By Gift Briton

In an effort to improve agricultural productivity while enhancing crop resilience to climate variability, a digital tool that helps farmers to assess soil moisture levels has been developed.

The innovation, developed with support from the International Development Research Centre (IDRC), is part of a farmer-led smallholder irrigation project in Mozambique (FASIMO).

Most smallholder farmers irrigate their crops to be able to grow during the dry season. However, they are unable to tell when their crops need to be irrigated.

According to them, when the soil surface is looking dry, they irrigate-often on a daily basis. However, such frequent irrigation leads to excessive water use and high fuel pump costs.

Therefore, through using the soil moisture sensors the farmers are now able to determine when and how much to irrigate their fields. The sensory tool detects soil moisture levels and is helping them to significantly reduce water use and irrigation costs while improving crop productivity.

“By using the system coloured lights, the amount of irrigation water has been reduced by half and we have dramatically reduced water usage by up to 50%, cut fuel costs by 40%, and significantly increased productivity with crop yield increases of 10%,” said Emilio Magaia, principal investigator of FASIMO.

Using the sensors has enabled a significant reduction in fuel costs for irrigation pumps allowing farmers more money and time to invest, with some now diversifying the crops that they grow.

The technology has also enabled some farmers to start growing beans even during the dry season, a crop which is known to only do well during wet season. This has attracted higher prices for the beans thereby enabling farmers to purchase new irrigation equipment and expand their cultivated area.

Similar to a road traffic light system, the soil moisture sensors operate on three lights that are based on soil moisture levels. The colour of the light guides farmers’ decisions to irrigate.

The device has three sensors, which are buried into the soil at different depths to monitor soil moisture. Blue indicates that the soil is wet, usually right after an irrigation or rainfall event. A green light indicates that there is sufficient moisture in the soil and no irrigation is needed. If the lights turn red, it is an alert that the soil is dry and it is time for the farmer to irrigate.

As a result, more than 300 smallholder farmers have been trained in the use of soil-moisture sensors and approximately 80 farmers have benefitted directly from the tools by having them installed in their fields.