Last reviewed: 14 September 2026.

Source order

Carbonnest prefers, in order: direct farm records and original photographs; Zambian government data; original research papers and datasets; documentation from FAO, CGIAR, the World Bank and comparable institutions; then clearly identified secondary reporting. A secondary summary is not cited when the primary source is available.

Farm records

A useful field record includes a date, field or plot, crop or activity, quantity, unit, price in ZMW, labour time and an explanatory note. Inputs and outputs are recorded separately. Missing values are left blank—not estimated after the fact unless the estimate and method are explicit.

Comparisons

Comparisons use a stated denominator such as ZMW per square metre, ZMW per kilogram harvested, litres per irrigation event or labour hours per plot. Capital costs, recurring costs and maintenance are separated. Results from one plot or season are treated as local observations, not universal recommendations.

Photographs

Original farm photographs are identified as Carbonnest or AgroCode Farm images. Captions should say what the image shows and avoid claiming a date or result the image cannot prove. External images must be licensed and credited.

Uncertainty and failure

Weather, pests, uneven soil, equipment faults, missing readings and changes to the planned method are recorded. A failed trial can still be useful if the failure is described. Data may be downloadable so readers can check calculations.