Membranes offer hope to farmers in arid area

The presence of sandy soils in lowland parts of Makueni negatively affects the quantity of food produced and types of crops that can be grown. Sandy soils have poor water holding capacity, low organic matter and do not retain nutrients in the root-zone when fertilised.

But there is hope. Researchers from Jomo Kenyatta University of Agriculture and Technology (Jkuat), Jkuat Enterprises Ltd (Jkuates), Alliance Bioversity-CIAT, Swedish University of Agricultural Sciences (SLU), and SWRT Solutions LLC installed soil water retention membranes on 18 demonstration farms in Mtito-Andei and Masongaleni wards in Kibwezi sub-county, Makueni county. Funded by the Nordic Development Fund, the project aims to increase farm system resilience, crop production and carbon accumulation in sandy soils in the county. The Subsurface Water Retention Technology (SWRT) involves the installation of subsurface impermeable water retaining membranes which disrupts large amounts of water and nutrients lost through natural deep percolation in sandy soils explains Dr Shem Kuyah.Dr Kuyah says, SWRT represents a long-term solution to increasing income and the capacity to mitigate and adapt to climate change on highly permeable soils. “Combining SWRT membranes with irrigation diversifies production, and can permit a three-season farming cycle which allows the possibility of year-round production,” says  Kuyah, one of the researchers of the project.The project will be concluded in October 2022. The project team is working on a business case beyond the funding period, which allows the scaling up of the benefits the technology brings to farmers. In addition to seven trained local membrane installers, the team includes a sales representative.

“Considering the large area of sandy soils in Kenya, SWRT can be beneficial to farmers that eke out a living on these soils,” says Jemimah Kanini, sales representative of the business unit of SWRT.One of the beneficiaries of the technology, Gladys Musembi says the technology is a gamechanger.“Before I was introduced to the technology, my maize crops were always stunted. On my six-acre farm, my maize production was depressing to say the least. The plot with SWRT had significantly high yield. It is a marvel to see mature, non-stunted maize in the month of July in Kibwezi,” says Musembi.

Acknowledging that SWRT installation is expensive and labour-intensive especially for smallholder farmers with meager resources, Dr Kuyah says it would make economic sense if the farmers invest in high-value crops such as kales.

Ms Musembi, who has a nursery of kales in readiness to transplanting at the SWRT installed parcel of land, is confident that the growing of kales will be economically viable and will absorb the costs of the installation of the technology and water used for irrigation.

Florence Mutisya says for them to get profits from this innovation there is need to grow high-value crops such as vegetables that take a shorter period to mature.“Even though the cost of installing SWRT is high, if we join hands as small farmers’ groups we will be able to afford the installation and reap the benefits of the technology,” says Mutisya. The cost of a membrane required to cover one metre square is Sh37.97. It takes ten people six days to install membranes on a 400 metre square section of land.