Agricultural Science (All Classes)

FACTORS OF SOIL FORMATION The factors that control soil formation include;  climate, parent materials, topography, biotic factors (living organisms) and time.   CLIMATE Climate refers to the average weather condition of a place measured over a long period of time. Elements of climate include sunlight, temperature, wind, relative humidity, rainfall and pressure. Rainfall: Running water as a result of from rainfall causes gradual wearing away of rocks during erosion giving rise to soil. Impact of rain drops can also break rocks to form soil. Temperature: The alternate heating and cooling of rocks give rise to continuous expansion and contraction of rocks. This causes cracks in rock and over time lead to formation of soil. Wind: High wind velocity most especially in desert regions carries tiny rocks which hit themselves or other rocks leading to breakdown of rocks into tiny pieces to form soil. Pressure: High pressure in a hanging rock… Read More »FACTORS OF SOIL FORMATION

ROCK WEATHERING The process of soil formation is referred to as weathering. Weathering is defined as the disintegration of rocks into smaller particles to form soil.   PROCESSES OF ROCK WEATHERING The processes of soil formation (rock weathering) include: Physical process Chemical process Biological process   PHYSICAL PROCESS OF ROCK WEATHERING Agents of physical weathering include temperature, ice, rainfall, wind and pressure. Temperature: The rise and fall of temperature brings about the expansion and contraction in rocks respectively. After a long time, rocks begin to crack and break down which later give rise to soil. Ice: When rivers overflow their banks or when it rains, water collects in the openings. At a cool temperature or freezing point, the water in the openings freezes and increases in volume, the force of expansion makes the rock to expand thereby cracking them to particles. As the temperature rises, ice melts and carries the… Read More »ROCK WEATHERING

ROCK A rock is any mineral material of the earth. It may be a combination of different mineral elements such as silica (silica contain silicon and oxygen). TYPES OF ROCKS Rocks can be classified into three major groups based on how they are formed and their appearances. These include Igneous rock Sedimentary rock Metamorphic rock   MODE OF FORMATION OF IGNEOUS ROCK They are formed as a result of cooling and solidification of molten magma erupted from the earth crust. Magma occurs from high temperature and pressure underneath the earth and forces itself towards the earth surface through the cracks. As the magma approaches the earth surface, it cools as a result of lower temperature of the earth surface and solidify to form igneous rocks.   TYPES OF IGNEOUS ROCK PLUTONIC [OR INTRUSIVE] IGNEOUS ROCK:These are rocks formed when molten magma solidifies slowly before it gets to the surface of… Read More »ROCK FORMATION AND TYPES

MEANING OF AGRICULTURAL ECOLOGY Agricultural Ecology is defined as the study of crop plants and farm animals in relation to their environment. Ecology is derived from a Greek word “Oikos” which means home or dwelling place. In order words, agricultural ecology can be defined as a field of study which deals with the relationship of living organisms with one another and with the environment in which they live. Agricultural Ecology is dividedinto: Autecology B.Synecology.   Autecologyis concerned with the study of an individual organism, or a single species of organism and its environment. For example the study of a single cattle and its environment.   Synecologyis concerned with the study ofthe inter-relationshipsbetween groups of organisms or species of organisms living together in an area. For example the study of different fishes in a fish pond in relation to their aquatic environment.   Ecosystem refers to a community of crop plants… Read More »AGRICULTURAL ECOLOGY

CULTIVATION OF CEREALS   MAIZE (Zeamays) RICE (Oryzasativa) Description Maize also called corn is a member of the grass family (Gramineae). It produces grains, use as food by human beings and livestock. The seed/fruit is called caryopsis. Rice is a member of the grass family (Gramineae). The seed/ fruit is called caryopsis Varieties / cultivar Sweet maize, flint maize, dent maize, flour maize and popcorn Swamp rice (Toma) and upland rice (Agbede). Land preparation Clearing the land and making ridges either manually or mechanically. Clearing the land and making ridges either manually or mechanically. Climatic requirement Temperature – 260C-300C, Rainfall – 75cm-150cm per annum Temperature of 200c, Rainfall of 75cm-120cm for upland rice and over 250cm for swamp rice. Soil requirement Sandy-loamy soil of PH 6-7 Loamy-clayey soil. Method of propagation By seeds By seeds Planting date Early maize – March/April Late maize – July/August South – April/May, North –… Read More »HUSBANDRY AND CULTIVATION OF SOME SELECTED CROPS

Post planting operations are the operations carried out after planting. It creates a good condition and proper maintenance for plants growth. Post planting operations include the following: Thinning Supplying Irrigation/ watering Use of manure and fertilizer Mulching Weeding Harvesting Processing Storage, etc   Thinning is the removal of excess, weak or not well positioned seedlings from a seedbed after the viable seeds have germinated   Advantages of Thinning It helps to avoid over crowding Proper aeration is ensured leading to high yield   Supplyingis the replanting of propagative materials where they fail to germinate. Supplying should be done as soon as possible.   Advantages of supplying Correct plant population can be maintained The farmer can achieve uniform maturity   Irrigation(watering)is the artificial watering of farmland especially during dry season.   Advantages of irrigation It makes the soil temperature moderate for plant growth It enables a good nutrient supply to plant… Read More »POST – PLANTING OPERATIONS

PLANTING OPERATION These are the operations carried out when inserting the planting materials (cutting or seeds) into the soil. When seeds are sown in the soil, they develop root and shoots, this is called germinationand the young plants that emerge are called seedlings.   A seed when planted undergoes the following processes. Germination: the process whereby the embryo of a seed resumes growth under favourable conditions. Emergence: this refers to the appearance of a seedling above soil level.   Conditions necessary for germination of seeds are Adequate moisture Viable seed (living embryo) Optimum temperature Adequate air   Methods of sowing In-situ (directly into the field/farm land) Nursery In-situ planting/sowing is sowing directly in the field on flats (plain land) ridges or garden beds e.g. of crops sown in-situ are maize, okra, cowpea, millet etc.   Sowing/Planting methods Drilling: sowing a seed by drilling with stick or knife, followed by dropping… Read More »PLANTING OPERATIONS – DISTANCE, DATE, SEED RATE, NURSERY AND NURSERY PRACTICE

planting operations  are the operations carried out before planting, while planting is the sowing of seeds and  post-posting operations  include thinning, supplying, irrigation, manuring, mulching and weeding.  PRE-PLANTING OPERATIONS Landclearing: this is the removal of pre-existing vegetation on the farm land. It is carried out by cutting the vegetation and grasses with cutlass or hoes; and trees fell with axes. It can also be done mechanically with the aid of bulldozers and tree pullers. Stumping: This is the removal of stumps by digging them out manually using cutlasses and axes. It can also be done mechanically by using bulldozer. Stumps are the left over cut trees on the farm left on the soil surface. Farm layout: Farm layout is a judicious way of using the farmland where the plots are divided into sections and each section is used to give maximum yield. Land preparation: this is ensuring the soil is… Read More »CULTURAL PRACTICES

METHODS OF PEST CONTROL Crop pests can be prevented or controlled through the following methods: Physical control Cultural control Biological control Chemical control PHYSICAL CONTROL This involves the physical removal of pests by: Hand picking of insects and larvae Setting traps to catch rodents Shooting rodents with gun Fencing round the farm with wire nets. Use of scarecrow. EVALUATION List the methods of pest control List three ways by which pests can be removed physically   CULTURAL CONTROL This method involves the use of farm practices to prevent or control pests, examples of cultural control are: Practicing crop rotation Use of pest resistant varieties of crops Appropriate tillage operations Burning crop residues Timely planting of crops Proper weeding or sanitation Timely harvesting Close season practices (no living plant is allowed for a certain period).   BIOLOGICAL CONTROL This involves the introduction of natural enemies of pests to control or keep… Read More »PREVENTION AND CONTROL OF CROP PESTS

MEANING OF CROP PEST A crop pest can be defined as any organism capable of causing damage to the crop.  TYPES OF CROP PEST Important crop pest are grouped in to the following classes; Insects Birds Rodents Monkeys Man Nematodes   CLASSIFICATION OF INSECT PEST Biting and chewing insects: they possess strong mandible and maxillae (mouth parts) which enable them to bite and chew plant parts e.g termites, grasshoppers, leafworm, mantids, locusts and beetles. Piercing and sucking insects: they possess stong mouthparts called proboscis which enable them to pierce through plants and suck liquid materials from them. Examples are aphids, cotton strainers, mealy bugs, scale insects, capsids, mirids and white flies. Burrowing insects: they and their larva stage are capable of burrowing the tissue of the plant parts or fruits or seeds. Examples are bean beetles, stem borers, maize weevils and rice weevils.  EVALUATION What are crop pests? List the… Read More »PESTS OF CROPS | MEANING, TYPES, CLASSIFICATION, IMPORTANT

MEANING AND CAUSES OF DISEASE A crop is a plant cultivated by man for a specific purpose. A plant disease is a deviation of the plant from the normal state of health, presenting outward visible signs. Diseases are caused by pathogens and enhanced by some physiological factors.  CAUSES OF DISEASE Plant diseases are caused by pathogens. Pathogens are disease causing organism which passes through a regular cycle of development and reproduction. Examples of pathogens that cause plant disease are viruses, bacteria, fungi, parasitic worms and rarely protozoa. Some of these pathogens are carried by vectors and other agents. Physiological factors such as nutrient deficiency in the soil, heat, presence of inorganic salts in the soil and soil moisture content has a major role to play in influencing plant susceptibility to diseases.   SELECTED DISEASE OF CROPS Name Casual organism Method of transmission Symptoms and economic importance Prevention and control measure… Read More »DISEASES OF CROPS | MEANING, CAUSES, EFFECTS, CONTROL

Floriculture: is a discipline of horticulture that is concerned with the production and management of ornamental plants. Ornamental plants are beautiful trees or shrubs which can be used to decorate our environments.  IMPORTANCE OF ORNAMENTAL PLANTS Sources of employment e.g florists. Serves as source of income. For expression of love and as gift on special occasions. For decoration. For fencing. For medicinal preparation. Sources of food. Purification of the air. For teaching and learning purposes. Provision of shades. Serves as wind breaks. Beautification of the environment. Sources of livestock feed. Serves as tourist centres. Source of revenue to the government. For preparation of dyes. EVALUATION What is floriculture? List seven uses of ornamental plants.   COMMON SPECIES OF ORNAMENTAL TREES, SHRUBS AND FLOWERS ORNAMENTAL TREES Frangi pani Neem cassia Royal palm Balsam Flame of forest India almond Casuarinas Delonix   ORNAMENTAL SHRUBS Allamanda Crotons Ixora Cauliflower Acalypha Hibiscus Wild rose… Read More »FLORICULTURE – ORNAMENTAL PLANTS | IMPORTANCE, SPECIES, CULTIVATION, SOURCES, MAINTENANCE

Forest can be defined as a large area of land covered with trees and bushes, either growing wild or planted for some purposes which serves as habitat to various kinds of animals. Forestry is the management of forest and forest resources. Silviculture is the growing and cultivation trees.  Forest ecology is the scientific study of interrelated organisms in the forest.  COMMON FOREST TREES Common forest trees found in the forest are Iroko, Obeche, Mahogany, Nigerian walnut, Ebony, Camwood, Opepe, Afara, Teak and Abura.  FOREST RESERVES IN NIGERIA Forest reserves are large areas of land where plants, either growing naturally or planted are specially preserved for specific purposes.  SOME FOREST RESERVES IN NIGERIA Mamu River Forest Reserve in Anambra State. Omo Forest Reserve in Ogun State. Afi River Forest Reserve in Cross Rivers State. Okomu Forest Reserve in Edo State. Shasha River Forest Reserve in Ogun State. Zamfara Forest Reserve in… Read More »FOREST MANAGEMENT