#213Leaf analysis
213⸱AConcept
- Facilitates informed decision-making
- Improves plant nutrition
- Enhances fertilizer efficiency
- Improve coffee quality
- Increases the coffee yield
Leaf analysis is a laboratory procedure that gives insight into the plant’s nutritional status. A coffee tree may appear healthy, yet hidden nutrient deficits can reduce yield and waste resources. While soil analysis shows nutrient availability, leaf tissue analysis reveals what the plant actually absorbs.
Coffee plants need certain elements in large quantities, so-called macronutrients: Nitrogen (N), Phosphorus (P), and Potassium (K) as well as Calcium (Ca), Magnesium (Mg), and Sulphur (S). Other nutrients are necessary in smaller amounts, so-called micronutrients: Chlorine (Cl), Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B), and Molybdenum (Mo). All these nutrients are taken up by the plant from the soil.
Leaf analysis results help optimize fertilizer use, manage nutrient supply, improve plant health, and increase yield – while reducing costs and potential harm to the environment.
Leaf analysis should be combined with soil analysis. Combining soil analysis, water, and leaf analysis is the gold standard in coffee cultivation: Soil testing reveals which nutrients are present, leaf testing shows what the plant is absorbing, and water analysis explains the transport, availability, and chemical quality of the nutrients. Besides soil and leaf analysis, simple visual observation of the plant growth and the appearance of the leaves can give a hint of nutrient deficiencies.
213⸱BTo be considered
Representative sampling is key. One composite sample requires leaves from 25 trees per hectare, 4 leaves from each.
Leaf analysis results are only valid if sampling procedures and laboratory protocols are correctly followed. Laboratories must be officially accredited by state or coffee authorities, or certified to quality standards like ISO 9001, and transparent about their methods. Results should include agronomic recommendations. Ideally, soil and leaf analysis should be performed by the same laboratory for consistent understanding. Laboratories should analyze leaf tissue for all macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Cl, Fe, Mn, Zn, Cu, B, Mo). Always follow the laboratory’s specific sampling procedures.
Leaf analysis can be costly. It is advisable to compare rates and availability across several laboratories. Agricultural university laboratories or those contracted by coffee cooperatives often offer competitive rates. Long waiting times may delay corrective actions. For large-scale plantations or cooperatives, investing in a mobile near-infrared spectroscopy tool can be a time- and cost-effective alternative.
Timing
Leaf analysis should be conducted in the "chumbinho" stage, before grain filling, usually in December.
The sample should be collected at least 30 days after the second fertilizer application or after a foliar spraying.
Leaves should be collected in the morning when turgid.
Results may take 2-4 weeks.
213⸱CImplementation
Materials
213⸱1Preparation
Each block should be as uniform as possible. Areas with differences in tree size, age, soil type, fertilization, or other major characteristics should be treated as separate samples.
Use the same blocks as for soil sampling to be able to relate the results.
213⸱2Procedure
In each block, sample only average - type trees.
A minimum of 25 trees per hectare and 4 leaves per tree should be sampled to have representative results.
213⸱3
Do not sample from odd/unusual, obviously sick, or exceptionally productive coffee trees.
Cleanliness is critical to prevent falsified results. Use clean and disinfected hands or clean rubber gloves, and ensure all materials (e.g., paper bags) in contact with the leaves are clean.
213⸱4
Keep leaves dry and out of the sun. Prevent decay and rot of leaves.
213⸱5
Make sure not to mix up the different composite samples, so that you can always trace back the analysis result to the block sampled.
213⸱6
213⸱7
Make sure fresh leaves are not exposed to heat and moisture during transport or shipment.
213⸱8
Compare with soil analysis of the same block, if available.
213⸱9
213⸱DEconomic benefits
Lower fertilizer costs
This tool allows for a lower demand for synthetic fertilizers and therefore saves input costs over time.
Reduction of losses
This tool can prevent losses in coffee yield and quality.
Higher coffee yield
The effects of this tool can lead to a higher coffee yield and therefore a higher income.
Better coffee quality
The effects of this tool can lead to a better coffee quality and therefore a higher income.
Informed Decision-Making
This tool helps make data-driven choices for investments, input use, and labor.
213⸱EGreen benefits
Less synthetic fertilizers needed
This tool reduces the need for syntheticfertilizers. This reduces carbon emissions and water pollution, improves soil life, and saves resources.
Efficient resource use
This tool helps reduce excessive use and environmental impact of inputs like fertilizers, water, and energy by tracking them.