify differences in such exchange rates for a variety of agricultural practices. Four Bowen ratio energy balance (BREB) systems were established on the following agricultural management practices: (1) no-till (NT) followed by planting of winter wheat (Triticum aestivum), (2) NT followed by planting of blue lupin (Lupinus angustifolios L.), (3) maize crop residue (Zea mays L.) left on the surface, and (4) maize crop residue incorporated with tillage. Over a period of 139 days (from 15 June to 31 October 2013) the winter wheat cover crop produced a net accumulation of 257 g CO2-C m -2 , while the tilled plot with no cover crop produced a net emission of 197 g CO2-C m -2 and the untilled plot with no cover emitted 235 g CO2-C m -2 . The blue lupin cover crop emitted 58 g CO2-C m -2 , indicating that winter cover crops can sequester carbon and reduce emissions over land left fallow through the non-growing season. The micrometeorological methods described in this work can detect significant differences between treatments over a period of a few months, an outcome important to determine which smallholder soil management practices can contribute towards mitigating climate change.