Highland Ethiopia is one of the most densely populated regions of Africa and has long been associated with both Malthusian disasters and Boserupian agricultural intensification. This paper explores the race between these two countervailing forces, with the goal of informing two important policy questions. First, how do rural Ethiopians adapt to land constraints? And second, do land constraints significantly influence welfare outcomes in rural Ethiopia? To answer these questions we use a recent household survey of high-potential areas. We first show that farm sizes are generally very small in the Ethiopian highlands and declining over time, with young rural households facing particularly severe land constraints. We then ask whether smaller and declining farm sizes are inducing agricultural intensification, and if so, how. We find strong evidence in favor of the Boserupian hypothesis that land-constrained villages typically use significantly more purchased input costs per hectare and more family labor, and achieve higher maize and teff yields and high gross income per hectare. However, although these higher inputs raise gross revenue, we find no substantial impact of greater land constraints on net farm income per hectare once family labor costs are accounted for. Moreover, farm sizes are strongly positively correlated with net farm income, suggesting that land constraints are an important cause of rural poverty. We conclude with some broad policy implications of our results.

Continued population growth, rapidly changing consumption patterns and the impacts of climate change and environmental degradation are driving limited resources of food, energy, water and materials towards critical thresholds worldwide. These pressures are likely to be substantial across Africa, where countries will have to find innovative ways to boost crop and livestock production to avoid becoming more reliant on imports and food aid. Sustainable agricultural intensification - producing more output from the same area of land while reducing the negative environmental impacts - represents a solution for millions of African farmers. This volume presents the lessons learned from 40 sustainable agricultural intensification programmes in 20 countries across Africa, commissioned as part of the UK Government's Foresight project. Through detailed case studies, the authors of each chapter examine how to develop productive and sustainable agricultural systems and how to scale up these systems to reach many more millions of people in the future. Themes covered include crop improvements, agroforestry and soil conservation, conservation agriculture, integrated pest management, horticulture, livestock and fodder crops, aquaculture, and novel policies and partnerships.

Ethiopia has made substantial efforts in the last three decades to increase agricultural productivity through modern input intensification and stimulate overall economic growth. Despite the high growth rates in recent decade, Ethiopia’s overall intensification and yield levels remained below what is considered optimal. This study examines the patterns, trends, and drivers of agricultural intensification and productivity growth during the recent decade (2012 - 2019) using three rounds of representative household data collected from the four main agriculturally important regions of the country. The descriptive results indicate a positive trend in both the adoption rate and intensity of inputs and output, albeit from a low base compared to other contexts and with considerable heterogeneity by access to information, rainfall levels and variability, labor, soil quality, remoteness, among others. The econometric results show significant association between intensification, yield growth, household dietary diversity (a proxy measure for food and nutrition security), and consumer durables. However, the results on the association between current yield levels and per capita consumption expenditures are mixed (i.e., while an increase in cereal yield only improve food consumption expenditures, an increase in cash crops yield mainly improve non-food consumption expenditures). In sum, while the increasing input intensification and the resulting yield gains are associated with improvement in household diets and consumer durables, it falls short to have strong impact on incomes (as measured by total consumption expenditures), indicating that more efforts have to be made to see meaningful impacts on higher order outcomes. Additional welfare improving productivity gains through increased input intensifications may require investments to put in place appropriate fertilizer blends linked with localized soil nutrient requirements, investments to generate locally suited improved seeds and appropriate mechanisms to reach farmers, ways to mitigate production (rainfall) risk, and investments to remodel Ethiopia’s extension system to provided much needed technical support to farmers on production methods.

Increasing population pressure and population density in many African countries are inducing land scarcity and land constraints. These increasing land constraints are expected to trigger various responses and adaptation strategies, including agricultural intensification induced by land scarcity, as postulated by the Boserup hypothesis. However, most empirical evaluations of the Boserup hypothesis come from rainfed agriculture and mostly from Sub-Saharan Africa (SSA), where application of improved agricultural inputs remains historically low. Agricultural intensification practices as well as the relevance of the Boserup hypothesis in irrigated agriculture and in contexts where application of improved inputs is high remains unexplored. Furthermore, while much of the debate on the topic in Africa has focused on how to boost agricultural intensification, there is scant evidence on whether evolving agricultural intensification practices in some parts of Africa are sustainable, yield-enhancing, and optimal. In this paper we investigate the implication of land scarcity on agricultural intensification and the relevance of the Boserup hypothesis in the context of Egypt, where agriculture is dominated by irrigation and input application rates are much higher than SSA. We also examine whether evolving agricultural intensification practices induced by land scarcity are agronomically appropriate and yield-enhancing. We find that land scarcity induces higher application of agricultural inputs, mainly nitrogen fertilizers, sometimes beyond the level that is agronomically recommended. More importantly, land scarcity increases overapplication of nitrogen fertilizer relative to crop-specific agronomic recommendations. This implies that land constraints remain as important challenges for sustainable agricultural intensification. Finally, we find suggestive evidence that such overapplication of nitrogen fertilizers is not yield-enhancing, but, rather, yield-reducing. We also document that land scarcity impedes mechanization of agriculture. Our findings have important implications to inform appropriate farm management and sustainable intensification practices. Furthermore, our results can inform long-term policy responses to land scarcity.

The book offers a rich toolkit of relevant, adoptable ecosystem-based practices that can help the world's 500 million smallholder farm families achieve higher productivity, profitability and resource-use efficiency while enhancing natural capital.

The humid highlands in sub-Saharan Africa (SSA) are characterized by high population densities and require intensification. The Consortium for Improving Agriculture-based Livelihoods in Central Africa (CIALCA) has set up a research for development platform in various mandate areas in DR Congo, Burundi, and Rwanda, aiming to identify improved production, market, and nutrition options and facilitating the access for development partners to these options. This platform is supported by capacity building, multi-stakeholder dialogue, and monitoring and evaluation efforts. The conference, facilitated by CIALCA, aimed to (i) take stock of the state-of the art in agricultural intensification in the highlands of SSA and (ii) chart the way forward for agricultural research for development in the humid highlands of SSA, and more specifically in the recently launched Humidtropics Consortium Research Programme, through keynote, oral and poster presentations, and strategic panel discussions.