43. soil amendments and fertilizers by allah dad khan

2. Soil Amendments and
Fertilizers
 What is a soil amendment and what is a
fertilizer?
 Soil amendment – is a material that primarily adds
_________________ matter to the soil

Organic matter important for soil organisms

Does contain nutrients needed by plants
 Fertilizer – is a material that primarily adds
_________________ to the soil

Some fertilizers may contain organic matter

May not have all the nutrients that plants need

3. Soil Amendments
 The impact of soil amendments on the soil and
vegetable plants is dependent on the amount of
____________ and nitrogen in the amendment
 Carbon to nitrogen ratio
 Normal carbon-to-nitrogen (C:N) ratio in soils is
about _____:_____
 Adding organic matter alters this ratio
 Problem

Materials with too ___________ a C:N ratio will tie up
nitrogen making it unavailable for vegetable plants

Soil organism use the carbon as an energy source and
the nitrogen for ________________

4. Soil amendments
 Examples
 _______________

Is a living culture of organic matter similar to yogurt

Rule: anything that is entirely organic in origin can be
composted
 Peat ____________
 Sawdust

C:N ratio of 450:1
 Green manures

5. Soil amendments – Green manures
Introduction
 _____________ manures – are rapidly growing
plants that are incorporated into the soil before
planting the vegetables
 Advantages
 Can supply ____________ to the vegetable plant
 Some green manures are legumes
 _____________ loss of nutrients
 Makes plant nutrients available to the vegetable
crop
 Improves the ___________

6. Soil amendments
 What is a legume?

7. Soil amendments
 What is a legume?
 It is a plant that has nodules on their roots
which contain ___________________ bacteria
 The bacteria are able to convert nitrogen in
the air into a form that plants can use
 Were used as a ____________ source before
synthetic fertilizers were widely available

8. Soil amendments - Cover crops
 Cover crops – are plants that are rapidly
growing and after they die they are left on the
soil surface
 Purpose
 Protect the soil from _______________
 Tie-up nutrients
 Prevent ____________ growth
 Cover crops are most commonly fall-seeded
 Examples of plants used
 Cereal ______________
 _______________ vetch

9. Soil amendments/ Fertilizers
Animal manures
 Are intermediate between a soil amendment
and a fertilizer
 Vary greatly in their ___________ composition
 Caused by:

Animal

Feed used

Type of litter or bedding

Degree of composting or decomposition
 Must be _________________ before use

10. Animal Manures
 Problems with manures
 May contain harmful or undesirable contaminants
 _________ and other harmful bacteria may be in
fresh manure
 Manures are _________ in nutrients compared to
synthetic fertilizers
 The most common commercially available
types of manures
 ____________ manure
 Chicken (Poultry) manure

11. Animal manures

12. Table: Typical Composition of
Manures
Source _____ P2O5 K2O
Alfalfa hay _____ 0.5 2.1
Cow
manure
0.6-2.1 0.7-1.1 2.4-3.6
Composition (% Dry Matter)

13. Fertilizers
Introduction
 Plants take up the same nutrients
whichever category of fertilizer is used
 Several categories of fertilizers
 ____________ versus synthetic
 Rapid versus slow _____________
 Solid versus liquid

14. Organic Fertilizers
 Advantages
 Nutrients are released ________________

May improve the taste of the vegetable

Nutrients are less likely to leach
 May benefit the soil microorganisms
 Problems
 Are low in potassium

“Semi-organic” or “________________ based”
 Cost per unit of nutrient

15. Organic Fertilizers
 Rapid release forms of plant nutrients
 Most of the plant nutrients are available
soon after application of the fertilizer
 Most organic examples are general
compound fertilizers contain a number of
________ nutrients

16. Organic Fertilizers – Rapid release
 Animal byproducts
 Source are
processing plants or
slaughterhouses
 Include
 Dried ________
 Fish meal
 _________ meal

17. Organic Fertilizers – Rapid
release
 Bone meal
 Excellent source of
phosphorus and
_____________
 Problem

Might transmit
diseases

Mad cow

____________
 No evidence that has
occurred

18. Organic Fertilizers
 Slow release
 Are either plant byproducts or ground rock
materials
 Release nutrients over a growing season
or more
 Examples

_______________ meal

Rock __________

Greensand

19. Organic Fertilizers
 Slow release
 Plant byproducts
 _________ meal

Rich in minor
nutrients

Contains 60 to 70
different chemical
compounds

20. Organic Fertilizers
 Rock phosphate
 A finely ground natural
rock powder
 There are two kinds:

Hard rock phosphate

__________ phosphate
 Potassium
 Rock potash (greensand)
 Wood ashes

Are very ____________

21. Organic Fertilizers
 Liquid fertilizers
 Fertilizer nutrients are dissolved in __________
 Advantages

Easy to apply

The nutrients are available immediately
 Problems

Can injure plants

Easy to over apply

May ______________ or contaminate surface waters
 Organic Examples

________________ teas

Manure teas

Seaweed extract

22. Typical Composition of Some
Organic Fertilizers
Fertilizer N P2O5 K2O
Blood 13.0 2.0 1.0
Bone
meal
_____ 15.0 ----
Fish meal 10.0 6.0 ----
Greensan
d
---- ---- ____
Composition (% Dry Weight)

23. Synthetic Fertilizers
Introduction
 Many “_________________” fertilizers are
derived from natural deposits
 The nutrients are concentrated
 Converted into a form that is readily
available in the soil

24. Synthetic Fertilizers
 Advantages
 Easy to apply
 ________________
 Are readily available
 Disadvantages
 May easily be over-applied
 Can lead to ___________ build-up
 May have adverse effects on soil organisms
 Can be leached from __________ zone

25. Synthetic Fertilizers
 Nitrogen fertilizer
 Most important component of synthetic fertilizers
 Synthesized from nitrogen in the air

Offshoot of World War II ammunition production

Production is very _________________ intensive
 Forms of nitrogen fertilizer

Ammonia

_____________

Urea