Issues for cropping and agricultural science in the next 20 years

doi:10.1016/j.fcr.2018.03.008

Field Crops Research

Volume 222, 1 June 2018, Pages 121-142

https://doi.org/10.1016/j.fcr.2018.03.008 Get rights and content

Abstract

This position paper honours agricultural scientist and colleague, Professor Bob Loomis, by discussing the urgent global challenge of food security and the related impacts on the environment facing agricultural science and society in the next critical 20 years. It uses the concepts of potential and actual (farm) crop yields and the yield gap between them to assess current and future opportunities for food supply to satisfy increasing demand. The cropping world is seen in two parts. The first part predominantly comprises low-input farming with very large yield gaps and a faster growing demand that can only be met with increasing imports. For these regions, a well-established strategy is outlined for crop intensification through yield-gap closure that is essential for reducing rural malnutrition and poverty, and curtailing the likelihood of high food prices. For success, it must be complemented with strategies to remove the serious institutional and infrastructural barriers faced by farmers. The second part has more or less intensified, and yield gaps are generally small to moderate: it will fairly comfortably meet the demand from population growth. For these regions, some further yield gap closure is still possible but more importantly greater potential yields are required although the chances of accelerating this are discussed and seen to be limited. For all regions, sustainable intensification of cropping, predominantly on existing arable lands, is the best way forward. Combining sustainability with intensification is not a contradiction and is, in fact, essential; sustainability requires the efficient use of all inputs in cropping, and husbandry of the soil and agricultural biodiversity needed to continue to raise productivity. Off-farm environmental impacts are inevitable, but not insurmountable, hurdles. All aspects of sustainability require boosted RD&E and sound rural policies. Greater management skills for farmers and all others involved in crop production are also essential. Contestation based on biophysical aspects of food production and its impacts can be resolved through effective research and development with farmers, while that based on Northern cultural and normative views must not be allowed to obscure the goal of affordable food for all, and reward for farmers comparable with the rest of their societies.

Section snippets

Dedication

Professor Robert (Bob) S. Loomis (11 October 1928–27 March 2015), Professor of Agronomy¹ at the University of California, Davis, was a crop scientist famous for the breadth and depth of his interests. These ranged from plant tissue culture and basic metabolism, through crop canopies, growth and yield, to cropping and farming systems of North

Global perspective

World grain production increased by 227% between 1961 and 2014 (Fig. 1) comprising +161% for yield and a much smaller increase (31%) in crop area, with more than half of the latter coming from increased intensity of cropping on existing arable lands. As a result per capita food availability has improved notably for a population that has risen 141%, and real food prices have fallen overall (Fig. 1).

Looking ahead to 2050, Fischer et al. (2014) concluded that a minimum target linear yield increase

Prospects for typologies with large yield gaps

As Table 2 shows demand increases in WANA and especially in SSA dominate the global challenge to feed the world, and in recent years these countries have been increasing food imports (partly as food donations). Here we concentrate on the more populous and poorer SSA that unlike WANA does not have economic capacity to support continued food importation. The principles of agricultural development to be discussed for SSA are, however, also applicable to WANA, hopefully will be soon when a more

Cropping intensification and natural resource-use efficiency

Implications of natural resource-use efficiency and sustainability deserve attention because some have argued, we consider erroneously, that intensification of cropping inputs can neither be resource efficient nor sustainable, that SI is an oxymoron. Natural resource-use efficiency in cropping refers to yield-scaled efficiency (output/input) with which water, nutrients and energy are used to produce food. These also relate to Sustainability (Section 6) in so much as these natural resources are

Sustainability of intensification

Here we will discuss aspects of our biophysical definition of sustainability, namely as the long-term maintenance, or improvement if feasible to optimize productivity, of the agricultural resource base (water supply, soil, agricultural biodiversity), while protecting the environment. Some prefer to expand the understanding of SI sustainability to include desirable outcomes in the realm of environmental services (e.g., Wezel et al., 2015) and in socioeconomics (Struik et al., 2014), with

Farm management: a key element for sustainable intensification

Dealing with all issues of natural resource-use efficiency and sustainability is obviously complex. Taking a 50% yield gap down to 25 or 30%, at the same time as PY is increasing, is a slow process (e.g. Iowa maize, USA soybean, UK wheat, in Fischer et al., 2014) and also managerially complex. Neither are “transformational”, both are decidedly incremental and involve the refinement of many technologies, some yet to be discovered, and are ultimately dependent on the technical and managerial

Alternative visions, contested agronomy, and wicked trade-offs

Needless-to-say there is concern arising from perceived problems with sustainable intensification, including among agricultural scientists. Environmental concern intensified in the 1960s with the publication of Silent Spring (Carson, 1962), the excesses of the Common Agricultural Policy of the EU (de Wit, 1988), and overuse of pesticides in some rice systems following the Green Revolution in Asia. Equity issues that were raised regarding the Green Revolution were clearly outweighed by the gains

Conclusions

•
This paper honours Professor Bob Loomis, a colleague and leading agricultural scientist. We look at the challenges for agricultural science in the short-to-medium term as cropping sustainably intensifies across all the world’s arable lands to meet continuing growth in demand for crop products, and in poorer nations, to alleviate rural poverty and drive economic growth.
•
Two major regions (Sub-Saharan Africa and West Asia-North Africa) show very large gaps between farm yield and potential yield

Acknowledgements

We thank two anonymous reviewers and the editor for many valuable suggestions which have improved the manuscript.

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Loomis ReviewIssues for cropping and agricultural science in the next 20 years

Abstract

Section snippets

Dedication

Global perspective

Prospects for typologies with large yield gaps

Cropping intensification and natural resource-use efficiency

Sustainability of intensification

Farm management: a key element for sustainable intensification

Alternative visions, contested agronomy, and wicked trade-offs

Conclusions

Acknowledgements

Trends Plant Sci.

Glob. Food Secur.

Glob. Food Secur.

Field Crops Res.

Agric. Syst.

Field Crops Res.

Soil Tillage Res.

Field Crops Res.

Field Crops Res.

Field Crops Res.

Field Crops Res.

Field Crops Res.

Field Crops Res.

Field Crops Res.

Geoderma

Agric. For. Meteorol.

Field Crops Res.

Agric. Ecosyst. Environ.

Eur. J. Agron.

World Dev.

Geoderma

Factors that transformed maize productivity in Ethiopia

Food Secur.

Agricultural Technologies and Tropical Deforestation

Break crops and rotations for wheat

Crop Pasture Sci.

Potential for crop production increase in Argentina through closure of existing yield gaps

Field Crops Res.

Organic agriculture and the gobal food supply

Renew. Agric. Food Syst.

Bandwagons I, too, have known

Theor. Appl. Genet.

Rural and Agricultural Mechanization. A History of the Spread of Small Engines in Selected Asian Countries. IFPRI Discussion Paper 01443

The resources outlook: by how much do land, water and crop yields need to increase by 2050?

Southern corn leaf blight: A story worth retelling

Agron. J.

Greenhouse gas mitigation by agricultural intensification

PNAS

Farmers’ stepwise adoption of technological packages: evidence from the Mexican altiplano

Am. J. Agric. Econ.

Silent Spring

Simulating the yield impacts of organ-level quantitative trait loci associated with drought response in maize: a gene to phenotype modeling approach

Genetics

Alternate wetting and moderate drying increases rice yield and reduces methane emission in paddy field with wheat straw residue incorporation

Food Energy Secur.

Crop Ecology. Productivity and Management in Agricultural Systems

Mining nutrients in African soils due to agricultural intensification

Grain yield and nitrogen accumulation in maize hybrids released during 1934 and 2013 in the US Midwest

Crop Sci.

Interpretation of soil microbial indicators as a function of crop yield and organic carbon

Soil Sci. Soc. Am. J.

Environmental impact of CAP

Eur. J. Agric. Econ.

Rising Global Interest in Farm Land: can It Yield Sustainable and Equitable Benefits?

Glyphosate effects on plant mineral nutrition, crop rhizosphere microbiota, and plant disease in glyphosate-resistant crops

J. Agric. Food Chem.

Progress in achieving and delivering drought tolerance in maize—an update

Global Status of Commercialized Biotech/GM Crops: 2012. ISAAA Brief No. 44

Constraints and potentials of future irrigation water availability on agricultural production under climate change

Proc. U. S. Natl. Acad. Sci.

Status of the World’s Soil Resources. Main Report. Food and Agriculture Organization of the United Nations and Intergovernmental Technical Panel on Soils, Rome, Italy

Balancing crop yield and water productivity tradeoffs in herbaceous and woody crops

Funct. Plant Biol.

Loomis Review
Issues for cropping and agricultural science in the next 20 years