Matthew P. Reynolds (Ed): Climate change and crop production

Reynolds Ed: Climate change and crop production CAB International, Wallingford, 292pp.. Matthew Reynolds has done a good job in bringing together a range of high-quality authors to explo

BOOK REVIEW

Matthew P Reynolds (Ed): Climate change and crop

production

CAB International, Wallingford, 292pp 2010

Peter J Gregory

Received: 29 November 2010 / Accepted: 29 November 2010 / Published online: 7 December 2010

# Springer Science+Business Media B.V & International Society for Plant Pathology 2010

This volume is the first in a new series from CAB

International on climate change Matthew Reynolds has

done a good job in bringing together a range of high-quality

authors to explore the issues raised for crop production by

the recorded and projected changing climate, in a book that

goes well beyond the conventional explorations of impact,

adaptation and mitigation The 13 chapters comprising the

main elements of the book are grouped under four

head-ings: predictions of climate change and its impact on crop

productivity (2 chapters); adapting to biotic and abiotic

stresses through crop breeding (5 chapters); sustainable and

resource-conserving technologies for adaptation to and

mitigation of climate change (3 chapters); and finally, new

tools for enhancing crop adaptation to climate change (3

chapters) As might be imagined from these headings, the

book is focussed on technological ways of dealing with the

changing climate, and there is little acknowledgement of

agriculture as a socially constructed activity, nor of the

contributions of markets, institutions and governance

arrangements in the way societies might organise

them-selves to cope with the challenges that climate change

poses

Underlying the narrative is the realisation that, even

without the challenges posed by a changing climate, crop

production will need to increase substantially in the next

few decades to feed a growing population with, on average,

a higher standard of living than at present Robert Watson

(Chief Scientific Advisor, Defra, UK) captures this well in

his introduction to the book, writing that “doubling food

availability over the coming decades in the context of climate change and other stresses will require advances in crop research and agricultural practices, with emphasis on the sustainable management of water and soils” Through-out the book there are many attempts to marry these multiple requirements of increased crop production, of new crop genotypes that are less susceptible to biotic and abiotic stresses, and of sustainable production practices to gain multiple benefits in addition to coping with the challenges

of a changing climate

Chapter 2 gives a measured account of what is known and unknown about the future climate It recognises that the amount of warming will depend on the quantities of radiatively-active gases emitted and suggests a 1-3°C global increase in temperature by 2050, rising to 2-4°C by 2100

Of course, for crop production, the changes in rainfall are likely to be of greater importance than those in temperature for much of the world Here the projections are much more uncertain because precipitation is driven by a wider range

of atmospheric processes than temperature, with regional changes more likely than global ones So, as today, there may be drought in some places and waterlogging elsewhere (but just more variable?) Overall, if temperature increases

by more than a degree or so, warming effects are likely to decrease crop growth and yield However, as the authors state very clearly, the high degree of uncertainty about impacts on crops “makes the prediction of effects on agriculture difficult and can result in contradictory results” This is a good start because it frames well the challenge facing crop scientists as they seek to develop appropriate interventions to deal with an uncertain future

The chapters on crop breeding deal with these uncer-tainties in different ways The physiological and genetic bases for adaptation of germplasm to heat and drought stresses are only partially understood so, despite some

P J Gregory ( *)

Scottish Crop Research Institute (SCRI),

Invergowrie,

Dundee DD2 5DA, UK

e-mail: peter.gregory@scri.ac.uk

Food Sec (2011) 3:111–112

DOI 10.1007/s12571-010-0090-3

advances in the development of markers for these traits,

empirical multi-location testing of elite materials is still

required The authors emphasise the need for better

characterisation of environments to assist with the

deploy-ment of markers for complex, adaptive traits but there is

silence as to how this might be achieved in practice in a

more climatically variable, and uncertain, world Moreover,

while much literature predicts increases in the prevalence of

agricultural pests and diseases, only a handful of studies

have quantified the possible impacts Several authors point

out that this has been a much neglected area of research

despite ample evidence that pests and diseases are major

causes of inefficiency and waste in our current production

systems In part this is because of the difficulty of

separating the influences of normal, regional, seasonal

variations in weather from global climate change effects

With or without climate change, though, the increases in

production required in the next few decades mean that

breeding for pest and disease resistance is an essential

component of germplasm improvement

Chapters 9 and 10 on greenhouse gas mitigation and

conservation agriculture contain highly complementary

messages although they are written from different

perspec-tives Both highlight the need for research that more closely

integrates the links between sustainability, resource use

efficiency and the reduction of greenhouse gas emissions

The links between these facets of crop production are

complex but there are currently few experiments or data

sets that contain simultaneous measurements of methane,

nitrous oxide and carbon dioxide emissions together with

those of carbon sequestration Conservation agriculture,

based on minimal soil disturbance, permanent ground cover

and rotations, has been shown in several locations to result

in improved soil biological and physical fertility, better

nutrient cycling and crop growth In rice production

systems, it can also result in less methane emissions when

flooding is reduced, but considerable care is required with

the method and timing of N fertiliser applications if nitrous

oxide emissions are also to be reduced If conservation

agriculture is to play its full part as a mitigation strategy for

greenhouse gas emissions, then the understanding of the integrated effects of the practices on all greenhouse gases, and the development of technologies and fertilisation practices, will require the sort of research effort that has previously been expended on production systems involving inversion of the soil

Unusually for a book on this subject, the final set of chapters examines some of the new tools that are emerging

to assist with speeding up the rate of crop improvement Throughout the chapters the message is clear: that conven-tional and biotechnological approaches will be needed to decrease the impact of agricultural production by increasing the efficiency of production and simultaneously decreasing greenhouse gas emissions The chapter on the use of biotechnology in agriculture combines both a conventional account of the range of methodologies that are now available with an original description in a series of boxes distributed throughout the text of thirty examples of the benefits that biotechnology has brought to crop improve-ment These examples range from the well-known introgres-sion of the Rht gene from the Japanese Norin-10 into elite wheat varieties, through gamma-irradiation mutation of cereals to produce, for example, Golden Promise, which was a top malting barley in Scotland in the 1970s and 1980s,

to the recent use of TILLING populations to identify 196 new alleles in the A and B genome waxy genes (granule bound starch synthase genes) in chemically induced mutants

of wheat These examples should be compulsory reading for all students of crop science The final two chapters demonstrate the vital role that mathematical and statistical scientists play in modern programmes of crop improvement and how their skills can be employed to understand a more climatically uncertain future

In summary, this is one of the best collections of papers that I have read on the subject of climate change and crop production and contains much to challenge the reader Its implicit message to simultaneously research crop improve-ment through breeding, and crop husbandry through improved pest, disease, tillage, fertiliser and water manage-ment is to be applauded