HUMAN NUTRITION

Detailed explanation-1: -Soils can be classified according to their pH value: 6.5 to 7.5-neutral. over 7.5-alkaline. less than 6.5-acidic, and soils with pH less than 5.5 are considered strongly acidic.

Detailed explanation-2: -Any value below 7 means the H+ ion concentration is greater than at neutral pH and the solution is acidic. Soils are considered acidic below a pH of 5, and very acidic below a pH of 4. Conversely, soils are considered alkaline above a pH of 7.5 and very alkaline above a pH of 8.

Detailed explanation-3: -The relative acidity or alkalinity of soil is indicated by its pH. The pH scale runs from 0 to 14. Any pH reading below 7 is acidic and any pH above 7 is alkaline. A pH of 7 indicates a neutral soil.

Detailed explanation-4: -At a higher pH, soil builds up toxic levels of certain nutrients. For example, molybdenum, typically a plant nutrient, becomes poisonous to plants in large amounts. Molybdenum soil levels increase in a high pH environment. Introducing a plant food that results in high pH levels can be toxic to that plant.