Transcript 7.CHAPTER VII land preperation and nutrients application

CHAPTER VII
Soil and Water Management
Plant Science: Pages 195-221
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
1
• Introduction
• To a large extent, crop productivity is determined by
the way soil is managed.
• Soil management is the combination of tillage,
cropping systems, and soil treatments that either
complement or compete with each other.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
2
Land Preparation
•The purpose of land preparation are to:
1.Level the land where needed.
2.Incorporate crop residues, green manure
and cover crops.
3.Prepare and maintain a seedbed in good
tilth.
4.Help control weeds, diseases and insects.
5.Improve the physical condition of the soil.
6.Help control erosion where needed
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
3
Land Preparation
•Tilth is the physical condition of the soil in respect
to its capability to grow a specific crop.
•Tillage is defined as the mechanical manipulation
of soil to provide a favorable environment for
crop growth.
•Tillage is done any time soil conditions permit.
•Objective: seedbed should provide seeds with an
environment conductive to rapid germination
and growth (fine seed bed).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
4
Land Preparation
•Tilth. ‫حراثة‬
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
5
Land Preparation (Tillage).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
6
Land Preparation = Seedbed.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
7
Land Preparation (Plowing)
•Generally, the first step in seedbed preparation is
to plow the land.
•Plows invert the soil and cover the trash, but they
often leave the soil in large liner lumps that must
be reduced in size.
•A farmer has the choice between two types, the
moldboard or the disk plow each adapted to
certain soil characteristics.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
8
Land Preparation
•Moldboard plows are used when the soil is
sufficiently moist to allow the plow to pass through
easily.
•The ideal moisture content for plowing loam soil is
about 2 or 3 % below field capacity.
The disk plow consists of a series of large disks 6075 cm in a diameter that cut the soil by rotating as
the plow moves forward.
•The disk plow are best adapted to dry hard soils.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
9
Land Preparation (Moldboard plow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
10
Land Preparation (Moldboard plow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
11
Land Preparation (Disk plow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
12
Land Preparation (Disk plow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
13
Land Preparation (Disk Harrow)
•Disk harrows have general purpose of tillage
= implements consisting of gangs ‫ طقم‬of
concave disks.
•Disk harrow are used to reduce the size of
larger soil clods by fracturing them by
cleavage and pressure.
•Disking )harrowing) generally follows
plowing, but under some conditions disking
can eliminate the need for plowing.
14
Land Preparation (Harrowing)
•The function of the harrow is to further reduce
the size of soil clods left after disking, to
smooth the soil surface and to do small scale
leveling. Harrowing also kills any small weeds.
•The principle types of harrows include:
–Spike-tooth,
–Spring-tooth,
–chain or drag and
–cultipackers.
- Rotivators.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
15
Land Preparation (Spring-tooth harrow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
16
Land Preparation (Spike-tooth harrow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
17
Land Preparation (Lister)
•In some areas, row crops are planted on ridge
formed by listers.
•A lister is a plow equipped with a two
moldboards that cuts a furrow slice two ways
on both directions.
•Some farmers flatten the tops of the ridges
with a roller or a drag.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
18
Land Preparation (Lister)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
19
Land Preparation (Cultivation)
•Cultivation is the tillage between seedling
emergence and crop harvest.
•The main reason for cultivation is to
–control weeds,
–improve soil aeration,
–the conservation of soil moisture and
–loosening compacted soils.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
20
Land Preparation (Cultivation)
•Cultivation equipment can be divided into
three main classes:
1.Row-crop cultivators.
2.Field cultivators.
3.Rotary hoes.
4.Rototillers.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
21
• Land Preparation (Row-crop cultivators)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
22
Land Preparation (Row-crop cultivators)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
23
Land Preparation (Field cultivators)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
24
Land Preparation (Rotary hoes)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
25
Land Preparation (Roto-tillers)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
26
• Land Preparation (Deep Tillage)
•Some farmers use deep tillage to improve problem soils.
•Extra heavy equipment is used for deep tillage when soil is
dry and before seedbed preparation.
•Equipment include: Slip plow, deep moldboard plow and
ripper or deep chisel.
•Deep tillage is expensive and it does not materially
increase crop yields.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
27
Land Preparation (Deep tillage)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
28
• Land Preparation (Slip plow)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
29
• Land Preparation (Minimum Tillage)
•Using large machine in tillage compacts the soil.
•To avoid soil compaction, minimum tillage is
recommended.
•Yield differences between minimum and normal
tillage is small.
•The saving in reduced fuel costs and machinery
cost is appreciable with minimum tillage.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
30
• Land Preparation (Minimum tillage)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
31
Land Preparation (Minimum tillage)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
32
Land Preparation (Land leveling)
•Irrigated land generally needs to be leveled,
especially if row crops are grown.=Furrows
•Land is leveled to permit water to flow and
spread evenly over the soil surface without
causing erosion.
•Land should be leveled in rainy season
because leveling is injurious to wet soil.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
33
Land Preparation (Soil Fumigation)
•To grow some crops, the soil has to be
fumigated before seedbed preparation.
•These are high-value crops with a potential
for pest damage severe enough to justify the
cost of treatment.
•The most widely used soil fumigant is methyl
bromide, a colorless, odorless and toxic gas.
•Steam or solar fumigations are used instead
of chemicals.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
34
• Land Preparation (Soil Fumigation using
chemicals)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
35
• Irrigation (Methods of Application)
•In areas where 300 mm of rain falls during growing season,
an average 400 mm of supplementary irrigation is needed.
•Some factors that determine the method of irrigation system
include:
•Climate.
•Type of crops.
•Cost of water.
•Slope of field.
•Physical properties of soil.
•Water quality.
•Water availability
•Drainage capability
•Salinity.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
36
Irrigation (Methods of Application)
•Border or flood method is used where the topography is flat an
level. A uniform down slope of 0.1 to 0.4 percent is used.
•This method is used with drilled or broadcast crops such as
cereal grains.
•The land needs to be graded and levels and this depends
upon:
–Topography.
–Cropping system.
–Cost.
•Excessive percolation and inadequate wetting of the soil in
different areas should be avoided.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
37
• Irrigation (Border or flood method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
38
Irrigation (Methods of Application)
•Furrow irrigation is a modification of floodingwater is confined to furrows rather than wide
checks. Water is used more efficiently.
•Furrow irrigation is frequently used for row
crops, orchards and vineyards.
•The length of furrow varies from 30 m to 450
m. Long furrows cause greater loss of water
because of deep percolation and excessive soil
erosion.
•Furrow spacing is determined by the plant row
length.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
39
Irrigation (Furrow irrigation method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
40
Irrigation (Furrow irrigation method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
41
Irrigation (Methods of Application)
•Sprinkler irrigation is often used when flood or
furrow irrigation is impractical.
•Sprinklers are selected over other methods
because:
–Excessive high or low soil permeability.
–Germination rate of small seed crops.
–Soil topography.
–Water cost + farmer budjet.
•There are several types of sprinklers including:
the permanent set, the hand set, the wheel line,
the hose drag and the central pivot.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
42
Irrigation (The permanent set sprinkler
irrigation method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
43
Irrigation (The wheel line sprinkler irrigation
method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
44
Irrigation (The central pivot sprinkler
irrigation method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
45
Irrigation (Methods of Application)
•In drip irrigation small amounts of water are
allowed to trickle slowly into the soil through
mechanical devices called emitters wetting the
soil without runoff.
•In this system, a control station will filter the
water, will add fertilizers and will regulate the
pressure and timing of application.
•The system uses less water than other
methods but the system is expensive.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
46
Irrigation (The drip irrigation method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
47
Irrigation (The drip irrigation method)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
48
Mineral Nutrition
•Fertilizers have probably
increased crop yields and
reduced hunger more than other
single agricultural practice.
•In addition to supplying
nutrients to crops to increase
yields, fertilizers can also cause
marked changes in soil
characteristics, some beneficial,
some not.
•Seventeen chemical elements
are known to be essential for
the growth of the most plants
and few others are used under
certain conditions.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
49
Mineral Nutrition
•For essential element, it must met the
following criteria
1.A plant must be unable to complete its life
cycle in the absence of the element.
2.The function of the element must not be
replaceable by another element.
3.The element must be directly involved in
plant metabolism.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
50
• How do plants absorb nutrients from the soil?
•Nutrients do not simply
flow into the cytoplasm
of a plant cell in the
absorbed water.
•It is important to
emphasize that the
plant nutrients are
charged forms (ions)
of the elements
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
51
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
52
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
53
Mineral Nutrition
Based on this seventeen chemical elements are known to be
essential elements and they include:
–Non mineral Nutrients :
•Carbon (C), Hydrogen (H) and Oxygen. They are supplied by air
and water.
–The mineral nutrients and they are divided into three groups:
•Macronutrients, they are required by plants in large amounts and
they include:
–Primary macro: Nitrogen (N), Phosphorus (P), Potassium (K),
–Secondary macro: Calcium (Ca), Magnesium (Mg), and Sulfur
(S).
•Micronutrients, they are required in low amounts and they
include:
–Boron (B), Chlorine (Cl), Copper (Cu), Iron (Fe), Manganese (Mn),
Sodium (Na), Zinc (Zn), Molybdenum (Mo), and Nickel (Ni).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
54
Mineral Nutrition
•Nitrogen is a major component of proteins,
hormones, chlorophyll, DNA, vitamins and
enzymes essential for plant life.
•In nature, nitrogen exists in several forms that plants
can have access to. Plants absorb nitrogen only as
inorganic nitrate ions (NO3-) and, in few cases, as
ammonium (NH4+).
•The transformation of organic matter to the mineral or
inorganic form by microorganisms is called
mineralization. The conversion of the mineral form to
the organic form is known as immobilization.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
55
Mineral Nutrition (The Nitrogen Cycle)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
56
• Mineral Nutrition
Nitrogen fertilizers are applied as solid, liquid or gases.
Ammonia, or azane, is
a compound of nitrogen and hydrogen with
the formulaNH3. It is a colourless gas with a
characteristic pungent smell
•Nitrogen fertilizers must not be placed directly over
foliage because they burn the leaves.
•Continued use of nitrogen fertilizers can affect the pH
of the soil. Fertilizers containing ammonium ions are
residually acid. Fertilizers contain basic cation and
nitrate are residually basic.
•Many plants deficient in nitrogen show pale green to
yellow leaves in lower leaves since it is mobile.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
57
Mineral Nutrition (Nitrogen burns leaves)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
58
Mineral Nutrition (Nitrogen deficiency
symptoms).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
59
Nitrogen fixation can be carried out by several groups of
bacteria. The bacteria that are of greatest agricultural
importance are named rhizobia.
•These bacteria infect legumes such as
–The vegetable crops peas and beans and
–The agronomic crops soybean and alfalfa
•They enter the root through root hairs and form growths on the
root called nodules
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
60
• The plant supplies the bacteria with organic
nutrients (e.g., carbohydrates), and in return
the bacteria supply the plant with ammonium.
• In general, a species of rhizobia infects only
one species of legume. Thus:
• 1.Pea rhizobia do not form nodules on bean
plants and soybean rhizobia do not form
nodules on alfalfa.
• 2.When a legume is first grown in the field, it is
very important to supply an appropriate
rhizobial inoculant.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
61
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
62
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
63
Complete Flowers
• Complete flowers usually have four parts—sepals,
petals, stamens, and pistil—which are usually borne on a
receptacle (Fig. 8-36).
• The sepals are the leaflike scales that encircle the other
flower parts.
• Most often the sepals are green, The sepals collectively
are called the calyx.
• The petals are the next whorl of colored floral leaves
inward from the sepals. The collective term for petals is
corolla.
• Sepals and petals collectively are called the perianth.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
64
• The next whorl of floral organs in a complete flower is
the male part, or stamen. Each stamen consists of
1. A filament and
2. An anther; the anther produces the pollen.
• The pistil, the central female component of the flower, is
composed of three parts:
1. The stigma, the receptive surface that receives the
pollen;
2. The style, a tube connected to the stigma; and
3. The ovary, attached to the lower end of the style.
• The ovary contains undeveloped ovules that are
attached to a placenta; the ovules develop into seeds
after pollination and fertilization.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
65
Incomplete Flowers
Incomplete flowers lack of one or more of the four parts:
sepals, petals, stamens, or pistil.
- Flowers with both stamens and pistils are called
Perfect flowers.
- Flowers with stamens only and no pistils are called
Staminate flowers;
- Those with pistils but no stamens are called
Pistillate flowers.
- Staminate or pistillate flowers are by definition
Imperfect flowers.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
66
• Plants having both
staminate and pistillate
flowers borne on the
same plant are termed
monoecious (e.g., corn)
(Fig. 8-40). As corn
• If the pistillate and
staminate flowers are
borne on separate
individual plants (male
and female plants), the
species is called
dioecious. (e.g., date
palm and pistachio)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
67
Some flowers, like the tulip, are borne singly on a stalk and are called
solitary, but others are arranged in multiples or in clusters known as
inflorescences (see Fig. 8-37).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
68
FRUITS
• A fruit is a matured ovary plus associated parts;
it is generally a seed-bearing organ, but there
are parthenocarpic fruits that are seedless.
• Fruit may
1. Protects seeds
2. Helps disseminate ‫ نشر‬seeds.
• Fruits develop after pollination and fertilization.
• The ovary wall, which is called the pericarp, can
develop into different structures.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
69
Simple Fruits
• Simple fruits have a
single ovary formed from
one flower.
Aggregate and Multiple
Fruits
• Aggregate fruits develop
from many ovaries on a
single flower. (strawberry)
• Multiple fruits develop
from many individual
ovaries fused into a
single structure borne on
a common stalk. (fig)
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
70
SEEDS
• A seed is a mature ovule. The three basic parts are
1. The embryo,
2. The food storage tissue (endosperm, cotyledons, or
perisperm = the nutritive tissue surrounding the embryo
in certain seeds as beet,), and
3. The seed coats.
• The embryo is a miniature plantlet formed within the
seed from the union of the male and female gametes
during fertilization.
• Basically, the embryo has two growing points:
– Radicle, which is the embryonic root, and
– Plumule, which is the embryonic shoot.
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
71
• Food can be stored in the form of
1. Starch,
2. Fats, or
3. Proteins.
• There may be one or two seed coats (testa), which
form from the integuments, the outer layers of the
ovule.
• The scar that remains after breaking the seed from the
stalk is called the hilum, and the small opening near
the hilum is the micropyle. The ridge on the seed is the
raphe (Fig. 8-4).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
72
Monocots and dicots plants differ in
many anatomical details:
Fig 35-1. A comparison of monocots and dicots. These two groups of angiosperms are named for the number of cotyledons, or seed leaves, present
on the embryo of the plant. Monocots include orchids, bamboos, palms, lilies, and yuccas, as well as the grasses, such as wheat, corn, and
rice. A few examples of dicots are roses, beans, sunflowers, and oaks (which are all eudicots, the largest class of angiosperms with the dicottype anatomy).
4/4/2016
DMA: Chapter 8 Hartmann's Plant
Science, 4th edition
73