Closing Yield Gaps: Consequences for the Global Food Supply, Environmental Quality & Food Security

Daedalus ◽  
2015 ◽  
Vol 144 (4) ◽  
pp. 45-56 ◽  
Author(s):  
Nathaniel D. Mueller ◽  
Seth Binder

The social, economic, and environmental costs of feeding a burgeoning and increasingly affluent human population will depend, in part, on how we increase crop production on under-yielding agricultural landscapes, and by how much. Such areas have a “yield gap” between the crop yields they achieve and the crop yields that could be achieved under more intensive management. Crop yield gaps have received increased attention in recent years due to concerns over land scarcity, stagnating crop yield trends in some important agricultural areas, and large projected increases in food demand. Recent analyses of global data sets and results from field trials have improved our understanding of where yield gaps exist and their potential contribution to increasing the food supply. Achieving yield gap closure is a complex task: while agronomic approaches to closing yield gaps are generally well-known, a variety of social, political, and economic factors allow them to persist. The degree to which closing yield gaps will lead to greater food security and environmental benefits remains unclear, and will be strongly influenced by the particular strategies adopted.

2019 ◽  
Vol 11 (7) ◽  
pp. 2104 ◽  
Author(s):  
Chong Wang ◽  
Jiangang Liu ◽  
Shuo Li ◽  
Ting Zhang ◽  
Xiaoyu Shi ◽  
...  

Confronted with the great challenges of globally growing populations and food shortages, society must achieve future food security by increasing grain output and narrowing the gap between potential yields and farmers’ actual yields. This study attempts to diagnose the climatic and agronomic dimensions of oat yield gaps and further to explore their restrictions. A conceptual framework was put forward to analyze the different dimensions of yield gaps and their limiting factors. We quantified the potential yield (Yp), attainable yield (Yt), experimental yield (Ye), and farmers’ actual yield (Ya) of oat, and evaluated three levels of yield gaps in a rain-fed cropping system in North and Northeast China (NC and NEC, respectively). The results showed that there were great differences in the spatial distributions of the four kinds of yields and three yield gaps. The average yield gap between Yt and Ye (YG-II) was greater than the yield gap between Yp and Yt (YG-I). The yield gap between Ye and Ya (YG-III) was the largest among the three yield gaps at most sites, which indicated that farmers have great potential to increase their crop yields. Due to non-controllable climatic conditions (e.g., light and temperature) for obtaining Yp, reducing YG-I is extremely difficult. Although YG-II could be narrowed through enriching soil nutrients, it is not easy to improve soil quality in the short term. In contrast, narrowing YG-III is the most feasible for farmers by means of introducing high-yield crop varieties and optimizing agronomic managements (e.g., properly adjusting sowing dates and planting density). This study figured out various dimensions of yield gaps and investigated their limiting factors, which should be helpful to increase farmers’ yields and regional crop production, as long as these restrictions are well addressed.


Nature Food ◽  
2021 ◽  
Author(s):  
Juan I. Rattalino Edreira ◽  
José F. Andrade ◽  
Kenneth G. Cassman ◽  
Martin K. van Ittersum ◽  
Marloes P. van Loon ◽  
...  

AbstractFood security interventions and policies need reliable estimates of crop production and the scope to enhance production on existing cropland. Here we assess the performance of two widely used ‘top-down’ gridded frameworks (Global Agro-ecological Zones and Agricultural Model Intercomparison and Improvement Project) versus an alternative ‘bottom-up’ approach (Global Yield Gap Atlas). The Global Yield Gap Atlas estimates extra production potential locally for a number of sites representing major breadbaskets and then upscales the results to larger spatial scales. We find that estimates from top-down frameworks are alarmingly unlikely, with estimated potential production being lower than current farm production at some locations. The consequences of using these coarse estimates to predict food security are illustrated by an example for sub-Saharan Africa, where using different approaches would lead to different prognoses about future cereal self-sufficiency. Our study shows that foresight about food security and associated agriculture research priority setting based on yield potential and yield gaps derived from top-down approaches are subject to a high degree of uncertainty and would benefit from incorporating estimates from bottom-up approaches.


2021 ◽  
Vol 10 (1) ◽  
pp. 9-26
Author(s):  
Wubetie ADNEW ◽  
Bimrew ASMARE ◽  
Yeshambel MEKURIAW

Still food security has not been attained fully in many tropical African countries including Ethiopia. However, the issue of food security achievement has been able to realize due to various setbacks among which low productivity of crops and livestock take the lion share. Among the various constraints the parasitic weed Striga, and Stemborer pests are responsible for lower crop yields in the region. Regarding livestock feed, shortage in terms of quantity and quality are the major impediment to the livestock sector. To achieve food security, increasing crop yield and livestock production is vital in Ethiopia and other tropical countries. Crop yields can be enhanced through the control of weeds using biological systems to increase food crop yield apart from chemical inputs. In case of livestock, full production and reproduction potential of animals can be met through fulfilling nutritional requirements of livestock. The major livestock feed resources in Ethiopia are natural pasture and crop residues. Both feed resources; however, are poor in nutritional value and they are listed as low maintenance feed category. Therefore, it is vital to intensify integrated crop- livestock production systems for sustainable economy and environment. Introducing forage grasses in the crop production system has been practiced in the tropics as push pull technology. In Ethiopia, Brachiaria grass is an emerging forage for integrated agricultural production that has been getting considerable recognition as an option to overcome the pests in crop production in the tropics due to its high adaptive and yielding as well as climate smart forages. In the country, Brachiaria is recently introduced by different organization in different agro-ecology of the country mainly as push-pull integrated agricultural system and considering its fodder potential for the livestock feed. Therefore, this review paper aimed to looking for the available research knowledge in Ethiopia and somewhere else in the glob for better utilization of Brachiaria grass in the integrated agricultural system. All available information regarding the research and utilization of Brachiaria grass were reviewed in the published papers. The review reveal that Brachiaria has many advantages over other grass species in terms of adaptation to drought and low fertility soils, ability to sequester carbon; increase nitrogen use efficiency through biological nitrification inhibition (BNI) and arrest greenhouse gas emissions. The knowledge has been established in quantifying the multiple contributions of Brachiaria grass inclusion as push pull technology in different parts of the world (South America, Kenya, Rwanda). Limited report showed that cut-and-carry system is the utilization practice of brachiaria grass grown the push pull integration. The potential of improved Brachiaria grass in Ethiopia to address the challenge of livestock feed scarcity and other environmental managements; however, remain unexploited/limited which calls researchers to work on. The review concluded that B. cultivars could have a significant contribution on both animal and cereal production in the tropics but limited research and utilization in Ethiopia.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 480
Author(s):  
Zhichao An ◽  
Chong Wang ◽  
Xiaoqiang Jiao ◽  
Zhongliang Kong ◽  
Wei Jiang ◽  
...  

Increasing plant density is a key measure to close the maize (Zea mays L.) yield gap and ensure food security. However, there is a large plant density difference in the fields sown by agronomists and smallholders. The primary cause of this phenomenon is the lack of an effective methodology to systematically analyze the density loss. To identify the plant density loss processes from experimental plots to smallholder fields, a research methodology was developed in this study involving a farmer survey and measurements in a smallholder field. The results showed that the sowing density difference caused by farmer decision-making and plant density losses caused by mechanical and agronomic factors explained 15.5%, 5.5% and 6.8% of the plant density difference, respectively. Changing smallholder attitudes toward the value of increasing the plant density could help reduce this density loss and increase farm yields by 12.3%. Therefore, this methodology was effective for analyzing the plant density loss, and to clarify the primary causes of sowing density differences and plant density loss. Additionally, it was beneficial to identify the priorities and stakeholders who share responsibility for reducing the density loss. The methodology has wide applicability to address the sowing density differences and plant density loss in other areas to narrow crop yield gaps and ensure food security.


2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.


Nature ◽  
2011 ◽  
Vol 480 (7375) ◽  
pp. 39-39 ◽  
Author(s):  
Robert Finger
Keyword(s):  

2019 ◽  
Author(s):  
Matias Heino ◽  
Joseph H. A. Guillaume ◽  
Christoph Müller ◽  
Toshichika Iizumi ◽  
Matti Kummu

Abstract. Climate oscillations are periodically fluctuating oceanic and atmospheric phenomena, which are related to variations in weather patterns and crop yields worldwide. In terms of crop production, the most widespread impacts have been observed for the El Niño Southern Oscillation (ENSO), which has been found to impact crop yields in all continents that produce crops, while two other climate oscillations – the Indian Ocean Dipole (IOD) and the North Atlantic Oscillation (NAO) – have been shown to impact crop production especially in Australia and Europe, respectively. In this study, we analyse the impacts of ENSO, IOD and NAO on the growing conditions of maize, rice, soybean and wheat at the global scale, by utilizing crop yield data from an ensemble of global gridded crop models simulated for a range of crop management scenarios. Our results show that simulated crop yield variability is correlated to climate oscillations to a wide extent (up to almost half of all maize and wheat harvested areas for ENSO) and in several important crop producing areas, e.g. in North America (ENSO, wheat), Australia (IOD & ENSO, wheat) and northern South America (ENSO, soybean). Further, our analyses show that higher sensitivity to these oscillations can be observed for rainfed, and fully fertilized scenarios, while the sensitivity tends to be lower if crops are fully irrigated. Since, the development of ENSO, IOD and NAO can be reliably forecasted in advance, a better understanding about the relationship between crop production and these climate oscillations can improve the resilience of the global food system to climate related shocks.


2010 ◽  
Vol 34 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Osvaldo Guedes Filho ◽  
Sidney Rosa Vieira ◽  
Márcio Koiti Chiba ◽  
César Hideo Nagumo ◽  
Sônia Carmela Falci Dechen

Soil properties are closely related with crop production and spite of the measures implemented, spatial variation has been repeatedly observed and described. Identifying and describing spatial variations of soil properties and their effects on crop yield can be a powerful decision-making tool in specific land management systems. The objective of this research was to characterize the spatial and temporal variations in crop yield and chemical and physical properties of a Rhodic Hapludox soil under no-tillage. The studied area of 3.42 ha had been cultivated since 1985 under no-tillage crop rotation in summer and winter. Yield and soil property were sampled in a regular 10 x 10 m grid, with 302 sample points. Yields of several crops were analyzed (soybean, maize, triticale, hyacinth bean and castor bean) as well as soil chemical (pH, Soil Organic Matter (SOM), P, Ca2+, Mg2+, H + Al, B, Fe, Mn, Zn, CEC, sum of bases (SB), and base saturation (V %)) and soil physical properties (saturated hydraulic conductivity, texture, density, total porosity, and mechanical penetration resistance). Data were analyzed using geostatistical analysis procedures and maps based on interpolation by kriging. Great variation in crop yields was observed in the years evaluated. The yield values in the Northern region of the study area were high in some years. Crop yields and some physical and soil chemical properties were spatially correlated.


Author(s):  
R. Ford Denison

This chapter considers some of the challenges that agriculture is facing now or will face in the near future, including resource-use efficiency and food security. It begins with a discussion of the goals of agriculture, such as improving productivity (yield per acre, to use no more land than necessary), efficiency in the use of scarce resources (to use no more water than necessary, for example), stability over years (to prevent even occasional famines), and sustainability (to maintain all of these benefits over the long term). It then examines the effects of agriculture on everyone, not just farmers, as well as agriculture's underlying long-term problems such as those relating to food supply, food production, and transportation. It also looks at threats to sustainability, particularly those farming practices that lead to long-term decreases in crop yield. Finally, it offers suggestions for limiting the negative environmental impact of agriculture.


2018 ◽  
Vol 55 (2) ◽  
pp. 311-338
Author(s):  
JOÃO VASCO SILVA ◽  
JOSHUA J. RAMISCH

SUMMARYYield gaps have become a useful tool for guiding development-related agronomy, especially in the global South. While critics have challenged some aspects of the yield gap methodology, and the relevance of food security advocacy based on yield gaps, very few studies question the actual relevance, application and scalability of yield gaps for smallholder farmers (and researchers) in the tropics. We assess these limitations using two contrasting case studies: maize-based farming systems in Western Kenya and rice-based farming systems in Central Luzon, the Philippines. From these two cases, we propose improvements in the use of yield gaps that would acknowledge both the riskiness of crop improvement options and the role that yield increases might play within local livelihoods. Participatory research conducted in Western Kenya calls into question the actual use and up-scaling of yield measurements from on-station agronomic trials to derive estimates of actual and water-limited yields in the region. Looking at maize yield gaps as cumulative probabilities demonstrates the challenges of assessing the real magnitude of yield gaps in farmers’ fields and of deciding whose yield gaps count for agricultural development in Kenya. In the case of rice-based farming systems, we use a historical dataset (1966–2012) to assess changes in rice yields, labour productivity, gross margin and rice self-sufficiency in Central Luzon, the Philippines. While large rice yield gaps persist here, there appear to be few incentives to close that gap once we consider the position of crop production within local livelihoods. In this context, economic returns to labour for farm work were marginal: labour productivity increased over time in both wet and dry seasons, but gross margins decreased in the wet season while no trend was observed for the dry season. Since most households were rice self-sufficient and further increases in crop production would offer minimal returns while relying increasingly on hired labour, we question who should close which yield gap. Our case studies show the importance of contextualising yield gaps within the broader livelihood context in which farmers operate. We propose that this should be done at farm and/or farming systems level while considering the risks associated with narrowing yield gaps and looking into multiple performance indicators.


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