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The Profitability of Fertilizer in Mali
Initial registration date
October 20, 2016
October 20, 2016 12:02 PM EDT
Other Primary Investigator(s)
Additional Trial Information
Intensified use of agricultural inputs, particularly fertilizer, is a possible route to improved agricultural productivity. Field trials of these technologies show substantial increases in yields, but are typically done on highly monitored experimental plots rather than by farmers themselves. We conducted a field experiment in southern Mali and randomly provided free fertilizer to female rice farmers to measure how farmers chose to use the fertilizer, what changes they made to their agricultural practices, and the profitability of these changes. We find that farmers who received fertilizer were more likely to use fertilizer, increased the quantity of fertilizer used on their plots, used more complementary inputs such as labor and herbicides and had increased yields. We however find no evidence of increase in agricultural profits.
A simple field experiment was conducted with female farmers from 23 villages in Bougouni, southern Mali. We first conducted a census in the selected villages, randomly sampled one woman per household, and conducted a baseline survey. A sample of 383 rice farmers were then randomly assigned to the following two treatment groups and a control group:
i) Full grant: Farmers received the total recommended quantity per hectare (on average 308.20 kg/ha) ii) Half grant: Farmers received half of the recommended quantity per hectare (on average 156.20 kg/ha)
iii) Comparison group: Farmers in the control group received no fertilizer.
The two groups that received fertilizer were given a 30-minute explanation of fertilizer use, with no further training or monitoring.
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
- Use of fertilizer
- Fertilizer quantity used (kg)
- Family labor (days)
- Fertilizer expenses - Herbicides - Expenses on hired labor - Total expenses (excl. fertilizer)
- Total inputs (incl. value of fertilizer used)
- Value output
- Profits (subtracting value of family labor)
- Profits (subtracting fertilizer costs only)
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
A simple field experiment which provided free fertilizer to female rice farmers in southern Mali was conducted to measure how farmers chose to use the fertilizer, what changes they made to their agricultural practices, and the profitability of this set of changes. First, a census of female farmers in 23 selected villages was conducted, in which one woman per household was randomly sampled, and a baseline survey was conducted. Detailed information was collected on agricultural activities, other economic activities, assets, consumption, expenditures, etc. A total of 383 women who had cultivated rice in the agricultural season prior to the survey constituted our sample frame for the experiment. The experiment had two treatment groups: those who received the full recommended quantity of fertilizer per hectare, and those who received half of the recommended quantity per hectare. Farmers in the control group received no fertilizer. Teams were sent to the villages to distribute the fertilizer to women in the treatment groups. A short, 30-minute explanation on how to use the fertilizer was provided - no other training or monitoring was provided. A few months after the fertilizer distribution, a follow-up survey was conducted that focused on input use. A second follow-up survey was conducted immediately after the harvest to measure output.
Experimental Design Details
Randomization was done using a re-randomization routine that stratified by village and guaranteed that for all of the following variables (whether or not there was an extended household, use of fertilizer, use of plow, and an agricultural asset index), the p-values for the comparisons of means between any of the three groups were larger than 0.5
Individual women rice farmers
Was the treatment clustered?
Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
135 women received the total recommended quantity of fertilizer per hectare
123 women received half of the recommended quantity per hectare
125 women received no fertilizer (control)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
INSTITUTIONAL REVIEW BOARDS (IRBs)
Northwestern University IRB
IRB Approval Date
Details not available
IRB Approval Number
Details not available
Post Trial Information
Is the intervention completed?
Intervention Completion Date
December 31, 2010, 12:00 AM +00:00
Is data collection complete?
Data Collection Completion Date
December 31, 2010, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
133 women received the total recommended quantity of fertilizer per hectare
121 women received half of the recommended quantity per hectare
124 women received no fertilizer (control)
Reports, Papers & Other Materials
Intensified use of agricultural inputs, particularly fertilizer, is a possible route to improved agricultural productivity. Field trials of these technologies show substantial increases in yields, but typically are done on highly monitored experimental plots rather than by farmers themselves. Returns to a certain technology might be quite different on real-world farms than on experimental farms. We use a simple field experiment to provide free fertilizer to women rice farmers in southern Mali to measure how farmers chose to use the fertilizer, what changes they make to their agricultural practices, and the profitability of this set of changes.
Beaman, Lori, Dean Karlan, Bram Thuysbaert, and Christopher Udry. 2013. "Profitability of Ferlizer: Experimental Evidence from Female Rice Farmers in Mali." American Economic Review: Papers and Proceedings 103(3): 381-386.
REPORTS & OTHER MATERIALS