A case story of using moisture-meter to test effectiveness of mulching technology in Irrigation-Constrained Areas
Soil moisture in Northern Bangladesh’s char lands is affected by seasonal flooding, sandy soil types, and climate variability. These conditions make moisture-retaining practices and efficient irrigation essential for improving crop productivity.
Farmers in the region face a range of irrigation-related challenges that stem not only from soil moisture variability and climate fluctuations, but also from socio-economic factors that differ across localities. Key constraints include ownership and access to irrigation pumps, land tenure and size, spatial arrangement of plots, prevailing farming practices in neighboring areas, and—most critically—farmers’ perceptions of irrigation needs. These interconnected factors collectively influence agricultural decision-making and limit farming efficiency in northern Bangladesh.
In such context in Hatibandha Upazila of Lalmonirhat District, 49 farmers adopted water-saving technologies for brinjal cultivation through the Rupantar project. These included mulching (straw or polyethylene), raised beds, and eco-friendly pest control methods. Around 10% of these farmers use poly-mulch where the rest follows different combination of the rest of the technologies. Straw mulching gained more traction in first two years due to its availability and zero cost. Traditionally, irrigation decisions were based on visual assessment, often leading to over-irrigation and disease. To improve precision and demonstrate mulching benefits to fellow farmers in the region, one farmer used a soil moisture sensor (Chameleon).
Photo: Soil moisture data collection in a mulched field to support irrigation advice.
From traditional practice to improved practice
Jagadish Chandra Roy, a 50-year-old farmer from northern Bangladesh, has been engaged in agriculture since childhood. His curiosity and openness to learning have transformed him from a conventional farmer into an innovative practitioner. Through active participation in training programs offered by the Department of Agricultural Extension and various agricultural development projects, Jagadish has adopted a range of improved practices—shifting from mono-cropping to crop rotation, intercropping, multi-cropping, and mixed cropping. He now uses organic fertilizers and biopesticides, applies chemical inputs more judiciously, follows crop-specific fertilizer recommendations, and regularly consults experts to address farming challenges. After taking part in the Rupantar intervention he said, “Brinjal involves a lot of work. Now, if we grow brinjal using ploy mulching or straw mulching, we need less fertilizer and see fewer weeds, which means fewer workers are needed to control the weeds. Because mulching technique preserves soil moisture, it can also reduce the frequency of irrigations.”
However, when it comes to irrigation, his decisions still rely on traditional methods—primarily visual assessment of topsoil moisture and intuitive guesswork—highlighting a gap between innovation in crop management and irrigation practices.
Though being a part of Rupantar intervention few of the farmers are using mulching technology but the calibration of irrigation still is guesswork. How much water is required and how irrigation reduced, the clear-cut scenario is absent. When proposed, farmer Jagadish Chandra Roy agreed on using the soil moisture meter (Chameleon) in his farm in real-world environment. In an 8-decimal plot divided equally into control (no mulch) and treatment (poly-mulch) sections, farmer selected chili for the experiment. All other variables—bed structure, plant spacing, chili variety, sowing time, irrigation method, and fertilization—were kept constant. Irrigation frequency was determined by weekly sensor readings and farmer observations during dry periods. Initially, irrigation recommendations were made during bi-monthly field visits. Later, more frequent weekly data was captured. The plant growth parameters (leaf count, branching, flowering, fruit count, length, weight, and yield) recorded with project guidance.
Results
The treatment plot (poly-mulched) showed clear advantages over the control in terms of plant health, branching, leaf volume, and early yield. However, heavy rainfall during fruiting caused approximately 40% yield loss in both plots. Additionally, high temperatures in April led to disease outbreaks in the treatment plot. Initial reliance on instinct-based irrigation also hindered proper calibration of the moisture sensors.
Despite these challenges, the farmer observed a significant reduction in irrigation frequency. Previously, chili plants required 4–5 irrigations in the first month; with sensor-guided irrigation, this dropped to two in the control and just one in the mulched plot. The farmer noted, “If mulched, the irrigation also comes down to half the required amount.”
The visual differences between mulched and non-mulched plots boosted the farmer’s confidence. During a demonstration visit, neighboring farmers expressed interest in adopting mulching after witnessing the results. This test also highlighted the importance of timing: mulching during the Rabi season and using straw during Kharif yielded better outcomes. However, unpredictable monsoon patterns, such as the early and intense rains during the experimentation, remain a major challenge for smallholder farmers.
Photo: Farmers visit the experimental field to observe the visible differences between mulched and non-mulched chili plots.
Conclusion
The experimentation highlighted the promise of poly-mulching and moisture monitoring in enhancing water efficiency and crop performance in irrigation-constrained areas. There is clear potential to support farmers through cost-effective moisture management tools—either alongside mulching or independently. Despite ongoing climate uncertainties, the experience reinforces the importance of sustainable, data-informed farming. Scaling such innovations is vital to strengthen resilience among smallholder farmers in vulnerable regions.
Authors
Anupama Islam Nisho, CIMMYT
Pallab Goswami, RDRS
Acknowledgement:
We acknowledge the support of the Australian Awards Fellowship (Department of Foreign Affairs and Trade, Australia) and our host organization, International Agriculture for Development (IFAD). Special thanks to the farmer, the farming community, and our fellowship colleagues Md. Mamunur Rashid and Md. Ajazul Haque.