Chickpea is an important food crop with approximately 12 million tonnes produced annually. Chickpea is grown in semi-arid environments in countries such as India, Australia, Myanmar, Pakistan, Turkey and Ethiopia. In low income countries chickpea is an important source of protein. Together with other legumes, chickpea provides food security and income for smallholder and subsistence farmers. Chickpea is quite drought tolerant. However, predicted changes to climate such as elevated temperatures and more erratic rainfall patterns make it more likely that the major chickpea cropping areas will experience drought and excess heat affecting yields.
Chickpea can thrive in quite poor soils, and as a legume can benefit from interactions with nitrogen-fixing bacteria. However, it often grows in degraded and acidic soils with a low content of organic carbon. Restoring such soils is possible by addition of charcoal (biochar), but a long-term endeavour. Biochar when prepared accordingly, can also provide missing nutrients directly to the plant.
One of the most important factors determining drought tolerance and nutrient uptake is the size, depth and spread of the root system of the plant, commonly referred to as root system architecture (see Figure 1). Root system architecture is not easy to study in the field, as one must dig up all the fragile roots of a crop. However, when doing so, it is very hard to get a meaningful understanding of the spatial organisation of the root system, and it can only be done once. Powerful instruments to analyse root growth in soil exist, such as X-ray tomography, but these are very expensive, complex, unaffordable and unavailable for breeders in low-income countries.
We therefore aim to develop and validate a simple, but powerful system to study the development of chickpea root system architecture in soil over time which can be made and used by breeders in low and middle-income countries to inform the breeding of hardier and resilient varieties.
Our multidisciplinary team based in Edinburgh, Ethiopia and USA has experience in root biology, plant physiology, phenotyping and breeding; image analysis, innovation financing and soil sustainability. With this expertise, our team aims to improve root system architecture for enhanced drought tolerance and nutrient use efficiency in semi-arid agriculture of chickpea.
The first stage of this project is to develop a growth system for chickpea plants which allows imaging and measurement of the root system architecture. This includes a container (rhizobox) to grow individual plants in soil, a support to hold several rhizoboxes and an imaging system to take photos of the root systems. This system is designed to be simple to assemble, low cost and is being co-developed and deployed in both Edinburgh and Ethiopia from locally sourced material to show its suitability for use anywhere.
After the system is developed it will be used in Ethiopia to investigate how root system architecture of chickpea could be improved to enhance drought tolerance and nutrient efficiency.
With this project we aim to:
- Develop a growing and measuring system for soil-grown chickpea roots and characterise root system architecture;
- Rhizoboxes and a support system which are simple in construction and low cost so that large numbers can be produced
- Imaging system made of affordable cameras which still gives high resolution images suitable for subsequent analysis
- Software to image and analyse the root system will be open access and designed to be used with the growing system anywhere in the world
- Machine learning to identify the root system architecture parameters with the best predictive value for achieving the goal of crop improvement.
- Once the system is operational, we will investigate how changes to soil quality, biochar, water availability, and the presence of nodulating and non-nodulating microorganisms affect root system architecture and crop performance.