Preparing Land for Planting, Soil Sampling Procedures
1. Collection of samples for soil analysis.
1.1
Importance of Soil Sampling
Every
area is different when it comes to soil types and nutrient contents in soil.
Soil sampling and testing can show you the plant available nutrients and other
soil chemical factors important for Vegetable production.
Nutrient
levels in soil also vary from year to year, so it is important to perform soil
sampling and testing prior to planting any new crop. It is important for
farmers to follow certain recommended steps for soil sampling and testing to
develop a fertility management program.
To
ensure accurate results, standards must be set for performing soil sampling and
testing. Here are some guidelines:
Begin
by evaluating each field to determine representative areas
· Major areas within fields that have
distinctly different soil properties, such as texture, should be sampled and
fertilized as separate fields because of the potential for different nutrient
requirements
· Samples should be taken at 0.6, 6 to
12, and 12 to 24 inch depths from 15 to 20 locations within each field
· Each depth should be bulked into
composite samples, air dried, and sent to a reputable soil testing lab.
Sample Collection and Handling Proper soil sample collection relies on three principles:
1. Organization:
having an orderly system for soil sample collection and handling simplifies
sample collection and minimizes the chance of human errors such as mislabeling
or misplacing soil samples.
2. Consistency:
collecting each sample in a uniform manner between years and within the course
of a sampling event will greatly improve the quality and reliability of your
results. This means taking samples in the same manner for each sample.
3. Simplicity:
following simple procedures will help ensure sample collection is consistent
and easily organized.
Samples
and subsamples
Soils can be highly variable, even over
short distances. Because of this variability, it is often insufficient to
collect soil at just one location. Instead, it is preferable to collect
so-called composite samples. Composite samples are a mixture of individual
samples, or subsamples, generally collected from multiple locations and mixed
together to form a single composite sample. By combining multiple subsamples into
a single composite sample, we can minimize the effects of soil variability by
averaging the soil properties over larger areas. Composite samples are less
sensitive to unusually high or low soil test values that might occur due to
concentrated fertilizer applications (e.g. banded applications) or natural soil
variation.
Sample collection before collecting
soil samples, you will need to gather certain materials and tools
• A clean plastic bucket
•
A
trowel
•
Permanent
markers
•
Sample
bags.
Many soil testing laboratories will
provide wax-lined sample bags. In lieu of laboratory provided bags, consider
using paper bags or zip-top bags.
•
Clipboard
and paper or field notebook
•
GPS-enabled
smartphone or handheld gaps unit (optional)
To collect a composite sample, use
the following procedure:
1.
Before
arriving to the field, determine the number and approximate location of soil
samples. (See the Sampling locations and strategies section for details.)
2.
Once
the appropriate materials have been collected, travel to the first sampling
location. If you’d like, you may record the location with a GPS or GPS
application on your smartphone. This information can be useful later for
tracking where samples have been collected. You may find it helpful to return
to the same sampling locations in subsequent sampling events.
3.
At
the sample location, remove any crop residue from the soil surface.
Factors
to consider in selecting the site for planting vegetable crops.
1.
Sunlight
The more sunlight the site receives the
better for a vegetables garden because sunlight is the most important factor
for growing healthy vegetables. Most vegetables need full sun (at least six
hours of direct sunlight per day) to grow their maximum potential, so avoid
spots that are shaded by tress or buildings during the heat of the day. Use the
traditional planting arrangement of rows running north to south to provide a
maximum and even quantity of sunlight throughout the day.
To determine if your site has the right
light conditions, stand facing the south with your left hand pointing east ( in
the direction the sun rises ) and your right hand pointing west ( in the
direction the sun sets). Now take your east-facing finger and follow it to the
southern sky and then down behind the western horizon. This is the course the
sun will take throughout the day.
2.
Water and Drainage
Water is the life-blood of vegetable
production. Vegetables crops generally require more total water and more
frequent irrigation than most other horticultural crops. The water source
should have the capability to provide the volume required for the maximum needs
of the highest water-using crop to be planted.
Vegetable crops develop water
requirements which are specific to their variety, maturity, and the surrounding
atmospheric and soil characteristics. With respect the drainage, it is the
physical topography of a particular site which assumes the most significant
role. The most suitable types of location have gentle surface slopes and
contain deep and well drained soils. Many vegetable growers prefer a moderately
heavy loam with at least several feet of topsoil.
3. Topography of the land
Topography refers to the physical
characteristics of the overall field site and includes conditions such as the
contour , soil, depth, water, air drainage, and the presence of rock. These
characteristics can have a significant influence on crop production and
management. Poorly drained fields or those with low areas can become water
logged during periods of excessive rain. Such conditions can enhance the
incidence of diseases, reduce plant vigor and yield, and under excessive
conditions, cause plant death.
An ideal topography for vegetable
production is one that is nearly flat to slightly sloping, well drained, and
free of trees, rocks, and low areas. Efficiency of crop maintenance,
irrigation, and harvest operations are greatly enhanced in fields with this
type of topography.
4.
Types of Soil
Soil type refers to the physical
composition or properties of the soil. Soil basically consists of decomposed
mineral water (sand, silt, and clay) and decomposed organic matter. Optimum
vegetable production is achieved on well-drained sandy by loan soils. Although
vegetables can be grown on a wide range of soil types. Most vegetables are not
well adapted heavy clay soil types. Soil of this type tend to have poor
aeration and drainage and can restrict root growth. Consequently, theses soil
should have avoided. Soil is the fundamental resource base for all agricultural
production systems.
5.
Accessibility to road and transportation
Vegetables are highly perishable. They
are best liked when they are fresh and of good quality. If the site is
accessible to all forms of transportation, vegetable products are easily
without much damage.
6.
Climatic requirements
The climate is mainly governed by: (a)
temperature; (b) water; and (c) light.
·
Temperature affects some vital processes of the
plant like photosynthesis, respiration, absorption of water and minerals, and
in the germination of seeds.
There are three basic temperatures
necessary for the germination and growth of each plant species. First, the
minimum temperature limits of the growth of plants. If the temperature goes
below the minimum temperature, the plant will not grow or will be stunted.
Second, the maximum temperature the plants can still survive. Third, the
moderate temperature which is between the maximum and the minimum temperature
will make the plants grow fast.
·
Water serves as a solvent, nitrogen,
phosphorus, potassium, and other nutrient elements cannot be absorbed by the
plant unless there is water in the soil. It serves as a solvent for the plant
nutrient which is in the form of a solution absorbed by the roots.
·
Light affects the growth of crop plant mainly
through effecting (1) their structural development, (2) their food production,
and (3) the time required of certain species of varieties to produce seeds.
Light, is necessary for photosynthesis and is therefore required by green
plants for the manufacturing of food. Many plants are influenced by the length
of day especially with regards to flowering, fruiting, and production seeds.
The long day plants need a comparatively long day for flowering and their
vegetative growth increases when the days are short.
Name: ___________________________________________ Date: _____________
Grade/Section: ___________________________________ Score: ____________
I.
TRUTH OR FALLACY?
Direction: Read and analyze the statement carefully. Check Time. If
the statement is correct and check false if the statement is incorrect.
TRUE FALSE
1.
Samples should be taken at 0.6, 6 to
12, and 12 to 24 inch ______ ______
depths from 15 to 20 locations within each
field.
air dried, and sent to a reputable
soil testing lab.
field site.
vegetables.
with
at least several feet of topsoil
flowering.
steps for soil sampling.