MEANING OF FARM SURVEYING

Farm surveying is defined as the process by which the measurement of land is made on the farm. Such measurements by tables, plans, or layouts are done for specific purposes.  It can also mean the measuring and mapping out of the position, size, and boundaries of an area of farmland.

Importance of Farm Survey and Planning in Agriculture

1. It helps to determine the area of land
2. Farm surveying exposes the gradient of the land.
3. It helps in determining the amount of input of Labour, seeds, fertilizers, and chemicals to be used in the farm
4. It helps the farmer to make decisions on the locations of various farm buildings and structures.
5. It enables farmers to make the best use of available resources in order to achieve maximum profits.
6. Loans can be obtained with the help of farm survey plans
7. A farm survey gives the owner of the land security.
8. It does not allow for wastage of land.
9. It helps to determine the yield or productivity of crops.
10. Farm surveying and planning can be used as a basis for feasibility studies.

SOME COMMON SURVEYING EQUIPMENT/INSTRUMENTS

Some common surveying equipment or instruments include

1. Ranging pole;
2. Gunter’s chain
3. Measuring tape
4. Prismatic compass
5. Theodolite
6. Arrows or pins;
7. Offset staff
8. Beacons or pillars

Ranging poles

1. A ranging pole is made of wood or metal
2. It is of varying lengths, e.,g, 1.8m, 2.4m, or 3.0m
3. It is generally circular in section, though some octagonal types are obtainable.
4. It is usually painted black, bright red, and white to enable it to be seen from a distance.
5. It has a pointed end.

Function/Uses:

1. It is used for making stations.
2. It is also used for marking straight lines.
3. Gutter’s Chain
4. It consists of a series of dumb bell-shaped links of steel wires joined together by three small rings.
5. It has brass handles on either side.
6. It is divided into 100 links so that each link is 19.8cm or 7.92i ins.
7. One Gunter’s chain is normally 20.13m (66ft) in length
8. A link is the distance from the middle of the central ring to the middle of the next central ring.
9. The chain is entirely metallic.

Precautions that should be taken when chaining a farmland.

1. Pull taut chains, tapes, or ropes.
2. Avoid errors of transposing figures on papers
3. Equipment such as a theodolite should be placed on a perfect horizontal plane.
4. All chains, tapes, ropes, etc. must be properly aligned before taking measurements.
5. Avoid the error of parallax when reading measurements
6. Make sure the chain is not faulty before use.

Functions/Use: 

It is used in taking short or detailed measurements of length and breadth.

Measuring Tapes

Description: (i) It is usually made of linen or fine steel sheet.  (ii) It is usually marked on one side with metric units and the other side with imperial units. (iii) The tape is of various types and lengths.  (iv) The tape is normally wound in a small case from which it is unwound for use.

Function/Use

It is used for taking measurements of length, breadth, and height.

Arrows or Pins

Description: (i) These are thin, pointed steel wires of about 30cm long with one end curved into a ring.  (ii) A red cloth is normally attached to the ring so that it can be seen from afar.

Function/Uses: (i) It is used during chaining for making off-chain lengths as measured.  (ii) It can also be used for marking stations.

Offset Staff

Description: (i) This is a graduated rod-3m long.  (ii) A hook may be fitted at the top to pull a chain through a hedge.  (iii) Each telescopic link is 0.3m (30cm) in length.

Function/Use:  (i) it is used for taking short offset measurements.

Beacon or Pillar

Description:  (i) It is made of a rectangular block, usually in concrete form.  (ii) Marks are usually inscribed on top of the block.  (iii) The beacons are always buried in the ground with marked heads raised a little above the ground.

Function/Uses: (i) It is used for marking off points measured.  (ii) It is also used for the recognition of the measured or surveyed area.

General Maintenance of Surveying Instruments

1. All instruments must be cleaned after use.
2. Keep instruments in dry and cool places.
3. Those with metal parts should be oiled or greased or painted before they are put away for a long time.
4. Keep the instrument away from heat and rain to prevent damage and rust, respectively.
5. Replace worn-out parts.
6. Use the instrument only for the intended functions.
7. Let a competent surveyor handle and use the instrument only as he may direct