Manual - Participatory rapid diagnosis and action ... - FAO.org

56 Annex A. Description of toolsPlot areaSoils texture andplasticityPlant densityFarmers may be reluctant to tell the actual size of their plot. Itcan be useful, therefore, to check in a “disguised” manner.• Prepare yourself before going to the field by measuringthe average length of your steps. For this you need tocount your steps while walking 20 metres. Try to walk asconstantly as possible.• Estimate the length and width of the plot by walkinground it while counting your steps (length = number ofsteps x average step length).• The total area = length x width.• Irregular-shaped plots are more complex and requireimprovisation.• Try to roll a pipe of soils between your hands. If it breaksthen the predominant texture is sand.• Try to make a loop (360 degrees turn) of the pipe. If thisis possible, then you are dealing with clay. Otherwise it isa loamy soil.• Measure the exact length and width of a rectangular partwithin a cropped plot using a centimetre.• Count the number of plants within the rectangle andcalculate the plant density per square metre.• Compare with recommended planting distance inagronomic literature.• For crops planted in rows the distance between andwithin rows should be measured separately.Results are more accurate when a larger number ofindividual plants are included by using larger rectangles.However, a larger area also requires more counting timeand effort.Yield Method 1:• Weigh all products coming from the field.Method 2: sub-sampling• Weigh yield only in pre-selected sub-sections of the plotin a known area.It is important to consider what “yield” to measure: totalbiomass, human consumable biomass, human consumablebiomass after cleaning/treatment.