Closing Yield Gaps: How Sustainable Can We Be?

Abstract

Global food production needs to be increased by 60–110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45–73%, P2O5-fertilizer by 22–46%, and K2O-fertilizer by 2–3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way management strategies for closing yield gaps are chosen and implemented.

Can sub-Saharan Africa feed itself?

“…Although growth in total factor productivity has become the most important source of growth in global agricultural production in the past two decades, in SSA this metric grew by less than 1% per year over that period, even while it faces the world's highest population growth rates (20). A recent global study (11), based on the use of gridded spatial analysis and coarse global datasets, suggests it will be challenging for Africa to feed itself, whereas other global and continental analyses (15,21) project that cereal imports will increase in SSA in the coming decades.…”

“…Increased price volatility of major food crops (3,4) and an abrupt surge in land area devoted to crop production since approximately 2002 (5) reflect the powerful forces underpinning this challenge. A number of studies argue it is possible to meet projected global food demand on existing agricultural land by narrowing gaps between actual farm yields and yield potential (3,(6)(7)(8)(9)(10)(11). Yield potential assumes unconstrained crop growth and perfect management that avoids limitations from nutrient deficiencies and water stress, and reductions from weeds, pests, and diseases (12,13).…”

Confronting Climate Change Challenges to Dryland Cereal Production: A Call for Collaborative, Transdisciplinary Research, and Producer Engagement

“…Ecosystem services are dynamic and complex natural processes that significantly determine water quality, surface water flows, groundwater replenishment, soil formation, soil fertility, and erosion control, habitats for pollinators, pests and pest predator biodiversity, and other environmental conditions (Daily, 1997(Daily, , 1999Kremen, 2005;Palmer et al, 2005). Identifying and measuring how agricultural practices impact ecosystem services is challenging because farm operations tend to generate "non-point source" changes to the environment that are often subtle and only discernable over longer time frames than that of seasonal crop harvests and annual returns on investment (Pradhan et al, 2015).…”

Closing Pakistan's Yield Gaps Through Nutrient Recycling

“…Closing global yield gaps through better nutrient and water management would go a long way to meet food security goals (Mueller et al, 2013), within a multi-pronged approach (e.g., reducing waste, changing diets, expanding agriculture; Godfray et al, 2010). In fact, closing yield gaps on irrigated and rain-fed land alone could boost globally available calories by 80% (Pradhan et al, 2015). Still, any approach to increase food security, including increasing yields, will have to account for constrained resource availability and increased ecosystem sensitivity to change, notably those associated with essential nutrients (Dawson and Hilton, 2011;Foley et al, 2011).…”