Biosaline Agriculture

Key Considerations & Context

As the global population continuously increases, it is estimated that agricultural production also needs to increase by 70-100% to meet global food demand in 2050. Yet there are significant barriers to achieving this.

Soil water stress (drought) and salt stress are the two most common growth limiting factors in arid and semi-arid regions. In Europe alone, the economic impact of salinization exceeds half a billion Euros, and this is predicted to rise as sea levels continue to rise. Salinization is the increase of salt concentration in soil, which can happen from seawater flooding the land, or seeping in through soil from groundwater, and harms crops and crop yields.

Agriculture needs to become more climate-smart, drawing on soil, nutrient, and water management strategies to enhance yields while at the same time minimize exposure to and impact of biotic and abiotic stresses. Biosaline agriculture combines the ability of specific plants to grow under highly saline conditions with more sustainable use of resources, soil, and water.

Technological Solutions Involved

Halophytes are plants which are naturally tolerant to high levels of salt. They combine several strategies to survive in such harsh conditions, such as succulence, synthesis of osmolytes, compatible solutes, and increased antioxidant activity. Being able to adapt to such conditions make them indispensable in managing salt contaminated land, rehabilitating soil, performing desalination, capturing heavy metals, and producing feed for livestock.

Researchers at North Dakota State University’s Carrington Research Extension Center are experimenting with techniques to optimize crop yields in highly saline areas, including planting cash and cover crops that are salt tolerant, such as barley and rye.

Desert Control have developed and patented a Liquid Nanoclay which is sprayed directly on dry, sandy land to create an organic, water-retaining network in the soil profile. With water retention of up to 65%, higher yields can be gained with less water and lower costs.

As an alternative to reducing the effect of salinity in the soil, biofertilizers such as Seaweed Biofertilizer and nanofertilizers including Nano Silica Fertilizer may improve defense mechanisms of plants against salt stress toxicity by augmenting the transpiration rate, water use efficiency, total chlorophyll, proline, and carbonic anhydrase activity in the leaves of plants.

Key Players

• The International Center for Biosaline Agriculture (ICBA) is working with smallholder farmers, including women, in salt-affected areas of seven sub-Saharan African countries to help them better deal with the challenges of soil salinity and climate change. Under the RESADE project (Improving Agricultural Resilience to Salinity through Development and Promotion of Pro-poor Technologies), salt-affected areas are being mapped and preliminary studies are being conducted to establish best practice hubs.

• The Brazilian Agricultural Research Corporation (Embrapa) partnered with ICBA to share knowledge and resources since Embrapa has experience in tropical agriculture and the management of the saltwater-tolerant forage plants such as the saltbush and forage palm. This partnership is key for research and innovation across the Global South.

• SalFar is a European research project which investigates opportunities for innovative agriculture that can adapt to climate change and sea-level rise. It promotes climate-resilient agriculture and aims to reduce the use of freshwater through saline farming.

Opportunities & Challenges

The costs resulting from salinity intrusion range from € 577 to €610 million per year in Europe alone and are projected to increase significantly with rising sea-levels. The need to strengthen both soil salinity monitoring mechanisms and tools for adaptation is urgent, and it is a race against time.

Since halophytes are great tools to desalinize and detoxify degraded soils, this practice may allow for traditional crops to grow and develop in restored soil. Further, the specific halophytic trait of salinity tolerance could improve the gene-expression of commercial crops. By using epigenetics or gene-editing technology such as CRISPR/Cas9, future plants could become more tolerant to abiotic stresses, perform better under extreme conditions, and improve both biomass and yields.