1. Environmental Requirements

2. Soil
composed of sand, silt, and clay, organic matter, living organisms, and pore spaces

3. Soil
classified according to percentage of sand, silt, and clay they contain.

4. Soil Particles vary greatly in size sand is the largest silt - medium
clay - smallest

5. Clay
particles hold moisture and plant food elements more effectively than larger particles.

6. Soil Profile
consists of 3 basic layers
topsoil
subsoil
soil bedrock

7. Topsoil
represents depth normally plowed

8. Subsoil
deep rooting plants send roots down into subsoil

9. Sandy Soil silt and clay make up less than 20% by weight drain well
little water holding capacity

10. Clayey Soil must contain at least 30% clay
holds more moisture than is good for plants
poor drainage

11. Loamy Soil
most desirable soil
equal parts sand, silt and clay

12. Soil Improvement Drainage change soil structure
add organic matter to encourage earth worms

13. Worms
their tunnels and castings result in better soil structure - aggregation - clinging together

14. Drainage
drainage tiles
raise planting beds
ditching between beds

15. Moisture retention adding organic matter (o.m.) sources of o.m.
animal manure
green manure - crop grown and plowed under to improve the soil

16. Sources of O.M.
peat moss
sawdust
mulches - compost or wood chips

17. Mulches placed on the surface to help retain moisture
reduce runoff and evaporation
reduce weeds

18. Moisture retention
irrigation

19. Fertilizing
fertilize according to soil test results

20. Diseases plant resistant varieties chemicals soil pasteurization
heat to 180 degrees F for 30 minutes.

21. Nutritional deficiencies
show on leaves of plants
Nitrogen - pale green leaves
Phosphorus - purple color on underside of leaves

22. Planting Media Mixes Soil less mixes
advantages include : uniformity - doesn’t vary in pH, fertility or texture

23. advantages sterile lightweight good moisture retention and drainage
free of weed seeds

24. disadvantages light weight - pots tip in strong wind
minor elements are missing
transplants may not adjust well to new media

25. Content of mixes
perlite
improve aeration
volcanic origin

26. Vermiculite
exploded Mica
improves aeration

27. Plant food and fertilizers
divided into two groups
Major elements (macro)
Nitrogen - N
Phosphorus - P
Potassium - K

28. minor elements (micro)
Calcium - Ca
Magnesium - mg
Sulfur - S
Iron - Fe

29. minor elements (micro)
Manganese - Mn
Boron - B
Copper - Cu
Zinc - Zn

30. Plant requirements large amounts of major elements
relatively small amounts of minor elements

31. Commercial fertilizers
shows % or pounds per cwt. (100#) of the three major elements in large numbers on the container or bag.

32. Commercial fertilizers
5-10-5
5% N, 10% P, 5% K
remaining 80% is filler
NP&K are always listed in that order.

33. Soil tests
determine amount of elements needed for various plants.

34. Nitrogen generally purchased in one of four forms Nitrate of soda
ammonium nitrate

35. Nitrogen
ammonium sulfate
urea formaldehyde

36. Nitrogen has most noticeable effect on plants
encourages above ground vegetative growth
regulates use of other elements

37. Too much N lower disease resistance
weaken stem because of long soft growth
lower fruit quality

38. Too much N
delay maturity
increase winter damage to plants

39. Not enough N
yellow or light green color
stunted root and top growth

40. N lost easily from soil
leaching - being filtered down through soil with water
not held by soil particles, dissolved in water
O.M. holds insoluble N for slow release

41. Don’t use excess N
quickly lost through leaching
can damage plants

42. Phosphorous
held tightly by soil particles
not easily leached

43. Phosphorous
effects plants in several ways
encourage cell division

44. Phosphorous flowers and seeds don’t form without it
hastens maturity, offsetting quick growth caused by N.

45. Phosphorous encourage root growth makes K more available
increase disease resistance
improves quality of grain, root and fruit crops

46. Phosphorous container plants can be damaged by excess P
increases soluble salt content of medium
causes dehydration of roots

47. Phosphorous Insufficient P purple color on underside of leaf
reduced flower fruit and seed production

48. Insufficient P susceptibility to cold injury
susceptibility to plant diseases
poor quality fruit and seeds

49. Potassium modifies both fast soft growth of N and early maturity of P
is essential

50. Potassium increase disease resistance encourages healthy root systems
essential for starch formation

51. Potassium
development of chlorophyll
efficient use of CO2

52. Insufficient K
leaves appear dry and scorched with irregular yellow areas on the surface

53. Lime CaCO3- Calcium Carbonate acts as a plant food
affects soil acidity
soil acidity affects availability of plant food elements

54. Lime
furnishes Calcium

55. pH measure of acidity or alkalinity pH scale - runs from 0 - 14
most plants grow best from

56. pH 7.0 is neutral pH of 7 or above is alkaline or basic
pH below 7 is acidic

57. pH as numbers decrease, solution becomes more acidic.
As numbers increase, solution becomes more basic or alkaline

58. pH if soil is too acidic, lime is added to raise the pH
if soil is too alkaline, sulfur is added

59. Above ground environment
temperature
some plants prefer cool weather
some plants prefer warm weather

60. Temperature
there are temperatures above and below which plants stop growth
generally, plant growth rate increases as temps increase up to about 90 degrees

61. Light must be present before plants can manufacture food
plants vary in light requirement
effects flowering

62. Photoperiodism
response to different periods of day and night in terms of growth and maturity

63. Photoperiodism short day plants chrysanthemum and Christmas Cactus
bloom when days are short and nights are long

64. Photoperiodism long day plants lettuce and radishes
bloom when days are long and nights are short

65. Photoperiodism day length indifferent
do not depend on length of light or darkness
African Violet and tomato

66. Phototropism
plants appear to grow towards the sun or light source

67. Humidity moisture level of the air most plants grow best in 40- 80% RH
Relative Humidity

68. Humidity
too high humidity may cause the spread of fungus diseases

69. Plant diseases and Insects
reduce production
lower fruit and vegetable quality

70. Gases and Air Particles
CO2 is vital to plants for Ps
Air pollutants can cause damage

71. Air Pollutants Sulfur Dioxide - SO2 - from burning coal
Carbon Monoxide - CO - exhaust from cars

72. Carbon Monoxide
reduces plant growth
can kill plants