CLASS : JSS 2
SUBJECT : AGRICULTURAL SCIENCE
TERM : FIRST TERM E-NOTE
The aim of the farmer is to get maximum yield from his farm operations. For this reason, he adopts a number of measures to get the best out of the soil.
This include all operations carried out in the farm before planting is done e.g. selection of site, bush clearing, stumping, farm layout, ploughing, harrowing, ridging.
- Selection of Site– It is necessary to choose a good site. A flat well drained sandy-loamy soil should be chosen. This is ideal for most food crops.
- Bush Clearing– This is the removal of bushes through Mechanical or Chemical means. Mechanically through manual cutting of bushes with crude implements eg Hoes and Cutlasses or through the use of machines. Chemically through the use of Herbicides (chemicals used to kill weeds) e.gParaquat.
- Stumping– The removal of perennial roots and tree stumps present in the soil. It is an energy consuming operation
- Ploughing– The primary purpose of ploughing is to turn over the upper layer of the soil, bringing fresh nutrients to the surface, while burying weeds, the remains of previous crops, and both crop and weed seeds, allowing them to break down. It also aerates the soil, allows it to hold moisture better and provides a seed-free medium for planting an alternate crop. It can be carried out using manually with a hoe or a plough. A plough is an implement used in farming for initial cultivation of soil in preparation for sowing seed or planting to loosen or turn the soil. As the plough is drawn through the soil it creates long trenches of fertile soil called furrows.
- Harrowing – This is the breaking up and smoothing out the surface of the soil. This is a method for shallow cultivation of soil and care of agricultural It is accomplished by toothed or disk harrows and revolving hoes. It is often carried out on fields to follow the rough finish left by ploughing operations. The purpose of this harrowing is generally to break up clods (lumps of soil) and to provide a finer finish, a good tilth or soil structure that is suitable for seedbed use.
- Ridging– This involves making ridges for planting. This is a strip of ground thrown up by a plow or left between furrows where seeds can be planted.
- Seed Bed Preparation– This involves making of ridges or nursery beds. A nursery is a place where plants are propagated and grown to usable size. Transplanting is the transfer or movement of ready seedlings from the nursery bed, seedling trays or pots to the main field. Transplanting is used in vegetable raising, fruit growing, forestry, tobacco farming, and flower raising. Seedlings are transferred from seedbeds, hotbeds, hothouses, andnurseries topermanent sites, where they continue to grow and to produce a crop. For potatoes, tubers are planted; for onions, smallbulbs raised from seeds; for mint, rootstock cuttings; and for sugarcane, stemcuttings. To obtainthe seeds of root crops,the root is planted.
- A ___ is a place where plants are propagated and grown to usable size.
- ____ is the breaking up and smoothing out the surface of the soil
- ____ is the removal of perennial roots and tree stumps present in the soil
- ____ involves making of ridges or nursery birds.
Topic: Cultural Practices – Planting Operations
These are operations carried out while planting is done. Planting operations include spacing, seed selection, seed rate and planting.
Spacing – This refers to the distance between two plants. The distance between one plant and another along the sameridge or row is called Intra or Within the Row spacing while the distance between one plant and another on different ridges or rows is called inter or between row spacing. Different crops have different spacing depending on whether they branch extensively or not. Correct spacing encourages high yield.
Seed rate – This refers to the quantity of seeds or planting material required to cover the planting of an area of land. To determine the sed rate of a piece of land, the area of the land, the actual spacing and the number of seeds per hole must be known. Assuming we wnat to plant a crop in a piece of land which is 500m long and 200m wide, if the spacing is 2m x 2m and 3 seeds are planted per hole, then the seed rate is determined as follows
Area of Land = Length x Breadth = 500m x 200m = 100,000m2
Spacing = 2m x 2m = 4m2
Seeds per hole = 3
Number of stands along the side = 500/2 = 250 stands
Number of stands along the breadth = 200/2 = 100 stands
Total number of Stand – 250 x 100 = 25,000 stands
Thus seed rate = stands x number of seeds per hole = 25,000 x 3 = 75,000 seeds
Seed Selection – The quality of seeds affect the early life of the plants and has a direct effect on the type of crops produced. The following points must be considered when selecting seeds
- Large seeds should be selected in a group
- Seeds should be well filled and not wrinkled
- The seeds should be free from holes. The presence of holes in seeds signify insect attack
- Avoid using seeds that have been stired for a long time.
Planting – Planting is the act of sowing the desired seeds on a prepared field. There are different fabricated machinery that could be used to achieve this, depending on the type of crop (planter). Sowing is the process of planting seeds. An area or object that has had seeds planted will be described as being sowed. Planting is the act or an instance of putting seeds or young plants into the soil. There are different methods of sowing and the crop to be sowed determines the method to be used. There are 6 sowing methods which differ in their merits, demerits and adoption. These are:
1. Broad casting
2. Broad or Line sowing
6. Putting seeds behind the plough.
- ___ refers to the quantity of seeds or planting material required to cover the planting of an area of land
- The quality of seeds affect the early life of the plants and has a direct effect on the type of crops produced. This process is called ____
- Calculate the spacing and seed rate for a piece of land which is 800m long and 600m wide, if the spacing is 4m x 3m and 4 seeds are planted per hole.
- Calculate the number of stands along the side (length), if the seed rate is 160,000 seeds, the piece of land is 400m x 200m and the spacing is 2m x 2m. The number of seeds per hole is 4.
Post Planting Operations and Harvesting
Post planting operations in agriculture refers to all the other process that take place after planting. This includes watering, weeding, applying fertilizers, pruning, weeding etc
- Thinning and Supplying – Thinning is a term used in agricultural sciences to mean the removal of some plants, or parts of plants, to make room for the growth of others. Selective removal of parts of a plant such as branches, buds, or roots is typically known as pruning. Supplying can be defined as the process of planting so many crops for the nursey stage of pre-planting process in other to make available crops for planting.
- Weeding – This is the systematic removal of weeds. A weed is a plant considered undesirable in a particular situation, “a plant in the wrong place”. Weeding should be done t intervals, 3 times per season.
- Rouging– This refers to the act of identifying and removing plants with undesirable characteristics from agricultural Rogues are removed from the fields to preserve the quality of the crop being grown.
- Fertilizer Application – A fertilizer is any material of natural or synthetic origin (other than liming materials) that is applied to soils or to plant tissues (usually leaves) to supply one or more plant nutrients essential to the growth of plants. It is the adding of nutrients to the soil. The placing of organic or chemical manure to the soil helps to improve nutrients. Application of this susbtance is called Fertilizer Application.
- Mulching – Mulching is the placing of dry grass, cardboard or plastic to keep soil moist and prevent soil erosion. This involves the use of either plant residue or mulching material, to cover the soil in a bid to prevent excessive moisture loss; or to reduce the effect of high temperature on germinating seedlings, plant root etc.
- Harvesting – Harvesting is the process of gathering a ripe crop from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper. On smaller farms with minimal mechanization, harvesting is the most labor-intensive activity of the growing season. It is also is the act of removing a crop from where it was growing and moving it to a more secure location for processing, consumption, or storage.
- Processing – This is the transformation of raw ingredients, by physical or chemical means into food, or of food into other forms. Food processing combines raw food ingredients to produce marketable food products that can be easily prepared and served by the consumer.
- Storage – Storage is an important marketing function, which involves holding and preserving farm products from the time they are produced until they are needed for consumption. Thestorage of products, therefore, from the time of production to the time of consumption, ensures a continuous flow of goods in the market.
- Staking: It is a situation whereby a stick is placed besides a plant to prevent it from bending or fruit from touching the ground. This help the efficient growth of the crop. Staking provides physical support so that plants don’t break under the strain of fruit or inclement weather. Staking enables better air flow through plants, which results in less internal moisture that can result in disease. Crops like tomato, yam requires staking.
- Irrigation– Irrigation is the method in which a controlled amount of water is supplied to plants at regular intervals for agriculture. It is used to assist in the growing ofagricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall. This is the watering of the plant for growth and development.
- Pruning – It is the removal of branches of the center and end of plant to allow sunlight. The sunlight mis very important in the growth of crops.
- Moulding – This is the gathering of soil around the plant to avoid soil erosion, and for proper aeration.
- Pest Management – Pests are organisms that attack crops at different stages of growth, which often have adverse consequence on the productivity of the crop, and reduced output realizable from the farm. There are different approach to pest management which include: Pesticide based approach such as fungicide, insecticide, fungicide etc. Biological pest control approach: such as the use of trap crops, cover crops. Biotechnology-based approach: such as plant breeding and genetic modification.
- Disease management: is the practice of minimizing disease in crops to increase quality or quantity of harvest yield. It involves making conscious decisions related to numerous agronomic factors over which control can be exercised. Plant diseases are caused by microorganisms such as fungi, bacteria, viruses, nematodes. Various methods used to control pest includes: Developing new crop variety, Crop rotation, rouging etc.
- Marketing– This is usually the last stage of farm operations. After harvesting and processing crops to be sold will be sent to the market. Farm products should be disposed off in time expecially perishable products such as tomatoes, pepper, garden eggs.
Thinning, Supplying, Disease management, Marketing, Harvesting, Staking, Ploughing, Pruning, Irrigation, Processing, Storage, Mulching, Rouging, Weeding, Moulding, Pest management
Use the options above to answer the following questions
- ___ is the systematic removal of weeds
- _____ is the gathering of soil around the plant to avoid soil erosion, and for proper aeration.
- _____ is the process of gathering a ripe crop from the fields
- ____ is a situation whereby a stick is placed besides a plant to prevent it from bending or fruit from touching the ground.
- _____ is a term used in agricultural sciences to mean the removal of some plants, or parts of plants, to make room for the growth of others
- _____ is the transformation of raw ingredients, by physical or chemical means into food, or of food into other forms.
- ______ refers to the act of identifying and removing plants with undesirable characteristics from agricultural fields.
- ____ refers to the act of identifying and removing plants with undesirable characteristics from agricultural fields.
- ____ is the practice of minimizing disease in crops to increase quality or quantity of harvest yield
- ____ can be defined as the process of planting so many crops for the nursey stage of pre-planting process in other to make available crops for planting