Surface capping arises when soil particles bond together, preventing water and air from entering the soil. This prevents seedling growth and root respiration. Cultivation pan is formed by iron or stones compacting the subsoil, hindering root penetration and growth. Cultivation pan can be addressed through double digging. Rotavation has benefits of single digging like tilth improvement but risks clay smearing while no-dig systems avoid soil disturbance but require organic matter and may not remedy structure issues. Proper soil moisture is maintained between field capacity and permanent wilting point to provide available water for plants.

1. RHS Level 2 Certificate Year 2 Week 3 – cultivation and soil water

7. Benefits and limitations - digging Leaves a bare surface which may lead to leaching or capping Incorporates organic matter and buries crop residues and weeds Brings dormant weed seeds to the surface where light will stimulate germination Breaks up cultivation pans and improves drainage. Can damage soil structure if the texture and wetness of the soil are not taken into account. Exposes pests to predators and the weather. Allows clay clods to be frosted. Disturbs natural structure of the soil and may harm beneficial organisms Improves the structure of the soil – allows access for water and air Limitations Benefits

8. Benefits and Limitations - Rotavation Not ideal for incorporating organic matter Has most of the benefits of single digging. Will not effectively break up hard or stone pan and may cause a cultivation pan by smearing wet clay soils. Provides a good tilth in a short period of time Can produce a very ‘fluffy’ tilth with large air pockets – will need raking and possibly firming before planting Makes larger areas more manageable Expensive to buy or hire, safety considerations. Less hard work than manual digging Limitations Benefits

9. No Dig Systems Pests may build up in the soil as the larvae are not exposed by winter digging Soil organisms are not disturbed Some risk of long term soil acidification – which reduces beneficial organisms Weed seeds are not brought to the surface Large amounts of organic matter are required Does not damage soil structure where this is already good Will not remedy soil structure problems like hard pan or poor drainage Less work than traditional digging approaches to soil management Limitations Benefits

10. How Water is lost from the soil

11. What water is available to plants?

12. Saturation Point, Field Capacity and Permanent Wilting Point