Governing agriculture-forest landscapes to achieve climate change mitigation

This introduction to the special section on Governing Agriculture-Forest Landscapes to Achieve Climate Change Mitigation reviews external interventions to improve forest conditions and reduce deforestation, and by extension, influence carbon storage in agriculture-forest landscapes. The review is based on a careful survey of 123 cases of project-based and policy interventions to influence land use and forest cover outcomes. We propose that outcomes of interventions can be explained in terms of rights, incentives, and technologies related to land use and apply this framework to examine 12 types of interventions in agriculture-forest landscapes. The analysis of the identified 123 cases raises concerns about consistency of data and comparability of cases. Our preliminary evidence suggests limited association between the stated objective of an intervention and its success. This evidence also suggests that smaller scale and effective enforcement may be positively associated with improved forest outcomes. But the effectiveness of interventions across different agriculture-forest landscapes varies and available evidence does not permit easy generalizations. The variable effects of interventions across different agriculture-forest landscapes point to the need to better understand the forms and functions of interventions and to problems associated with assessing their relative efficacy

Comparison of wood basic density and basal area of 5-year-old Acacia crassicarpa, A. julifera, A. leptocarpa, Leucaena pallida and Senna siamea in rotational woodlots trials in western Tabora, Tanzania

Improvement and Culture of Nitrogen Fixing TreesIntroduction The term rotational woodlot connotes a technology which involves growing trees, normally N-fixing, with crops for 2-3 years until the trees out-compete the crops. The woodlot may then be used as a source of fuelwood, building poles or fodder. Soil fertility is also restored during this time until the farmers can cut the trees and start growing crops between the stumps, 4 to 5 years later. The technology was designed to mimic the traditional practice of shifting cultivation by introducing trees into the crop and shrub land with shortened fallow. The cropping and fallow phases take place concurrently. This allows the farmers to crop for an extended period without returning the land to bush fallow. The technology is flexible in the sense that it allows the farmers to adopt both the cropping phase and trees to suit individual needs which diversifies production base, enhances trees and crops productivity and allows a sustainable cropping system (Ramadhani et al. 2002). This technology is being promoted by the World Agroforestry Centre (ICRAF) in collaboration with farmers, Tanzania Forestry Research Institute (TAFORI), and the Agricultural Research and Development Institute (ARDI) Tumbi. The main objective is the provision of fuelwood for tobacco curing and other domestic uses to rural farmers and improvement of soil fertility in the tobacco-cereal land use system of Tabora, Tanzania. It reduces pressure on the 'miombo' woodlands. Despite the potential of this technology, there are few studies on wood basic density and basal area on trees currently used in rotational woodlots. Wood density is highly affected by woodlot manipulation through silvicultural and cultural practices. This study reports comparison of wood basic density and basal area of 5-year-old N-fixing trees of Acacia crassicarpa, A. julifera, A. leptocarpa, Leucaena pallida and Senna siamea grown in rotational woodlots both on-station and in farmers fields

Comparison of wood basic density and basal area of 5-year-old Acacia crassicarpa, A. julifera, A. leptocarpa, Leucaena pallida and Senna siamea in rotational woodlots trials in western Tabora, Tanzania

Improvement and Culture of Nitrogen Fixing TreesIntroduction The term rotational woodlot connotes a technology which involves growing trees, normally N-fixing, with crops for 2-3 years until the trees out-compete the crops. The woodlot may then be used as a source of fuelwood, building poles or fodder. Soil fertility is also restored during this time until the farmers can cut the trees and start growing crops between the stumps, 4 to 5 years later. The technology was designed to mimic the traditional practice of shifting cultivation by introducing trees into the crop and shrub land with shortened fallow. The cropping and fallow phases take place concurrently. This allows the farmers to crop for an extended period without returning the land to bush fallow. The technology is flexible in the sense that it allows the farmers to adopt both the cropping phase and trees to suit individual needs which diversifies production base, enhances trees and crops productivity and allows a sustainable cropping system (Ramadhani et al. 2002). This technology is being promoted by the World Agroforestry Centre (ICRAF) in collaboration with farmers, Tanzania Forestry Research Institute (TAFORI), and the Agricultural Research and Development Institute (ARDI) Tumbi. The main objective is the provision of fuelwood for tobacco curing and other domestic uses to rural farmers and improvement of soil fertility in the tobacco-cereal land use system of Tabora, Tanzania. It reduces pressure on the 'miombo' woodlands. Despite the potential of this technology, there are few studies on wood basic density and basal area on trees currently used in rotational woodlots. Wood density is highly affected by woodlot manipulation through silvicultural and cultural practices. This study reports comparison of wood basic density and basal area of 5-year-old N-fixing trees of Acacia crassicarpa, A. julifera, A. leptocarpa, Leucaena pallida and Senna siamea grown in rotational woodlots both on-station and in farmers fields

Techniques and skills of indigenous weather and seasonal climate forecast in Northern Ghana

There are strong calls to integrate scientific and indigenous forecasts to help farmers adapt to climate variability and change. Some studies used qualitative approaches to investigate indigenous people's techniques for forecasting weather and seasonal climate. In this study, we demonstrate how to quantitatively collect indigenous forecast and connect this to scientific forecasts. We identified and characterized the main indigenous ecological indicators (IEIs) local farmers in Northern Ghana use for forecasting. Mental model was constructed to establish the relationship between IEIs and their forecasts. Local farmers were trained to send their rainfall forecast with mobile apps and record observed rainfall with rain gauges. Results show that farmers forecast techniques are based on established cognitive relationship between IEIs and forecast events. Skill assessment shows that on the average both farmers and Ghana Meteorological Agency (GMet) were able to accurately forecast one out of every three daily rainfall events. Performance at the seasonal scale showed that unlike farmers, GMet was unable to predict rainfall cessation in all communities. We conclude that it is possible to determine the techniques and skills of indigenous forecasts in quantitative terms and that indigenous forecasts are not just intuitive but a skill developed over time and with practice.</p

Towards weather and climate services that integrate indigenous and scientific forecasts to improve forecast reliability and acceptability in Ghana

The livelihood of many farmers across the globe is affected by climate variability and change. Providing weather and seasonal climate information is expected to support farmers to make adaptive farming decisions. Yet, for many farmers, scientific forecast information provided remains unreliable for decision-making. Scholars have called for the need to integrate indigenous and scientific forecasts to improve forecast information at the local level. In Northern Ghana, scientific forecast information from meteorological agency is unacceptable to farmers, making them rely on indigenous forecasts for adaptive decisions. This study proposed an integrated probability forecasting (IPF) method that integrates indigenous and scientific forecasts into a single forecast. As a proof of concept, we tested the reliability of IPF using binary forecast verification method and evaluated its acceptability to farmers through internally consistent multiple-response questions. Results of the reliability test show that IPF performed on average better than indigenous and scientific forecasts at a daily timescale. At the seasonal timescale, IPF and indigenous forecast performed better than Scientific forecast, although in terms of probability IF showed better results overall. Majority of the farmers (93%) prefer the IPF method as this provides a reliable forecast, requires less time, and at the same time resolves the contradictions arising from forecast information from different sources. The results also show that farmers already integrate (complementary) scientific and indigenous forecasts to make farming decisions. However, their complementary approach does not resolve the issue of contradictory forecast information. From our proof of concept, we conclude that integrating indigenous and scientific forecasts can potentially increase forecast reliability and uptake

The Fate of Nitrogen During Agricultural Intensification in East Africa: Nitrogen Budgets in Contrasting Agroecosystems

The intensification of agricultural systems in sub-Saharan Africa (SSA) is necessary to reduce poverty and improve food security, but increased nutrient applications in smallholder systems could have negative consequences for water quality, greenhouse gas emissions, and air quality. We tracked nitrogen (N) inputs and measured maize (Zea mays) biomass, grain yields, N leaching, and nitric oxide (NO) and nitrous oxide fluxes from a clayey soil in Yala, Kenya and a sandy soil in Tumbi, Tanzania, with application rates of 0, 50, 75, 100, 150, and 200 kg N ha−1 yr−1 over two cropping seasons. Maize yields were 4.5 times higher in Yala than Tumbi, but yields plateaued at both sites with fertilizer applications at or above 100 kg N ha−1 yr−1. Partial N budgets in Yala were typically negative, meaning more N was exported in maize biomass plus grain or lost from the system than was added in fertilizer. In Tumbi, N budgets were negative at lower fertilizer levels but positive at higher fertilizer levels. At both sites most (96%) of the N was lost through maize biomass/grain removal and N leaching. Fertilizer additions at or less than 50 kg N ha−1 yr−1 on these two contrasting sites resulted in minor gaseous N losses, and fertilizer additions less than 200 kg N ha−1 yr−1 caused relatively little change to N leaching losses. This indicates that the modest increases in fertilizer use required to improve maize yields will not greatly increase cropland N losses.https://doi.org/10.1029/2022JG00712

Diagnosing the potential of hydro-climatic information services to support rice farming in northern Ghana

Hydro-climatic information has a potential to improve agricultural productivity under climate variability. Recent developments in information sharing platforms (Environmental Virtual Observatories, EVOs) could make information provisioning more actionable. Here we present the results of a diagnostic study for the development of a hydro-climatic EVO that enables rice farmers in Northern Ghana to deal with climate variability and water shortage. The hydro-climatic EVO aims to combine data from scientific and indigenous forecast systems, facilitating information exchange using two-way interaction with stakeholders to co-produce knowledge. Data was collected through informal interviews with field practitioners, through focus group discussions with farmers and content analysis of documents. Results show that both the biophysical and socio-institutional circumstances need be taken into account for the development of the EVO. Existing governance and information exchange arrangements and lack of collaboration between actors were found to limit current hydro-climatic information flow, interpretation, and use. Our study reveals existing models of information exchange and their limitations in the study area. We discuss the proposed design of a hydro-climatic EVO from a responsible innovation perspective, considering possible future eventualities in a process that aims to be anticipatory, inclusive, reflexive and responsive. We conclude that such a hydro-climatic EVO has a potential to contribute to rice farmers’ adaptive decision-making in Northern Ghana, but there are challenges that need to be considered. The diagnostic study has helped to refine these challenges and offers concrete suggestions to improve both the design and implementation of the proposed platform in a responsible way.</p