Leaves

The leaves are part of the plant that has a function as a place of assimilation, transpiration, respiration, and photosynthesis. The leaves have the form of a thin, green, and its position on the stem facing upwards is already aligned with the function of leaves for plants, namely:
1. transpiration
2. respiration
3. assimilation
4. photosynthesis
Plants that have full leaves still a little kind. Plants have a full leaf when having vaginal, petioles, and lamina. In adapting to the environment, the leaves change its shape according to environmental conditions. Changes in leaf shape called a modified leaf. leaf modification includes several parts:
a. bud. seen as forming the stem and leaves.
b. interest.
c. spines. creation stems and leaves to reduce evaporation.
d. tunica
e. bulbs
f. assidium
g. utriculus
Often we find the term Filofaxes. Filofaxes is a method to count the number of leaves on one plant using Fibonacci series.
Filofaxes in the monocotyl plant there is only one leaf attached to the stem, while the dicotyl plant, the number of leaves attached to the stalk can be one or more.
there are several types of filofaxess:
a. at 1 stalk attached one leaf

b. at 1 stalk attached two leaves

c. at 1 stalk attached three leaves

Consistency

In the Basic Sciences of the soil, there are several kinds of soil properties. On this occasion, will be explained about consistency. Consistency is the soil's ability to retain the shape of land size, due to pressure from outside the force of cohesion and adhesion. There are several kinds of consistency, ie:
1. Wet 

    a. Sticky: not sticky, somewhat sticky, sticky, and 

        very sticky
    b. plastically: no plastic, somewhat plastic, plastic, and

        highly plastic
2. Dried
    freelance, somewhat hard, hard, and very hard
3. Moist
    friable, somewhat firm, firm, and very firm.

To measure the consistency can be done in two ways, ie:
a. Qualitative methods
This method is done by determining the resistance of the land mass of the pressure or massage hands on a variety of soil moisture content.
b. Quantitative Methods
This method is termed as the number Atterberg. This method is done by stating the number of water content in the liquid limit and plastic limit of a soil.

There are several factors that are influenced by the consistency, ie:
a. root crops
if the soil has a friable consistency (clay), so root crops will be easy to move in the ground

b. organism
if the soil has a friable consistency, it will be easy living organisms and easy to breed in the soil
c. tillage
if the soil has a friable consistency, it would be easy to do tillage
d. erosion
more strong consistency of the soil, the erosion will often happen

Pests and Diseases of Plant

Pests are living things whose existence is disturbing crops, causing economic losses. Some scientists explain the meaning of pests, almost all explanations about pests are living things that cause economic loss.
In the agriculture, when pests attack crops, pests will leave a mark. Mark is a guide that can be observed on a plant to identify the pest. Every pest has a specific host plants according to nutritional needs. Almost every pest has a major host plant and alternative hosts. 

examples:

Valanga Nigricornis have primary host is the leaves of corn and rice leaves are alternate hosts. Signs crop pests are leaf shreds erratically and sometimes leaving only the veins.

Valanga Nigricornis

While the disease is a deviation from normal behavior, causing the plants or plant parts can not be normal activity. The plant can be known by the symptoms. Symptoms are changes in the plant which is a reaction to the influx of foreign plants just as bacteria, viruses, and others. Agrios explained that the disease will occur if three conditions fulfilled from the disease triangle. The following is the disease triangle:

disease triangle

Disease will occur at a time and place for three terms, namely, (1) if the plants are vulnerable / susceptible to disease, (2) capable of infecting pathogens (virulent), and (3) a supportive environment or appropriate. disease will not occur if one of the conditions above not fulfilled, although two other conditions fulfilled.
Examples of pathogens that attack the plant:
Gleousporium Frugtigenum disease in apples caused by fungi. characteristics of this disease include: patches on the outside of the apple, the patches are get into the meat, and potholes.

Gleousporium Frugtigenum

Soil

Soil has many functions in our live. Soil can be place for we live, etc. Without soil, we cannot live because 0.25 percent of earth is soil. And almost of our activity, we do on the soil. Almost plants in this earth are like human, because they do their activity on the earth, like absorbing nutrition from root, absorbing mineral and water, etc.

Soil has five important meaning for plant, that is:

1. to make plant up straight. Plant can stand and reach the sunlight for photosynthesis because plant is supported by soil.

2.Soil provides water, mineral, and nutrition for plant. Almost plant look their nutrition and water in the soil by root to grow and develop. If nutrition, mineral, and water available in the soil is only slightly, plant growth and development will be disrupted, so plant production will be slightly.

3. Soil as a place for microbe. Microbe bulks large in process of decomposition organic materials. Result of the decomposition process will be nutrition which will be absorbed by root. And microbe can make pores in the soil with their activity.

4. as growing media. Soil is a place for plant to grow and develop.

5. Soil as filter. Soil capable of filtering toxins carried by pesticides or chemical fertilizers.

Soil is formed from weathering of rocks, and there are two process which play a part weathering of rocks process. The process are pedogenesis and geogenesis process. and these process will produce particle soil. Soil is composed by three particles, three particles of soil cover sand, silt, and clay. and these particles are explained in soil textural triangle.

The particles determine the characteristic of soil physical like texture, aggregate, structure, and consistency of soil.

Soil is divided by three characteristic, the characteristic are physical, biology and chemical.

The characteristic of soil physical like texture, aggregate, structure, and consistency of soil. The characteristic of soil biology like organic materials, microbe, and all of life cycle in the soil. While the characteristic of soil chemical like soil PH, N, P, Zn, Al, Mg, S, and all chemical element. Every soil characteristic has relationship each other.

 bibliography for the picture:

Anonymous,2012.http://upload.wikimedia.org/wikipedia/commons/0/0d/USDA_and_UK-ADAS_textural_triangle.jpg accessed on 16th September 2012

definition of agriculture

what is agriculture?

what for do we study about agriculture?

there are our questions in our main...

agriculture is the important thing that we should keep

agriculture is all about plant and crop

human have responsibility to take advantage and manage crop to product something useful

the parts of agriculture are farmer, crop, pest, soil, human, and nature

we cannot dispel one of agriculture's part because they are related each other 

  

agriculture is not only about nature but bussiness too.

but in era modern many things in agriculture have been changed like using pesticide and fertilizers.

these change had maked many problem in agriculture like soil reduction, pest-resistant, etc.

but now we have a solution for these problem, the solution of it is applying sustainable agriculture