Habtamu Alem

Research Scientist

(+47) 993 67 513
habtamu.alem@nibio.no

Place
Ås O43

Visiting address
Oluf Thesens vei 43, 1433 Ås

Attachments

CV

Biography

Alem holds Ph.D. and M.Sc. in Economics from the Norwegian University of Life Sciences (NMBU). He works as a research scientist at the Norwegian Institute of Bioeconomy Research (NIBIO) in the Department of Economics and Society. Alem was a researcher for the Ethiopian Institute of Agricultural Research and an executive officer for the Norwegian Institute of Agricultural Research. He is now the project coordinator for the SYSTEMIC project, which covers eight EU nations.

His research interest is food and nutrition security; Environmental and production economics; Climate change; Econometrics; impact assessment; circular economics; cost benefit analysis; consumer economics; Risk analysis; and topics related to development economics (developing and developed countries)

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Abstract

Abstract Water hyacinth is among the world’s most damaging aquatic invasive plants, forming dense mats that disrupt ecosystem functioning, fisheries, navigation, and livelihoods across tropical and subtropical freshwater systems. Its rapid spread is driven by clonal propagation, short life cycles, and prolific seed production, particularly under nutrient-enriched conditions. Although mechanical, chemical, and biological control methods are widely applied, their long-term effectiveness remains uncertain when underlying eutrophication persists. Here, we present a large-scale, one-time water hyacinth removal campaign in Lake Tana, Ethiopia’s largest lake and a UNESCO Biosphere Reserve, as a representative nutrient-rich tropical freshwater system. Using high-resolution satellite imagery, we quantified coverage one month before removal, one month after removal, and one year later. We integrated SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis with a socio-ecological system map to assess mitigation mechanisms and identify sustainable management pathways capable of providing long-term solutions to halt water hyacinth proliferation in freshwater bodies. The campaign removed over 75% (~1271 ha) of water hyacinth, yet within one year the plant resurged to levels ~18% higher than pre-removal. This rebound highlights the ecological resilience of water hyacinth and the limitations of short term, noncontinuous control strategies. Our analysis identifies unmanaged catchment nutrient inputs as the primary driver of proliferation. Lake Tana serves as a model system demonstrating that water hyacinth functions less as a traditional invader and more as a bioindicator of eutrophication. We propose a transferable conceptual and methodological framework combining continuous removal, catchment-based nutrient management, and circular bioeconomy approaches, offering globally relevant lessons for sustainable management of nutrient-enriched tropical freshwater systems.

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Abstract

Sustainable food production in West Africa is increasingly challenged by declining soil fertility, erratic rainfall, and demographic pressures that intensify demand for land. In this context, farmers often respond to stagnating yields by expanding cultivated areas, a strategy that accelerates the conversion of fallows and natural habitats into cropland. This study investigates whether agroecology informed sustainable intensification (SI) packages can improve technical land use efficiency and thereby reduce the incentive for agricultural expansion. The analysis focuses on smallholder maize systems across Northern Ghana, where land degradation and climate variability pose persistent constraints. Using farm level survey data from 372 maize producers across the Northern, Upper East, and Upper West regions, we estimate technical land use efficiency with a translog stochastic frontier model that treats land as a fixed input. This methodological choice provides a direct interpretation of efficiency as the effective land required to produce observed output. The SI package examined includes improved seed, more balanced fertilizer applications, and agroecological practices such as residue retention and intercropping. A matched comparison group of non adopters allows us to isolate adoption effects. The results show that SI adopters are, on average, 21% more land efficient than non participants, implying that approximately 24% less land would be needed to produce the same quantity of maize. Efficiency improvements are most pronounced among farmers initially furthest from the production frontier, indicating substantial equity gains when targeting less efficient producers. The analysis further highlights the importance of enabling conditions: education, advisory services, and access to credit all significantly enhance the likelihood and effectiveness of adoption. These findings strengthen the argument for agroecological transition pathways that bundle technological, institutional, and financial interventions. Such integrated approaches can raise productivity, limit pressure on land expansion, and contribute to land degradation neutrality and climate resilience in the savanna agroecosystems of West Africa.

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Abstract

Sustainable intensification technologies (SITs) are widely promoted across sub-Saharan Africa to improve productivity and reduce land degradation. However, their relationship with land use efficiency remains insufficiently understood. This study uses a translog stochastic frontier model and farm-level data from 372 smallholder maize farmers in northern Ghana to examine how SIT adoption is associated with technical land use efficiency (TLUE). On average, SIT adopters are 21% more land efficient than non-adopters, requiring approximately 24% less land to achieve the same output. Since land is treated as a fixed input in the frontier, the TLUE score directly reflects the effective land needed to produce observed yields. Adoption of improved seed, balanced fertilizer use, and agroecological practices is linked to better resource use, with the largest gains among farmers who initially operate furthest from the frontier. These efficiency improvements may reduce pressure for cropland expansion and support sustainable land management, especially when combined with enabling conditions such as credit access, extension support, and secure tenure. This study provides novel empirical evidence on how productivity improvements through SIT can enhance land use efficiency and contribute to land sparing outcomes. The findings offer insights for policies targeting land degradation neutrality and inclusive agricultural transformation in Ghana and similar contexts.