What we’ve been reading this week

This week’s summary on the news stories, reports and blogs that have grabbed our attention. We welcome your thoughts and comments on these articles.

Back agriculture to get the most out of aid to Africa, SciDev.Net

No-till agriculture may not bring hoped-for boost in global crop yields, study finds, UC Davis

Family farms produce 80 percent of world’s food, speculators seek land, Thomson Reuters Foundation

Can We Feed the World in 2050? A Scoping Paper to Assess the Evidence, GDAE

Principles for responsible agriculture and food investments are approved, FAO

Oxfam response to UN Committee on World Food Security Endorsement of Principles, Oxfam

Why ‘climate-smart agriculture’ isn’t all it’s cracked up to be, The Guardian

The Race Is On to Find Organic Pesticides, The Wall Street Journal

Yield gaps, trade liberalisation and biotechnology: three new reports on the way to tackle food insecurity

Three new publications investigate proposed solutions to global food insecurity, exploring the potential consequences of liberalising trade, increasing crop yields and introducing biotechnology. The first, written by agricultural scientists Tony Fisher, Derek Byerlee and Greg Edmeades, Crop Yields and Global Food Security, investigates the rate at which crop yields must increase if we are to meet global demand for staple crops by 2050. They explore how such targets might be achieved and what the consequences would be for the environment and natural resources.

Population growth, rising incomes per capita and growing biofuel usage mean we expect demand for staple crop products to increase by 60% between 2010 and 2050. This increase can either be met by expanding land area under agriculture or by increasing the yields of crops grown on current land. With land being in short supply and much potential agricultural land requiring deforestation and natural habitat clearance, the latter option has far more support. Indeed crop area is expected to grow only 10% between 2010 and 2050, with some of this increase originating from increased cropping intensity. To date yields of wheat, rice and soybean have been steadily rising over the past 20 years. The rate of growth, however has been declining and wheat yields are increasing at approximately 1% each year compared to 2010 figures (1.5% for maize). Crop models tell us that if we are to meet future demand and keep food prices at less than 30% higher than the low prices of 2000-2006 then yields of staple crops must rise by 1.1% each year. Of course these figures do not take into account the other resource challenges agriculture faces, climate change or tackling hunger and thus authors suggest a higher rate of increase of 1.3% per annum.

The book explains key concepts in crop physiology and yield, for example, a term often used when discussing agriculture in developing countries, “closing the yield gap”. The yield gap is effectively the difference between the yields obtained on a farm (Farm Yield or FY) and the yields obtained under field trial conditions (Potential Yield or PY). For wheat, although the book also explores other staple crops, the yield gap is on average around 48% of the FY. This varies by location with developing countries (and crops produced under rainfed conditions) showing a larger gap and Western Europe showing the smallest gap, some 30%. Progress towards closing this gap is worryingly slow, occurring at a global average rate of just 0.2% per year, and in Western Europe may actually be increasing. Yield gaps are difficult to close and on average closing a yield gap by 10% of FY takes some 20 years. Here authors highlight the difficulty of increasing Farm Yields through technology adoption and improved agronomic practices, and the importance of increasing PY to stimulate Farm Yield gains, likely through improved varieties.

Addressing these yield gaps, authors say, will require a combination of plant breeding of higher yielding and more resilient varieties, public agricultural extension to train farmers in improved farming practices and greater integration between farmers, scientists and businesses. While examples of yield gaps being significantly closed do exist, particularly where new technologies are adopted and markets are reliable – the One Acre Fund being given as an example, the rural transformation required to help subsistence farmers in developing countries close the gap will require substantial investment that as yet is missing.

Efficiency the key to feeding more people without environmental damage

A new report by researchers at the University of Minnesota’s Institute on the Environment, published in Science, shows that an extra 3 billion people in the world need not lead to higher levels of hunger if existing cropland is used more efficiently, additionally reducing agriculture’s environmental impact. The report focused on 17 crops that account for 86% of the world’s crop calories as well as the majority of irrigation and fertilizer use. The hope is that the report can help guide and prioritise donors’ and policy makers’ activities for the greatest benefit.

The report identifies three areas of priority that, with the suggested actions, hold the most potential for meeting global food needs and reducing agriculture’s environmental footprint, a key pillar of sustainable intensification. Geographically the majority of these opportunities occur in China, India, U.S., Brazil, Indonesia, Pakistan and Europe. To summarise we need:

1. To produce more food on existing land, in particular closing yield gaps. An estimated 850 million people could be fed by closing the most dramatic yield gaps, in Africa, Asia and Eastern Europe, by 50%.

Closing yield gaps may seem a simple task through technology and access to productive resources but the International Center for Tropical Agriculture (CIAT) believe that we need to rethink how we approach yield gaps, taking a whole systems approach.

2. To grow crops more efficiently, in particular using water and nutrients more precisely and reducing climate impacts. The largest potential gains in reducing greenhouse gas emissions, as pinpointed by the study, could come from deforestation in Brazil and India, rice production in China and India and crop fertilization in the U.S.

The U.S., China and India, and particularly their maize, rice and wheat production, were also found to be the largest sources of the overuse of nutrients in the world. Across the globe 60% of nitrogen and around 50% of phosphorus applications are in excess of amounts needed by crops. A 2012 article on China Dialogue highlights the dangers of overusing fertilizer. Improving the efficiency of fertilizer use would also reduce greenhouse gas emissions. Together with Pakistan these countries are also responsible for the majority of irrigation water use, water that could be reduced by 8 to 15% without yield penalties by improving crop water use efficiency.

3. To use crops more efficiently, in particular reducing food waste and reducing the proportion of crop calories going into livestock feed as opposed to directly for human consumption. Current crop animal feed, predominantly maize, could feed approximately 4 billion people. Such a shift would require widespread behavioural change, reducing the overreliance on meat in developed countries, although the report’s authors highlight the potential to shift crops from livestock to humans in times of crisis.

Closing yield gaps through nutrient and water management

Could ‘sustainable intensification’ be the solution to meeting future food needs and reducing agriculture’s negative impact on the natural environment? Gordon Conway has defined this approach simply as ‘producing more while using fewer resources’, and the practical implementation of the term has been increasingly scrutinised and the subject of controversy. Indeed it is the topic of an upcoming Chatham House Food Security 2012 conference in London entitled, Sustainable intensification: miracle or mirage?

A recent paper in Nature discussed the possibility of agricultural intensification and specifically of closing yield gaps – the gap between yields which are attainable and yields which are observed – for 17 major crops. The variability in yields achieved for different crops was found to be largely due to differences in fertiliser use, irrigation and climate.

Authors of the paper found that closing the yield gaps by 100% would result in an increase of crop production for most major crops of 45% to 70%. Significant opportunities for intensification of major cereals exist in Eastern Europe and sub-Saharan Africa. Reaching this level of yield gap closure would, however, require increases in irrigation and nutrient application, actions that are not necessarily in line with the paradigm of sustainable intensification. Sub-Saharan Africa does, however, have large untapped water sources that, if used responsibly and, yes sustainably, could improve food production.