SPSS 1060E: Exam 4

soil sampling

• Take representative samples

  • limit each sample to 15 acres

  • 12-20 subsamples

  • established turfgrass (3”4” depth of sample)

• Mix subsamples in plastic bucket

  • not metal

  • Submit at least ½ pint

• Avoid unusual areas

  • or sample them separately

• sample randomly to consistent depth

• Best sampling time is right before next fertilization (fall is prob best time)

• Aerification cores are not good samples

chemical properties of interest

1. soil pH

2. nutrient levels

soil pH

• MOST IMPORTANT

• importance: nutrient availability

• modifies balance of cations on CE sites

• influences chemical forms

• alters microbial activity

• ph:

  • as hydrogen ions increase, pH decreases

  • as hydroxide increases, pH increases

nutrient level: macronutrients

• Primary: Nitrogen, Phosphorous, Potassium

• Secondary: Calcium, Magnesium, Sulfur 

nutrient level: micronutrients

Iron, Manganese, Copper, Zinc, Molybdenum, Boron, Chlorine 

nutrient levels

• Primary macronutrients:

  • Nitrogen: Constituent of chlorophyll, Constituent of proteins

  • Phosphorus: Energy transformations in the plant, Carbohydrate transformations, Important in establishment, Root development

  • Potassium: Regulates plant turgor, Regulates transpiration, Regulates respiration, plants utilization of carbohydrates, Cell wall thickness 

• Soil nutrient analysis: Estimate availability (P,K,Ca,Mg) by using chemical solutions to extract a portion of the total nutrients from the soil 

  • Micronutrients can be estimated as well 

• Nutrients extracted have to be related to the availability of nutrients in field trials with plants as the indicators of availability

• Sufficiency level of available nutrients concept: 

  • There are definable levels of each essential nutrient in the soil that will maximize plant performance

  • The idea is to maintain soils at or above these levels

  • Focus more on meeting turfgrass requirements and less toward building soil levels 

how to determine if liming is needed: soil test

• Do not exceed 50lbs/1000ft^2 on established turf (fine-sized material)

• <25lbs/1000ft^2 on close-cut turf

• Coordinate w/ cultivation on est. turf

• Irrigate to wash all materials off leaves

• Pelleted liming products are good options

developing a fertility program

• Soil test

• Turfgrass species

• Age of the turfgrass stand

• Clipping removal or collection

• Soil texture/organic matter content

• Environmental conditions

• Quality of turf desired/use of turf

• Irrigation

• Determine annual nitrogen needs

• Set approximate dates & rates if n appl

• Select appropriate N source

• Consider needs for P2O5, K2O, lime etc

quickly available N fertilizer materials

(high solubility, rapid, short term response, up to 4 weeks)

1. urea

2. ammonium nitrate

slowly available N materials

(water insoluble nitrogen: WIN) (1&2 slower release product 4-10 weeks)(3 very slow, Available over many weeks to months)

1. sulfur coated urea

2. resin or plastic coated urea

3. natural organic carrier (have lower amnts of N per lb of product)

   • dependent on microbial activity: consider temp, pH, soil mositure

things to consider when choosing a fertilizer

1. grade/analysis- % comp of 3 primary nutrients

2. Ratio- ration between 3 primary nutrients

3. Source of Nitrogen: WSN (water soluble N), WIN (water insoluble N)

4. Homogenous vs. blend

calculating how much fertilizer per 1000ft²

Target nutrient rate/amnt of nutrient=lb fertilizer needed per 1000ft^2

• EX: target: .75lbs, fertilizer available: 28-3-10

  • .75/.28= 2.68lbs per 1000ft²

important things for creating a lawn

• Topsoil: soil texture, organic matter content (% by weight), nutrient retention, water retention

• Soil chemical properties: soil pH, nutrient content

• Intended use: kids age/activity level, pets

• Turf grass selection (species): irrigation/no irrigation: fine fescue, tall fescue

• Integrated pest management (IPM): genetic: drought tolerance, insect resistant(FF, TF, PRG), disease resistant, diversity of species (cultivars)

5 primary cultural practices

1. mowing

2. fertilization

3. cultivation

4. pest control

5. irrigation

what to do: MOWING

• Lawn Areas:

- Height of Cut 3.5”

- Frequency 1X/week

- Frequency 2X/week during peak growth periods

- Return clippings – reduce N needs by 20-40% • Keep blades sharp!

what to do: fertility

- 3-4 lbs N/1000ft2 (New)

- 1-3 lbs N/1000ft2 (> 10 yrs old)

- Slow- release sources: 1.5-2.0 lbs N/1000ft2 (May and Aug.) •

• Soil test and apply nutrients accurately 

- Particle Size Analysis (ASTM 1632)

- Organic Matter (ASTM 1647)

- Nutrient Analysis (P, K, Ca, Mg, pH)

what to do: cultivation

• Lawn areas

- Hollow-tine cultivation: (Aug. 1-Sept.15)

• Reduce organic matter accumulation

• Reduce surface compaction

• Seed bed preparation

• Some control for white grubs (McGraw and Holdrege, 2012)

• 2 passes  

  • 2” X 2” hole spacing

  • 5/8” tines

what to do: WEEDS

• Fertilize properly

• Overseed aggressively

• Lawn areas

- Overseed (Aug./Sept)

- 60-20-10-10 

- KBG-PRG-CRF-CF

overseeding

• overseeding during traffic (more effective in maintaining cover of turf)

• using synthetic fertilizer along w/ overseeding causes the LEAST amount of weeds in the turfgrass area

turfgrass water conservation alliance

• Science-based approach

• 3rd party review of objective data from 13 test locations

• Qualifies only turfgrasses that show statistically significant water saving potential over turfgrasses of the same species

  • Perennial ryegrass, Kentucky bluegrass, Tall fescue, Creeping Red Fescue, Chewings Fescue, Hard Fescue

best species w/ weed competition

1. perennial ryegrass

2. tall fescue

3. chewings fescue & creeping red fescue

4. kentucky bluegrass

what to do: PESTS

• Disease: 

  • select diverse seed mixture (4-5 species)

  • select disease resistant cultivars (2-3 of each species)

  • irrigate carefully

  • manage organic matter accumulation

  • maintain good drainage

• insects

  • select endophytic var. PR, TF, FF

  • white grubs: chlorantraniliprole (Acelepryn, GrubX)

  • Appy EPNs at the correct time for curative approach (late July-mid sept)

  • consider preventative approach (late july-early august)

what to do: IRRIGATION

employ wilt-based irrigation strategies: if you don’t do this you can encourage shallow root patterns)