Search

Ecological practices such as intercropping maize (Zea mays) with cowpea (Vigna unguiculata L.) have been promoted to combat parasitic weeds like Striga (Striga asiatica). Intercropping has been promoted across Africa as a Striga control practice (SCP) and food security measure. Despite past efforts, millions of smallholder farmers (cultivating < 2 ha of maize) still struggle to implement SCPs. Social and ecological factors that prevent SCP implementation are well documented in the literature, but their underlying interactions have remained elusive. System dynamics modeling can uncover these interactions and assess their effect on intercropping rates as well as Striga emergence. This study presents a participatory mixed methods approach to build a system dynamics model based on two theories: diffusion of innovations and resource pool dynamics. The model estimates the population of fields where Striga emerged in response to intercropped fields when various interventions were implemented. According to model simulations, if new policies are not enacted to support intercropping, Striga is likely to spread to 2,625,000 maize fields, parasitizing almost 75% of smallholder farms across Central Malawi by 2036. The participatory approach allowed us to evaluate several policies, one of which sustained enough adopters to limit Striga emergence to < 500,000 fields, reducing the weed's threat to food security. This policy considers how input costs and erratic rainfall can lead to disadoption, therefore, supporting the implementation of five to six consecutive years of intercropping by providing both fertilizer subsidies and demonstration plots. In this study, our participatory approach has shown to develop a model that can highlight interactions in social ecological systems, their leverage points, and how they can be exploited to develop effective food security policies [ABSTRACT FROM AUTHOR]

Malawi is a sub-Saharan African country at the forefront of the contemporary forest landscape restoration movement that places local smallholder farmers and resources users at the center of restoration actions. However, the manifestations of farmer-led bottom-up restoration efforts at individual and collective levels, and how they add up to landscape-scale restoration outcomes remain understudied. We analyze the nature of restoration efforts across interlocked forest and agricultural landscapes, estimate the extent of farmlands under restoration, and examine the contextual drivers and barriers of restoration. We use a mixed-methods approach combining a multivariate Tobit regression model and a Poisson model based on a 2019 household survey (N = 480 households), and qualitative insights from seven focus group discussions from Malawi's Dedza and Ntchisi Districts. The estimated mean total area of restored farmlands per household was 1.10 (± 0.76) and 1.07 (± 0.72) acres, representing, on average, about 54 % and 43 % of the total household landholdings in Dedza and Ntchisi, respectively. Results also indicate restoration diversification and intensification patterns whereby farmers generally combine two or more land-management practices based on complementarities in achieving specific livelihoods, food security, and ecological goals of restoration, and on compatibility regarding labor and other inputs demand. Land configuration mattered. Land plots that were spatially consolidated and tenure-secured were associated with higher restoration efforts. Also, women restoration efforts are limited by their inadequate access to productive inputs. Therefore, restoration policies should center on strategies that improve land-ownership security while minimizing fragmentation within landholdings and promote gender-responsive interventions. Drivers of collective resources restoration include strong local leadership; perceived tangible benefits for firewood, NTFPs, and timber resources; secure rights to collect firewood and free access to grazing areas; and perceived balanced among payoffs for energy needs, climate change adaptation, and ecological goals. These can inform restoration programs involving collective actions and their governance. • Farmers diversify and harness complementary restoration practices to meet socioecological goals. • Relative proportions of farmland restoration substantiate farmers' efforts and critical roles for restoration targets. • Limited access to inputs and other challenges, especially for women, constrained local restoration efforts. • Improving land tenure and spatial consolidation of landholdings can boost land restoration. • Strong leadership, benefits, and resources rights encourage collective forests restoration. • Balancing payoffs among socioecological goals is capital for collective forests restoration. [ABSTRACT FROM AUTHOR]

Perennial crops have numerous ecological and agronomic advantages over their annual counterparts. We estimate discrete choice models to evaluate farmers' preferences for perennial attributes of pigeon pea intercropped with maize in central and southern Malawi. Pigeon pea is a nitrogen-fixing leguminous crop, which has the potential to ameliorate soil fertility problems related to continuous maize cultivation, which are common in Southern Africa. Adoption of annual pigeon pea is relatively low but perennial production of pigeon pea may be more appealing to farmers due to some of the ancillary benefits associated with perenniality. We model perennial production of pigeon pea as a function of the attributes that differ between annual and perennial production: lower labor and seed requirements resulting from a single planting with multiple harvests, enhanced soil fertility and higher levels of biomass production. The primary tradeoff associated with perennial pigeon pea intercropped with maize is competition with maize in subsequent years of production. While maize yield is approximately twice as valuable to farmers as pigeon pea yield, we find positive yet heterogeneous demand for perenniality driven by soil fertility improvements and pigeon pea grain yield. [ABSTRACT FROM AUTHOR]

Across southern Africa (SA), significant maize yield losses are attributed to invasive and parasitic weeds. Abundance of Striga (Striga asiatica) has become more frequent in smallholder farms (<2 ha) in the past decade. Various Striga control practices (SCPs) have been disseminated across SA, yet often, without decision support tools to inform extension officers and researchers which ones are most appropriate for smallholder contexts. System dynamics modeling (SDM) provides an opportunity to evaluate the efficacy of SCPs across multiple seasons in different agroecosystems and their associated environments. We developed a SDM to evaluate the long-term efficacy of four SCPs popularly used in maize-based cropping systems. Observations from studies outlining local soil seedbanks, emergence and flowering rates in farmer fields were used to calibrate the SDM. Model simulations indicate that while a combination of SCPs are necessary to manage the weed, future research should focus on developing smallholder-adapted SCPs that address the attachment stage of the weed's lifecycle (e.g., timely manure application) rather than its germination, emergence or flowering stages. Given the devastating effects S. asiatica has had on food security in Malawi and across SA, it is imperative to develop decision support tools like systems models to evaluate SCPs for smallholders. Models that do not capture the underlying mechanisms driving S. asiatica infestations may provide extension officers with potentially misleading information, and subsequently, the delivery of ineffective SCPs. • Capturing the dynamic behavior of attachment informs better Striga control models. • Crop models made for smallholders must account for inconstant implementation rates. • Manure may replace synthetic fertilizer after 2 seasons to receive similar results. • Striga control must offer options that consider labor and financial constraints. • Practices that delay strigolactone exudation may be more effective for smallholders. [ABSTRACT FROM AUTHOR]