Illinois Valley Community College, Oglesby, IL 61348
In order to quantitatively understand how crops interact with the environment, the statistical characteristics of a crop canopy must be measured. Currently, scientists simply guess the amount of plants that are needed to find mean values of characteristic like plant height and stem diameter. We sample the canopy height and stem diameter of 105 plants in three different sites distinguished by soil type in a corn field and a soybean field in order to determine how many plants are needed to determine mean characteristics and if this number varies within a single field. The 105 plants represent 15 plants in 7 rows. We used MATLAB to find mean values and to determine how the estimate of mean values changes when fewer than 105 plants are sampled. We found that scientists trying to capture crop canopy characteristics should measure 30 plants in a sampling area in order to collect data within the natural standard deviation of the whole field while still being close to the average field value.
[Abstract (DOCX)]