Soils & Soilless Mixes, pH BDHS Hort

Three Types of Soil - Review Sandy ◦Silt and clay make up less than 20% Clay ◦At least 30% clay Loamy ◦Best soil is equal parts of sand, silt, and clay

Soil Improvement Drainage and aeration—add organic matter – Add lime and gypsum (calcium sulfate) – Raise plant beds (continued)

Soil Improvement Moisture retention—add organic matter ◦ Animal manures ◦ Mulches ◦ Peat moss, sawdust ◦ Fertilizers

Soil Deficiencies Nutritional Deficiencies – Nitrogen—yellow or pale green leaves – Phosphorous—purple color underside of the leaves – Potassium- rare; crispy brown edges to leaves Pests and Diseases – Examples—nematodes, insects, or root rot Soil Pasteurization – Soil is heated to 180°F for 30 minutes

Content of Soilless Mixes Perlite – from ? Sphagnum moss - from ? Peat moss – from ? Vermiculite – from ? Limestone Tree bark – in mixes for container growing (continued)

Content of Soilless Mixes Slow-release fertilizers ◦Most mixes contain two or more of the above ◦Soil is designed for specific plant requirements ◦We use OSMOCOTE which releases fertilizer over 6-9 months.

Plant Food and Fertilizers Water—is the most important element Nitrogen: – is absorbed by plants in the form of ammonium and nitrate – has the most noticeable effects on plants – Necessary for green growth of leaves (continued)

Plant Food and Fertilizers Phosphorous—encourages plant cell division, increases resistance to disease and encourages strong root growth Potassium—is essential for tuber development (potatoes and peanuts)

Soil Acidity (pH) To lower pH in alkali soils – Add sulfur, iron sulfate, or aluminum sulfate – In areas where water evaporation from the soils is more than the amount of rainfall Buildup of salts of calcium and sodium increase the pH level Irrigation with low-salt-content water can wash the alkali- producing elements out of some of these soils (continued)

The pH number comes from the exponent of the number of H+ ions. 10 X vs. 10 X vs Which is bigger? This is why the number is lower when you have more.

SOIL ACIDITY CONT. B. LOWER THE pH THE MORE ACID THE SOIL. C. LIME IS USED TO RAISE THE pH D. SULFUR CAN BE USED TO LOWER pH COMMON AG. LIME Is normally used to raise the pH.

SOIL ACIDITY pH SCALE 1 TO 14 7 IS A NEUTRAL SOIL > 7 is an alkaline (basic) soil <7 is an acidic soil

SOIL ACIDITY CONT. DIFFERENT CROPS NEED DIFFERENT pH LEVELS TO GROW WELL.

Soil Acidity (pH) ◦Lime:  Lowers the pH levels ◦ Lowering the amount of H+ ions, raises the number  activates soil organisms  encourages the release of food

Soil Alkalinity More common in soils West of the Mississippi where there is less rainfall and OH + salts build up in soil. To increase acidity, add sulfur To raise the pH measurement, you are lowering the number.

Plant Hardiness Zones 12 zones—based on the average number of days the daily high temperature reaches or exceeds 86°F Use zones as a guide of plant adaptability Factors used to determine plant choice include rainfall, wind, sun, humidity, snow cover

Wrap up For successful plant growth: ◦It is extremely important to consider the plant environment both underground and aboveground Soil conditions and soilless mixes must match plant needs (continued)

Wrap up Plant medium must be evaluated in terms of soil, pH, drainage, and fertility Soilless mixes specially formulated for most plants grown in containers are now available ◦There is little, if any, need to mix your own anymore (continued)

Wrap up Important aboveground factors ◦Temperature, sun, and wind exposure Select only plants adapted to the environment they will be placed in