A commercial grower wants to find out if the type of irrigation and nutrient delivery system used affects the yield of butterhead lettuce plants.
She grows lettuce plants in a vertical farming facility:
After five weeks, the grower harvests the shoots from each plant, dries them to find their dry mass, and calculates the mean shoot dry mass of lettuce per system.
State the independent variable in this investigation.
Describe the steps the grower takes to make sure her results are reliable.
To make a valid comparison, the grower needs to control abiotic factors. She keeps all the growing channels in the same indoor grow room to control the ambient temperature. Name three other abiotic factors the grower should control.
Suggest two biological reasons why lettuce plants grown using aeroponic misting yield a higher dry mass of shoot compared to those grown using drip irrigation on a rockwool substrate.
