Modelling impacts of climate change and alternative management interventions on the multi-functionality of agricultural landscapes in southern Africa

2020 ◽  
Author(s):  
Reimund Roetter ◽  
Simon Scheiter ◽  
Munir Hoffmann ◽  
Kwabena Ayisi ◽  
Paolo Merante ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Agricultural Landscapes ◽  
Sub Saharan Africa ◽  
Ecosystem Functions ◽  
Drought Risk ◽  
Crop Models ◽  
Landscape Level

<p><span><span>On the background of increasing welfare and continued population growth, there is an ever-increasing pressure on land and other natural resources in many parts of the world. The situation is, however, particularly severe in the drylands of Sub-Saharan Africa. Southern African landscapes, composed of arable lands, tree orchards and rangelands, provide a range of important ecosystem functions. These functions are increasingly threatened by land use changes through competing claims on land by agriculture, tourism, mining and other sectors, and by environmental change, namely climate change and soil degradation. Among others, climate models project that drought risk in the region will increase considerably. Based on comprehensive data sets originating from previous groundwork by several collaborative projects on the functioning of these ecosystems, a number of biophysical and bio-economic models have been developed and evaluated. In the framework of the South African Limpopo Landscapes network (SALLnet) we have now refined and tailored these models for combined use for the assessment of changes in multiple functions of the prevailing agroecosystems when affected by alternative climate and land management scenarios - from field to regional scale. We apply vegetation models (such as aDGVM), crop models (such as APSIM) and integrative farm level models (e.g. agent-based) for different farming systems in conjunction with geo-referenced databases. Model outputs are combined to assess the impact of management x environment interactions on various ecosystem functions. Of special interest in our study are the ecosystem services related to the provision of food, feed and fuel, soil and water conservation, as well as recycling and restoring carbon and nutrients in soil. To illustrate how the combination of various modelling components can work in assessing management intervention effects under different environmental conditions on landscape level ecosystem services, a case study was defined in Limpopo province, South Africa. We investigated effects of current management practices and an intensification scenario over a longer period of years on soil organic carbon change under rangeland and arable land, potential erosion, productive water use, biomass production, monthly feed gaps, and rangeland habitat quality. Tentative results showed that sustainable intensification closed the livestock feed gap, but further reduced soil organic carbon. More generally, coupling the output of vegetation and crop models regionally calibrated with sound ground/ experimental data appears promising to provide meaningful insights into the highly complex interconnections of different ecosystem services at a landscape level.</span></span></p>

The impact of hedges maturation on soil organic carbon stocks in agricultural landscapes

2021 ◽  
Author(s):  
Sofia Biffi ◽  
Pippa j Chapman ◽  
Richard P Grayson ◽  
Guy Ziv
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Agricultural Landscapes ◽  
Net Zero ◽  
Wide Range ◽  
Soc Stock ◽  
The Impact

<p>Hedgerows can provide a wide range of regulatory ecosystem services within improved grassland landscapes, such as soil function improvement, soil erosion reduction, biodiversity, water quality, and flood prevention and mitigation. Because of their beneficial effects, farmers are incentivised to retain their hedgerows and the planting of hedges has been encouraged in agri-environment schemes in Europe. Today, hedgerow planting it is one of the most popular practices adopted in the Countryside and Environmental Stewardships in England. The role of hedgerows in climate change mitigation has been increasingly recognized over the past decade, however, while other services have been more widely studies, less is known about hedges soil organic carbon (SOC) storage capacity. The Resilient Dairy Landscapes project aims at identifying strategies to reconcile dairy systems productivity and environment in the face of climate change, and with the Committee on Climate Change calling for a 30% - 40% increase in hedgerow length by 2050 in the UK, it is important to determine the role of hedgerows in meeting Net Zero targets. In this study, we estimate the extent of SOC stock beneath hedges and how it may vary with depth, hedge management and age, as well as how it may compare to SOC stock in adjacent agricultural fields. Thus, we measured SOC under 2-4 years old, 10 years old, 37 years old, and 40+ years old hedgerows at 10 cm intervals up to 50 cm of depth under 32 hedges located on dairy farms in Cumbria, UK. We found that the time since planting and the depth of samples play a crucial role in the amount of SOC stock stored underneath hedgerows when accounting for differences in soil type. Our results contribute measurable outcomes towards the estimate of targets for Net Zero 2050 and the extent of ecosystem services provision by hedgerow planting in agricultural landscapes.  </p>

scholarly journals Production of Carbon Offsets Using Conservation Agriculture Practices

2011 ◽  
Author(s):  
Jean-Francois Rochecouste ◽  
Paul Dargusch
Keyword(s):  
Climate Change ◽  
Developing Countries ◽  
Ecosystem Services ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
United Nations ◽  
Conservation Agriculture ◽  
Developed Countries ◽  
Carbon Offsets ◽  
The United Nations

This paper examines opportunities for the United Nations Framework Convention on Climate Change (UNFCCC) to consider financial mechanisms for the uptake of conservation agriculture (CA) practices in developing countries to reverse the loss of soil organic carbon. Conservation agriculture, commonly described as the reduction of tillage, maintaining soil cover and introducing crop rotations, is currently being promoted by the United Nations Food and Agriculture Organisation as the most sustainable form of farming into the future. It was found that the increasing uptake of CA practices by developed countries improved soil organic carbon benefit and reduced energy inputs. Furthermore industrial agriculture has evolved a range of new technologies that can be adapted in developing countries to improve food security, increase environmental benefits and provide carbon offsets. This is in line with the climate change mitigation strategy of putting atmospheric carbon back in the soil to increase soil organic carbon. It is also noted that recognising conservation agriculture methodologies in carbon offset schemes would require the development of alternative economic instruments specifically to support small landholder changes in farming practices such as exist for hydrological and biodiversity ecosystem services schemes. Some of the constraints for small landowners providing agricultural carbon offsets are investment capital and an established trading mechanism that recognises the inherent issues of agriculture. Adaptation of conservation agricultural practices from industrialised agriculture to developing countries is examined along with current offset schemes being proposed in developed countries. A review of the literature examines Payment for Ecosystem Services (PES) and suggests a number of methodologies for consideration as part of an offset market. It was found that the two main obstacles in market terms are the acceptance of a level of soil carbon sequestration that can be easily calculated and the degree of attached liability for farmers in selling the equivalent of a Certified Emission Reduction unit from a highly volatile system.

scholarly journals Restoration of degraded grasslands, but not invasion by Prosopis juliflora, avoids trade-offs between climate change mitigation and other ecosystem services

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Purity Rima Mbaabu ◽  
Daniel Olago ◽  
Maina Gichaba ◽  
Sandra Eckert ◽  
René Eschen ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Climate Change Mitigation ◽  
Arid Regions ◽  
Prosopis Juliflora ◽  
Trade Offs ◽  
Change Mitigation ◽  
Semi Arid

AbstractGrassland degradation and the concomitant loss of soil organic carbon is widespread in tropical arid and semi-arid regions of the world. Afforestation of degraded grassland, sometimes by using invasive alien trees, has been put forward as a legitimate climate change mitigation strategy. However, even in cases where tree encroachment of degraded grasslands leads to increased soil organic carbon, it may come at a high cost since the restoration of grassland-characteristic biodiversity and ecosystem services will be blocked. We assessed how invasion by Prosopis juliflora and restoration of degraded grasslands in a semi-arid region in Baringo, Kenya affected soil organic carbon, biodiversity and fodder availability. Thirty years of grassland restoration replenished soil organic carbon to 1 m depth at a rate of 1.4% per year and restored herbaceous biomass to levels of pristine grasslands, while plant biodiversity remained low. Invasion of degraded grasslands by P. juliflora increased soil organic carbon primarily in the upper 30 cm and suppressed herbaceous vegetation. We argue that, in contrast to encroachment by invasive alien trees, restoration of grasslands in tropical semi-arid regions can both serve as a measure for climate change mitigation and help restore key ecosystem services important for pastoralists and agro-pastoralist communities.

scholarly journals Building Climate Change Adaptation and Resilience through Soil Organic Carbon Restoration in Sub-Saharan Rural Communities: Challenges and Opportunities

2021 ◽  
Vol 13 (19) ◽  
pp. 10966
Author(s):  
Alex Taylor ◽  
Maarten Wynants ◽  
Linus Munishi ◽  
Claire Kelly ◽  
Kelvin Mtei ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Health ◽  
Sub Saharan Africa ◽  
Soil Function ◽  
Challenges And Opportunities ◽  
Sub Saharan ◽  
Soc Stocks

Soil organic carbon (SOC) is widely recognised as pivotal in soil function, exerting important controls on soil structure, moisture retention, nutrient cycling and biodiversity, which in turn underpins a range of provisioning, supporting and regulatory ecosystem services. SOC stocks in sub-Saharan Africa (SSA) are threatened by changes in land practice and climatic factors, which destabilises the soil system and resilience to continued climate change. Here, we provide a review of the role of SOC in overall soil health and the challenges and opportunities associated with maintaining and building SOC stocks in SSA. As an exemplar national case, we focus on Tanzania where we provide context under research for the “Jali Ardhi” (Care for the Land) Project. The review details (i) the role of SOC in soil systems; (ii) sustainable land management (SLM) techniques for maintaining and building SOC; (iii) barriers (environmental, economic and social) to SLM implementation; and (iv) opportunities for overcoming barriers to SLM adoption. We provide evidence for the importance of site-specific characterisation of the biophysicochemical and socio-economic context for effective climate adaptation. In particular, we highlight the importance of SOC pools for soil function and the need for practitioners to consider the type of biomass returns to the soil to achieve healthy, balanced systems. In line with the need for local-scale site characterisation we discuss the use of established survey protocols alongside opportunities to complement these with recent technologies, such as rapid in situ scanning tools and aerial surveys. We discuss how these tools can be used to improve soil health assessments and develop critical understanding of landscape connectivity and the management of shared resources under co-design strategies.

scholarly journals Dynamics of soil organic carbon in the steppes of Russia and Kazakhstan under past and future climate and land use

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Susanne Rolinski ◽  
Alexander V. Prishchepov ◽  
Georg Guggenberger ◽  
Norbert Bischoff ◽  
Irina Kurganova ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Organic Carbon ◽  
Land Use Change ◽  
Soil Organic Carbon ◽  
Arable Land ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Scenarios ◽  
The Impact

AbstractChanges in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

Soil organic carbon monitoring to assess agricultural climate change adaptation practices in Navarre, Spain

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Rodrigo Antón ◽  
Francisco Javier Arricibita ◽  
Alberto Ruiz-Sagaseta ◽  
Alberto Enrique ◽  
Isabel de Soto ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Climate Change Adaptation ◽  
Adaptation Practices

Soil organic carbon storage by shaded and unshaded coffee systems and its implications for climate change mitigation in China

2021 ◽  
pp. 1-8
Author(s):  
Ziwei Xiao ◽  
Xuehui Bai ◽  
Mingzhu Zhao ◽  
Kai Luo ◽  
Hua Zhou ◽  
...  
Keyword(s):  
Climate Change ◽  
Linear Regression ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Multiple Linear Regression ◽  
Carbon Storage ◽  
Soil Ph ◽  
Soil Bulk Density ◽  
Soil N ◽  
And Storage

Abstract Shaded coffee systems can mitigate climate change by fixation of atmospheric carbon dioxide (CO2) in soil. Understanding soil organic carbon (SOC) storage and the factors influencing SOC in coffee plantations are necessary for the development of sound land management practices to prevent land degradation and minimize SOC losses. This study was conducted in the main coffee-growing regions of Yunnan; SOC concentrations and storage of shaded and unshaded coffee systems were assessed in the top 40 cm of soil. Relationships between SOC concentration and factors affecting SOC were analysed using multiple linear regression based on the forward and backward stepwise regression method. Factors analysed were soil bulk density (ρb), soil pH, total nitrogen of soil (N), mean annual temperature (MAT), mean annual moisture (MAM), mean annual precipitation (MAP) and elevations (E). Akaike's information criterion (AIC), coefficient of determination (R2), root mean square error (RMSE) and residual sum of squares (RSS) were used to describe the accuracy of multiple linear regression models. Results showed that mean SOC concentration and storage decreased significantly with depth under unshaded coffee systems. Mean SOC concentration and storage were higher in shaded than unshaded coffee systems at 20–40 cm depth. The correlations between SOC concentration and ρb, pH and N were significant. Evidence from the multiple linear regression model showed that soil bulk density (ρb), soil pH, total nitrogen of soil (N) and climatic variables had the greatest impact on soil carbon storage in the coffee system.

scholarly journals Modeling soil organic carbon in corn ( Zea mays L.)-based systems in Ohio under climate change

2017 ◽  
Vol 72 (3) ◽  
pp. 191-204 ◽  
Author(s):  
E.D.v.L. Maas ◽  
R. Lal ◽  
K. Coleman ◽  
A. Montenegro ◽  
W.A. Dick
Keyword(s):  
Climate Change ◽  
Zea Mays ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Zea Mays L

scholarly journals Impact of grazing intensity on seasonal variations in soil organic carbon and soil CO 2 efflux in two semiarid grasslands in southern Botswana

2012 ◽  
Vol 367 (1606) ◽  
pp. 3076-3086 ◽  
Author(s):  
Andrew D. Thomas
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Seasonal Variations ◽  
Field Experiments ◽  
Grazing Intensity ◽  
C Sequestration ◽  
Ecosystem Functions ◽  
Semiarid Environments ◽  
The Impact ◽  
And Storage

Biological soil crusts (BSCs) are an important source of organic carbon, and affect a range of ecosystem functions in arid and semiarid environments. Yet the impact of grazing disturbance on crust properties and soil CO 2 efflux remain poorly studied, particularly in African ecosystems. The effects of burial under wind-blown sand, disaggregation and removal of BSCs on seasonal variations in soil CO 2 efflux, soil organic carbon, chlorophyll a and scytonemin were investigated at two sites in the Kalahari of southern Botswana. Field experiments were employed to isolate CO 2 efflux originating from BSCs in order to estimate the C exchange within the crust. Organic carbon was not evenly distributed through the soil profile but concentrated in the BSC. Soil CO 2 efflux was higher in Kalahari Sand than in calcrete soils, but rates varied significantly with seasonal changes in moisture and temperature. BSCs at both sites were a small net sink of C to the soil. Soil CO 2 efflux was significantly higher in sand soils where the BSC was removed, and on calcrete where the BSC was buried under sand. The BSC removal and burial under sand also significantly reduced chlorophyll a , organic carbon and scytonemin . Disaggregation of the soil crust, however, led to increases in chlorophyll a and organic carbon. The data confirm the importance of BSCs for C cycling in drylands and indicate intensive grazing, which destroys BSCs through trampling and burial, will adversely affect C sequestration and storage. Managed grazing, where soil surfaces are only lightly disturbed, would help maintain a positive carbon balance in African drylands.

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