Agriscience Unit 18: Plant Growth

681030

Soil or growing media pH

• Proper soil or growing media pH will have the most impact on the availability of nutrients in the soil

pH

• pH stands for the potential hydrogen ions in the soil

• Is a characteristic of water and it affects the growth of plants

• Affects the availability of nutrients in the soil

• Is the measure of the acidity or alkalinity of the soil

pH range

• 5.0 – 7.5 is ideal pH range suited for most plants

Lime

• Is used to raise the pH in soils

• Is usually applied as finely ground dolomite limestone that supplies both calcium and magnesium for plant growth

Sulfur

• Is used to lower the pH in soils

High alkalinity

• A soil or growing media with a high alkalinity level is made more acidic by lowering the pH value with sulfur or aluminum sulfate

High acidic levels

• A soil or growing media with high a acidic level is can be made more alkaline by adding lime to raise the pH value

Types of Growing Media

• Soil (sand, silt and clay) (inorganic)• Perlite (inorganic• Water (inorganic)• Sphagnum moss (organic)• Peat moss (organic)• Vermiculite (inorganic)• Tree Bark (organic)

Perlite

• Is a volcanic glass material used for starting new plants and is used in media mixes

Sphagnum moss

• Is a growing media used for encouraging root growth on plants under certain conditions

Vermiculite

• Is a mineral mica-type material used for starting new plants from seeds or cuttings and is used in growing media mixes

Soil

• Is the top layer of the earth’s surface and is the primary medium for cultivated plants

Temperature

• 60 – 80 degrees Fahrenheit is best temperature range for plant growth of warm season vegetables (tomatoes, carrots, peas, cucumbers, squash, peppers, butter beans, okra, water melons, sweet corn, or eggplant) and annual flowering plants

Compost

• Is partially decayed organic matter composed of leaves, manure, or household waste

Hydroponics

• Means growing plants in water (cucumbers, lettuce and tomatoes)

• Plants grown in a hydroponics system will need mechanical support mechanisms

Amendment

• Is anything added to make a soil better such as organic matter, nutrients, and pH modifiers (lime or sulfur)

Ions

• Most plant nutrients are absorbed in solutions called ions

Plant Nutrition

• The availability and type of basic chemical elements in the plant

Fertilizer in the soil

• When fertilizer is added to soil, it causes more nutrients to be available to the plant and high concentration of nutrients moves to areas of low concentrations in the plant

Fertilizers

• Come in various forms, but most nutrients within a fertilizer must become liquid forms (soluble) in order for plants to use them

Organic fertilizers

• Organic fertilizers are usually slow acting and long lasting forms of nitrogen but lacking in the other primary nutrients (except bone meal).

• Include animal manures and compost make with plant or animal by-products

Examples of organic fertilizers

• Dried and pulverized manures which are slow acting and long lasting

• Bone meal (phosphorus's is the primary element)

• Soybean meal

• Cotton seed meal

Complete fertilizer

• Is a fertilizer that contains the 3 primary nutrients (nitrogen, phosphorus, and potassium

Primary Nutrients

• Nitrogen (N)

• Phosphorus (P)

• Potassium (K)

• Plants need large amounts of these nutrients to grow and be productive

Macronutrients (N-P-K)

• Are nutrients needed in large amounts by the plant

Inorganic fertilizers

• Have a higher analysis of soluble nutrients which have been blended together for a specific purpose in growing plants

Side-dressing

• Is a fertilizer application that involves placing fertilizer in bands about 8 inches from the growing plants planted in rows by growers

Broadcasting

• Is a fertilizer application that involves spreading evenly fertilizer over the entire area and is used on turf and home lawns

Foliar application

• Is a fertilizer application that involves the spraying of a water soluble fertilizer (micronutrients) directly onto the leaves of the plants

80 lb. Of 5-10-10

• How many lbs of nitrogen, phosphorus, and potassium are in a 80 lb bag of fertilizer?

• nitrogen _______

• phosphorus _______

• Potassium _________

• Formula: 80 x .05 = 4.00 (N)

• 80 x .10 = 8.00 (P)

• 80 x .10 = 8.00 (K)

Chlorosis

• Is the yellowing of the leaves of a plant caused by lack of nitrogen

Plant Growth