Abstract
Rising competition for crop usage presents policy challenges exacerbated by poor understanding of where crops are harvested for various uses. Here we create high-resolution global maps showing where crops are harvested for seven broad use categories—food, feed, processing, export, industrial, seed and losses. Yields for food crops are low relative to other crop-use categories. It is unlikely, given current trends, that the minimum calorie requirement to eliminate projected food undernourishment by 2030 will be met through crops harvested for direct food consumption, although enough calories will be harvested across all usages. Sub-Saharan African nations will probably fall short of feeding their increased population and eliminating undernourishment in 2030, even if all harvested calories are used directly as food.
Main
Competition for crops harvested for various uses has mounted in recent decades1. Crops used for animal feed, crop-based biofuels and other end uses can result in a smaller fraction of the same crop being available for direct human consumption as food. This competition also includes crop switching from those that are directly consumed as food to those that are not. In addition, rising demand for animal feed combined with inefficient feed conversion ratios ultimately mean reductions in calories left for human consumption2,3, challenging the achievement of the United Nations’ (UN’s) Sustainable Development Goal (SDG) 2 of food security for all by 20304. There are many dimensions of food insecurity, and merely increasing food production does not ensure food access, utilization and stability5. Yet, at present, there is widespread yield stagnation in major global food cereals6,7, and a growing global middle class is increasing its demand for food products that rely on crops harvested for feed and processing8. Shifting uses and demands are also producing profound environmental and climate impacts through unsustainable resource use and the clearing of natural landscapes, raising questions about whether the trends in crop harvests, when not meant for direct food consumption, are aligned with the common interests of meeting the SDGs9,10,11.
There is a current lack of detailed understanding of the patterns and trends of crops harvested for initial usage across the world. This has hampered the development of effective, locally relevant policies that balance global needs of food security and minimizing environmental impacts12,13,14,15 through reconfigurations of cropping systems. Here we combine annual country-level information on seven uses of crop production1 —food, feed, processing, export, industrial, seed and losses—over 50 years (1964–2013) with recently developed annual global gridded harvested areas and yields of ten major individual crops16. These ten major global crops—barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugar cane and wheat—account for ~83% of all harvested food calories17 and ~63% of global harvested areas18, a proportion that has remained stable for the past half century (between ~58% and 64%). Specifically in our analysis, a crop’s grid cell-level harvested area is split (Methods and Supplementary Data 1) and combined with yields (tons ha−1 per year) to give seven uses of crop production (tons per year). Using the crop-specific calorie, protein and fat contents (which can vary widely among crops), we estimate the total grid cell-level calories, protein and fat production and nutritional yields for the seven utilization categories.
Results
Growth in harvests of crops meant for exports, processing and industrial use, together with their higher yields and faster yield gains, stands out globally; at a more granular level, this was driven by specific global regions that are getting increasingly specialized in harvesting crops for these usages.
Changes in global-level harvested areas
At the global scale, we find that crops harvested for direct food utilization have the highest area and have been relatively stable over the study period . However, as the total harvested hectares have increased globally , this has translated into decreasing fractions of crops harvested for direct food utilization, from ~51% in the 1960s (average over 1964 to 1968) to ~37% in the 2010s (average over 2009 to 2013), with a similar reduction in feed crop harvests . Conversely, there has been a substantial increase in crops for processing, exports and industrial use . The increase in industrial crop harvests occurred after year 2000. Around the same time, harvested hectares for exported crops ramped up and by the 2010s had surpassed those of crops harvested for feed use . Crops harvested for seed usage and losses are relatively minor, and we will not discuss them further. If the global trends observed in the past 20 years continue , by 2030, crops harvested for exports, processing and industrial use will account for ~ 23%, 17% and 8% of overall harvested hectares, whereas those for food will decrease to ~29%.
Changes in global-level crop yields
We find that crops harvested for direct food usage generally have had lower yields than all other sectors at the global scale over the time period of the study . This is not a new phenomenon, as crops harvested for direct food utilization have always had lower yields relative to other sectors . What has changed, however, is the ramping up (steeper positive slopes) of industrial, export and processing crop yields . At these rates, caloric yields of industrial-use crops could increase by 28% from the 2010s to 2030 compared with 24% and 21% yield increases of crops harvested for directly consumed food and for feed use . Given that caloric yields of industrial-use crops are already substantially higher than food and feed crops (2× and 1.4×, respectively, in the 2010s), the faster caloric yield increases for industrial-use crops will widen this gap (2.1× and 1.5×, respectively). Yield measurements in other units of protein and fat show similar results
Changes in the spatial patterns of harvested areas and production
Within country-level information on harvested areas and productivity based on utilization categories is required for developing more locally effective agricultural policies. Over the course of the study time period 1964 to 2013 , we find changes in all continents when spatially analysed at the grid-cell level, except for most parts of Africa. Even in Africa, there are locations with fractional reductions in food crop harvests over the study period, such as parts of Angola, Ghana, Nigeria and South Africa. Within these and other countries, the exact location, magnitude and direction of the change varies from one region to the next.
Crops harvested for direct food utilization have been prevalent in Asia, though much has changed since the 1960s . In China, there appears to be an imaginary belt, north and west of which harvests of crops used as directly consumed food decreased between the 1960s and 2010s , while those for other uses increased. This belt appears to roughly extend from the northern half of Jiangsu (a province on the Yellow Sea in the east), curving westwards and southwards through northern Anhui, southern Henan, central Hubei and the northern tip of Hunan, and then turning sharply south and splitting Guangdong (a province on the South China Sea) through the middle. The sector gaining from the 10–20% fractional food harvest reduction varies. The increase in crops for feed, processing and industrial usage increases as one moves northward, especially north of Jiangsu and Anhui
Similarly, in India, there is a north–south zone encompassing eastern Haryana in the north, moving southwards through eastern Rajasthan, western Madhya Pradesh to eastern Maharashtra in the south, where there was a drastic reduction in crops harvested for direct food utilization over the study period; crops harvested for processing primarily increased. Changes in South and Southeast Asia over the study period are primarily away from once-dominant harvests of directly consumed food crops to feed crops, followed by processing crops, export crops and industrial-use crops, as in Myanmar and Thailand. In Malaysia, the growth was in export and industrial-usage crops, whereas in Indonesia, it was export crops and smaller increases in industrial-utilization crops. Central Asian states, especially Kazakhstan and some parts of Russia, witnessed a large reduction in crops harvested for direct food use over the study period, replaced by the crops destined for exports between the two periods .
In Australia in the 1960s, food crops were harvested everywhere, accounting for ~10% of the total, which declined to ~5% by the 2010s. This was accompanied by small reductions in crops harvested for feed and export and balanced mainly by increases in crops for processing and industrial utilization
In Europe in the 1960s, crops were dominantly harvested for food and feed, but by the 2010s, this changed to include crops harvested for processing . In France, major reductions in feed crops have been balanced by growth in processing, export and industrial-use crops. In Spain, the primary change is from crops harvested for direct food to those of feed. In Germany, crops harvested for export have replaced those for direct food utilization.
Latin America used to dominantly harvest food crops (as in Mexico) or food and feed crops (as in Brazil and Argentina) . Midwestern Brazil used to harvest only food crops, and feed and processing crop harvests were restricted to the Atlantic states (the 1960s; , but by the 2010s , harvests of food crops had become a negligible fraction in Midwestern Brazil (as in Mato Grosso), and crops harvested for processing and exports are dominant now. In the Atlantic states of Brazil, one of the major changes is the increased proportion of harvests for industrial crops. In Argentina, over the study period, the proportion of crops harvested for food and feed has decreased, and this utilization has been mainly replaced by crops harvested for processing; crops harvested for exports changed, but the direction of change was spatially heterogeneous across Argentina . In Mexico, the primary change is the reduction in the fraction of crops harvested for direct food consumption and the increased harvests of crops for feed.
Crops harvested for food and feed are also on the decline proportionally in North America. The United States has experienced a change from the dominance of food and feed crops in the 1960s to processing and industrial-usage crops in the 2010s. Detailed changes in the United States and Canada vary from one location to the next , though the major change is the lower fraction of crops harvested for direct food consumption.
Results are similar when viewed through the lens of calories, protein and fat with local-level differences as yields vary based on the measurement units. Further dramatic changes can be expected if observed linear trends from 1994 to 2013 at each grid cell continued until 2030 .
Calories harvested in 2030 and achieving UN SDG 2
We compare the extra food calories that will potentially be harvested in 2030 and Supplementary Data to those required for both the projected extra population and feeding the projected undernourished population in each country and Supplementary Data . As an extreme case, we also compared whether total calories (all seven utilization sectors) would be sufficient and Supplementary Data . Altogether, we evaluated 156 countries, of which 86 had reported undernourished populations (Supplementary Data . On the basis of the minimum dietary energy requirement (MDER), we find that countries with reported undernourished populations will have a shortfall of ~675.4 trillion kcal per year to nourish the increased population and the expected undernourished from their extra harvested food calories. However, compared with the more realistic average dietary energy requirement (ADER), this shortfall will be ~993.9 trillion kcal per year (or ~70% from requirements) in 2030 (15 additional scenarios of undernourished populations in 2030 (provided in Supplementary Data 3) show global calorie shortfalls may similarly range from ~587.2 trillion kcal per year to ~1,269.3 trillion kcal per year based on the MDER level of nutrition requirement, and ~880.7 trillion kcal per year to ~1,755.6 trillion kcal per year based on the more realistic ADER level of nutrition requirement in 2030).
