A. Primary Plant Food Elements
Nitrogen Plants rapidly utilize these elements and unfertilized Phosphorus soils normally cannot provide them in quantities needed for Potassium (Potash) best plant growth.
1. Promotes rapid vegetative growth (leaf and stems) hastening recovery after mowing and imparting vigor to the turf.
2. A vital element in the formation and function of chlorophyll–the key ingredient imparting dark green color.
3. Synthesizes amino acids which in turn form protein.
4. Regulates the uptake of other nutrients.
5. Basic ingredient of vital compounds – Nucleic acid and enzymes.
1. Stimulates early root formation and growth–gets plants off to a good start and forms a root filter system in the soil to efficiently pick up the other available plant nutrients and water. Improves the strength and stamina of the plant.
2. Hastens maturity (conversion of starch to sugar).
3. Stimulates blooming and seed development.
4. Causes energy transformation and conversion processes in which sugars are converted to hormones, protein and energy to grow new leaves and fruit.
5. Forms nucleic acids (DNA and RNA).
6. Vital for photosynthesis (greening for plants).
7. Essential for cell division.
1. Aids in the development of stems and leaves.
2. Increases disease resistance and hardiness which helps wear ability.
3. Strengthens cell walls, causing grass to stand up and reduces lodging.
4. Affects water intake by plant cells–plants with inadequate potassium may wilt in the presence of ample moisture.
5. Acts as a catalyst in Iron uptake.
6. Essential to the formation and translocation of protein, starches, sugar and oil–improving the size and quality of fruit, grains and tubers.
B. Secondary Plant Food Elements
Calcium They are used in somewhat less quantities than the primary Magnesium elements, but they are just as essential for plant growth and Sulfur quality.
1. Calcium is an essential part of cell wall structure and must be present for the formation of new cells.
2. Deficiency of calcium causes weakened stemsand premature shedding of blossoms and buds.
1. Essential for photosynthesis (greening of plant).
2. Activator for many plant enzymes required in growth process.
1. A constituent of three amino acids and is therefore essential in the formation of protein.
2. Helps maintain green color in plants.
3. Improves alkaline soils.
4. Helps compacted soils–making them loose and allowing better water penetration. Sulfur Note–There are commonly two types of sulfur applied to plants and soils:
Sulfate Sulfur (SO4) Elemental Sulfur (S)
1. Sulfate Sulfur (SO4) is the form taken up for plant food. Many plants require as much sulfur as phosphate in their growth processes. Sulfate Sulfur (SO4) is contained in gypsum (CaSO4) and other sulfate fertilizers–Ammonium Sulfate, Ammonium Phosphate Sulfate and many turf fertilizers.
2. Gypsum (CaSO4) will help reclaim alkali soils and make them loose and friable. Alkali soils contain sodium which causes soil to disperse, puddle and seal up. The free calcium from gypsum will replace the sodium on the clay particle and allow the sodium to be leached out of the soil.
3. It also causes the small soil particles to flocculate (join together in small crumbs), leaving space between them for air and water movement.
C. Micro nutrients
• Necessary for the formation of the chlorophyll
• Iron deficiencies are most common in wet, cold or high pH soils
• Aids in the activation of a number of biochemical processes within the plant
• Zinc is an essential component of several plant enzymes. It is a part of auxins and controls the synthesis of indoleacetic acid which regulates growth compounds.
• Zinc also affects the intake and efficient use of water by plants.
• Manganese serves as an activator for enzymes in plants. Without Manganese, the plants cannot use theiron which they have absorbed. It assists the iron in chlorophyll formation which causes yellowish turf to green up.
• Important in the synthesis of certain plant growth substances
• Serves as an activator for several essential enzymes
• Needed only in small quantites; large amounts can be toxic to turfgrass plants
• Deficiencies are usually only found in highly alkaline (high pH) organic soils or heavily leeched soils
• Although essential for proper plant function, only small quantities are required
• May help in the regulation of osmotic pressure within the plant cell
• Deficiency is rarely observed
Chlorophyll in the plant cell (causes turf to maintain a healthy green color). It serves as a catalyst for biological processes such as respiration, symbiotic fixation of nitrogen and photosynthesis.
Applications of iron can correct iron deficiency, but it may be temporary in high pH soils, due to tie up with calcium.
This may require acidification of the soil with elemental sulfur or the use of ammonium forms of nitrogen or some other acidification agents.
As ammonium converts to nitrate in the soil, it has an acidifying effect. This acidifying effect makes iron and many other elements more available in high pH soils.