Crop Portfolios Research Articles

Portfolio Agriculture: A Model for Resilient Regional Agricultural Planning

Food security is threatened by climate change worldwide; consequently, agriculture and farming livelihoods must adapt to new and unpredictable conditions. These conditions vary along spatial scales, and since agricultural yields are sensitive to microclimate conditions, a locally tailored data-driven approach may be helpful. Furthermore, limited agricultural resources like water and labor increasingly constrain food production. This research proposes a regional portfolio model for identifying crop choices and regional portfolio compositions that align with known and forecasted microclimate variation in temperature and humidity. The model will enable farmers to assess tradeoffs between the financial returns and agricultural production risks. The goal of this work is to provide new insights into agricultural planning in the face of climate risk and limited access to water and labor resources. Three steps are taken. Firstly, regional agricultural land is divided into farming subunits, with each representing a terroir characterized by temperature and humidity. Then a simulated yield coefficient is used to assess the effect of microclimate variables on the yield of the different crops in the portfolio of each subunit. Secondly, farming resource allocation, represented by water and labor, across crops and farming subunits is optimized to maximize the yield and associated financial return from farming across the agricultural region. Finally, a resilient agricultural planning model is developed based on the assumed data for regional microclimate and agricultural resources. The results of this research can be used by regional farmers as a reference for selecting crop portfolios and resource allocations to maximize overall profit.

Policy Impact and Voter Mobilization: Evidence from Farmers’ Trade War Experiences

How does the extent of policy benefits—not simply their presence—affect political engagement? While fundamental to understanding the electoral implications of economic policymaking, addressing this question is challenging due to the difficulty of measuring individual voters’ policy outcomes. We examine a natural experiment embedded in President Trump’s Market Facilitation Program (MFP), which aided a core Republican constituency: farmers harmed by his 2018 trade war. Due to idiosyncrasies of program design, the MFP undercompensated some farmers for their trade war losses—and significantly overcompensated others—based solely on their 2018 crop portfolios. Analyzing over 165,000 affected voters, we show that improved compensation outcomes had negligible impacts on Republican farmers’ midterm turnout and campaign contributions, even though such variation in benefits significantly affected farmers’ propensity to view the intervention as helpful. This null result is important—our estimates suggest that even highly salient variation in policy outcomes may have limited mobilizing capacity.

Crop diversity buffers the impact of droughts and high temperatures on food production

Weather extremes like droughts and heat waves are becoming increasingly frequent worldwide, with severe consequences for agricultural production and food security. Although the effects of such events on the production of major crops is well-documented, the response of a larger pool of crops is unknown and the potential of crop diversity to buffer agricultural outputs against weather extremes remains untested. Here, we evaluate whether increasing the diversity of crop portfolios at the country level confers greater resistance to a country’s overall yield and revenues against losses to droughts and high temperatures. To do this, we use 58 years of annual data on weather, crop yields and agricultural revenues for 109 crops in 127 countries. We use the spatial distribution of each crop and their cropping cycle to determine their exposure to weather events. We find that growing greater crop diversity within countries reduces the negative impacts of droughts and high temperatures on agricultural outputs. For drought, our results suggest that the effect is explained not only by crop diversity itself, but also by the sensitivity of the most abundant crops (in terms of harvested areas) to this extreme. Countries dedicating more land to minor, drought-tolerant crops reduce the average sensitivity of country-scale crop portfolios and show greater resistance of yield and revenues to drought. Our study highlights the unexploited potential for putting crop biodiversity to work for greater resilience to weather, specifically in poorer developing countries that are likely to suffer disproportionately from climate change impacts.

Evolution of farm-level crop diversification and response to rainfall shocks in smallholder farming: Evidence from Malawi and Tanzania

This study investigates how exposure to short and long-term measures of rainfall shocks and past crop diversification decisions influence subsequent diversification in Malawi and Tanzania. We use balanced household panel data combined with corresponding historical monthly weather data to achieve our aim. Crop diversification is studied as a state-contingent risky investment decision that households make before the state of nature is revealed. We model crop diversification decisions using correlated and dynamic random effects panel Poisson and Tobit models that control for unobserved heterogeneity in household crop diversification decisions plus initial conditions that may influence crop diversification across space and time. We establish that smallholder farmers in Malawi and Tanzania respond to rainfall shocks by diversifying their crop portfolios and that crop diversification decisions are state-dependent. Thus, farmers with knowledge and experience gained from past crop diversification have elevated chances to intensify subsequent crop diversification and adapt to recurrent rainfall shocks. Heterogeneity analysis reveals that the relatively better-off farmers with sufficient land and non-land household assets to a greater extent diversify the crop portfolio post-drought shock exposure. Pro-poor policies addressing seed access constraints are needed to support diversification and adaptation to shocks.

Crop Species Production Diversity Enhances Revenue Stability in Low-Income Farm Regions of Mexico

Stabilizing farm revenues is a goal of agricultural policies around the world, especially in vulnerable regions with limited access to crop insurance. One potential pathway to revenue stability follows the agricultural “insurance hypothesis”, which holds that crop diversification has stabilizing effects on productivity that mitigate risks from environmental stressors and market shocks, thereby producing a form of natural insurance against crop loss. While substantial support for the hypothesis exists, most studies testing the hypothesis have occurred at the farm or landscape levels and have controlled for a limited range of socioeconomic and environmental factors. This study tests the insurance hypothesis by examining the effects of crop species production diversity on revenue stability in low-income regions of southern Mexico. Here, rural farms experience chronic vulnerability to climatic shocks and market forces. Using parametric and non-parametric approaches, three groups of models are used to examine the effects of socio-environmental factors and farm structural and functional characteristics on the crop diversity-revenue stability relationship. Additionally factored in the relationship are the effects of cropping portfolios: statistical groupings of different crop species (n = 304) that characterize distinct farming areas (1340 municipalities). Findings support the insurance hypothesis and underscore the importance of crop diversification in the region. However, findings also show that irrigation plays an even stronger role than crop diversification in stabilizing farm revenues. Furthermore, some crop portfolios negatively impact revenue stability, including some portfolios with high crop diversity. In sum, a better understanding of farm contexts—contributing factors and cropping portfolios—is key to designing policies that help stabilize farm revenues through crop diversification.

Global trends of cropland phosphorus use and sustainability challenges.

To meet the growing food demand while addressing the multiple challenges of exacerbating phosphorus (P) pollution and depleting P rock reserves1-15, P use efficiency (PUE, the ratio of productiveP output to P input in a defined system) in crop production needs to be improved. Although many efforts have been devoted to improving nutrient management practices on farms, few studies have examined the historical trajectories of PUE and their socioeconomic and agronomic drivers on a national scale1,2,6,7,11,16,17. Here we present a database of the P budget (the input and output of the crop production system) and PUE by country and by crop type for 1961-2019, and examine the substantial contribution of several drivers for PUE, such as economic development stages and crop portfolios. To address the P management challenges, we found that global PUE in crop production must increase to 68-81%, and recent trends indicate some meaningful progress towards this goal. However, P management challenges and opportunities in croplands vary widely among countries.

Farming Systems, Food Security and Farmers' Awareness of Ecosystem Services in Inland Valleys: A Study From Côte d'Ivoire and Ghana

Inland valleys (IVs) in West African countries have increasingly been used for crop production, including rice cultivation. Though it is widely assumed that IVs have a high potential to contribute to food security of West African countries, a comprehensive assessment of farming systems addressing agricultural, institutional, food security, poverty, and ecosystem indicators is still lacking. This study characterizes IVs' smallholder farm households at the regional and farm type level using Rural Household Multiple Indicator Survey (RHoMIS) data collected from 733 randomly selected farm households in four agro-ecological regions, i.e., Bouaké and Gagnoa in Cote d'Ivoire, and Ahafo Ano North and Ahafo Ano South in Ghana. A farm typology is developed, and farm households are characterized with regard to demographic, agricultural, economic, and institutional indicators. Furthermore, farm households' food security and poverty status, and the importance of rice in the portfolio of crops, is assessed. Finally, farmers' awareness of different ecosystem services (ES) for their food security is examined. Four farm types are identified, i.e., farmers who rent all the land cultivated, farmers who own some land and rent extra land, farmers who own and cultivate all their land, and farmers cultivating only a part of the land they own. We find that the variation in farm households' demographic, economic, and institutional characteristics is greater between regions than within regions. Crop production, either for direct consumption or marketing, especially rice production, is the main contributor to daily energy intake, followed by wild food consumed. Still, a substantial percentage of the farm households (16–38%) in all regions cannot meet minimum daily energy requirements. Farmers of all farm types, and in all regions, attach high relevance to IVs' provisioning ES, particularly the ability to provide food. A majority of farmers in all regions highlighted the relevance of regulating ES, including climate regulation, water storage, and groundwater values for their wellbeing. In contrast, farmers attached relatively lower relevance to cultural ES. Interventions to improve national rice production need to acknowledge and preserve the diversity ES that IVs provide to smallholder farm households.

From the ground up: Patterns and perceptions of herbaceous diversity in organic coffee agroecosystems

Abstract Smallholder farms that transition to organic and biodiverse production are increasingly recognized as strongholds of agrobiodiversity, with emerging work identifying important outcomes such as enhancing crop portfolios, mitigating extreme climate events and contributing to farmer well‐being. Yet the emergent herbaceous communities in these organic systems remain understudied, with the functional diversity and management of this stratum relatively unknown. This study identifies the taxonomic and functional diversity of the herbaceous community in organic coffee agroforestry systems, and describes the extent of this diversity with farm, and farmer, attributes. We measured leaf‐level functional traits (e.g. specific leaf area) of the herbaceous community to derive functional diversity indices and collected localized environmental conditions on 15 organic coffee farms in Central Valley, Costa Rica. We also conducted semi‐structured interviews with nine farmers to construct mental models on herbaceous community management using a cognitive mapping approach. In total, 38 species from 20 taxonomic families were present in these organic coffee systems. The herbaceous communities were functionally diverse; however, functional evenness increased with canopy openness, suggesting that farms adopting agroforestry tend to have a more functionally diverse herbaceous stratum. Farmer perception of plant traits in the herbaceous community was differentiated into competitive (weeds) or neutral/positive effects. These perceptions aligned with well‐established functional trait trade‐offs. The mental models representing farmer decision‐making processes were highly variable, with a nearly 30% increase in cognitive map density from the simplest map to the most complex; this complexity in mental models was a key explanatory variable in the level of functional diversity of the herbaceous community. Organic management practices that support agroforestry practices also, in turn, promote a functionally diverse herbaceous stratum. We show that functional trait syndromes in these herbaceous communities in agroforestry systems are linked with farmer perceptions of traits, and that highly interconnected farm decision‐making is related to greater functional diversity in the herbaceous community. Understanding pathways of farmer decision‐making on managing this herbaceous community can appropriately situate on‐farm practice and policy for the transition to organic production, and inform emerging agri‐environmental programs.

Modelling crop portfolios that minimize human macronutrient deficiency on subsistence farms in Burundi

Modelling crop portfolios that minimize human macronutrient deficiency on subsistence farms in Burundi

Optimal design of controlled environment agricultural systems under market uncertainty

We present a novel methodology for the simultaneous robust design and scheduling of controlled environment agricultural (CEA) systems under multi-period risk. This problem is formulated as a semi-infinite program with several semi-infinite constraints pertaining to mean-variance risk exposure with uncertain covariance over each period in the planning horizon. The general model enables robust optimization of CEA systems for cultivation of any crop portfolio under any number of cultivation modes, with a solution that represents an optimal design and operating schedule that is robust to worst-case uncertainty. Therefore, this methodology provides a conservative basis for engineering and investment decision-making and represents, to our knowledge, the first robust optimization approach to CEA systems. Our approach effectively increases the robustness of CEA systems to market uncertainty, improves the long-term economics of CEA systems over naïve operating strategies, and validates the economic viability of single and multi-mode CEA production of distinct crop portfolios.

Large-scale farms in Zambia: Locational patterns and spillovers to smallholder agriculture

The accelerated growth of large-scale farming operations in developing countries, in particular Africa, has raised concerns that smallholders may be negatively affected. Drawing on nationally representative smallholder data and a census of large-scale farms in Zambia, this study investigates spillovers from large-scale farms to smallholders. First, we conceptually discuss potential spillovers from larg-scale farms to smallholders and sources of spillover heterogeneity. Second, we analyze the large-scale farm sector and its locational pattern. Large-scale farms operate in areas with good infrastructure and market access, i.e. in proximity to smallholders. Third, we adopt a difference-in-differences approach to estimate the spillovers of large-scale farms to smallholders’ area cultivated, access to fertilizer, and maize yields. We observe that the establishment of large-scale farms has little effect on average farm sizes of smallholders. However, we find a strong shift of crop portfolios towards maize among smallholders near recently established large-scale farms to the detriment of other staple crops. We do not find any spillovers on fertilizer adoption by smallholder farmers but large positive effects on maize yields. The locational pattern suggest that large-scale farms compete with smallholders for land. In sum, it is crucial not to overestimate the development potential of large-scale farms. Instead, immediate threats to smallholders need to be addressed, in particular through securing land tenure rights. Further, the mechanisms of spillovers need to be better understood in order to design infrastructure and agricultural extension policies that can complement and reinforce positive spillovers from large-scale farms and mitigate potential negative spillovers including environmental impacts.

Gendered differences in crop diversity choices: A case study from Papua New Guinea

Abstract Crop choice, including the conservation of traditional crops and the uptake of novel ones, is a central issue in agricultural development. This paper examines differences between male and female farmers’ motivations for growing diverse crop portfolios in Papua New Guinea, a highly agro-biodiverse context facing rapid social change. Q methodology, a mixed qualitative-quantitative approach, is used to examine how alignment with different viewpoints related to crop diversity differs across male and female farmers. We show that, of five distinct ‘types’ of farmers identified with regards to crop diversity choices, all include both men and women, and three of five groups show no significant gender-related differences. However, there are also some significant gender differences. A large proportion of women farmers associate with being highly motivated by crop marketing, whereas male farmers are more likely to favor agricultural diversity due to tradition or status motivations. Overall, strict gendering of crops does not appear highly salient. The results confirm earlier work in the region on women’s roles in marketing but contrast to those on crop gendering. Altogether, they underline the complexity of gender and identity in agricultural choices. The results also have implications for the targeting and implementation of crop conservation and promotion policies and programs, including those aiming for improved nutrition or agricultural development.

Conflict-Risk and Agricultural Portfolios: Evidence from Northern Uganda

Although the impact of insecurity on agricultural decisions is widely discussed, it remains largely unstudied empirically. This study estimates the effect of risk of violence on livestock and crop portfolios using spatially disaggregated risk measures and data from over 690,000 households, approximately 75 per cent of all rural households in Northern Uganda. As the risk of violence increases, households decrease their livestock holdings while shifting its composition towards smaller, less risky animals that can be kept within villages. The similarly strong shifts in the choice of crops, however, are not always consistent with a shift towards less risky crops. Since households remain reliant on agriculture, these ex ante behavioural responses to insecurity suggest important consequences for welfare.

Factors and scenarios affecting a farmer’s grain harvest logistics

This paper explores how changes in Australia’s grain industry supply chains are likely to impact on the nature and profitability of an Australian farmer’s grain harvest logistics. A simulation model is used to show how receival site rationalisation, cheaper on‐farm storage, larger trucks, higher‐yielding crops and new harvest technologies, separately and in combination, affect the nature and profitability of a farmer’s grain harvest logistics. Applying the model to a typical Australian grain farm shows that many of these changes unambiguously advantage the farm business, and often, the combination of these changes increases a farmer’s harvest profits by at least 10 per cent. For many farmers, the task of efficiently designing and managing harvest logistics will be an increasingly difficult yet important series of choices due to the range of storage options, grain pathways, crop portfolios and market opportunities that are arising. A farmer’s decisions about cost‐effective on‐farm storage and transport, and their judicious use, will be a key contributor to additional profit in future years.

Crop diversity and stability of revenue on farms in Central Europe: An analysis of big data from a comprehensive agricultural census in Bavaria

Diversity of agricultural landscapes is important to maintain the provision of ecosystem services. In face of decreasing support measures for agricultural markets in the European Union, diversified crop portfolios could also offer a possibility to stabilize revenue at farm level (portfolio effect). We hypothesize that (i) diversity of crop portfolios changes along spatial gradients in the study area (Bavaria, Germany), (ii) the composition of portfolios depends on farm parameters, and (iii) more diverse portfolios on arable land provide higher revenue stability. We analysed agricultural census data comprising all farms (N = 105 314) in the study area and identified 26 typical crop portfolios. We show that portfolio composition is related to farm characteristics (whole farm revenue, farm type, farm size) and location. Currently, diversification of crop portfolios fails to promote stability of portfolio revenue in the study area, where policy still indirectly influences market prices of energy crops. We conclude that the portfolio effect as a natural insurance was less important in recent years due to high market prices for specific crops. This low need for natural insurances probably favoured simplified portfolios leading to decreased agricultural diversity.

Risk and diversification in coffee plantations in India: an empirical analysis

Coffee cultivators in India are prone to risks of different types. Risks associated with coffee cultivation arise due to variability in yields, volatility in prices, uncertainty in inputs, and problems associated with markets. With the primary information gathered from farmers in one of the largest coffee growing districts of India, the study analyses the risks and identifies sources of those risks in coffee plantations. As the coffee growing regions in India are also suitable for cultivation of different varieties of crops, we examine, through a quantitative analysis, the possible crop diversification scenarios before the farmers. Portfolio analysis using Markowitz mean variance theory reveals the relative risks associated with each crop and suggests on the portfolio of crops that would help farmers in minimising risks. The study, using the mix method of research, also tries to understand the extent to which coffee plantations are diversified, the reasons behind the reluctance of the farmers towards crop diversification and the policies that are needed to support diversification.

Heterogeneity of commercialization gains in the rural economy

AbstractFarmers in low‐income rural economies often fail to switch to cash crops from staple production despite the positive income effects of commercialization expected by policy makers. The literature suggests that market failures prevent households from cash crop adoption but remains inconclusive regarding farmers' motives and the effects of commercialization. This article contributes to the debate by offering an original approach to the analysis of commercialization outcomes and farmers' decisions. It consists of applying a model with essential heterogeneity and a semiparametric estimation technique to analyzing harvest value returns to cash cropping. Using Malawian data, we show considerable heterogeneity in harvest value returns to cash cropping both within and between groups of farmers choosing different crop portfolios. Importantly, the results imply rational choices based on comparative advantage considerations of farming households: farmers self‐select into the activity where they expect higher gains and adopt cash crops when facing weaker market barriers.

Implications of climate-smart strategy adoption by farm households for food security in Tanzania

As the climate changes, farmers in developing countries seek to employ strategies to help them sustain food production. The objectives of this paper were to identify adaptation strategies in response to climate change and the determinants for their adoption, and to explore the impact of these strategies on food security. The analysis was based on a survey of 900 small-scale farmers in a semi-arid (Dodoma) and a semi-humid (Morogoro) region in Tanzania. Farmers in the semi-humid region tended to diversify their crops, i.e. added additional crop types. Given the more challenging environment in the semi-arid region, farmers there changed their portfolio of crops, i.e. substituted some crops or cultivars with others. Logistic regressions highlighted higher tolerance to risk, land ownership, education and experiences of farmers as drivers of adoption, while income diversification had a negative effect. The propensity score matching approach showed that adopters of climate-smart strategies are on-average more food-secure. These users showed a more diverse pattern of food consumption, greater protein intake and better economic access to food. Changing crop portfolios can help households to cope with climate-related shocks such as droughts and thus appears to be the best performing strategy, especially in terms of more stable food provisioning throughout the year.

Adaptation to climate change: historical evidence from the Indian monsoon

AbstractEstimating the potential impacts of climate change requires understanding the ability of agents to adapt to changes in their climate. This paper uses panel data from India spanning from 1956 to 1999 to investigate the ability of farmers to adapt. To identify adaptation, the author exploits persistent, multidecadal monsoon regimes during which droughts or floods are more common. These regimes generate medium-run variation in average rainfall, and there is spatial variation in the timing of the regimes. Using a fixed-effects strategy, she tests whether farmers have adapted to the medium-run rainfall variation induced by the monsoon regimes. The author finds evidence that farmers adjust their irrigation investments and their crop portfolios in response to the medium-run rainfall variation. However, adaptation only recovers a small fraction of the profits farmers have lost due to adverse climate variation.

Feeding the Household, Growing the Business, or Just Showing Off? Farmers' Motivations for Crop Diversity Choices in Papua New Guinea

Understanding farmers' reasons for growing diverse crop portfolios is essential for supporting the conservation of agricultural biodiversity to foster social-ecological resilience and conserve crop genetic resources. In this paper, Q methodology is applied to examine the motivations for growing diverse crops among semi-subsistence rural farmers in Papua New Guinea. Various types of farmers are identified including so-called ‘marketer-consumers,’ who are highly motivated by crop sale, and ‘exhibitionists,’ who prioritize the ‘show’ values of crops. This approach can be applied to better target programs seeking to conserve crop diversity and promote new crop varieties in regions undergoing rapid transformation.