Quarterly Research Updates

Issue 8, June 2017


In this issue

Studying changes in Jordan’s barley genetic diversity and structure

Adapting durum wheat varieties to Senegal Basin for food security

Water harvesting for restoring rangelands in Jordan

How does local biodiversity respond to human pressures?

Increasing yields from improved chickpea and mung bean varieties in Afghanistan

In the Spotlight

Studying changes in Jordan’s barley genetic diversity and structure

Barley remains an essential component of Jordan’s landscape, providing food security in the country’s rainfed agricultural system. A recently published analysis demonstrates for the first time temporal variation in the country’s barley landrace diversity. The study underlines the importance of seed management practices and ex-situ conservation on shaping diversity of landraces in building resilience and adaptation to climate change.

Background

Landraces are a critical element of food security. They are used in breeding because they are an important source of unique variability, in particular, regarding adaptive traits. On-farm management of landraces, i.e. maintenance of genetic diversity in production systems, is an essential complement to ex- situ conservation. Importantly, it allows adaptive processes to continue, which shape landrace genetic diversity and result in unique resources for farmers and breeders.

Barley is the fourth most important dryland cereal crop worldwide in terms of production, yield and area harvested. It is adapted to marginal areas and stress-affected environments and is therefore important to small holders in developing countries. In Jordan, barley is the predominant crop in areas with less than 300 mm of annual rainfall. In these areas, barley is mainly grown for animal feeding; both grain and straw are utilized. Given that water scarcity is a major environmental challenge in Jordan and dry areas in general, a crop such as barley will likely remain an essential component of the landscape, providing food security in Jordan’s rain-fed agricultural system.

The study

To examine how landrace barley diversity has changed in Jordan over recent decades, researchers (Thormann et al., 2017) sourced landrace samples collected in Jordan in 1981 from a genebank, and re-collected contemporary samples from the same sites in 2012. The study examined genetic and phenotypic diversity at both time points to investigate the pattern of temporal changes in diversity, and sought to understand whether these changes were associated with geography or climate.

No significant changes were observed in the amount of genetic diversity, but samples collected in 2012 were more homogenous and less locally distinct. In two sites, replacement of the old material was observed. There was a change in phenotype, and phenotypes were found to be more homogeneous among sites in 2012. While the amount of genetic diversity for long-term potential for adaptability and persistence and the number of multi-locus genotypes was maintained, local distinctiveness among landrace barley populations in Jordan was reduced.

Conservation of landrace diversity: a potential for evolution

The study results underline the importance of seed management practices on shaping diversity in landraces maintained by farmers. The increased availability of varieties and centrally coordinated seed production and distribution have likely contributed to decreasing differentiation and reduction in population structure, because seed exchange and genetic population structure in landraces are found to be interdependent . The potential for evolution and adaptation to ever changing environmental conditions is one of the major advantages of active on-farm conservation of landrace diversity. The assessment of changes in landrace diversity over time, combined with analysis of seed management practices, diversity and partnership with national system can be extremely useful and help inform concrete interventions for the conservation of landrace and crop diversity for climate change adoption.

ICARDA genebank holds 32,560 accessions of Hordeum species with 30,201 accessions of cultivated barley including 246 originating from Jordan and 2,359 accessions of wild barley including 337 originating from Jordan. For the study cited, ICARDA has provided the samples collected prior to 2012.

Author: Chandrashekhar Biradar (ICARDA)


Adapting durum wheat varieties to Senegal Basin for food security

The durum wheat breeding initiative promoted in West Africa aims to help farmers raise their incomes and diversify diets, as well as improve agricultural systems.

Challenging rice mono-cropping

Senegal, Mauritania, Mali and Guinea are among the poorest countries in West Africa, home to over 2 million smallholder farmers families. The Senegal River traces some of the borders among these countries and offers irrigation water to over 200,000 ha of rice cultivation. Farmers that have the means cultivate rice twice a year between March-June and July-November, but leave the land bare during the rest of the year because rice cultivation is not suitable.

This double crop ensures harvests estimated at 1.5 to 1.6 million tons, which is approximately half of the need of the four countries to achieve food independence. The rice mono-cropping is starting to cause a severe increase of weeds and diseases, making the process hard to sustain in the long term. Besides, it is resulting in rice mono-diets, which is not healthy for children and mothers.

To combat these issues, a new harvest of cereal grains during the winter fallow months (December to March) could help diversify the cropping system, the people’s diets, as well as improve food security. Through the durum wheat breeding effort of ICARDA in collaboration with the Swedish University of Agriculture, Alnarp, supported by funds from the Swedish Research Council, it was possible to develop super-early and heat tolerant durum wheat varieties that can go from sowing to harvest in under four months, fitting perfectly in the winter fallow season.

New food from uncultivated land

The key innovation proposed by Dr Filippo M. Bassi was the development of top yielding durum wheat cultivars that can withstand the tropical winter temperatures in excess of 37⁰ C. The success of the project “Deployment of Molecular Durum Breeding to the Senegal Basin: Capacity Building to Face Global Warming” granted to be awarded the 2017 Olam Prize for Innovation in Food Security.

Some 400 potential varieties collected from 32 countries were tested for two years at two experimental farms in Mauritania and Senegal on the opposite shores of the river (approximately 400 km apart) with different environments in terms of soil type and temperatures. The statistical analysis and performance evaluation have allowed to identify three new durum varieties that combine all required traits: yields above 3 tons per ha, with a top yield peak of 6 tons, growing in just 92 days, and  excellent industrial quality of the produced grains.

The potential impact of the project is estimated at 600,000 tons of new food produced from normally uncultivated land (3 tons from each of the 200,000 ha currently under rice cultivation). The high industrial quality of the grains means they could be sold at the international price of USD 340 per ton, equivalent to a new hypothetical business trade of over USD 200 million per year. North Africa imports an estimated of USD 2.1 billion of durum grains per year. If properly politically supported, farmers along the Senegal River can sell the grain to neighboring states, gaining additional income to diversify their diets, promote children education and improve agricultural systems.

The seeds of the three varieties have been multiplied to produce sufficient amounts for farmers sowing. Their delivery to farmers is expected to start in 2018.

Author: Filippo Bassi (ICARDA)


Water harvesting for restoring rangelands in Jordan

Optimizing mechanized micro water harvesting technique can help restore degraded rangelands in Jordan, a research using Rangeland Hydrology and Erosion Model suggests.

Population growth, refugee movement, and boundary restrictions affect the livelihoods of nomadic communities and increase pressures on fragile rangelands throughout the Middle East, including Jordan’s Badia. Overgrazing, caused by an increase in livestock herds degrades native vegetation and harms the soils, which leads to decreased rainwater infiltration and retention capacity, accelerating surface runoff and erosion.

Optimizing traditional techniques

To cope with water scarcity, communities in Jordan have traditionally applied simple yet efficient water harvesting (WH) techniques. ICARDA developed that concept further and mechanized the approach, creating small and intermittent ridges across the sloping land for capturing the excess rainwater. Through intermitting the hill slopes this technique also prevents erosion. Native shrub seedlings, provided by US Forest Service project (SEED), were planted in water harvesting troughs at a research site approximately 10 kilometers (km) from the Jordanian capital, Amman; the troughs acting as ‘vegetation islands’ that would grow and spread out over time.

In order to optimize micro water harvesting and the revegetation of degraded rangeland ecosystems, ICARDA has been promoting a special Vallerani plow, among other techniques, which is composed of a reversible mouldboard and deep ripper. The moulboard creates a micro basin to mainly collect water, but also seeds, topsoil and organic material, while the ripper digs an underground splitted furrow for better water infiltration and storage.

A recent study, jointly carried out with USDA ARS scientists around Dr. Mark Weltz, research leader at the Great Basin Rangelands Research (GBRR) Unit, Nevada, uses the Rangeland Hydrology and Erosion Model (RHEM) to investigate water and sediment dynamics, thereby optimizing the design of the Vallerani water harvesting system. RHEM helps comparing actual stage degraded conditions, mainly due to overgrazing and barley agriculture, with a micro WH restoration scenario.

RHEM is in use to simulate runoff and erosion for the interspacing between the WH structures helping to optimize the implementation design. The model is forced through a 300-year rainfall time series generated by climate generator CLIGEN, thus to investigate long-term hydrological behavior and to conclude on the occurrence probability of certain events. A risk assessment approach will be further developed that considers variable thresholds of surface water yields, both minimum and maximum, as well as erosion and consequential sediment accumulation to better understand the impacts of the micro-WH pits on the ecosystem. This will support the decision making process for targeted Badia restoration efforts – towards a multi-criteria tool trading off shrub growth, water retention, soil conservation and biodiversity.
The research was supported by the USAID-funded Water and Livelihoods Initiative (WLI), the Arab Fund for Economic and Social Development (AFESD),the International Fund for Agricultural Development (IFAD), the OPEC Fund for International Development (OFID) and the US Forest Service. Shrub seedlings were provided by USFS/Hashemite Fund nursery, Sabha, Jordan, through the SEED project for rangeland restoration.

Author: Stefan Strohmeier, Associate Scientist, Soil and Water Conservation (ICARDA).


How does local biodiversity respond to human pressures?

Strategic herd’s mobility to improve biodiversity conservation in arid and semi-arid ecosystems. Photo credit: Slim Jerradi, Southern Tunisia

A global database helps identify how land use and related pressures have influenced the occurrence and abundance of species and the diversity of ecological assemblages.

Human activities have caused major changes in biological communities (animal populations and plants) worldwide, affecting biodiversity and ecosystem function. Understanding how land use and related pressures influence global biodiversity at a local scale can help make predictions of future changes.

Meta-analytic approach

Bringing more than 500 scientists worldwide, the PREDICTS project (Projecting Responses of Ecological Diversity in Changing Terrestrial Systems) uses a meta-analytic approach to investigate how local biodiversity typically responds to pressures like land-use change, pollution, invasive species and infrastructure. Since 2012, this global database has collated data on local biodiversity at different levels of human pressure from published studies.

The result is a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. This evidence base has been used to develop global and regional statistical models of how local biodiversity responds to these measures.

The freely available 2017 release of the database contains more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. They represent all of the world’s 14 terrestrial biomes, in approximate proportion to their contribution to global total primary productivity.

Understanding the global status of biodiversity

Although the database focuses on land use, it also includes data from regions that have so far seen relatively little land-use change, such as some high biodiversity wilderness areas like Amazonia, Congo forests, and North American deserts to gain a better picture of biodiversity hotspots.  

The data has been enhanced by scoring site characteristics relating to human pressures, such as the predominant land use and how intensively the land is used.

In a recently published paper, the project team outlines how the database can help in answering a range of questions in ecology and conservation biology. The PREDICTS database will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Author: Mounir Louhaichi (ICARDA)

Increasing yields from improved chickpea and mung bean varieties in Afghanistan

Although legumes are essential to meet the nutritional needs of Afghanistan’s growing population, the productivity of these vital crops remain low under farmer conditions. In response, ICARDA and its national partners are introducing improved varieties of chickpea (Cicer arietinum) and mung bean (Vigna radiata), and promoting optimal agronomic practices through demonstration trials in three provinces. The study uses a Bayesian approach (BA) for analyzing future on-farm trials.

Background

To reverse the low productivity of locally grown legumes, and enhance the adoption of improved varieties, ICARDA and Afghanistan’s Ministry of Agriculture, Irrigation and Livestock initiated demonstration trials in 2009 with improved varieties of chickpea and mung bean.

Statistical analysis of data from the on-farm trials is normally based on the estimation and comparison of means using two-sample t-test, paired t-test or analysis of variance. However, an approach based on stochastic dominance of the improved varieties appears more appropriate in the context of on-farm trials when the farmer has to make a decision on preference of a crop production package/technology.

In the given project, BA appeared appropriate to weigh in the information from past trials. Given that past data from on-farm trials was gathered in a broadly similar biophysical environment, the objective of this study was to present a BA for analysis of on-farm trials data and apply the method and computing codes for an analysis of chickpea and mung bean trials in Afghanistan in 2012, with prior information extracted from 2009 to 2011 data. Mean productivity of the improved varieties has been estimated, as well as the probability that the variety under evaluation exceeds the set target level.

The study

The study used datasets generated under ICARDA-Afghanistan project from farmer participatory demonstration trials in eight districts of Baghlan, Mazar and Uruzgan provinces during 2009-2012. Farmers’ participatory demonstrations were laid out in order to popularize improved varieties of chickpea (Sehat and Madad) and mung bean (Mai-2008 and Mash 2008) along with their associated best practices.

Each demonstration was laid out in an area of 1,000 sq. m. Besides, best agronomic practices such as use of seed rate (100 and 50 kg per ha for chickpea and mungbean, respectively), optimum fertilizer (50 kg urea and 100 kg diammonium phosphate (DAP) for chickpea and 50 kg urea and 120 kg DAP for mungbean per ha) and applying weed control methods were included in the demonstrations.

The yields obtained in the demonstrations were compared with the yields obtained by farmers growing local varieties with local agronomic practices. The datasets for 2012 were evaluated to compare the packages for productivity and risk, while the data from 2009 to 2011 were used for prior information on the variance parameters in the Bayesian analysis.

Author: Murari Singh, Senior Biometrician (ICARDA)

dryWIRE is published quarterly by the Communications, Documentation and Information Services of ICARDA.

icarda

The International Center for Agricultural Research in the Dry Areas (ICARDA) works with countries in the world's dry and marginal areas to help increase productivity, raise smallholder incomes, improve nutrition and strengthen national food security.