Synergies and trade-offs for sustainable agriculture: Nutritional yields and climate-resilience for cereal crops in Central India

A systematic review of the methodology of trade-off analysis in agriculture

Trade-off analysis (TOA) is central to policy and decision-making aimed at promoting sustainable agricultural landscapes. Yet, a generic methodological framework to assess trade-offs in agriculture is absent, largely due to the wide range of research disciplines and objectives for which TOA is used. In this study, we systematically reviewed 119 studies that have implemented TOAs in landscapes and regions dominated by agricultural systems around the world. Our results highlight that TOAs tend to be unbalanced, with a strong emphasis on productivity rather than environmental and socio-cultural services. TOAs have mostly been performed at farm or regional scales, rarely considering multiple spatial scales simultaneously. Mostly, TOAs fail to include stakeholders at study development stage, disregard recommendation uncertainty due to outcome variability and overlook risks associated with the TOA outcomes. Increased attention to these aspects is critical for TOAs to guide agricultural landscapes towards sustainability.

Climate resilience of dry season cereals in India

India is the world's second largest producer of wheat, with more than 40% increase in production since 2000. Increasing temperatures raise concerns about wheat's sensitivity to heat. Traditionally-grown sorghum is an alternative rabi (winter season) cereal, but area under sorghum production has declined more than 20% since 2000. We examine sensitivity of wheat and sorghum yields to historical temperature and compare water requirements in districts where both cereals are cultivated. Wheat yields are sensitive to increases in maximum daily temperature in multiple stages of the growing season, while sorghum does not display the same sensitivity. Crop water requirements (mm) are 1.4 times greater for wheat than sorghum, mainly due to extension of its growing season into summer. However, water footprints (m³ per ton) are approximately 15% less for wheat due to its higher yields. Sensitivity to future climate projections, without changes in management, suggests 5% decline in wheat yields and 12% increase in water footprints by 2040, compared with 4% increase in water footprint for sorghum. On balance, sorghum provides a climate-resilient alternative to wheat for expansion in rabi cereals. However, yields need to increase to make sorghum competitive for farmer profits and efficient use of land to provide nutrients.

Sustainable agricultural practices for food security and ecosystem services

The notion of food security is a global phenomenon that impinges on every human. Efforts to increase productivity and yields have historically degraded the environment and reduced biodiversity and ecosystem services, with the significant impact on the poor. Sustainable agriculture-farming in sustainable ways based on an understanding of ecosystem services-is a practical option for achieving global food security while minimizing further environmental degradation. Sustainable agricultural systems offer ecosystem services, such as pollination, biological pest control, regulation of soil and water quality, maintenance of soil structure and fertility, carbon sequestration and mitigation of greenhouse gas emissions, nutrient cycling, hydrological services, and biodiversity conservation. In this review, we discuss the potential of sustainable agriculture for achieving global food security alongside healthy ecosystems that provide other valuable services to humankind. Too often, agricultural production systems are considered separate from other natural ecosystems, and insufficient attention has been paid to how services can flow to and from agricultural production systems to surrounding ecosystems. This review also details the trade-offs and synergies between ecosystem services, highlights current knowledge gaps, and proposes areas for future research.

Climate Change and Household Debt in Rural India

Climate change and indebtedness have been repeatedly highlighted as major causes of distress for rural households in India. However, despite the close connection between climate conditions and rural livelihoods, there has been little attempt to systematically examine the association between the two. To address this gap, we combine national-level longitudinal data from IHDS, MERRA-2, and the Indian Ministry of Agriculture to study the impact of climate anomalies on household indebtedness across rural India. Using a longitudinal approach that accounts for potential confounders at household, village, and district levels, we find pervasive effects of season-specific, five-year climate anomalies on multiple dimensions of household debt, particularly in arid and semi-arid areas. Most notably, temperature anomalies in the winter cropping season in arid and semi-arid areas are associated with increasing household indebtedness. We further find that climate change interacts with existing socioeconomic differences-caste and landholding in particular-to deepen both the size and the depth of indebtedness for rural households.

Dietary Change and Global Sustainable Development Goals

Food production for human consumption is a leading cause of environmental damage in the world and yet over two billion people suffer from malnutrition. Several studies have presented evidence that changes in dietary patterns across the world can lead to win-win outcomes for environmental and social sustainability and can complement ongoing technological and policy efforts to improve the efficiency of agricultural production. However, the existing evidence have been compiled in “silos” by a large range of researchers across several disciplines using different indicators. The aim of this quantitative review is to bring together the existing knowledge on heterogeneity of current dietary patterns across the world and how a transition toward healthy diets in different countries can aid in progress toward multiple global Sustainable Development Goals (SDGs). We first summarize the nutritional quality, economic cost, and environmental footprint of current diets of over 150 countries using multiple indicators. Next, we review which shifts in dietary patterns across different world regions can help toward achievement of SDG2 (Zero hunger), SDG3 (Good health and wellbeing), SDG 6 (Clean water and sanitation), SDG13 (Climate action), SDG14 (Life below water), and SDG15 (Life on land). Finally, we briefly discuss how to enable the shift toward sustainable dietary patterns and identify the research and data gaps that need to be filled through future efforts. Our analysis reveals that dietary change is necessary in all countries as each one has unique priorities and action items. For regions such as Sub-Saharan Africa and South Asia, increased intake of nutrient dense foods is needed to address deficiency of essential nutrients like folate, potassium, and vitamin A. For North America and Europe, shifting toward more plant-based diets would be healthier and simultaneously reduce the per capita environmental footprints. The results can be useful for policymakers in designing country-specific strategies for adoption of sustainable dietary behaviors and for food industry to ensure the supply of sustainable food items customized with regions' need.

A bibliometric analysis of sustainable agriculture: based on the Web of Science (WOS) platform

The global trends of sustainable agriculture (SA) have expanded dramatically through many scholarly studies in this area. Many literary works have focused on several aspects of sustainable agriculture (SA), such as the effectiveness of pesticide management, impacts on cultivation and enhancement, quantifying with soil, water, and air, agro-ecological activities, ecological aspects, and other areas of focus. The review offers a structured bibliometric and network evaluation that will profoundly observe the recent trends of SA, which other studies in this field have not comprehensively analyzed before. The study's prime objectives are to investigate the progress, trends and themes, and provide a comprehensive mapping of the field of sustainable agriculture. The study utilizes the Web of Science core collection database to search, filter, and extract the published article from 1992-2020. The review commences by exploring over 3000 journal articles, those then filtered into some well-recognized matrix of impacts and published by impactful journals, institutions, and authors. The results indicate a stable growth in publications since 2006, with a sharp improvement from 2010. Thematic assessment of key concepts by exploring the abstract discovered a robust emphasis on quantitative resource associations within a strong subjective focus with farm capacities and inner-sectorial dominations. We reveal how the outcome may assist the sectors to facilitate better understandings and comprehend the challenging transitions based on brainstorming to action formulation.

A sustainable phosphorus management in agriculture: Assessing trade-offs between human health risks and nutritional yield regarding heavy metals in maize grain

High-quality products in sustainable agriculture require both limited health risks and sufficient dietary nutrients. Phosphorus (P) as a finite and non-renewable resource is widely used in agriculture, usually exerting influence on the accumulation of heavy metals (HMs) in soil and crops. The present research explores, for the first time, the combined effects of long-term P fertilizer and repeated zinc (Zn) application in field on the human health risks and nutritional yield regarding trace elements in maize grain. A field experiment was conducted using maize with six P application rates (0, 12.5, 25, 50, 100, and 200 kg P ha^-1) and two Zn application rates (0 and 11.4 kg Zn ha^-1). The results showed that the concentrations of Zn, copper (Cu), and lead (Pb) in the maize grain were significantly affected by P application and can be further affected by Zn application. The concentrations of chromium (Cr) and arsenic (As) showed opposite tendency as affected by P fertilizer rates while did not affected by additional Zn application. Zn application decreased the cadmium (Cd) concentration at high P levels and Pb concentration at low P levels, particularly. No HMs contamination or direct health risk was found in maize grain after receiving long-term P and repeated Zn fertilizer. The threshold hazard quotient of an individual and all investigated HMs in this study were acceptable for human digestion of maize grain. While the carcinogenic risk of Cr was non-negligible in case of maize was taken as one of daily staple food for local residents. Combination use of P (25 kg ha^-1) and Zn fertilizer on maize enhanced its nutritional supply ability regarding Zn and Cu, and simultaneously mitigated potential human health risks associated with Cd and Pb.

Global relationships between crop diversity and nutritional stability

Nutritional stability – a food system’s capacity to provide sufficient nutrients despite disturbance – is an important, yet challenging to measure outcome of diversified agriculture. Using 55 years of data across 184 countries, we assemble 22,000 bipartite crop-nutrient networks to quantify nutritional stability by simulating crop and nutrient loss in a country, and assess its relationship to crop diversity across regions, over time and between imports versus in country production. We find a positive, saturating relationship between crop diversity and nutritional stability across countries, but also show that over time nutritional stability remained stagnant or decreased in all regions except Asia. These results are attributable to diminishing returns on crop diversity, with recent gains in crop diversity among crops with fewer nutrients, or with nutrients already in a country’s food system. Finally, imports are positively associated with crop diversity and nutritional stability, indicating that many countries’ nutritional stability is market exposed.

Crop diversification could be important for food security. Here, using methods from network science, the authors find that a positive relationship between crop diversity and nutritional stability globally does not necessarily equate to improving nutritional stability in a given country.

Life cycle assessment of a long-term multifunctional winter wheat-summer maize rotation system on the North China Plain under sustainable P management

In sustainable agriculture, sufficient crop yields and nutrients must be produced while maintaining environmental protection. Considering the role of phosphorus (P) fertilizer in influencing crops yield and environmental security, life cycle assessment was used to examine the environmental impacts of long-term P application on the grain yield and nutritional quality of winter wheat and summer maize. Thus, a long-term field experiment with six P application rates for winter wheat (0, 25, 50, 100, 200, and 400 kg P ha^-1) and summer maize (0, 12.5, 25, 50, 100, and 200 kg P ha^-1) was conducted on the North China Plain (NCP). The results showed that the cradle-to-farm gate eutrophication potential (EP), energy depletion (ED), and P depletion (PD) were significantly affected by the P application rate applied in winter wheat and summer maize production. The critical P rate required to ensure food security for wheat and maize was in line with the optimal rate for sustainable environmental development in terms of grain production and nutrient levels. On the NCP, the ED and PD of summer maize with optimized P management over 10 years were less than those of winter wheat regardless of using yield or nutrient level as the functional unit. However, the EP of the nutrient supply in winter wheat was less than that in summer maize under optimized P fertilization. The specific nutritional components that limited improvements in environment of wheat and maize production under the optimal P rate were energy (calories) and protein, respectively. In conclusion, in a multifunctional winter wheat-summer maize rotation system, optimized P fertilization (50 kg ha^-1 for winter wheat and 25 kg ha^-1 for summer maize) combined with the planting of high-yield wheat varieties and high-protein maize varieties showed great potential to reduce the environmental impacts of wheat and maize production.

Biodiversity in Tomatoes: Is It Reflected in Nutrient Density and Nutritional Yields Under Organic Outdoor Production?

In many regions of the world, human nutrition is still characterized by an insufficient intake of essential nutrients like minerals such as iron (Fe) and zinc (Zn). In view of decreasing resources and a growing world population, the efficiency and the sustainability of cultivation systems should be considered not only in terms of crop yield and profit margin but also in terms of the yield of essential nutrients. Tomatoes are the most consumed vegetable in the world. Organic outdoor tomato cultivation is generally characterized by a higher diversity of varieties and lower fertilization input compared to conventional production. A 2-year field experiment with a set of 20 cultivars was performed to evaluate their variation regarding fruit mineral concentrations [potassium (K), calcium (Ca), magnesium (Mg), phosphorous (P), Fe, and Zn], their contribution to the dietary reference intake (DRI), and the nutritional yields (adults ha^-1 year^-1). Results show that mineral concentrations differed significantly by cultivar and by year. However, even though significant genotype-by-year effects appear, several cultivars exhibit high genotype stability across years for the single traits studied. Taking this together with medium-to-high heritability, genetics strongly controls most studied traits. Among the cultivars, the contribution of 100 g fresh fruits varied from 4.5 to 7.7% for K, 0.8 to 1.8% for Ca, 2.3 to 4.4% for Mg, 3 to 6.6% for P, 3.1 to 6.9% for Fe, and 1.9 to 4.2% for Zn to meet daily requirements. Based on average fruit yields per hectare, the cultivars varied with regard to the nutritional yields for all the studied minerals, but most strongly for Fe (44-120 adults ha^-1 year^-1) and Zn (22-84 adults ha^-1 year^-1). In terms of contribution to the DRI and nutritional yield for Fe, the cocktail cultivar "Bartelly F1" produced the highest results, while for Zn the salad cultivar "Bocati F1" showed the highest values. Our results show that the targeted use of tomato biodiversity in organic outdoor production can be suitable to achieve high fruit yields as well as to produce high nutritional yields per unit area, thus contributing to more effective land use and improved food security. These findings also provide valuable insights for tomato breeders to improve the tomato fruit quality while maintaining yield.

Neglected and Underutilized Crop Species: The Key to Improving Dietary Diversity and Fighting Hunger and Malnutrition in Asia and the Pacific

Asia continues to suffer from a high prevalence of malnutrition. Persistent malnutrition can be attributed to low dietary diversity, together with low production diversity. Dietary diversity represents a more healthy, balanced, and diverse diet, which ensures nutrient adequacy. The principle of dietary diversity is affirmed in all national food-based dietary guidelines. Food-based approaches that address malnutrition, especially micronutrient deficiencies, are embedded in evidence-based healthy diet patterns; however, they are disconnected from the current agricultural production system. Promising neglected and underutilized species (NUS) that are nutrient-dense, climate-resilient, profitable, and locally available/adaptable are fundamental to improving dietary and production diversity. The Future Smart Food Initiative, led by FAO's Regional Initiative on Zero Hunger, aims to harness the enormous benefits of NUS in the fight against hunger and malnutrition. Recognizing that NUS covers crops, livestock, fisheries and aquaculture, and forests, the FAO has set crops as an entry point for NUS to address hunger and malnutrition.

Evolution and Future Needs of Food Chemistry in a Changing World

The agriculture system is tasked with the responsibility to deliver adequate quantities of food, which meet national needs, provide health benefits, and deliver these in an environmentally sustainable system. Efforts by the food industry to deliver safe and nutritious foods, which also improve health and wellness, are complicated by a constantly changing landscape. As early as the 1950s, fat in diets was a concern, and in the 1980s and early 1990s, fat was an evil component in foods. In response, the industry developed zero/low fats and foods and low-fat foods. The evolution in dietary guidelines in the 2000s has evolved to greater concern over simple sugars and starches as negative sources of calories in an environment of increasing obesity. With the world population approaching 9 billion individuals by 2050, food production, which relies on large amounts of water and energy, must become more efficient. Food production and delivery also must find innovative ways to reduce food waste, environmental pollutants, and greenhouse gas production. The nexus of food, energy, and water is and will continue to be a major research and political and communication emphasis for the scientific community. We must find clear and consumer friendly communications to explain the utilization of modern technology in food production. Solutions to these issues must also include sustainably produced, safe, nutritious, satisfying, and wholesome foods.

Identifying key drivers for geospatial variation of grain micronutrient concentrations in major maize production regions of China

Micronutrient deficiencies are prevalent health problems worldwide. The maintenance of adequate concentrations of micronutrients in maize grain is crucial for human health. We investigated the overall status and geospatial variation of micronutrients in Chinese maize grains and identified their key drivers. A field survey was conducted in four major maize production areas of China in 2017 with 980 pairs of soil and grain samples collected from famers' fields. At a national scale, grain zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) concentrations varied substantially, with average values of 17.4, 17.3, 4.9, and 1.5 mg kg^-1, respectively, suggesting a solid gap between grain Zn and Fe concentrations and the biofortification target values. Significant regional difference in the concentrations of Zn, Mn and Cu, but not Fe, were observed in grain, with much higher levels in Southwest China. The nutritional yields of Zn, Fe and Cu were lower than the energy and Mn yields, indicating an unbalanced output between energy and micronutrients in current maize production system. Grain Zn, Fe, Mn and Cu correlated negatively with maize yield in most test regions. Increased nitrogen (N) rate positively affected grain Zn and Cu, while increased phosphorus (P) rate negatively affects grain Zn and Fe. Apart from Fe, available Zn, Mn and Cu in soil exerted significant positive effects on grain Zn, Mn and Cu concentrations, respectively. Decrease in soil pH and increase in the organic matter content may increase the accumulation of Fe and Mn in grain. Grain Zn and Cu concentrations increased as available soil P decreased. Of the factors considered in this study, grain yield, N and P rates, soil pH and organic matter were the main factors that affect grain micronutrient status and should be more extensively considered in the production and nutritional quality of maize grain.

Bridging the food security gap: an information-led approach to connect dietary nutrition, food composition and crop production

BACKGROUND

Food security is recognized as a major global challenge, yet human food-chain systems are inherently not geared towards nutrition, with decisions on crop and cultivar choice not informed by dietary composition. Currently, food compositional tables and databases (FCT/FCDB) are the primary information sources for decisions relating to dietary intake. However, these only present single mean values representing major components. Establishment of a systematic controlled vocabulary to fill this gap requires representation of a more complex set of semantic relationships between terms used to describe nutritional composition and dietary function.

RESULTS

We carried out a survey of 11 FCT/FCDB and 177 peer-reviewed papers describing variation in nutritional composition and dietary function for food crops to identify a comprehensive set of terms to construct a controlled vocabulary. We used this information to generate a Crop Dietary Nutrition Data Framework (CDN-DF), which incorporates controlled vocabularies systematically organized into major classes representing nutritional components and dietary functions. We demonstrate the value of the CDN-DF for comparison of equivalent components between crop species or cultivars, for identifying data gaps and potential for formal meta-analysis. The CDN-DF also enabled us to explore relationships between nutritional components and the functional attributes of food.

CONCLUSION

We have generated a structured crop dietary nutrition data framework, which is generally applicable to the collation and comparison of data relevant to crop researchers, breeders, and other stakeholders, and will facilitate dialogue with nutritionists. It is currently guiding the establishment of a more robust formal ontology. © 2019 Society of Chemical Industry.

How Do Fruit and Vegetable Markets Operate in Rural India? A Qualitative Study of the Impact of Supply and Demand on Nutrition Security

BACKGROUND

Diets in rural India are cereal based with low intakes of micronutrient-rich foods. The value chains for nutrition approach aims to study supply and demand of such foods. This may aid in development of interventions to improve diets and livelihoods.

OBJECTIVES

(1) To identify how fruit and vegetables are accessed, (2) to describe and map the structure of value chains for exemplar foods, (3) to understand how foods are priced, and (4) to explore factors that affect decisions about which crops are grown, marketed, and sold.

METHODS

After stakeholder consultation, we identified 2 fruits (mango and guava) and 2 vegetables (shepu and spinach) as exemplar foods. Criteria for these exemplar foods were that they should be known to participants and there should be variability in intakes. We held 24 interviews with value chain actors including farmers, wholesalers, and vendors of the exemplar foods. Data collection was stopped when no new information emerged. We used inductive thematic coding for our analysis.

RESULTS

The value chains for each of the exemplar foods were relatively simple and involved farmers, middlemen, and vendors at either city or village level. The main themes identified as being factors considered when making decisions about which foods to grow and sell were (1) farming resources and assets, (2) quality of produce, (3) environmental conditions, (4) financial factors, (5) transport availability, and (6) consumer demand.

CONCLUSIONS

There are opportunities to intervene within fruit and vegetable value chains to increase availability, affordability, and access to produce in rural India. Future research is required to determine which interventions will be feasible, effective, and acceptable to the community and other stakeholders.

Impact of Historical Changes in Coarse Cereals Consumption in India on Micronutrient Intake and Anemia Prevalence

BACKGROUND

Production of rice and wheat increased dramatically in India over the past decades, with reduced proportion of coarse cereals in the food supply.

OBJECTIVE

We assess impacts of changes in cereal consumption in India on intake of iron and other micronutrients and whether increased consumption of coarse cereals could help alleviate anemia prevalence.

METHODS

With consumption data from over 800 000 households, we calculate intake of iron and other micronutrients from 84 food items from 1983 to 2011. We use mixed-effect models to relate state-level anemia prevalence in women and children to micronutrient consumption and household characteristics.

RESULTS

Coarse cereals reduced from 23% to 6% of calories from cereals in rural households (10% to 3% in urban households) between 1983 and 2011, with wide variations across states. Loss of iron from coarse cereals was only partially compensated by increased iron from other cereals and food groups, with a 21% (rural) and 11% (urban) net loss of total iron intake. Models indicate negative association between iron from cereals and anemia prevalence in women. The benefit from increased iron from coarse cereals is partially offset by the adverse effects from antinutrients. For children, anemia was negatively associated with heme-iron consumption but not with iron from cereals.

CONCLUSIONS

Loss of coarse cereals in the Indian diet has substantially reduced iron intake without compensation from other food groups, particularly in states where rice rather than wheat replaced coarse cereals. Increased consumption of coarse cereals could reduce anemia prevalence in Indian women along with other interventions.

Alternative cereals can improve water use and nutrient supply in India

Humanity faces the grand challenge of feeding a growing, more affluent population in the coming decades while reducing the environmental burden of agriculture. Approaches that integrate food security and environmental goals offer promise for achieving a more sustainable global food system, yet little work has been done to link potential solutions with agricultural policies. Taking the case of cereal production in India, we use a process-based crop water model and government data on food production and nutrient content to assess the implications of various crop-shifting scenarios on consumptive water demand and nutrient production. We find that historical growth in wheat production during the rabi (non-monsoon) season has been the main driver of the country's increased consumptive irrigation water demand and that rice is the least water-efficient cereal for the production of key nutrients, especially for iron, zinc, and fiber. By replacing rice areas in each district with the alternative cereal (maize, finger millet, pearl millet, or sorghum) with the lowest irrigation (blue) water footprint (WFP), we show that it is possible to reduce irrigation water demand by 33% and improve the production of protein (+1%), iron (+27%), and zinc (+13%) with only a modest reduction in calories. Replacing rice areas with the lowest total (rainfall + irrigation) WFP alternative cereal or the cereal with the highest nutritional yield (metric tons of protein per hectare or kilograms of iron per hectare) yielded similar benefits. By adopting a similar multidimensional framework, India and other nations can identify food security solutions that can achieve multiple sustainability goals simultaneously.

Contribution of Nutrient Diversity and Food Perceptions to Food and Nutrition Security Among Smallholder Farming Households in Western Kenya: A Case Study

BACKGROUND

Sub-Saharan Africa is the only region in the world where hunger is prevalent in over one-third of the population, with smallholder farming households, producers of over 80% of Africa's food, facing both calorie and micronutrient deficiencies. With agricultural systems serving as the main source of all nutrients, little is known about the extent to which agricultural diversity in different seasons can meet macro- and micronutrient needs in rural Africa.

OBJECTIVE

Linkages between nutrient diversity and food species were investigated.

METHODS

A case study was conducted in Western Kenya to assess the seasonal nutrient diversity, seasonal nutrient accessibility levels, and food perceptions in 30 smallholder farms, 7 markets, and among 97 focus group discussion participants, respectively. All present food plant and animal species were inventoried and assigned to 1 of the 7 major Food and Agriculture Organization-defined food groups. Based on 2 macronutrients and 5 micronutrients, dendrogram-based nutrient functional diversity metrics were calculated.

RESULTS

On-farm and market food species offered all 7 macro- and micronutrients under investigation, regardless of seasonal variation in species numbers. Although there were varying seasonal nutrient accessibility levels in markets, farms were especially effective in readily availing 4 of the 7 nutrients. However, the main food shortage months coincided only with maize shortage, but a diversity of local foods, deemed to be of low cultural and culinary preferences, were available.

CONCLUSIONS

Nutrition education on the importance of a diversity of local foods in meeting dietary needs, thus stimulating the demand side, can contribute to achieving year-round household food security.