Reducing Imbalanced Fertilizer Use in Bangladesh

Mahnaz Islam
Fieldwork by:
2000 farmers
2013 - 2014
Target group:
  • Farmers
Outcome of interest:
  • Pollution
  • Technology adoption
Intervention type:
  • Extension services
  • Fertilizer and agricultural inputs
  • Information
  • Training

Both overuse and underuse of fertilizers have harmful effects on short-term yields and long-term sustainability, but farmers often do not know how much fertilizer to apply to their crop. Leaf color charts are a cheap and simple technology that indicates whether a rice plant needs more fertilizer based on its color. In an ongoing study in Bangladesh, researchers are evaluating the adoption and impact of this innovative technology on crop yields and agricultural income.

Policy issue

Overuse and underuse of chemical fertilizers can harm short term-yields and long run sustainability. Inadequate fertilizer use where land is intensively farmed can strip nutrients from the soil, contributing to soil fertility degradation and threatening the farm’s long-run sustainability. Overuse of fertilizer may result in run-off that contaminates the local environment. Recommendations for fertilizer use are often based on regional (not plot-specific) soil and climate conditions, and therefore their usefulness is limited. Innovative technologies, such as leaf color charts (LCCs), which provide farmers with plot-specific information on when to apply nitrogen fertilizers, offer a simple solution to address this gap in information. Researchers are evaluating the impact of this technology on crop yields, and farmer income.

In addition, this study looks at which factors determine technology adoption and utilization. Farmers in the developing world often fail to adopt promising technologies, such as LCCs. There are many possible explanations for low adoption, such as lack of access to credit and insurance, lack of awareness, low tolerance for the risk of an unknown technology, or insufficient cognitive ability to understand how to use it. This study focuses on the role of farmer characteristics—such as risk preferences and cognitive ability—on the adoption and utilization of LCCs.

Context of the evaluation

Bangladesh has a large agricultural sector. Agriculture forms 21 percent of the national GDP, and accounts for almost 50 percent of the labor force (about 56 million people). Rice is the dominant crop, accounting for 77 percent of agricultural land use and providing about 70 percent of calorie intake. The country’s food security and economic stability depend largely on the rice harvest.

The Centre for Development Innovation and Practices (CDIP) is a microfinance institution operating in 13 districts in Bangladesh. It has about 100,000 clients who are mostly smallholder farmers. In addition to financial services, CDIP runs primary school remedial programs at 2,325 education centers in rural areas, and has provided agricultural training sessions in partnership with government extension workers.

Details of the intervention

Researchers are working with CDIP to evaluate the adoption of leaf color charts (LCCs) and test whether the technology helps farmers apply fertilizer more effectively. From a sample of 2000 rice farmers, half were randomly assigned to receive free LCCs and training on how to use them. The remaining farmers, who did not receive free LCCs, served as the comparison group.

Rice farmers usually apply nitrogen fertilizer (urea) several times during a single season. However, if it is not applied at the right time, the fertilizer may not be properly absorbed by the crops, leading to substantial waste. The decision of how much and when to apply fertilizer is typically based on rules of thumb. In contrast, an LCC gives farmers an immediate clear signal about whether fertilizer should be applied and encourages farmers to apply urea fertilizer application to be timed with the needs of the crop, significantly improving the efficiency of fertilizer use. An LCC is a plastic strip with four panels displaying different shades of green. By comparing the leaf color on his plant with the chart, a farmer can determine whether to apply urea. Correct use of an LCC encourages farmers to check the crops frequently and apply the right quantity of fertilizer when needed. Each LCC costs less than US$1 and is expected to last for many years. Studies on demonstration plots have shown that the technology is effective, but it is less certain whether farmers will adopt and correctly use LCCs without incentives or supervision.

Researchers are collecting information on the rate of adoption, crop yields, and agricultural income. They will also conduct cognition tests to measure farmers’ patience, attention span, and reasoning ability to test whether there are cognitive constraints to adoption. They also plan to resurvey the farmers in 2014 to look at of the adoption and impact of LCCs during a second rice-growing season.

Results and policy lessons

Results forthcoming.