soil nutrients exam review

pH

potential hydrogen

pH of 1

H+ and acidic

pH of 7

neutral

pH of 14

OH- and alkaline

pH in soil

• affect availability of nutrients and the activity of micro-organisms

• pH too acidic: phosphorus is less available

• pH too alkaline: other nutrients like iron and magnesium are less available

micro-organisms in soil

• bacteria, fungi, and nematodes (micro worms)

• helps with the nitrogen cycle

• helps create space for air and water

• decomposers break down dead organisms and return to the soil

nitrogen cycle

atmosphere - bacteria - food chain - bacteria - atmosphere

nitrogen in soil

• important for growth, found in proteins

• major component of chlorophyll

• nitrogen deficient soil produces yellow leaves and stunts growth

phosphorus in soil

• important for root development, flowering, and fruiting

• phosphorus-deficient soil causes poor root growth and delays maturity

potassium in soil

• helps plants resist diseases

• regulates water use

• potassium deficient soil plant’s leaves turn brown on the edges and have weak stems