This study investigates the effect of in-field soil heterogeneity on Lettuce crop variation at harvest, through identifying and examining the key edaphic factors that influence the crop growth, development and maturity.
Lettuce transplants are produced in controlled environments from genetically uniform seeds, mechanically planted at regular spacing and manually harvested in a single pass. In-field variability in development occurs leading to variation in head weights and maturity at harvest and may also extend to post-harvest quality, which causes a significant issue in field grown lettuce. This variability is mostly influenced by heterogeneity in soil properties as relative plant growth in the field is affected by edaphic factors. Scans of soil apparent electrical conductivity (ECa) has been used for identifying soil variability and reducing the cost and the intensity of direct soil sampling. This study aims to reduce lettuce in-field variation by understanding the effect of soil heterogeneity. Aided by soil EC scans and aerial imagery, the project investigates how soil edaphic factors affect the uniformity of lettuce crop growth, development, maturity and post-harvest quality. The key edaphic factors that affect lettuce yield, as identified from field studies, will be examined in glasshouse experiments to determine critical ranges at which these factors impose difference in yield to help inform precision farming decisions in leafy vegetables.
Harper Adams University