Soil water sensors, detectors to the rescue of Mozambique farmers

Maria Sitoe is a happy farmer: this season she is expecting to harvest 3 tonnes of tomatoes grown under drip irrigation. Sitoe is president of the Rivoningo Irrigation Scheme in Gaza Province in Mozambique.

The scheme aims to transform smallholder irrigated agriculture into a productive and lucrative activity in the province, and countrywide. 

More than 3 million smallholder farmers contribute 95% of Mozambique’s agricultural production. However, the country is vulnerable to both flooding and droughts, which have been severely affecting food production. To help address such challenges, the Farmer-led Smallholder Irrigation in Mozambique (FASIMO) project of the Cultivate Africa’s Future programme – co-funded by Canada’s International Development Research Centre (IDRC) and the Australian Centre for International Agricultural Research – has introduced smallholders to Chameleon soil water sensors, and wetting front detectors.

The detectors measure soil water content and can be used to collect samples for nutrient and salinity tests. The Chameleon sensor is a digital tool that measures soil moisture levels, and displays a colour code to the user depending on how dry the soil is. This code is easily interpreted, even by illiterate farmers, and helps smallholders decide when to irrigate.

Sitoe: “The Chameleon has been helpful in enabling us to reduce our irrigation rates. We used to water our fields every day and this was costly in terms of fuel for the pumps (34,889 Mozambique metical - CAD 700/AUD 778), time, and labour to cover 4 ha over one cropping season. Now, we are only irrigating twice a week based on the readings from the Chameleon, reducing the irrigation costs to about 14,354 Mozambique metical (CAD 288/AUD 320).” Sitoe, who grows tomatoes, beans, onions and bananas under the Rivoningo Scheme is investing her increased income into her children’s education and in building her home. Her scheme has 40 members, the majority of them women, and is one of the eight sites where FASIMO is being implemented

For Rivoningo in particular, farmers have been gaining good yields even before the introduction of the water-saving tools, according to Andre Machava, an environmental specialist with the National Irrigation Institute, and co- principal investigator of FASIMO. Machava adds that farmers at Rivoningo benefit from assistance from Gaza Works, one of the NGOs operating in the Gaza Province. It has provided them with improved seeds, fertilizers, pesticides and training in  good agricultural practices.

Machava: “However, what was lacking was the knowledge on irrigation management and efficiency. They used to spend a lot of money on irrigation costs buying fuel; that is why in 2018, Rivoningo was ranked second in profits (revenue minus costs), despite having had the highest revenues (yield multiplied by price. The irrigation costs of that year were too high, and this meant they were not ranked first.”

 “Last year was a bad season because of the floods, pests, and the COVID-19 lockdown, which reduced our market. I only earned MZN 7,506 (CAD 150/AUD 167), but I am hopeful that this year, I will earn more money as I am expecting about 3 tonnes of tomatoes,” says Sitoe.

“Using the Chameleon has helped us save water and fuel costs, whilst ensuring we obtain good production from our fields,” agrees Berta Inácio Ngove, a member of another scheme in Makateco, also assisted by the FASIMO project. Esmeraldo Julio Ngovene, head of production at the Makateco Irrigation Scheme, says that, before being introduced to the water-saving technologies, they irrigated on a hunch. Since adopting the devices, he explains that they have managed to cut their irrigation costs by half – from MZN 9,470 (CAD190/AUD 211) to MZN 4,835 (CAD97/AUD 108) for the entire crop cycle.

Mercy Rurii from IDRC, which has supported deployment of the Chameleon technology, says that innovations in irrigation techniques and better water-management tools can help smallholder farmers achieve better outcomes in terms of irrigation productivity and sustainability.

“Farmers also need quality agricultural inputs, such as seed and fertiliser; and profits can only be realised if produce can reach markets. Proper operation and maintenance are essential for the sustainable and equitable functioning of irrigation systems,” says Rurii. 

Since 2020, the FASIMO project has continuously trained more than 400 smallholder farmers and 137 extension officers on improved crop management practices, including land preparation, optimum crop density, pest control and adopting water-efficient innovations. The project is currently targeting another eight irrigation schemes – five in Gaza province and three in Manica province – with the water-saving technologies.

The Mozambican Government has identified irrigation as a solution for adapting agriculture to climate change and has rolled out the National Irrigation Plan to irrigate 300,000 ha of land annually, over a 25-year period. According to Cremildo Nhalungo, director in the district services of economic activities in Guija District in Gaza Province, this development is expected to help boost food production.

“We are promoting agriculture production through irrigation development and we have supported smallholder farmers in this effort,” says Nhalungo, who further explains that, in the Guija District, there is potential to irrigate more than 12,600 ha of land. The government has secured drip irrigation kits and pumping units to support farmer-led irrigation in the area.

Machava says the deployment of the water-saving technologies has promoted efficient water use by farmers, while simultaneously saving costs and increasing crop yields. “Irrigation is definitely the way to go in ensuring food security as rainfall is becoming erratic and it also tends to be intense, meaning that even in the rainy season, you still have drought spells and crops cannot survive,” he notes.

According to Mario Chilundo, another FASIMO principal investigator and lecturer at Eduardo Mondlane University, irrigation is helping Mozambique restore its agricultural production, which was destroyed during the 15-year civil war. He explains that the trained smallholder farmers are leading the charge in boosting food security. “Over time, more farmers have engaged in irrigation, which the government has prioritised as a way to ensure food security,” he says. “The impact of climate change has reduced water flow into irrigated areas, making it ideal to embrace water-efficient technologies to help farmers produce more with less.”

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