FERTILIZERS AND GRASS CYCLING THREE MAIN POINTS: 1. Know why, how much, and what kind of fertilizer to apply. 2. Fast release, high nitrogen fertilizers have the potential to cause plant problems and water pollution. 3. Grass cycling is an effective lawn fertilizer, and saves money and time. 1
FERTILIZERS AND GRASS CYCLING What s Inside Your Binder? -Course Slides -Fertilizer Worksheet -Grass Cycling Facts -Selecting and Applying Fertilizer for Water Quality Protection -Fertilizer Basics - Self Assessment ---HOMEWORK!--- -Fertilizer Worksheet ---HOMEWORK!--- See the Addendum for: -Organic Fertilizer Descriptions (pages 37-40) 2
Why Do We Fertilize? Why do we fertilize? Replace nutrients that we ve removed through harvest, pruning, mowing, etc. Aid plants not naturally adapted to some soils Push plants to meet the function that we desire What is the function of landscaping? Beauty, visual satisfaction green leaves, colorful flowers Planting for function turf to play on, visual screen with hedge Consider PLANT FUNCTION before we consider FERTILIZER. 3
Your Clients Want Clean Water Less Greenwaste No Pesticides 4
Fertilizers Organic & Synthetic Reading A Bag of Fertilizer: What do the three numbers on a fertilizer bag stand for? 5
Example of Synthetic Fertilizer 6
Example of Organic Fertilizer 7
N - P - K 8
N -P -K Nitrogen - Phosphorus - Potassium Nitrogen (N) Stimulates photosynthesis, used for vegetative growth Sources: Grass clippings and green leaves Organic sources fish emulsion blood, fish, cottonseed, soybean or alfalfa meals high nitrogen bird or bat guanos Synthetic fertilizers 9
N -P -K Nitrogen - Phosphorus - Potassium Phosphorus (P) Stimulates flower, fruit and root production. Rose fertilizers have higher levels of phosphorus. Sources Synthetic fertilizers Organic sources Rock phosphates, bone meal, high P bird and bat guanos. 10
N -P -K Nitrogen Phosphorus - Potassium Potassium (K) Stimulates plant vigor and disease and pest resistance Sources Synthetic fertilizers Organic sources horse manures kelp mineral some soils 11
Nutrient Solubility 12
Soluble & Insoluble Nutrients Soluble = fast acting Insoluble = slow release How do plants get nutrients in nature? Slow Release (insoluble) fertilizers closer to natural system Fast Acting (soluble) fertilizers for emergency use Describe a situation where a plant might need a fast acting fertilizer? 13
Management Problems with High Solubility Nitrogen Fertilizers 1. Wasted resources Once soluble fertilizers get wet, available all at once. 2. Fast acting fertilizers flood roots with only a few nutrients. 3. High solubility fertilizers = pollution potential Only 30-50% fertilizers may reach plant 4. Fast acting fertilizers cause pest problems 14
Nutrient Source Advantage Disadvantage Greenwaste Organic fertilizer Synthetic fertilizer Slow release Synthetic fertilizer Fast release - Wide range of nutrients - Generated on-site: saves transport fees - No purchase costs - Compatible with existing soil micro-organism population - Wide range of nutrients - Benefits soil micro-organism populations - Low labor costs with infrequent app needs - Low labor costs with infrequent application needs - Inexpensive material costs - Immediate plant response - Low N-P-K value - May require shredding or composting, depending upon use - Slow release of nutrients - High material costs - Narrow range of nutrients - High material costs - Potentially destructive to soil micro-organism populations - Narrow range of nutrients - High labor costs w/ frequent apps. - Potentially destructive to soil micro-organism populations - Benefit only lasts a month - Potential to make plants more susceptible to pest problems 15
Ways To Prevent Problems From Fertilizers Avoid fast acting, high nitrogen fertilizers Add organic matter to soil (compost, mulch) Add organic supplements for plant strength and pest resistance Kelp Worm castings (worm manure) Compost tea (a liquid fertilizer made by soaking compost and other materials) Adequate irrigation Fertilize only as much as and when necessary 16
Grass Cycling Leave Clippings: More fertile soil More stable soil life Less compaction Healthier roots Better pest resistance Haul clippings: Must add fertilizer Starve micro-organisms Worse compaction Stressed roots More pest-prone 17
Grass Cycling Facts Nitrogen from clippings can be recycled in 2 to 3 days Average lawn = 300-400 lbs of clippings per 1,000 square feet per year 30 lbs of fertilizer with 8-4-6 analysis NO cost to buy: Save 35-75% of fertilizer costs SAVE time: 50% less time BETTER soil: Adds organic matter addition to soil SAVE your back: 300 400 lbs clippings per lawn 18
Fertilizer Field Exercise Distance of walking stride Square footage of two lawns Amount of fertilizer for each lawn 19
Selecting and Applying Fertilizers for Water Quality Protection 20
Review THREE MAIN POINTS: 1. Fertilize to meet plant FUNCTION 2. Benefits of insoluble and organic fertilizers 3. Grass cycling saves money, time, and fertilizes the lawn What do we mean by plant function? What does nitrogen do? What does phosphorus do? What does potassium do? Describe the links between fertilizers and pests: Ways to prevent problems from fertilizers: What is grass cycling? Why does it help you? 21
Homework Check fertilizer bags you use: Look for total analysis, total N, soluble N. Use the chart to determine how much of this fertilizer to use and how often. Write down this information and bring to next class. 22