Water is essential in the soil as:

• It allows organisms to live in the soil and break down organic matter to release nutrients for the plant.
• Maintains structure (e.g. prevents erosion)
• The plant absorbs most of its nutrients from the soil in water and relies on this water for the transport of nutrients and sugars within its body
• It keeps plant cells turgid ('bloated') to provide support

Vines need at least 500 mm of available water during the growing season.

Aeration is essential in the soil as:

• Provides oxygen to aerobic organisms and suppresses the growth of harmful anaerobic organisms.
• Removes carbon dioxide and other waste gasses formed by the breakdown of organic matter and by plant roots
• Provides the roots with essential oxygen thus sustaining their respiration & growth.
• Prevent the reduction of iron and manganese to their reduced forms that, particularly in acid conditions, are toxic to plants.

This movement of air can be severely restricted in poorly structured clay soils and in heavily compacted soils.