One year ago, James Nderitu, a farmer, would spend about KSh1300 as labor costs for irrigating his 5-acre farm where he grows vegetables.
Nderitu says his farm would consume about 50,000 liters of irrigation water in a single day.
“There are days during the dry season when I would fail to irrigate because of lack of money to pay farm hands and this had a negative impact on my crops,” said Nderitu.
Kiambu county, 8 miles North of Kenya’s capital Nairobi, is among the biggest suppliers of fresh food produce to the over 5 million residents of East Africa’s economic hub.
With the ever-changing and unreliable rainfall patterns occasioned by climate change, smallholder farmers in Kiambu county had to devise ways of keeping their farms green even during prolonged drought seasons.
Farmers come together in small village groups and build small, low-cost water collection and storage facilities that collect water which they then share to irrigate their farms during dry seasons.
But even with water available for irrigation, farmers still record diminishing harvests during prolonged drought seasons.
A study by Crop Nutrition Services Ltd established that the farmers were losing half of their soil nutrients through leaching because of unmonitored irrigation.
According to Emmanuel Kibet, a crop nutrition agronomist who led the research, farmers lost up to 60 percent of nutrients to the lower soil regions where crop roots may not reach.
“We found out that as much as farmers had devised ways of harvesting water for irrigation, they ended up wasting much of the water due to poor irrigation patterns,” said Kibet.
Kibet notes that unmonitored irrigation led to low productivity because excess irrigation washed away most nutrients, leaving crops stunted.
“In irrigation of 16 cubic meters per acre in one day, there was evidence of strong nutrient leaching in all sites, with nitrates and calcium being the most lost at 60cm and 90cm depth consecutivrly,” Kibet explained.
Kibet led other crop nutrition agronomists to come up with an irrigation monitoring device to cure what he describes as “blind irrigation” which he says “does not give farmers value for their money.”
The device known as the Aquacheck soil moisture probe helps farmers monitor their soil’s moisture content to help them establish the right times to irrigate and when not to.
“Aquacheck-soil moisture probe ensures efficient use of irrigation water by farmers, hence increasing productivity,” Kibet explains.
The device, which has sensors that go up to 10cm inside the soil, can measure moisture up to six depths and even beyond.
“This allows the farmer to know the moisture levels all the way down the rooting depth thus allowing them to decide when it is right time to irrigate and what amounts of water to irrigate,” Kibet explains.
For the two months Nderitu and his group have been using the Aquacheck tool, they have cut the cost of irrigation by 50%.
“Initially, five acres would cost us some KSh1300 in irrigation labour costs but since we got the tool, we only spent half of that amount,” Nderitu said.
He adds, “On some days we only irrigate once depending on the moisture content in the soil and this saves not only water but also nutrients from being wasted through excess water.”
Mary Rugene, a tomato farmer, says efficient use of water and irrigating only when the soil needs water has helped them keep their farms green and increase their harvest.
“This tool has helped us deal with the problem of water scarcity because we only irrigate when necessary,” she said.
“We are also witnessing increased harvests in our farms, and this means more income for us,” Ms. Rugene added.
Aquacheck is installed in the soil where it keeps track of the amount of available water moisture against soil particles at a two-hour intervals.
The data is sent to a computer or a smartphone and can be presented in graphs and text messages.
Training, future plans
A total of 10,000 smallholder farmers have been trained in data interpretation.
Kibet says there are plans to scale out the use of the tool across Kenya, especially in arid and semi-arid areas.
“With this technology, we can have Kenyan farms produce enough food to feed the nation through irrigation agriculture even during the dry seasons,” he concluded.
They can be reached on:
Crop Nutrition Laboratory Services, Limuru, off Limuru road, P.O. Box 66437-00800 Nairobi – Kenya
+254 711 094 444 / or firstname.lastname@example.org