WHOSE GAP COUNTS? THE ROLE OF YIELD GAP ANALYSIS WITHIN A DEVELOPMENT-ORIENTED AGRONOMY

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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Wheat yield gaps across smallholder farming systems in Ethiopia

Agronomy for Sustainable Development ◽

10.1007/s13593-020-00654-z ◽

2021 ◽

Vol 41 (1) ◽

Author(s):

João Vasco Silva ◽

Pytrik Reidsma ◽

Frédéric Baudron ◽

Moti Jaleta ◽

Kindie Tesfaye ◽

...

Keyword(s):

Stochastic Frontier Analysis ◽

Stochastic Frontier ◽

Wheat Yield ◽

Farming Systems ◽

Smallholder Farming ◽

Yield Gap ◽

Frontier Analysis ◽

Ecological Zones ◽

Relative Contribution ◽

Yield Gaps

AbstractWheat yields in Ethiopia need to increase considerably to reduce import dependency and keep up with the expected increase in population and dietary changes. Despite the yield progress observed in recent years, wheat yield gaps remain large. Here, we decompose wheat yield gaps in Ethiopia into efficiency, resource, and technology yield gaps and relate those yield gaps to broader farm(ing) systems aspects. To do so, stochastic frontier analysis was applied to a nationally representative panel dataset covering the Meher seasons of 2009 and 2013 and crop modelling was used to simulate the water-limited yield (Yw) in the same years. Farming systems analysis was conducted to describe crop area shares and the availability of land, labour, and capital in contrasting administrative zones. Wheat yield in farmers’ fields averaged 1.9 t ha− 1 corresponding to ca. 20% of Yw. Most of the yield gap was attributed to the technology yield gap (> 50% of Yw) but narrowing efficiency (ca. 10% of Yw) and resource yield gaps (ca. 15% of Yw) with current technologies can nearly double actual yields and contribute to achieve wheat self-sufficiency in Ethiopia. There were small differences in the relative contribution of the intermediate yield gaps to the overall yield gap across agro-ecological zones, administrative zones, and farming systems. At farm level, oxen ownership was positively associated with the wheat cultivated area in zones with relatively large cultivated areas per household (West Arsi and North Showa) while no relationship was found between oxen ownership and the amount of inputs used per hectare of wheat in the zones studied. This is the first thorough yield gap decomposition for wheat in Ethiopia and our results suggest government policies aiming to increase wheat production should prioritise accessibility and affordability of inputs and dissemination of technologies that allow for precise use of these inputs.

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Diagnosing the Climatic and Agronomic Dimensions of Rain-Fed Oat Yield Gaps and Their Restrictions in North and Northeast China

Sustainability ◽

10.3390/su11072104 ◽

2019 ◽

Vol 11 (7) ◽

pp. 2104 ◽

Cited By ~ 1

Author(s):

Chong Wang ◽

Jiangang Liu ◽

Shuo Li ◽

Ting Zhang ◽

Xiaoyu Shi ◽

...

Keyword(s):

Northeast China ◽

Crop Production ◽

Crop Yields ◽

Climatic Conditions ◽

Planting Density ◽

Limiting Factors ◽

High Yield ◽

Yield Gap ◽

Potential Yield ◽

Yield Gaps

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.

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Spatial frameworks for robust estimation of yield gaps

Nature Food ◽

10.1038/s43016-021-00365-y ◽

2021 ◽

Author(s):

Juan I. Rattalino Edreira ◽

José F. Andrade ◽

Kenneth G. Cassman ◽

Martin K. van Ittersum ◽

Marloes P. van Loon ◽

...

Keyword(s):

Food Security ◽

Crop Production ◽

Spatial Scales ◽

Sub Saharan Africa ◽

Yield Potential ◽

Top Down ◽

Yield Gap ◽

Bottom Up ◽

Improvement Project ◽

Yield Gaps

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.

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

Daedalus ◽

10.1162/daed_a_00353 ◽

2015 ◽

Vol 144 (4) ◽

pp. 45-56 ◽

Cited By ~ 6

Author(s):

Nathaniel D. Mueller ◽

Seth Binder

Keyword(s):

Food Security ◽

Crop Yield ◽

Food Supply ◽

Crop Production ◽

Crop Yields ◽

Agricultural Landscapes ◽

Environmental Benefits ◽

Potential Contribution ◽

Yield Gap ◽

Yield Gaps

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.

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Towards Sustainable Intensification of Crop Production—Yield Gaps and Water Use Efficiency in Farming Systems

Agronomy ◽

10.3390/agronomy11040710 ◽

2021 ◽

Vol 11 (4) ◽

pp. 710

Author(s):

Anita Ierna

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

Crop Production ◽

Cropping System ◽

Farming Systems ◽

Primary Objective ◽

Sustainable Intensification ◽

Production Yield ◽

Yield Gaps ◽

Use Efficiency

The primary objective of any cropping system continues to be increasing the productivity and profitability of crops [...]

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Worldwide water constrains on closing yield gaps

10.5194/egusphere-egu2020-7500 ◽

2020 ◽

Author(s):

Bram Droppers ◽

Iwan Supit ◽

Michelle van Vliet ◽

Fulco Ludwig

Keyword(s):

Water Stress ◽

Water Availability ◽

Crop Production ◽

Human Impacts ◽

Nutrient Supply ◽

Crop Growth ◽

Production Model ◽

Yield Gap ◽

Macro Scale ◽

Yield Gaps

By 2050 a doubling of crop production may be necessary to meet the growing worldwide food demands. Several studies have indicated the potential to increase crop production by reducing the so-called yield gap, i.e. the difference between potential crop production and actual crop production. The focus is commonly on closing the yield gap by increasing nutrient supply through fertilization and/or by increasing irrigated cropland extent. This could potentially achieve water-limited production (limited by rainfall) in rain-fed croplands and climate-limited production (limited by temperature and radiation) in irrigated croplands. For irrigated croplands this assumes sufficient water availability for irrigation. However, water availability for irrigation may be insufficient under higher nutrient supply. In addition, irrigation expansion in upstream areas might negatively affect water availability in downstream areas.We aim to quantitatively assess the worldwide water constrains to close yield gaps, accounting for various nutrient inputs. To assess water constrains we integrated a macro-scale hydrological model, the Variable Infiltration Capacity model (VIC-5 including human impacts; Droppers et al. in review), with a crop production model, the World Food Studies (WOFOST; de Wit et al. 2019) model. The VIC and WOFOST models were coupled for two-way interactions. The VIC model simulates the water and energy balance, including runoff, evapotranspiration, discharge and water stress for crop growth. Water stress is used in the WOFOST model to limit and adapt crop growth, e.g. limited biomass production and adjusted relative root production. Simulated crop characteristics (height, leaf area index, CO2 effects) are subsequently returned to VIC. By coupling these models we are able to assess the feedbacks between crop production and water availability globally.References:Droppers, B., Franssen, W. H. P., van Vliet, M. T. H., Nijssen, B., and Ludwig, F.: Simulating human impacts on global water resources using VIC-5. Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2019-251, in review, 2019.de Wit, A., Boogaard, H., Fumagalli, D., Janssen, S., Knapen, R., van Kraalingen, D., ... & van Diepen, K. (2019): 25 years of the WOFOST cropping systems model. Agricultural Systems, 168, 154-167, https://doi.org/10.1016/j.agsy.2018.06.018.

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What Does Gender Yield Gap Tell Us about Smallholder Farming in Developing Countries?

Sustainability ◽

10.3390/su13010077 ◽

2020 ◽

Vol 13 (1) ◽

pp. 77

Author(s):

Eileen B. Nchanji ◽

Odhiambo A. Collins ◽

Enid Katungi ◽

Agness Nduguru ◽

Catherine Kabungo ◽

...

Keyword(s):

Selection Bias ◽

Crop Production ◽

Household Food Security ◽

Small Scale ◽

Smallholder Farming ◽

Yield Gap ◽

Cross Sectional ◽

Research Issues ◽

Farm Work ◽

Lower Productivity

This study examines the extent of the productivity gap between male and female bean producers, its discriminatory nature and implications for the policymakers in agriculture in Tanzania. Generally, women are distinctively “invisible” in agriculture, due to social norms and even from the national agricultural policy perspective. Their discrimination arises from uncounted and unaccounted for farm work, and their productivity is reduced by triple roles, limited access to education, having triple effects on access to technology, training and land rights. In research, issues of concern to them such as nutritious food crops, varietal selection on important attributes, household food security, convenient home storage and small-scale processing are widely ignored through unfavourable policy design. Given the above discriminatory issues surrounding women in agriculture, they are hypothesised to be less productive and often lag behind male counterparts in crop production. To test the above hypothesis, a three-stage stratified sampling method was used to collect cross-sectional data in 2016 across four regions of Tanzania. Then, an Oaxaca-Blinder decomposition method (at means) was used to apportion the sources of the difference between men and women into explained and unexplained variations. Further improvements through the newly developed Re-Centered Influence Functions (RIFs) remarkably improved outcomes as the differences were analysed through unconditional partial effects on quantiles. Using a counterfactual approach and correcting for selection bias, the model provided consistent estimates for easy comparison of the two groups. Besides this, it emerged that interventions such as providing improved bean seed varieties and training farmers on good agricultural practices reduced the gender yield gap and provided a potential avenue for addressing the discrimination observed in productivity among males and females. Controlling for selection bias also improved the model, but the real discrimination was observed at the 50th percentile, where the majority of the respondents lay within. However, if a female’s age, family size, additional years of schooling and discretion to spend income from beans were taken away, they would be worse off. Our study finds that females comprised 25 percent of the sample, had 6 percent lower productivity, provided 64.70 percent on-farm labour and had 0.32 hectares less land compared to males, ceteris paribus. Access to improved varieties contributed to a 35.4 percent improved productivity compared to growing indigenous/local varieties. The implication is that the gender yield gap can be reduced significantly if efforts are focused on preventing or correcting factors causing discrimination against women.

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Micro and Macro-level Analysis of Crop Diversification: Evidence from an Agrarian State West Bengal

Indian Journal of Economics and Development ◽

10.35716/ijed/20037 ◽

2020 ◽

pp. 489-499

Keyword(s):

Crop Production ◽

West Bengal ◽

Farming Systems ◽

Field Studies ◽

Farming System ◽

Structure Questionnaire ◽

Crop Diversification ◽

The Status ◽

Block Level ◽

Diversified Farming Systems

The farming system in West Bengal is being shifted by integration between the set of cash crops and the main food harvest process. This change in diversified farming systems, where smallholders have a production base in rice can complement production; affect technical efficiency and farm performance. The goal of this study was to investigate the status of crop diversification on smallholders in West Bengal. First, crop diversification regions were developed in West Bengal based on the Herfindahl index, which were categorized into three regions. Three sample districts were studied separately at the block level, and 915 small farmers from 41 sample villages of 9 sample blocks were interviewed through a good structure questionnaire for field studies from the sample districts. West Bengal was gradually moving towards multiple crop production. Furthermore, increasing rice production reduced the marginal use of inputs for the production of other crops. Farming and other vital factors such as HYVs area to GCA, average holding size and per capita income in some districts of West Bengal can be identified as determinants of crop diversification.

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Community seed network in an era of climate change: dynamics of maize diversity in Yucatán, Mexico

Agriculture and Human Values ◽

10.1007/s10460-021-10249-3 ◽

2021 ◽

Author(s):

Marianna Fenzi ◽

Paul Rogé ◽

Angel Cruz-Estrada ◽

John Tuxill ◽

Devra Jarvis

Keyword(s):

Climate Change ◽

Crop Production ◽

Management Strategies ◽

Farming Systems ◽

Seed Systems ◽

Farming Community ◽

Climate Resilience ◽

Maize Diversity ◽

Climatic Period ◽

Small Holder Farmers

AbstractLocal seed systems remain the fundamental source of seeds for many crops in developing countries. Climate resilience for small holder farmers continues to depend largely on locally available seeds of traditional crop varieties. High rainfall events can have as significant an impact on crop production as increased temperatures and drought. This article analyzes the dynamics of maize diversity over 3 years in a farming community of Yucatán state, Mexico, where elevated levels of precipitation forced farmers in 2012 to reduce maize diversity in their plots. We study how farmers maintained their agroecosystem resilience through seed networks, examining the drivers influencing maize diversity and seed provisioning in the year preceding and following the 2012 climatic disturbance (2011–2013). We found that, under these challenging circumstances, farmers focused their efforts on their most reliable landraces, disregarding hybrids. We show that farmers were able to recover and restore the diversity usually cultivated in the community in the year following the critical climate event. The maize dynamic assessed in this study demonstrates the importance of community level conservation of crop diversity. Understanding farmer management strategies of agrobiodiversity, especially during a challenging climatic period, is necessary to promote a more tailored response to climate change in traditional farming systems.

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Methodology of Analyzing Maize Density Loss in Smallholder’s Fields and Potential Optimize Approach

Agriculture ◽

10.3390/agriculture11060480 ◽

2021 ◽

Vol 11 (6) ◽

pp. 480

Author(s):

Zhichao An ◽

Chong Wang ◽

Xiaoqiang Jiao ◽

Zhongliang Kong ◽

Wei Jiang ◽

...

Keyword(s):

Decision Making ◽

Food Security ◽

Zea Mays L ◽

Plant Density ◽

Density Difference ◽

Yield Gap ◽

Farmer Decision Making ◽

Yield Gaps ◽

Farmer Survey ◽

Experimental Plots

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.

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