An Inexpensive and Simple Spectrophotometer for Measuring Grass Biomass in the Field

A simple spectrophotometer design, suitable for rapid grass biomass assessment over large areas, is described. Such an instrument replaces conventional time-consuming techniques of biomass measurement in studies monitoring extensive areas, and uses inexpensive components. It measures the ratio of far red to red radiation reflected from the grass canopy, this figure being closely correlated with dry green biomass.