Better land stewardship is needed to achieve the Paris Agreement’s temperature goal, particularly in the tropics, where greenhouse gas emissions from the destruction of ecosystems are largest, and where the potential for additional land carbon storage is greatest. As countries enhance their nationally determined contributions (NDCs) to the Paris Agreement, confusion persists about the potential contribution of better land stewardship to meeting the Agreement’s goal to hold global warming below 2°C. We assess cost-effective tropical country-level potential of natural climate solutions (NCS)—protection, improved management and restoration of ecosystems—to deliver climate mitigation linked with sustainable development goals (SDGs). We identify groups of countries with distinctive NCS portfolios, and we explore factors (governance, financial capacity) influencing the feasibility of unlocking national NCS potential. Cost-effective tropical NCS offers globally significant climate mitigation in the coming decades (6.56 Pg CO2e yr−1 at less than 100 US$ per Mg CO2e). In half of the tropical countries, cost-effective NCS could mitigate over half of national emissions. In more than a quarter of tropical countries, cost-effective NCS potential is greater than national emissions. We identify countries where, with international financing and political will, NCS can cost-effectively deliver the majority of enhanced NDCs while transforming national economies and contributing to SDGs. This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.
NbS Approach: Nature-based Agricultural Systems
Nature-based agricultural systems
The impending threats of changing climate have been well documented across sectors. The climate risks are best addressed through increasing adaptive capacity and building resilience. Ever since the global call during the Rio Summit in 1992 for establishing sustainability indicators across sectors, there have been several studies across the world on developing indicators for sustainability, vulnerability and climate resilience. Agriculture, the most vulnerable system to changing climate, depends on the resilience of both social and ecological systems. This paper focuses on integrating the variability of climate into the agricultural sustainability measurement with a broad base of indicators and bringing in the localized factors for representing the agroecosystem specificities. The paper also aims at identifying indicators for measuring climate resilient agriculture in Indian sub-continent and developing a conceptual framework for profiling the spatial resilience across various agro-ecosystems for appropriate location-specific policy interventions. In the current study 1209 indicators used in various research studies were screened, grouped for similarity and purpose and classified based on the various dimensions viz., social, economic, ecological, etc. After a critical review based on their appropriateness as a measurable indicator, extent of overlap, relevance in Indian context and possible data availability, 41 indicators were shortlisted for validation through a comprehensive structured online survey among subject matter specialists (n = 225). The responses from the experts (n = 36) were analysed using weighted sum model (WSM) and analytic hierarchy process (AHP). The study identifies a list of 30 sustainability indicators for climate resilient agriculture in India, that are particularly suitable for different agro-ecosystems of the sub-continent. The authors advocate an action-oriented model called Climate Risk Management Package for Agriculture (CRiMPA) to aid in planning spatial/agro-ecosystem specific interventions, which in turn could strengthen the National Action Plan for Climate Change (NAPCC) of Government of India.
Understanding changes in wave attenuation by emergent vegetation as wetlands degrade or accrete over time is crucial for incorporation of wetlands into holistic coastal risk management. Linked SLAMM and XBeach models were used to investigate potential future changes in wave attenuation over a 50-year period in a degrading, subtropical wetland and a prograding, temperate wetland. These contrasting systems also have differing management contexts and were contrasted to demonstrate how the linked models can provide management-relevant insights. Morphological development of wetlands for different scenarios of sea-level rise and accretion was simulated with SLAMM and then coupled with different vegetation characteristics to predict the influence on future wave attenuation using XBeach. The geomorphological context, subsidence, and accretion resulted in large predicted reductions in the extent of vegetated land (e.g., wetland) and changes in wave height reduction potential across the wetland. These were exacerbated by increases in sea-level from +0.217 m to +0.386 m over a 50-year period, especially at the lowest accretion rates in the degrading wetland. Mangrove vegetation increased wave attenuation within the degrading, subtropical, saline wetland, while grazing reduced wave attenuation in the temperate, prograding wetland. Coastal management decisions and actions, related to coastal vegetation type and structure, have the potential to change future wave attenuation at a spatial scale relevant to coastal protection planning. Therefore, a coastal management approach that includes disaster risk reduction, biodiversity, and climate change, can be informed by coastal modeling tools, such as those demonstrated here for two contrasting case studies.
Coffee is one of the most important tropical crops on earth, considering both its gross production value and the number of families that depend on it for their livelihoods. Coffee also grows within some of the world’s most biodiverse habitats, in areas predicted to experience severe climate change impacts. Like many other crops, coffee benefits from several ecosystem services (ES) that provide important inputs or conditions for production. Given coffee’s strong interactions with conservation, livelihoods, and climate change, it is important to understand the roles of biodiversity-regulated ES to coffee and how they are likely to change under future climates. Here we review the available literature on the provision of two essential and interacting ES that regulate coffee production: control of a beetle pest by birds and pollination by bees. Studies show that bird and bee communities provide pest control and pollination services that improve coffee quantity and quality, benefiting coffee farmers whose livelihoods depend on this crop. The literature also shows that a variety of plot, farm, and landscape management practices that support resources for bees and birds can enhance these ES. We also evaluate how these ES and their interactions may change under future climate change. Several studies have estimated likely climate impacts on coffee per se, but few have investigated climate vulnerability of pollination and pest control ES. Even less studies have quantified interactions between these ES. Although evidence is incomplete, managing coffee farms as diversified agroforestry systems could improve climate resilience of coffee cropping and communities of birds and bees, and therefore help farming families adapt to their changing environment. Based on our review, we identify six critical research priorities in this active area of study. Filling knowledge gaps would advance our understanding of interactions among landscapes, ES, and climate change, and would support climate adaptation for the millions of households whose livelihoods depend on coffee.
Coffea arabica is an indigenous understorey shrub of the moist evergreen Afromontane forest of SW Ethiopia. Coffee cultivation here occurs under different forest management intensities, ranging from almost no intervention in the ‘forest coffee’ system to far-reaching interventions that include the removal of competing shrubs and selective thinning of the upper canopy in the ‘semi-forest coffee’ system. We investigated whether increasing forest management intensity and fragmentation result in impacts upon potential coffee pollination services through examining shifts in insect communities that visit coffee flowers. Overall, we netted 2,976 insect individuals on C. arabica flowers, belonging to sixteen taxonomic groups, comprising 10 insect orders. Taxonomic richness of the flower-visiting insects significantly decreased and pollinator community changed with increasing forest management intensity and fragmentation. The relative abundance of honey bees significantly increased with increasing forest management intensity and fragmentation, likely resulting from the introduction of bee hives in the most intensively managed forests. The impoverishment of the insect communities through increased forest management intensity and fragmentation potentially decreases the resilience of the coffee production system as pollination increasingly relies on honey bees alone. This may negatively affect coffee productivity in the long term as global pollination services by managed honey bees are expected to decline under current climate change scenarios. Coffee agroforestry management practices should urgently integrate pollinator conservation measures.
A spatial analysis is presented that aims to synthesize the evidence for climate and social dimensions of the ‘regreening” of the Sahel. Using an independently constructed archival database of donor-funded interventions in Burkina Faso, Mali, Niger, and Senegal in response to the persistence of drought in the 1970s and 1980s, the spatial distribution of these interventions is examined in relation to population density and to trends in precipitation and in greenness. Three categories of environmental change are classified: 1) regions at the northern grassland/shrubland edge of the Sahel where NDVI varies interannually with precipitation, 2) densely populated cropland regions of the Sahel where significant trends in precipitation and NDVI decouple at interannual time scales, and 3) regions at the southern savanna edge of the Sahel where NDVI variation is independent of precipitation. Examination of the spatial distribution of environmental change, number of development projects, and population density brings to the fore the second category, covering the cropland areas where population density and regreening are higher than average. While few, regions in this category coincide with emerging hotspots of regreening in northern Burkina Faso and southern central Niger known from case study literature. In examining the impact of efforts to rejuvenate the Sahelian environment and livelihoods in the aftermath of the droughts of the 1970s and 1980s against the backdrop of a varying and uncertain climate, the transition from desertification to regreening discourses is framed in the context of adaptation to climate change.
Adaptation strategies to reduce smallholder farmers’ vulnerability to climate variability and seasonality are needed given the frequency of extreme weather events predicted to increase during the next decades in sub-Saharan Africa, particularly in West Africa. We explored the linkages between selected agricultural adaptation strategies (crop diversity, soil and water conservation, trees on farm, small ruminants, improved crop varieties, fertilizers), food security, farm household characteristics and farm productivity in three contrasting agro-ecological sites in West Africa (Burkina Faso, Ghana and Senegal). Differences in land area per capita and land productivity largely explained the variation in food security across sites. Based on land size and market orientation, four household types were distinguished (subsistence, diversified, extensive, intensified), with contrasting levels of food security and agricultural adaptation strategies. Income increased steadily with land size, and both income and land productivity increased with degree of market orientation. The adoption of agricultural adaptation strategies was widespread, although the intensity of practice varied across household types. Adaptation strategies improve the food security status of some households, but not all. Some strategies had a significant positive impact on land productivity, while others reduced vulnerability resulting in a more stable cash flow throughout the year. Our results show that for different household types, different adaptation strategies may be ‘climate-smart’. The typology developed in this study gives a good entry point to analyse which practices should be targeted to which type of smallholder farmers, and quantifies the effect of adaptation options on household food security. Subsequently, it will be crucial to empower farmers to access, test and modify these adaptation options, if they were to achieve higher levels of food security.
Traditional agroforestry parkland systems in Burkina Faso are under threat due to human pressure and climate variability and change, requiring a better understanding for planning of adaptation. Field experiments were conducted in three climatic zones to assess Sorghum bicolor (L.) Moench (Sorghum) biomass, grain yield and harvest index in parklands under different rainfall pattern and compared to simulations of sorghum biomass and grain yield with the Water, Nutrient and Light Capture in Agroforestry Systems (WaNuLCAS) model for calibration and parametrisation. For planning adaptation, the model was then used to evaluate the effects of different management options under current and future climates on sorghum biomass and grain yield. Management options studied included tree densities, tree leaf pruning, mulching and changes in tree root patterns affecting hydraulic redistribution. The results revealed that sorghum biomass and grain yield was more negatively affected by Parkia biglobosa (Jacq.) Benth. (néré) compared to Vitellaria paradoxa C. F Gaertn (karité) and Adansonia digitata L. (baobab), the three main tree species of the agroforestry parkland system. Sorghum biomass and grain yield in different influence zones (sub-canopy, outside edge of canopy, open field) was affected by the amount of precipitation but also by tree canopy density, the latter depending itself on the ecological zone. The harvest index (grain as part of total biomass) was highest under the tree canopy and in the zone furthest from the tree, an effect that according to the model reflects relative absence of stress factors in the later part of the growing season. While simulating the effects of different management options under current and future climates still requires further empirical corroboration and model improvement, the options of tree canopy pruning to reduce shading while maintaining tree root functions probably is key to parkland adaptation to a changing climate.
This paper offers a different framework for managing Mediterranean drought carob-tree orchard ecosystems. Two dry-farming systems were compared during two consecutive years: pure productive orchards and mixed orchards in a total of 360 mature trees distributed by 18 plots with areas of 0.55 and 0.30 ha per plot, respectively. Carob, fig, almond and olive trees compose mixed orchards. Trees of the mixed orchards were more productive than those of pure orchards. The main problem of both systems was the large variability and the low fruit production due to non-bearing trees, inducing unfavorable economic returns. Yield varied between 7.7 and 28.5 kg tree(-1) respectively in pure and mixed orchards. In this paper we propose to use carbon sequestration calculations as an added benefit to farmers. A carbon stocking model estimation was established, based on trunk diameters of different trees. We depicted two management scenarios based on fruits production and carbon sequestration incomes: a low value scenario, using mean fruit production, and a high valuable scenario based on the hypothesis that all trees reached its potential maximum. Since under dry-farming systems fruit production irregularity is still a pendent problem, mixed orchards may offer a potential higher revenue, while maintaining higher crop diversification and whole biodiversity. C sequestration benefit, as here we purpose, may represent 125-300 % of income, respectively under low or high valuable scenario. Thus, CO2 equivalent is a novel ecological economic incentive that may potentiate a new income for farmers while assuring carob ecosystem services.
Soil organic matter (SOM) plays an important role in terrestrial ecosystems and agroecosystems. Changes in the agricultural sector in the Czech Republic within the past 25 years have had a negative impact on SOM content and contribute to gradual soil degradation. The aim of this study is to estimate the effect of long-term application of different mineral fertilizers (NPK) and organic manures (manure, cattle slurry) on soil chemical properties (quality of humus, available nutrients, and soil reaction). Soil samples were collected from Luvisol during two selected periods 1994–2003 and 2014–2016 from long-term field experiment carried out in Prague-Ruzyně (Czech Republic). Average annual temperature is 8.5 °C, and annual precipitations are 485 mm. Different fertilization regimes have been applied for 62 years. The crop rotation was as follows: cereals (45%), root crops (33%) and legumes (22%). Soil analysis—soil organic carbon (SOC) was determined by oxidimetric titration method. Short fractionation method for evaluation of humic substance (HS), humic acid (HA) and fulvic acid (FA) content was used. Absorbance of HS in UV-VIS spectral range was measured by Varian Carry 50 Probe UV-VIS spectrometer. Degree of humification (DH) and color index (Q4/6) were calculated from fractional composition data. Soil reaction was measured by potentiometric method. Available nutrients (phosphorus, potassium, magnesium, calcium) were determined by Mehlich II and Mehlich I methods and by ICP-OES. For data analysis, the following are used: exploratory data analysis, ANOVA, and principal component analysis (PCA). PCA analysis differentiated fertilizers into two categories: (1) variant NPK (lower quality of humus)—higher acidity, lower SOC and HS content, predomination of FA, higher DH and lower content of available nutrients; (2) variants with organic manures (higher quality of humus)—lower acidity, higher SOC and HS content, predomination of HA, middle DH, and high content of available nutrients. The main result of presented study is to give a synthesis of effect of different type of fertilizers on a sustainable organic matter management in arable soils, with respect to yields, food security and adaptation to predict climate changes. Long-term application of mineral fertilizers (NPK) without organic matter input can accelerate humus mineralization and soil quality degradation with all negative consequences such as (nitrogen leaching, higher availability of toxic element for plants, slow energy for soil microorganisms etc.). Application of organic fertilizers (manure and cattle slurry) helps to achieve the long-term stable yields while maintaining soil at optimum quality (long-term sustainable management with SOM). Principal component analysis is a useful tool for evaluation of soil quality changes.
Agroforestry offers unique opportunities for increasing biodiversity, preventing land degradation, and alleviating poverty, particularly in developing countries, but factors explaining the adoption by farmers are not well understood. A survey of 524 farm households was conducted in Bhakkar district of Punjab, Pakistan to study factors that determine the adoption of agroforestry on the sand dunes in the resource-deficient region of Thal. Two types of agroforestry systems were studied: intercropping and border cropping (also known as boundary or perimeter planting). Both agroforestry systems included irrigated cultivation of the timber trees Eucalyptus camaldulensis (local name: sufeda) and Tamarix aphylla (local name: sars) with wheat, chickpeas (Cicer arietinum) (local name: chana) or cluster beans (Cyamous tetragocalobe) (local name: guars). The majority of the farmers was in favour of intercropping and border cropping. Most farmers reported the protection of nearby crops from dust storms as the most important positive perception about both agroforestry systems. Age, education, and farm to market distance were significant determinants of agroforestry adoption. Older and less-educated farmers, with farms closer to markets were less likely to adopt tree planting or border cropping in Thal. In general, the agroforestry systems examined were more likely to be adopted by farmers who can wait 3–4 years for harvesting crop outputs, but not by poorer farmers who are totally dependent on subsistence agriculture and cannot afford the high initial cost of agroforestry establishment, nor can they wait for crop output for extended periods. Furthermore, the adoption of both agroforestry systems was more likely in remote marginal areas than in areas close to markets. To increase agroforestry adoption rates, government policies should strengthen farmers’ knowledge of every stage of agroforestry through extension services, focusing particularly among the prime prospects, i.e. farmers who will be most likely to adopt agroforestry. Once the prime prospects have adopted it, the older, less-educated, and poor farmers of the rural population can be also focused on to motivate adoption.
Future food and nutrition security is threatened by climate change, overexploitation of natural resources and pervasive social inequalities. Promising solutions are often technology-focused and not necessarily developed considering gender and social disparities. This paper addresses issues of gender and human development opportunities and trade-offs related to promoting improved technologies for agricultural development. We examined these aspects for conservation agriculture (CA) as part of a cropping system with nutrition- and climate-smart potential. The paper is based on a literature review and field experiences from Zambia and Mexico. Findings point up situations where the promotion of CA for smallholders in developing countries may have undesired effects from gender and human development perspectives, specifically relating to drudgery, nutrition and food security, residue use, assets, mechanization and extension. The direction and magnitude of potential trade-offs depend on the local context and the specific intervention. The analysis is followed by a discussion of opportunities and pathways for mitigating the trade-offs, including gender transformative approaches; engagement with alternative or non-traditional partners with different but complementary perspectives and strengths; “smart” combinations of technologies and approaches; and policies for inclusive development.
Over the last decades, desertification, drought and erratic rainfall have become much debated and distressing issues for Niger, given the country’s reliance on natural resources and agriculture for livelihood. A decisive answer on the causes and extent of both meteorological and soil water drought is therefore of importance to enable effective policy and resilience, but adaption to future climate change often entails the very same practices as rehabilitating degraded land to enhance water productivity. This paper investigates the extent of both meteorological and soil water drought in Niger by combining rainfall and soil water analysis and assesses the potential of various small scale WSC techniques to tackle crop growth limitations in Niger. It presents a trend analysis of rainfall and drought parameters and compares the effect of 5 treatments (zai + manure, demi-lunes + manure, no till with scarification + manure, control + manure and control) on crop performance and soil moisture profiles. The WSC-treatments zai and demi-lunes produce significantly higher yields due to increased soil moisture levels throughout the season. Besides the improved soil moisture conditions, the potential of WSC practices to increase the agronomic efficiency is also largely explained by their impact on the soil nutrient status.
Ecosystem-based approaches have proven effective and efficient in reducing disaster risks while ensuring continued benefits to people from ecosystem services. In this article, a new concept of Ecosystem-based Disaster Risk Reduction (Eco-DRR) for enhancing social-ecological resilience is proposed, based on analysis of several case studies. Field studies in developing countries such as Ghana and Myanmar have shown the benefits of Eco-DRR as implemented by local communities. These projects improve local livelihoods and social-ecological resilience. In Japan, after the massive damage from the 11 March 2011, Great East Japan earthquake and tsunami, ecosystem-based approaches were an important element of the national government’s DRR efforts. Analysis of these cases shows that Eco-DRR is a socially, economically and environmentally sustainable tool for DRR that creates new value for a region. It also shows the importance of multi-stakeholder participation in the process of promoting Eco-DRR. It is likely to become even more important in the future, as a means for addressing the increase in disasters resulting from climate and ecosystem change as well as demographic change. The contribution of Eco-DRR to maintaining and restoring ecosystems is particularly valuable for countries where there is reduced capacity for land management, as currently occurring in Japan due to rapid population decline and aging.
The desertification paradigm has a long history in the Sahel, from colonial to modern times. Despite scientific challenge, it continued to be influential after independence, revived by the dramatic droughts of the 1970s and 1980s, and was institutionalized at local, national and international levels. Collaborative efforts were made to improve scientific knowledge on the functioning, environmental impact and monitoring of selected agricultural systems over the long term, and to assess trends in the ecosystems, beyond their short term variability. Two case studies are developed here: the pastoral system of the arid to semi-arid Gourma in Mali, and the mixed farming system of the semi-arid Fakara in Niger. The pastoral landscapes are resilient to droughts, except on shallow soils, and to grazing, following a non-equilibrium model. The impact of cropping on the landscape is larger and longer lasting. It also induces locally high grazing pressure that pushes rangeland resilience to its limits. By spatial transfer of organic matter and mineral, farmers’ livestock create patches of higher fertility that locally enhance the system’s resilience. The agro-pastoral ecosystem remains non-equilibrial provided that inputs do not increase stocking rates disproportionately. Remote sensing confirms the overall re-greening of the Sahel after the drought of the 1980s, contrary to the paradigm of desertification. Ways forward are proposed to adapt the pastoral and mixed farming economies and their regional integration to the context of human and livestock population growth and expanding croplands.
Modern plant breeding tends to focus on maximizing yield, with one of the most ubiquitous implementations being shorter-duration crop varieties. It is indisputable that these breeding efforts have resulted in greater yields in ideal circumstances; however, many farmed locations across Africa suffer from one or more conditions that limit the efficacy of modern short-duration hybrids. In view of global change and increased necessity for intensification, perennial grains and long-duration varieties offer a nature-based solution for improving farm productivity and smallholder livelihoods in suboptimal agricultural areas. Specific conditions where perennial grains should be considered include locations where biophysical and social constraints reduce agricultural system efficiency, and where conditions are optimal for crop growth. Using a time-series of remotely-sensed data, we locate the marginal agricultural lands of Africa, identifying suboptimal temperature and precipitation conditions for the dominant crop, i.e., maize, as well as optimal climate conditions for two perennial grains, pigeonpea and sorghum. We propose that perennial grains offer a lower impact, sustainable nature-based solution to this subset of climatic drivers of marginality. Using spatial analytic methods and satellite-derived climate information, we demonstrate the scalability of perennial pigeonpea and sorghum across Africa. As a nature-based solution, we argue that perennial grains offer smallholder farmers of marginal lands a sustainable solution for enhancing resilience and minimizing risk in confronting global change, while mitigating social and edaphic drivers of low and variable production.
Crop-livestock-forest (CLFi) and crop-livestock (CLi) systems are among the most recent agricultural developments in Brazil, and aligned with the principles of cleaner production. Such integrated systems can provide at least three types of product from the same land area over a defined period. This paper presents a holistic sustainability evaluation using life cycle assessment to compare combinations of integrated and conventional systems in the Brazilian Cerrado region. The study assesses a comprehensive set of indicators in the three sustainability dimensions: environmental, economic, and social (socio-eco-efficiency). By prioritizing CLFi, the production area to meet the demand of grains, meat and energy for 500 Brazilians, from 2007 to 2014, reached 70 ha, while the conventional systems would need 420 ha to meet the same demand. This result shows that it is possible to increase production to meet the growing food global demand without the need of expanding the agricultural frontier, preserving the remaining forestland. CLFi combinations systems decreased 55% in climate change potential (2389 t of CO2 equivalent), when compared to the conventional systems. It was also observed that the more integrated systems improved the quality of employment, promoted future generation investments in society, and decreased the total production costs in 54%, when compared to conventional systems. Therefore, intensification achieved through good practices such as association, rotation, and succession by an agroforestry system, optimization of inputs (including water, energy, fertilizers, and crop protection agents), land use, soil quality, biodiversity and social aspects
Faidherbia albida parklands cover a large area of the Sudano-Sahelian zone of Africa, a region that suffers from soil fertility decline, food insecurity and climate change. The parklands deliver multiple benefits, including fuelwood, soil nutrient replenishment, moisture conservation, and improved crop yield underneath the canopy. Its microclimate modification may provide an affordable climate adaptation strategy which needs to be explored. We carried out an on-farm experiment for three consecutive seasons in the Ethiopian Central Rift Valley with treatments of Faidherbia trees with bare soil underneath, wheat grown beneath Faidherbia and wheat grown in open fields. We tested the sensitivity of wheat yield to tree-mediated variables of photosynthetically active radiation (PAR), air temperature and soil nitrogen, using APSIM-wheat model. Results showed that soil moisture in the sub-soil was the least for wheat with tree, intermediate for sole tree and the highest for open field. Presence of trees resulted in 35–55% larger available N close to tree crowns compared with sole wheat. Trees significantly reduced PAR reaching the canopy of wheat growing underneath to optimum levels. Midday air temperature was about 6 °C less under the trees than in the open fields. LAI, number of grains spike−1, plant height, total aboveground biomass and wheat grain yield were all significantly higher (P < 0.001) for wheat associated with F. albida compared with sole wheat. Model-based sensitivity analysis showed that under moderate to high rates of N, wheat yield responded positively to a decrease in temperature caused by F. albida shade. Thus, F. albida trees increase soil mineral N, wheat water use efficiency and reduce heat stress, increasing yield significantly. With heat and moisture stress likely to be more prevalent in the face of climate change, F. albida, with its impact on microclimate modification, maybe a starting point to design more resilient and climate-smart farming systems.
This paper reports on early soil related outcomes from conservation agriculture (CA) benchmark sites located within the marginal rainfed environment of agro-ecological zone 4 (annual rainfall: 200–250 mm) in pre-conflict central Syria. The outcomes reported are specifically those that relate to beneficial soil quality and water retention attributes relative to conventional tillage-based soil management practices applied to the fodder barley–livestock system, the dominant system in the zone. On-farm operational research was established to examine the impact of a barley (Hordeum vulgare) and vetch (Vicia sativa) rotation intercropped with atriplex (Atriplex halimus) and salsola (Salsola collina), under CA and conventional tillage agriculture, on the soil quality parameters and crop productivity. Preliminary results showed that CA had a positive effect on the soil quality parameters and crop performance. The soil moisture and hydraulic conductivity were higher under CA (p < 0.05), combined with improved productivity (grain and above-ground biomass) under specific crop mixes. The results suggest that despite the marginal nature of the zone, the use of CA is a viable option for the future of farmers’ livelihoods within similar localities and agro-climates, given the benefits for soil moisture and grain and straw productivity. In addition, it is likely to positively impact those in marginal environments where both pastoralism and agro-pastoralism production systems co-exist and compete for crop biomass as a main source of livestock feed. The increase in grain and straw yields vis-à-vis improvements in biophysical parameters in the CA system relative to tillage agriculture does suggest, however, that the competition with livestock for biomass is likely to reduce over time, and farmers would be able to return increased levels of straw (as stubble and residue) as mulch, given improved biomass yields.
Annual row crops dominate agriculture around the world and have considerable negative environmental impacts, including significant greenhouse gas emissions. Transformative land‐use solutions are necessary to mitigate climate change and restore critical ecosystem services. Alley cropping (AC)—the integration of trees with crops—is an agroforestry practice that has been studied as a transformative, multifunctional land‐use solution. In the temperate zone, AC has strong potential for climate change mitigation through direct emissions reductions and increases in land‐use efficiency via overyielding compared to trees and crops grown separately. In addition, AC provides climate change adaptation potential and ecological benefits by buffering alley crops to weather extremes, diversifying income to hedge financial risk, increasing biodiversity, reducing soil erosion, and improving nutrient‐ and water‐use efficiency. The scope of temperate AC research and application has been largely limited to simple systems that combine one timber tree species with an annual grain. We propose two frontiers in temperate AC that expand this scope and could transform its climate‐related benefits: (i) diversification via woody polyculture and (ii) expanded use of tree crops for food and fodder. While AC is ready now for implementation on marginal lands, we discuss key considerations that could enhance the scalability of the two proposed frontiers and catalyze widespread adoption.
To achieve global food security, we need to approximately double food production over the coming decades. Conventional agriculture is the mainstream approach to achieving this target but has also caused extensive environmental and social harms. The consensus is that we now need an agriculture that can “multi-functionally” increase food production while simultaneously enhancing social and environmental goals, as committed to in the sustainable development goals (SDGs). Farming also needs to become more resilient to multiple insecurities including climate change, soil degradation, and market unpredictability, all of which reduce sustainability and are likely to exacerbate hunger. Here, we illustrate how agroforestry systems can increase yield while also advancing multiple SDGs, especially for the small developing-world agriculturalists central to the SDG framework. Agroforestry also increases resilience of crops and farm livelihoods, especially among the most vulnerable food producers. However, conventional yield-enhancement strategies have naturally dominated the debate on food production, hindering implementation of more multifunctional alternatives. Governments and institutions now have the opportunity to rebalance agricultural policy and investment toward such multigoal approaches. In doing so, they could achieve important improvements on multiple international commitments around the interlinked themes of food security, climate change, biodiversity conservation, and social well-being.
We investigated and compared management practices for dealing with uncertainty in agroecosystem dynamics in two cases of smallholder farming in different parts of the world: northeast Tanzania and east-central Sweden. Qualitative research methods were applied to map farmers’ practices related to agroecosystem management. The practices are clustered according to a framework of ecosystem services relevant for agricultural production and discussed using a theoretical model of ecosystem dynamics. Almost half of the identified practices were found to be similar in both cases, with similar approaches for adjusting to and dealing with local variability and disturbance. Practices that embraced the ecological roles of wild as well as domesticated flora and fauna and the use of qualitative biological indicators are identified as tools that built insurance capital for change and enhanced the capacity to respond to changing agroecosystem dynamics. Diversification in time and space, as well as more specific practices for mitigating pest outbreaks and temporary droughts, can limit the effects of disturbance. In both Sweden and Tanzania, we identified social mechanisms for the protection of species that served important functions in the agroecosystem. We also found examples of how old practices served as a source of adaptations for dealing with new conditions and that new knowledge was adjusted to local conditions. The study shows that comparing management practices across scales and in different cultural settings can reveal insights into the capacity of farmers to adjust, respond to, and shape ecosystem dynamics. We emphasize the importance of continuous learning for developing the sustainable management of complex agroecosystems and securing agricultural production for the future.
Legume tree-based farming systems sit at a crucial nexus of agroecological sustainability. Their capacity to support microbial N2 fixation can increase soil nitrogen (N) availability and therefore improve soil fertility, crop yields, and support long-term stewardship of natural resources. However, increasing N availability oftentimes catalyzes the release of N into the surrounding environment, in particular nitrous oxide (N2O) — a potent greenhouse gas. We summarize current knowledge on the agroecological footprint of legume-based agroforestry and provide a first appraisal of whether the technology represents a pathway toward sustainable development or an environmental hazard.
A potential impact of climate change in the south Asian context in general and the Indian subcontinent in particular is an increase in rainfall, in some areas up to 50%. Using an extensive information base available on the dynamics of landscape structure and function of the northeastern hill areas of India, scenarios on landscape changes, as an adaptation to climate change, have been constructed. Climate change would impose a variety of stresses on sustainable livelihood of the inhabitants of the rain-forested areas through stresses on ecosystem function. It is concluded that appropriate management strategies for natural forests and plantation forestry should go hand in hand with a comprehensive rural Ecosystem restoration plan.
The perception that agroforestry systems have higher potential to sequester carbon than comparable single-species crop systems or pasture systems is based on solid scientific foundation. However, the estimates of carbon stock of agroforestry systems in Africa — reported to range from 1.0 to 18.0 Mg C ha1 in aboveground biomass and up to 200 Mg C ha1 in soils, and their C sequestration potential from 0.4 to 3.5 Mg C ha1 yr1 –are based on generalizations and vague or faulty assumptions and therefore are of poor scientific value. Although agroforestry initiatives are promising pathways for climate-change mitigation, rigorous scientific procedures of carbon sequestration estimations are needed for realizing their full potential.