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Although global food demand is expected to increase 60% by 2050 compared with 2005/2007, the rise will be much greater in sub-Saharan Africa (SSA). Indeed, SSA is the region at greatest food security risk because by 2050 its population will increase 2.5-fold and demand for cereals approximately triple, whereas current levels of cereal consumption already depend on substantial imports. At issue is whether SSA can meet this vast increase in cereal demand without greater reliance on cereal imports or major expansion of agricultural area and associated biodiversity loss and greenhouse gas emissions. Recent studies indicate that the global increase in food demand by 2050 can be met through closing the gap between current farm yield and yield potential on existing cropland. Here, however, we estimate it will not be feasible to meet future SSA cereal demand on existing production area by yield gap closure alone. Our agronomically robust yield gap analysis for 10 countries in SSA using location-specific data and a spatial upscaling approach reveals that, in addition to yield gap closure, other more complex and uncertain components of intensification are also needed, i.e., increasing cropping intensity (the number of crops grown per 12mo on the same field) and sustainable expansion of irrigated production area. If intensification is not successful and massive cropland land expansion is to be avoided, SSA will depend much more on imports of cereals than it does today. [ABSTRACT FROM AUTHOR]

Intercropping is widely used by smallholder farmers in developing countries, and attracting attention in the context of ecological intensification of agriculture in developed countries. There is little experience with intercropping of food crops in Western Europe. Yields in intercrops depend on planting patterns of the mixed species in interaction with local growing conditions. Here we present data of two years field experimentation on yield and yield components of a wheat–maize intercrop system in different planting configurations in the Netherlands. Treatments included sole crops of wheat (SW) and maize (SM), a replacement intercrop consisting of strips of six wheat rows alternating with two maize rows (6:2WM), as well as subtractive or additive designs, based on skip-row (6:0WM, 0:2WM) and add-row (8:2WM, 6:3WM) configurations. The land equivalent ratio (LER) of intercrops varied from 1.18 to 1.30 in 2013 and from 0.97 to 1.08 in 2014. Wheat grown in the border rows of wheat strips had higher ear number per meter row, greater kernel number per ear, and greater yield per meter row than wheat in inner rows and sole wheat, indicating reduced competition. Wheat in the border rows in the intercrops had, however, reduced thousand kernel weight and harvest index, indicating that competition in border rows intensified over time. Intercropping negatively affected maize biomass and thousand kernel weight, especially in add-row treatments. This study indicates that there is a potential yield benefit for the wheat–maize intercropping system under Western European growing conditions. However, the LER was affected by yearly variation in weather conditions and significantly greater than one in only one of the two years of the study. [ABSTRACT FROM AUTHOR]

The war in Ukraine threatened to block 9% of global wheat exports, driving wheat prices to unprecedented heights. We advocate, that in the short term, compensating for such an export shortage will require a coordinated release of wheat stocks, while if the export block persists, other export countries will need to fill the gap by increasing wheat yields or by expanding wheat cropping areas by 8% in aggregate. We estimate that a production increase would require an extra half a million tons of nitrogen fertilizer, yet fertilizer prices are at record levels, driven by rising energy prices. Year-to-year variability plus more frequent climate change-induced crop failures could additionally reduce exports by another 5 to 7 million tons in any given year, further stressing global markets. Without stabilizing wheat supplies through judicious management of stocks and continuing yield improvements, food and national security are at risk across many nations in the world. • The war in Ukraine threatened to block 9% of global wheat exports. • Top export countries will need to increase wheat yields or cropping areas by 8% in aggregate. • A production increase would require an extra half a million tons of nitrogen fertilizer. • Climate induced crop failures could additionally reduce exports by 5–7 million tons. [ABSTRACT FROM AUTHOR]

Research is presented concerning the development of mixed-integer linear programming models which feature near optimal solution analysis. The use of branch-and-bound algorithms to determine near optimal solutions is discussed.

Producer organizations (POs) are often recognized as a pathway to boost rural development by enhancing farmers' access to market opportunities. Smallholder production and marketing of new crops (such as those for biodiesel feedstock) are constrained as farmers and buyers face high transaction costs. By investigating cases of POs outside the biofuel industry, the authors explore the extent to which POs could reduce transaction costs. The findings indicate that POs are capable of linking farmers effectively to markets in cases in which high value is added to farm products and/or farmers are highly specialized. However, the scope for POs in linking farmers to biodiesel markets is limited due to organization-specific characteristics, the low value added of the feedstock, plus multiple trade-offs with current farm activities. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained the following errors. [ABSTRACT FROM AUTHOR]

Sustainable intensification has been proposed as a pathway to achieve food security and reduce environmental impacts of agriculture by focusing on narrowing yield gaps on existing agricultural land while improving resource use efficiencies. There is a general consensus that regions with large yield gaps can benefit most from sustainable intensification but it remains unclear how sustainable this is for farmers given their current resource constraints and livelihood strategies. Here, we draw upon three contrasting case studies, for which detailed data at field and farm levels were available for yield gap decomposition, to assess how sustainable intensification of crops (at field level) works out at farm level using environmental and socio-economic indicators. Although there is large potential for future intensification (more output with more input) of cereal production in southern Ethiopia, current input use in these farming systems is not economically and environmentally sustainable at farm level. The same is true for rice production in Central Luzon where sustainable intensification (more output with less input) can help to narrow yield gaps and improve N use efficiency (NUE) but it is not profitable due to the heavy reliance on costly hired labour. Trade-offs between yield gap closure and labour productivity were also observed in the aforementioned farming systems. Arable farms in the Netherlands exhibit small yield gaps as well as higher economic performance, NUE and N surplus compared to those observed in Southern Ethiopia and Central Luzon. For improving environmental sustainability, these farms require increases in resource-use efficiency and a reduction of the environmental impacts through a lower use of inputs (same output with less input). We conclude that public investments conducive for innovation and profitable farming are essential to make technologies accessible and affordable for farmers and to ensure that yield gaps can be narrowed and sustainability objectives served at the farm level. • Yield gaps are large in Ethiopia, intermediate in the Philippines and small in the Netherlands. • Increasing input use is essential to improve the sustainability of cereal farms in Ethiopia. • Better N management and less hired labour are required to improve the sustainability of rice farms in the Philippines. • Reducing input use can contribute to increase the sustainability of arable farms in the Netherlands. • Sustainable intensification is only likely to take place where public investments to support farmers are ensured. [ABSTRACT FROM AUTHOR]