Diversity of components and interactions distinguishes complex agro-ecosystems from the simple agroecosystems which have replaced them in most of the temperate zone. In the tropics farmer decisions on agro-ecosystems have retained more similarity with natural ecosystems, but a strong trend toward specialization exists. As part of a re-appreciation of agro-ecosystem complexity, functional aspects of belowground diversity deserve more attention.
Tag: agroecosystems
Quantifying biological nitrogen fixation of agroforestry shrub species using 15N dilution techniques under greenhouse conditions
Some land-use systems in Saskatchewan, Canada include the nitrogen-fixing trees buffaloberry (Shepherdia argentea Nutt.), caragana (Caragana arborescens Lam.) and sea buckthorn (Hippophae rhamnoides L.). These species provide various ecological functions such as ameliorating soil moisture, light and temperature but little work has been done quantifying biological nitrogen fixation by these species. Greenhouse experiments were conducted to quantify N2-fixation using the 15N natural abundance and the 15N dilution methods. Buffaloberry failed to form nodules in all but one of the four replicates in the natural abundance experiment. Using the 15N dilution method, the percentage of N derived from atmosphere (%Ndfa) in the shoot of buffaloberry averaged 64 %. For caragana, the mean %Ndfa was 59 and 65 % and seabuckthorn was 70 and 73 % measured using the natural abundance and dilution methods, respectively. Because of large variability in biomass production between plants grown in the natural abundance experiment and the dilution experiment, the amounts of N2 fixed also were very variable. Buffaloberry fixed an average of 0.89 g N m-2; the average for caragana ranged from 1.14 to 4.12 g N m-2 and seabuckthorn ranged from 0.85 to 3.77 g N m-2 in the natural abundance and dilution experiments, respectively. This corresponds to 16 kg N ha-1 year-1 for buffaloberry; an average of 15-73 kg N ha-1 year-1 in caragana and 11-67 kg N ha-1 year-1 in seabuckthorn. The substantial amounts of N2 fixed by these species indicate that they have the potential to contribute to the overall N balance in land-use systems in which they are included
A potential feedback between landuse and climate in the Rungwe tropical highland stresses a critical environmental research challenge
Characteristic trends in landuse and climate highlight critical challenges in future resource management along the tropical topoclimosequence (TCS) of the Rungwe Volcanic Province (RVP), a major headwater biodiversity and food reservoir of Tanzania. The RVP orography supports a coherent distribution of agroecosystems and livelihoods, from hot irrigated lowlands to endangered afromontane forests above 1500 m.a.s.l. Recent increases in deforestation, land fragmentation and soil denudation/compaction in the densely populated TCS were combined with a strengthened need and consumption of water in the lower, warmer and drier end-member. Consistent with a regional decline of the long rains, a considerable (up to 30%) decrease in annual rainfall and a pervasive decline of the Lake Masoko (LM) aquifer testifies to a strong aridification trend. We suggest here that current landuse and demographic trends likely amplified the hydrological response of the TCS to regional and global warming. Testing such a hypothesis, however, requires improved local monitoring, to allow scaling and quantification of local hydrological budgets associated with landuse impacts, and evaluation of the contribution of trees and agroforestry systems to mitigating the aridification trend.
Biodiversity and nutrition
Malnutrition remains one of the greatest global health challenges we face and women and children are its most visible and vulnerable victims. Agricultural production is theoretically able to feed the world’s population in terms of calories (FAOSTAT, 2014), yet it is estimated that half the world’s population still suffers from one or more forms of malnutrition. In all its forms, malnutrition is closely linked to disease – as both a cause and effect – and it is the single largest contributor to the global burden of disease (WHO 2012a).Countries are increasingly facing complex multiple burdens of malnutrition, with undernutrition and micronutrient deficiencies coexisting with overweight and obesity in many parts of the world, often even within the same population or family (Shrimpton 2013). Based on data released in 2014, 161 million children under the age of five are estimated to be stunted, almost 1.5 billion people are estimated to be overweight, over 600 million to be obese (Ng et al. 2014) and two billion are estimated to be deficient in one or more micronutrients, a phenomenon referred to by some as “hidden hunger”. These conditions all have severe consequences for survival, for morbidity, and for the ability of individuals, the economy and society to thrive (IFPRI 2014)
Diversification of Coastal Agroecosystems for Climate Resilience and Livelihood Security
The Indian coastal region of India is known for its rich diversity of climate, topography, soils,crops, livestock, fisheries, etc. Despite the abundance of natural resources, the productivity of crops and livestock in this region is poor as compared to the inland regions. Unlike the other parts of the country, the region faces unique problems like demographic pressure, land degradation, rapid urbanization, industrialization, environmental pollution, and climate change effects like increased frequency of floods, droughts, cyclones, and sea level rises. The majority of nations with sizable coastal ecosystems are threatened by extreme weather and climate change. Therefore, appropriate measures must be adopted, especially in developing nations, to lessen the vulnerability of farming communities in coastal areas. An integral part of a diverse agroecosystem, agroforestry offers both rural and urban residents a variety of necessary goods and services. The benefits that trees offer are best retained by incorporating them into agriculturally productive landscapes as natural vegetation is cleared for agriculture and other development types. Various proven agroforestry models are available for different ecologies, farming systems and their management regimes, farmer’s resources and knowledge base. These can be practiced in a spectrum of combinations, designs and scales, from subsistence to commercial farming for different purposes, such as timber, fodder, fruits, medicinal, energy, etc. In essence, agroforestry provides two things: products, and services. Some of the common products are foods and beverages, fruits, nuts, oils,gums, resins, latex, flavours, leaves for food and nutrition, feed for livestock, wood for fuel,biomass for energy generation, and medications for treating illness. As hosts to edible insects, bee habitats for pollination, shelter from the sun and wind, modification of micro-climates, nitrogen fixation, increased soil carbon, erosion control, habitat for biodiversity, and better water regulation, including groundwater recharge, agroforestry also offer a variety of benefits. Tree integration in food-producing systems can be practiced in all ecologies, social settings, and farming systems in various designs and combinations. A portfolio of trees are developed for different purposes; income and nutrition security, resilience to climate change, enhance land productivity, market needs of timber, etc. without sacrificing the farm income. To understand the challenges, potential, and opportunities of agroforestry in the coastal ecosystem, and to promote co-learning through CIFOR-ICRAF’s Asia Continental Program in collaboration with ICARCCARI an International Training Program on Diversification of Coastal Agroecosystems for Climate Resilience and Livelihood Security is being organized at ICAR-CCARI, Goa, India during 07th to 11th November 2022. This training would be vital for priority setting of research and policy decisions. The training will also be very useful for planning the road map for sustainable development of the coastal agriculture and allied sectors.
One Million Voices Global Review: A review and analysis of existing citizen science initiatives and projects supporting agroecology and agroecological transitions
This report summarizes the results of a global review and analysis of citizen science projects supporting agroecology and agroecological transitions. The purpose of the review is to provide information on existing projects and inspire the development of a citizen science tool that enables inclusive participation in agroecology movements. The report aims to promote sustainable adoption of agroecology, fill knowledge gaps, and avoid duplication. It also contributes to four regional dialogues that were held to support the development of the One Million Voices of Agroecology digital platform.
The review used four data streams, including three citizen science platforms, a literature review, projects proposed by the One Million Voices citizen science initiative, and a Google search. The report includes 57 projects categorized into agricultural production, agroecosystems, and markets, consumption, and diets. Most projects focus on natural farming, with some addressing social justice and circular economy aspects. However, none of the projects fully encompass all aspects of agroecology, and there is a lack of accessible projects in the Global South and those focusing on elements beyond on-farm practices.
The report provides recommendations for the One Million Voices citizen science initiative. These recommendations include understanding participants’ motivations, providing benefits to participants, ensuring accessibility for diverse groups, keeping participation tasks simple, and leveraging existing networks and partnerships.
The politics of adaptiveness in agroecosystems and its role in transformations to sustainable food systems
Food systems are responsible for pushing human resource use past three thresholds of safe planetary operating space, yet the potential of agroecosystems to contribute to sustainability of food systems when managed for multiple benefits is underexplored. This gap has led to a call for food systems transformation. Previous reviews have acknowledged that governance of food systems transformations is not well understood. The aim of this review is to examine the challenges to transformative governance of agroecosystems, and the potential to apply existing paradigms of adaptiveness in agroecosystems for this transformation. Agricultural production landscapes have been found to be a key level of governance for realizing sustainability transformations of food systems and the landscape concept has been a key paradigm for managing multiple social and ecological objectives at a landscape scale. An examination of the landscape concept using five transformative governance characteristics and applying the earth system governance research lenses illustrated two key areas for further investigation and action for transformative governance. The first is landscape design for continuous social and ecological changes and evolving understandings of sustainability, and the second is the allocation of landscape costs, rights and benefits in present and future decision-making and among human and non-human entities. Managing the pluralistic diversities inherent to agroecosystems will be a key dynamic important to governance and policy for food systems transformations.
Integrating no-tillage with agroforestry augments soil quality indicators in Kenya’s dry-land agroecosystems
Conservation agriculture with trees (CAWT) is one of the best-bet strategies for enhanced soil quality under extensive and intensive smallholder farming. CAWT is an agroforestry system that integrates legume trees and shrubs into cropping fields under minimum soil disturbance and tillage. This study identified principal soil quality indicators (SQI) under CAWT system. The study further assessed the effects of CAWT components; i.e. tillage (convention or no-tillage), leguminous trees/shrubs (Calliandra calothyrsus, Gliricidia sepium and Cajanus cajan), and their inter-row spacing (1.5 m, 3.0 m or 4.5 m) on the SQI in the dry-land agroecosystems of eastern Kenya. We finally reported on the suitability of the SQI under CAWT intervention towards maize production. The experimental trials were both researcher (Mother-trials; MTs) and farmer (Baby-trials; BTs) hosted and managed. Principal Component Analyses (PCAs) identified soil fertility and textural components as the main factors explaining soil quality under the CAWT system. In particular, the exchangeable bases (ExBas) such as ExCa, ExK, and ExMg), Cation-Exchange-Capacity (CEC), total soil nitrogen (TSN), soil organic Carbon (SOC), pH, available Phosphorus(P), electrical conductivity (EC), clay and bulk density (BD) were identified as the principal soil quality indicators under the CAWT system. Tree species and varied inter-row spacing, significantly affected available P, BD, pH, ExBas, CEC, SOC, and TSN. The tillage systems significantly (P < 0.05) influenced soil pH, ExBas, CEC, SOC and TSN. A high concentration of TSN was recorded in no-tillage (NT) blocks integrated with C.calothyrsus (41.9 and 41.6 Mg N ha−1) and G. sepium (35.7 and 32.3 Mg N ha−1) both spaced at 1.5 m at the MTs and BTs, respectively. Combining NT with C.calothyrsus spaced at 1.5 m or Pigeon pea at 3.0 m significantly increases available P (from 22.9 to 28.8 mg kg−1 and 23.4–26.0 mg kg−1) at the MTs, respectively. Significant rise in ExK (1.91–2.25 cmolc kg−1), ExCa (6.86–8.17 cmolc kg−1), and ExMg (2.35–2.78 cmolc kg−1) were observed in NT block’s sub-plots with G. sepium spaced at 3.0 m at the MTs. Conclusively, a shift towards CAWT showed evidence of improving soil quality, nutrient availability and increasing soil nutrient thresholds that can potentially support maize production. By establishing the minimum datasets for soil quality determination through this study, key stakeholders in agroforestry and conservation agriculture (CA) have an efficient cost-effective and rapid tool for soil quality assessment, especially in dry-land agro-ecosystems.
Auctions in payments for ecosystem services and the plural values of nature
Payment for ecosystem service (PES) contracts encounters several challenges, encompassing information asymmetry in determining appropriate pricing, communication gaps involving multiple motivations and the evolving societal norms surrounding sustainability for voluntary contracts. Auctions serve as mechanisms for competitively awarding such contracts. However, their application and analysis have predominantly focused on their economic efficiency in overcoming information asymmetries and providing transparency in contract allocation. This instrumental perspective often overlooks the relational and intrinsic values that underlie PES contracts. By recognising PES auctions as multilayered processes of integrated valuation for nature, PES auctions can contribute to allocating resources efficiently, establishing new social relationships and restructuring existing ones while also providing opportunities for innovations.
Agroecologically-conducive policies: A review of recent advances and remaining challenges
The debate concerning the need for significant transformations towards more nutrition oriented, environmentally sustainable and inclusive food systems has generated increased attention towards agroecology in recent years. Literature on this subject has already demonstrated that transitions to agroecology will be context specific, as countries and regions have distinctive visions for the future of agriculture and food systems, unique starting points, and will therefore define their own transition pathways. This paper assesses how different policies (consumer oriented; producer oriented; market and food environment oriented; macro and trade oriented; and cross-cutting policies) can affect incentives for agroecology. It provides examples of policies and related actions taken by national, regional and city governments that intend to promote one or more agroecological principles. The assessment reveals that, until now, few countries have embarked on a broad set of reforms with sustained commitments. Many of these policies are new, weakly institutionalized and supported by limited budgets, making it difficult to analyze their actual effects. Because of this, there is very little research on how effective they have been in promoting agroecological transitions or the objectives that agroecology aims to achieve. Consequently, the paper’s main recommendation is for research to fill this gap so that future policy formulation and implementation can be better informed by experiences from different countries.