Suggest two reasons why more food is now produced using modern intensive agricultural methods, such as vertical indoor farming, than by traditional open-field farming.

Vertical hydroponic farming (VHF) systems differ from traditional open-field farming because:

• they continuously recirculate and filter nutrient solutions indoors rather than letting water drain into the soil
• they use automated monitoring and controlled indoor environments, which significantly reduces the need for chemical pesticides

Suggest one advantage of using a recirculated closed-loop nutrient solution in indoor tanks rather than standard open-field irrigation.

Suggest the advantage of using fewer chemical pesticides in crop production.

Another advantage of vertical hydroponic farming (VHF) is the reduction in nutrient runoff.

The nutrient runoff figures for a traditional open-field farm and an indoor VHF system are shown in the table below.

Calculate the total phosphorus in the runoff from the VHF system as a percentage of the total phosphorus in the runoff from the open-field farm. Show your working.

If agricultural runoff containing high concentrations of nutrients is released into natural waterways, it can cause severe pollution.

Design an investigation to compare the pollution (such as algal growth or oxygen depletion) caused by runoff from an open-field farming system with runoff from a vertical hydroponic farming system (VHF).

Your answer should include experimental details and be written in full sentences.