Water, water — not everywhere: Mapping water trends for African maize

Molly Sharlach at Princeton Journal Watch: Researchers analyzed water availability trends in African maize-growing regions from 1979 to 2010. Each quarter-degree grid cell represents a 200-square-mile area and is colored according to its average water availability level during the maize growing season. In redder areas, water availability is more limited by rainfall levels, while bluer areas are more limited by evaporative demand. (Image source: Environmental Research Letters)

Today’s food production relies heavily on irrigation, but across sub-Saharan Africa only 4 percent of cultivated land is irrigated, compared with a global average of 18 percent. Small-scale farming is the main livelihood for many people in the region, who depend on rainfall to water their crops.

To understand how climate change may affect the availability of water for agriculture, researchers at Princeton University analyzed trends in the water cycle in maize-growing areas of 21 African countries between 1979 and 2010. The team examined both levels of rainfall and the evaporative demand of the atmosphere — the combined effects of evaporation and transpiration, which is the movement of water through plants.

Overall, they found increases in water availability during the maize-growing season, although the trends varied by region. The greater availability of water generally resulted from a mixture of increased rainfall and decreased evaporative demand.

However, some regions of East Africa experienced declines in water availability, the study found. “Some places, like parts of Tanzania, got a double whammy that looks like a declining trend in rainfall as well as an increasing evaporative demand during the more sensitive middle part of the growing season,” said Lyndon Estes, the study’s lead author and an associate research scholar in the Program in Science, Technology and Environmental Policy at the Woodrow Wilson School of Public and International Affairs...

Researchers analyzed water availability trends in African maize-growing regions from 1979 to 2010. Each quarter-degree grid cell represents a 200-square-mile area and is colored according to its average water availability level during the maize growing season. In redder areas, water availability is more limited by rainfall levels, while bluer areas are more limited by evaporative demand. (Image source: Environmental Research Letters, from the Princeton website)

Floods, locusts leave Madagascar hungry

IRIN: ...Erratic weather and a locust plague have taken a toll on Madagascar’s rice and maize harvests this year, leaving as many as 4 million people - 28 percent of households - in rural areas food insecure, according to a recent World Food Program (WFP)/Food and Agriculture Organization (FAO) report. A further 9.6 million people are estimated to be at risk of food insecurity.

The joint Crop and Food Security Assessment Mission, conducted in June and July by WFP and FAO, attributed the poor agricultural season to a combination of factors including flooding caused by Cyclone Haruna earlier this year, followed by a period of poor rains.

...According to the WFP/FAO report, rice production declined by 21 percent this year, resulting in a significant national rice deficit. Maize production is also down and an estimated 28,000 metric tons of maize will need to be imported to meet domestic needs....

Rice paddies in Madagascar, shot by Jean-Louis Vandevivère, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Malawians rethink maize planting as climate dries

Karen Sanje in AlertNet: Less than three years after Ezelina Nyirongo reluctantly abandoned cultivation of her favourite local maize varieties, the 48-year-old from Rumphi in northern Malawi is thinking of going back to them. Back in 2010, Nyirongo was advised by agricultural extension officers working in her area, near the city of Mzuzu, to switch from late-maturing local maize to new hybrid varieties.

“The hybrid maize varieties they recommended we start growing have been maturing a little earlier than the local varieties, at least before the rains finished,” said Nyirongo. “And the harvest has also been a little better than when I was growing the local maize varieties.”

But now, officials from the ministry of agriculture and food security and non-governmental organisations (NGOs) are encouraging farmers to plant indigenous maize again, alongside the hybrid varieties.

“This is for adaptation to the effects of climate change, both by way of growing the local varieties themselves, which are more resilient to harsh climatic conditions, and production of early-maturing hybrid varieties,” Malawi’s deputy minister of agriculture and food security, Ulemu Chilapondwa, told AlertNet...

Maize diversity discoveries may help ease world’s hunger pangs

University of California, Davis, News and Information:  Researchers at the University of California, Davis, report that ancient farmers had a stronger impact on the evolution of maize, or corn, than modern plant breeders have had on the grain — now one of the world’s top production crops.

...“These two studies provide a new and more comprehensive understanding of genomic variation in maize, which will be critically important to plant breeders as they work to increase corn yield in the face of global population growth and climate change,” said plant geneticist Jeffrey Ross-Ibarra, the lead researcher on the UC Davis-directed study.

...The world’s population is expected to climb from 7 billion people this year to an estimated 9 billion by 2050. The Food and Agriculture Organization of the United Nations predicts that food production will need to increase by 70 percent over the next four decades to meet anticipated demand. Globally, 90 percent of these production increases will need to come from increasing crop yield on existing farmland rather than by bringing new land into agricultural production.

The new UC Davis-led study analyzed the evolution of maize during the period when it was domesticated 10,000 years ago, as well as during subsequent breeding.  The study was based on the resequencing of 75 genomes of maize and its relatives, including wild strains, traditional cultivated varieties and improved modern inbred lines. (The first sequencing of the reference maize genome was announced by a U.S.-based consortium of researchers in 2009.) The new maize genome study showed that:

• Though a substantial amount of diversity was lost during domestication, new diversity has arisen since domestication in the form of novel mutations;
• Hundreds of identified genes appear to have played a role in domestication of maize from the wild, and many of these genes also appear to have been important for modern breeding;
• Selection applied during initial domestication appears to have been much stronger than selection applied more recently during maize breeding; and
• Modern strategies of breeding for hybrid vigor have been accompanied by marked changes in gene expression in maize.

A corn labyrinth in Delingsdorf, shot by Karsten Eggert, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Water-efficient maize boosts harvests for drought-hit Tanzanian farmers

Kizito Makoye in AlertNet: Balisidya Jacob has been farming for many years, but it’s the novelty and size of his new crop of maize that is making him smile. The 56-year-old, who is sole breadwinner for an extended family of 17 children, is happy at the prospect of being able to feed them all, thanks to an experiment with drought-resistant seed.

Although maize is a staple crop in Tanzania, farmers in Makutupora, a village 27 km (17 miles) north of the capital, Dodoma, are more used to growing millet, sorghum and legumes. Tanzania’s great central plateau, which sprawls across Dodoma, Singida and parts of Tabora regions, has suffered from drought for years, and maize has not been widely cultivated here because it cannot withstand the arid conditions.

But as part of an international research project dubbed Water Efficient Maize for Africa (WEMA), Jacob and his neighbours are now using five varieties of maize seed that are being tested in an effort increase food production and help farmers adapt to the effects of climate change. “I was not sure these seeds would be any good, but it’s amazing - they require little water and they grow fast,” said Jacob.

WEMA’s lead researcher in Tanzania, Barnabas Kiula, said that one of the maize varieties being introduced, situka, can be grown in arid conditions and could be ready for harvest in just 75 days. Most maize varieties require at least 90 days to mature....

Shot of some maize by Joeriee, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Climate change squeezing Malawi’s maize production

Charles Mkula in New Times Africa: Despite Malawi registering surplus maize yields in recent years, food production in the southern African nation has been on the decline, a climate change study has indicated. Malawi has in the past six years basked in the glory of maize surpluses that came about partly because of the implementation of the world acclaimed Farm Input Subsidy Programme and favourable rains falling on the heels of serious droughts between 1978 and 2005 growing seasons that resulted in crop failures and low yields.

According to an IMF report, the droughts were evidence of famine that was triggered mainly by failure of the rain-bearing systems during the critical planting season. Rainfall distribution in Malawi has become more unpredictable to the extent that it has reduced crop production, Malawi’s Ministry of Agriculture, Irrigation and Water Development hydrologist Henrie Manford Njoloma has disclosed in his research study of over 60 years of rainfall data in the sub Saharan country. “Rainfall distribution is no longer uniform and predictable as it used to be in the past,” he says noting that maize, the country’s staple diet has been drastically affected by the erratic rainfall patterns.

Njoloma notes that the reliance on rain to produce maize for the national consumption has become Malawi’s great challenge with the main producers of the staple diet being smallholder farmers whose land holding size averages 0.3 ha. Malawi’s food production is mainly from rain-fed agriculture with maize produced by about 97% of all farming house-holds. “When rains fail there is less maize production therefore creating economic problems in the national economy despite maize not being categorized as an economic crop,” he points out....

Photograph by 3268zauber, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Field trials for drought-tolerant transgenic maize

Red Orbit: Crop specialists in Kenya and Uganda have laid the groundwork for confined field trials to commence later this year for new varieties of maize genetically modified to survive recurrent droughts that threaten over 300 million Africans for whom maize is life, according to a speech given today by the head of the African Agricultural Technology Foundation (AATF) at the World Food Prize Symposium.

Scientists working with AATF believe it's important to explore the potential of biotechnology to maintain and increase food production in Africa, given the large number of families dependent on maize, and warnings that maize yields could drop dramatically as climate change increases drought frequency and severity across the continent.

There is preliminary evidence that the Water Efficient Maize for Africa (WEMA) varieties, which were developed through a public-private partnership, could provide yields 24-35 percent higher than what farmers are now growing.

The process for testing the WEMA varieties has been informed by a series of "mock trials" conducted in 2009 in Kenya and Tanzania. The mock trials carefully simulated field conditions, procedures, and regulatory oversight that will occur in the actual trials.

…Drought is the most important constraint to African agricultural production, and its effects are particularly severe on maize, which is the most widely-grown staple on the continent. For millions of small-scale farmers who rely on rainfall to water their crops, risk of crop failure from drought is a major barrier to the adoption of improved farming practices….

From Anga Bottione-Rossi's Histoire naturelle, agricole et economique du maïs Paris: Madame Huzard; Turin: Bocca, 1836

Crop genetics, climate change and maize stability

American Society of Agronomy: Climate change is an ever-present threat to agriculture. Many experts predict sudden and unexpected changes in climatic conditions will bring new stresses to the environment. Ensuring the stability of crop varieties across environments and conditions is a critical breeding goal when dealing with the uncertainty of climate change.

Maize is one of three primary crops worldwide. Slight changes in climatic conditions may cause substantial yield losses, resulting in great food shortages and economic losses. Consequently, numerous breeding programs are currently evaluating maize stability under different climatic stress conditions. However, many breeders design yield improvement programs without first conducting preliminary studies to determine which environmental factors actually limit the crop and which genetic parameters are essentially affected.

Scientists in northwestern Spain, from the Spanish National Council (CSIC), have investigated the effects of multiple climatic stresses on maize grain yield. The study, which was funded by the Spanish Plan of Research and Development, evaluated 76 Spanish populations of maize, along with five commercial hybrids. Research was conducted at three distinct locations over three years, for a total of nine environments. Evaluations were made under multiple stress conditions, including a shortage of water, cold temperature, and low nutrient availability. No pesticide or herbicide treatments were applied during the growing cycle, and weeding was limited in order to allow competition. Data on several traits related to plant development and yield were collected on each plot. Environmental variables were also recorded to monitor variations in temperature and rainfall during the growth season.

The results of the study, which are published in the January/February 2010 issue of Crop Science, illuminate the effect of genotype and environment on yield stability, as well as the magnitude of genotype-environment interactions. Researchers determined that commercial hybrids had higher yield and stability than most populations, suggesting that breeding programs focusing on yield have released hybrids with high yield and stability under different stress conditions. Some non-hybrid populations also produced a reasonable compromise between yield and stability. If yield stability under stress conditions is a breeding goal, researchers recommended that several climatic variables, especially those related to high temperatures, and genotypic traits, such as kernel depth and ear length, be considered.

Although hybrids are more stable under diverse climatic conditions, it is important to remember that old populations are the reservoirs of genes from which these hybrids have been developed. In order to continue the development of improved hybrids, research with populations must also be emphasized. However, old populations need to be intensely improved for yield if they are going to be used for future breeding programs.

Multicolored corn cobs, shot by Waugsberg, Wiikimedia Commons, under the Creative Commons Attribution Share-Alike license version 2.0