讀書報(bào)告4土壤碳固定對(duì)全球氣候變化和糧食安全的影響

1、Soil Carbon Sequestration Impacts on Global Climate Change and Food SecurityTutor : Prof . ZHENGSpeaker : DongXiaogangDate : 2021-05-10R. Lal ,et al. 2004 Science 304, 1623土壤碳固定對(duì)全球氣候變化和糧食平安的影響.2.Soil Carbon Sequestration3.Soil Carbon Sequestration for Mitigating Climate Change4.Soil Carbon Sequestra

2、tion and Global Food Security5.Conclusions1.Background Content.The global soil carbon (C) pool of 2500 gigatons (Gt) includes about 1550 Gt of soil organic carbon (SOC) and 950 Gt of soil inorganic carbon (SIC). 1.BackgroundThe soil C pool is 3.3 times the size of the atmospheric pool (760 Gt) and 4

3、.5 times the size of the biotic pool (560Gt, fig. S1).25000億噸的全球土壤碳庫(kù)由15500億噸的土壤有機(jī)碳和9500億噸的土壤無(wú)機(jī)碳組成。土壤碳庫(kù)的容量是大氣碳庫(kù)的3.3倍，是生物碳庫(kù)的4.5倍。.Fig. 1. Processes affecting soil organic carbon (SOC) dynamics.The SOC pool represents a dynamic equilibrium of gains and losses (Fig. 1). 土壤碳庫(kù)處于收支動(dòng)態(tài)平衡。.Severe depletion of

4、 the SOC pool degrades soil quality, reduces biomass productivity, and adversely impacts water quality, and the depletion may be exacerbated by projected global warming.The depletion is exacerbated when the output of C exceedsthe input and when soil degradation is severe.當(dāng)輸出超越輸入和土壤退化嚴(yán)重時(shí)土壤碳庫(kù)的耗竭將加劇。土壤

5、碳庫(kù)的嚴(yán)重耗竭使得土壤質(zhì)量退化，生物產(chǎn)量降低，影響水質(zhì)量，預(yù)測(cè)的全球變暖能夠會(huì)加劇土壤碳庫(kù)的耗竭。.The estimates of historic SOC loss range widely, from 44 to 537 Gt, with a common range of 55 to 78 Gt (3).以往的土壤有機(jī)碳的損失量的估算值變化范圍寬廣約從440到5370億噸，而共識(shí)的損失量是550到780億噸。.2.Soil Carbon SequestrationCarbon sequestration implies transferring atmospheric CO2 into

6、 long-lived pools and storing it securely so it is not immediately reemitted. Thus, soil C sequestration means increasing SOC and SIC stocks through judicious land use and recommended management practices (RMPs).土壤碳固定意味著將大氣中的CO2轉(zhuǎn)移到長(zhǎng)期存在的土壤庫(kù)中并平安地儲(chǔ)存它，因此使碳不能立刻釋放到大氣中。因此土壤碳固定意味著經(jīng)過(guò)準(zhǔn)確的土地運(yùn)用和引薦的管理措施(RMPs)添加了土

7、壤有機(jī)和無(wú)機(jī)碳庫(kù)的容量。.The SOC sequestration is caused by those management systems that add high amounts of biomass to the soil, cause minimal soil disturbance, conserve soil and water, improve soil structure, enhance activity and species diversity of soil fauna, and strengthen mechanisms of elemental cycling

8、 (Fig. 2, table S2).土壤有機(jī)碳的固定是由向土壤中添加高生物量，使土壤遭到最小的擾動(dòng)，堅(jiān)持水土，提高土壤構(gòu)造，加強(qiáng)土壤動(dòng)物的種類和多樣性的活性，加強(qiáng)元素循環(huán)而實(shí)現(xiàn)的。 (Fig. 2, table S2)2.Soil Carbon Sequestration.Fig. 2.具有高的土壤碳固定潛能的態(tài)系統(tǒng)有:農(nóng)田，放牧的草地，退化的或沙漠化土地,灌溉的土壤放牧的草地的生態(tài)系統(tǒng)的土壤碳固定潛力不包括在全球的土壤碳固定中，這是由于它部分的被覆蓋在其它生態(tài)系統(tǒng)下以及具有很大的不確定性。.Common RMPs that lead to SOC sequestration are mu

9、lch farming, conservation tillage, agroforestry and diverse cropping systems, cover crops (Fig. 3), and integrated nutrient management, including the use of manure, compost, biosolids, improved grazing, and forest management.通常導(dǎo)致土壤有機(jī)碳固定的RMPs措施是：覆蓋農(nóng)業(yè)，維護(hù)性耕作，混農(nóng)林和多樣性種植系統(tǒng)(Fig. 3)，和包括由糞肥、堆肥、生物固體、改善的放牧方式和林

10、地管理的運(yùn)用的綜合營(yíng)養(yǎng)管理。2.Soil Carbon Sequestration.Fig. 3. Important recommended management practices are no-till farming, cover crops, manuring and agroforestry. (A: Long-term no-till plots B: Agroforestry).The rate of SIC sequestration as secondary carbonates is low (5 to 150 kg C/ha per year) and is accen

11、tuated by biogenic processes and leaching of carbonates into the groundwater (11, 12), especially in soils irrigated with water containing low carbonates.作為處于次要位置的碳酸鹽，土壤無(wú)機(jī)碳的固定的速率是很低的(每年5到150kgC/ha)，土壤無(wú)機(jī)碳作為生命必需的過(guò)程和碳酸鹽向地下水的淋洗過(guò)程被注重，(11,12)特別是在含有低碳酸鹽的水中的土壤灌溉區(qū)。2.Soil Carbon Sequestration土壤無(wú)機(jī)碳的固定.3.Soil C

12、arbon Sequestration for Mitigating Climate Change 土壤碳固定對(duì)氣候變化的緩解Estimates of the total potential of C sequestration in world soils vary widely from a low of 0.4 to 0.6 Gt C/year (9) to a high of 0.6 to 1.2 Gt C/year (13). Thus, the potential is finite in capacity and time. Nonetheless, soil C sequest

13、ration buys us time until the alternatives to fossil fuel take effect.Some issues related to this strategy are as follows:全球土壤碳固定總的潛力的估算值是非常廣泛的，從低的0.4 to 0.6 Gt C/year (9) 到高的0.6 to 1.2 Gt C/year (13)。因此，這種固定的潛力在容量和時(shí)間上是有限的。雖然如此，直到我們能找到化石燃料的替代品時(shí)，土壤碳固定為我們爭(zhēng)取了時(shí)間。.(1).Agricultural chemicals 農(nóng)化用品Most RMPs

14、 involve C-based input. Item (1 Kg)Need C (Kg)N0.86P2O50.17K2O0.12Lime0.36Herbicides4.7Fungicides5.2Insecticides4.9.However, inputs are needed not for soil C sequestration per se, but for increasing food production and ensuring sustainable use of soil and water resources.(1).Agricultural chemicals然而

15、輸入不僅是為了土壤碳固定本身，也是添加了糧食消費(fèi)，確保水土資源運(yùn)用的可繼續(xù)。.(2).Nutrients required 營(yíng)養(yǎng)需求It is estimated that sequestration of 1 Gt of C in world soils would require 80 million tons (Mt) of N, 20 Mt of P, and 15 Mt of K. In comparison, the global fertilizer use in 2000 was Mt (17).據(jù)計(jì)算，世界土壤中10億噸的碳固定需求8000萬(wàn)噸的N，2000萬(wàn)噸的P，1500

16、萬(wàn)噸的K。與此相比，2000年全球肥料的施用量為1.36億噸17。One ton of cereal residue contains 12 to 20 kg N, 1 to 4 kg P, 7 to 30 kg K, 4 to 8 kg Ca, and 2 to 4 kg Mg. Annually, 3 Gt of residues of grain crops are produced globally (table S3), which if recycled rather than removed for fuel and other uses, would improve soil

17、quality and sequester C.一噸的禾谷類作物殘?jiān)?2到20Kg的N，1到4Kg的P，7到30Kg的K,4到8Kg的Ca以及2到4Kg的Mg。每年全球有30億噸的禾谷類作物殘?jiān)幌M(fèi)(table S3)，這些作物殘?jiān)僭O(shè)是循環(huán)利用而不是用于燃料和其它方面的運(yùn)用，將提高土壤質(zhì)量和固定碳。.(2).Nutrients requiredCrop residue is also a potential source of energy by direct combustion, or for production of ethanol or H2.It can be used e

18、ither for biofuel production or to sequester C and improve soil quality. The economics of these two competing uses need to be assessed.作物殘?jiān)?jīng)過(guò)直接的熄滅也是能源的一個(gè)潛在的庫(kù)，或者也可以作為乙醇或氫氣的消費(fèi)原料。作物殘?jiān)瓤梢杂糜谏锶剂系南M(fèi)或用于碳的固定以提高土壤質(zhì)量。這二者的競(jìng)爭(zhēng)運(yùn)用的經(jīng)濟(jì)效益需求被評(píng)價(jià)。.(3).Soil erosion and deposition 土壤的侵蝕和堆積The SOC is preferentially removed

19、 by wind- and water-borne sediments through erosional processes. Some of the SOC-enriched sediments are redistributed over the landscape, others are deposited in depressional sites, and some are carried into the aquatic ecosystems (Fig. 1).Yet, an effective soil erosion control is essential to susta

20、inable use of agricultural soils and improving environment quality.土壤有機(jī)碳是經(jīng)過(guò)侵蝕過(guò)程優(yōu)先被風(fēng)傳和水傳沉淀的。一些是在陸地在分布，一些是在作用位點(diǎn)被堆積，而另一些是被挪動(dòng)到水生生態(tài)系統(tǒng)中(Fig. 1)。然而，一個(gè)有效的土壤的侵蝕的控制對(duì)于農(nóng)業(yè)土壤的可繼續(xù)運(yùn)用和改善環(huán)境質(zhì)量來(lái)說(shuō)是很重要的。.Fig. 1. Processes affecting soil organic carbon (SOC) dynamics.(4).Extractive farming practices 傳統(tǒng)的農(nóng)業(yè)措施The annual depl

21、etion rate of nutrients for sub- Saharan Africa (SSA) caused by low-input/ subsistence farming is estimated to be 40 kg of NPK/ha of cultivated land since the mid-1960s (20).Therefore, RMPs must enhance rather than deplete SOC pool and soil fertility, increase rather than maintain or decrease crop y

22、ield per unit use of fertilizer and other inputs, and improve rather than degrade soil quality.由于低投入或自給農(nóng)業(yè)引起的SSA每年的營(yíng)養(yǎng)耗竭速率從20世紀(jì)60年代的耕地開場(chǎng)被估算為每公頃40KgNPK20。因此，RMPs一定是提高而不是耗竭土壤有機(jī)碳庫(kù)和土壤肥力，添加而不是堅(jiān)持和減少每單位作物的產(chǎn)量經(jīng)過(guò)肥料和其它方面的投入，提高而不是退化土壤質(zhì)量。.(5).Societal value and hidden benefits 社會(huì)價(jià)值和潛在的效益Carbon trading markets have

23、 existed since 2002, especially in European Union countries (21).the price of soil C must be based on both on-site and off-site societal benefits (table S4). Undervaluing soil C can lead to a “tragedy of the commons.從2002年開場(chǎng)碳買賣市場(chǎng)開場(chǎng)存在，特別是在歐盟國(guó)家(21)。土壤碳的價(jià)錢必需基于社會(huì)各方面的利益。低估土壤碳會(huì)導(dǎo)致一個(gè)常識(shí)性的悲劇。.(6).Hydrologic a

24、nd carbon cycles 水文學(xué)和碳循環(huán)Because renewable freshwater is scarce, a projected increase in cereal production by 56% between 1997 and 2050 (23) must occur on the same or smaller land area and with the same or less water. Thus, linking the hydrologic and C cycles through conservation of water resources i

25、s crucial to improving agronomic yields and to soil C sequestration in dryland.Enhancing SOC stock in dryland ecosystems through notill farming is important to drought management: a truly win-win option (24).由于可更新的新穎的水很少，預(yù)測(cè)在1997年到2050年間禾谷類作物的產(chǎn)量將增長(zhǎng)56%23，而要實(shí)現(xiàn)這個(gè)目的需求現(xiàn)有一樣或比現(xiàn)有耕地面積小的耕地以及現(xiàn)有一樣或比現(xiàn)有水小的水用量。因此經(jīng)過(guò)

26、水資源的維護(hù)將水文學(xué)和碳循環(huán)聯(lián)絡(luò)起來(lái)以提高農(nóng)作物產(chǎn)量和在旱地上的土壤碳固定是非常重要的。.(7).Soil C sequestration and global warmingSoil C sequestration is a related but separate issue with its own merits of increasing productivity, improving water quality, and restoring degraded soils and ecosystems, irrespective of the global-warming debate

27、.Furthermore, soil C sequestration is a bridge across three global issues climate change, desertification, and biodiversity and a natural link among three UN conventions.Global warming is a “century-scale problem and a “global commons issue.(8).Other greenhouse gases 其它的溫室氣體Enhancing SOC stock incre

28、ases the soils capacity to oxidize CH4, especially under no-till farming (25), but may also exacerbate emission of N2O (26).添加土壤有機(jī)碳的同時(shí)也加強(qiáng)了土壤氧化CH4的才干，特別是在免耕農(nóng)業(yè)系統(tǒng)中(25)，能夠也加劇了N2O的排放(26)。.(9).Soils of the tropics 熱帶地域的土壤Because of its severe depletion and degradation, the C sink capacity of soils of the

29、tropics may be high, but the rate of sequestration can be low. The need for enhancing soil quality is also more urgent in soils of the tropics than in soils of high latitudes because of low crop yields.Soil-restorative farm policies must be implemented to mitigate soil degradative trends.由于嚴(yán)重的營(yíng)養(yǎng)耗竭和土

30、壤退化，熱帶地域的土壤碳庫(kù)的容量能夠是很高的，但是土壤碳固定的速率是很低的。添加土壤質(zhì)量的需求在熱帶地域的土壤比在高緯度地域的土壤是更緊急的，由于熱帶地域的作物產(chǎn)量是很低的。.(10).Permanence 耐久性Soil C sequestration is a natural, cost-effective, and environment friendly process.Soil sink capacity and permanence are related to clay content and mineralogy, structural stability, landscape

31、 position, moisture and temperature regimes, and ability to form and retain stable microaggregates.土壤碳固定是一個(gè)自然的，劃算的和環(huán)境友好的過(guò)程。土壤碳庫(kù)的容量和耐久性是與粘粒含量和礦物學(xué)、構(gòu)造的穩(wěn)定性，地理位置，水分和溫度形狀，以及穩(wěn)定性聚會(huì)體的構(gòu)成和堅(jiān)持的才干聯(lián)絡(luò)嚴(yán)密的。.4.Soil Carbon Sequestration and Global Food Security 土壤碳固定和全球糧食平安Global hotspots of soil degradation with a hig

32、h priority for soil restoration and C sequestration include SSA, central and south Asia, China, the Andean region, the Caribbean, and the acid savannas of South America.As a source of nutrients for growing crops, the SOC pool is a mean of production in subsistence farming systems of SSA, which accou

33、nts for only 2.5% of the fertilizer consumption and 2% of the worlds irrigated land area, both essential to SOC sequestration.當(dāng)生長(zhǎng)的作物作為營(yíng)養(yǎng)的一個(gè)源時(shí)，在SSA的自給農(nóng)業(yè)中土壤有機(jī)碳庫(kù)是作物消費(fèi)的一種手段。(SSA僅占世界肥料耗費(fèi)的2.5%，占世界灌溉土地的2%，而這些對(duì)于土壤有機(jī)碳的固定是很重要的。)4.Soil Carbon Sequestration and Global Food Security.Fertilizer application is an important strategy of increasing crop yield in SSA (27), but its effectiveness is enhanced when used in conjunction with crop residue mulch (28) or