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Environmental Requirements. Soil n composed of sand, silt, and clay, organic matter, living organisms, and pore spaces.

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Presentation on theme: "Environmental Requirements. Soil n composed of sand, silt, and clay, organic matter, living organisms, and pore spaces."— Presentation transcript:

1 Environmental Requirements

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

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

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

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

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

7 Topsoil n represents depth normally plowed

8 Subsoil n deep rooting plants send roots down into subsoil

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

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

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

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

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

14 Drainage n drainage tiles n raise planting beds n ditching between beds

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

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

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

18 Moisture retention n irrigation

19 Fertilizing n fertilize according to soil test results

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

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

22 Planting Media Mixes n Soil less mixes n advantages include : uniformity - doesnt vary in pH, fertility or texture

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

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

25 Content of mixes n perlite n improve aeration n volcanic origin

26 Vermiculite n exploded Mica n improves aeration

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

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

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

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

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

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

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

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

35 Nitrogen n ammonium sulfate n urea formaldehyde

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

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

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

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

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

41 Dont use excess N n quickly lost through leaching n can damage plants

42 Phosphorous n held tightly by soil particles n not easily leached

43 Phosphorous n effects plants in several ways n encourage cell division

44 Phosphorous n flowers and seeds dont form without it n hastens maturity, offsetting quick growth caused by N.

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

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

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

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

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

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

51 Potassium n development of chlorophyll n efficient use of CO2

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

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

54 Lime n furnishes Calcium

55 pH n measure of acidity or alkalinity n pH scale - runs from 0 - 14 n most plants grow best from 5.6-7.0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

72 Carbon Monoxide n reduces plant growth n can kill plants

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