Notes of chapter: Crop Production and Management are presented below. Indepth notes along with worksheets and NCERT Solutions for Class 8.
(1) All living organism require food. Plants can make their food by photosynthesis. Animals including humans cannot make their own food.
(3) Origin of agriculture-
People were wandering in groups in search of food and shelter till 10,000B.C. They ate raw fruits and vegetables. They also started to hunt animal for food. With the passage of time, they knew to cultivate land and started to produce wheat, rice etc. Therefore, people knew agriculture.
When same kind of plants are grown and cultivated at same place in large quantity, are known as crops.
Eg :- Cereals, vegetables, fruits.
(5) Types of cropping pattern in India-
India has different climatic condition (temperature, humidity and rainfall), so it has different crops at different places in different seasons. Crops can be divided in two broad pattern based on the season. These are explained below:
(i) Kharif Crops:-
(a) It is sown in rainy season, ie, June to September.
(b) Name of Kharif crops – Paddy, maize, soyabean, groundnut, cotton etc.
(ii) Rabi Crops:-
(a) It is grown in winter season, ie, October to March.
(b) Name of the Rabi Crops- Wheat, gram, pea, mustard, linseed etc.
(iii) Pulses and vegetables are grown during summer at many places.
The activities which are performed by farmers to produce crops are known as basic practice of crop production.
These activities are given below:
(i) Preparation of soil –
Turning and loosening of soil by farmer and earthworms and microbes are called preparation of soil or tilling, or ploughing.
Characteristics of preparation of soil-
(a) Turning and loosening of soil penetrate deep into the soil. It makes breathing easy for roots in deep inside the soil.
(b) Turned and loosened soil is good for growth of earthworms and microbes. They again turned and loosened the soil and add humus.
(c) Decayed or dead plants and animals decomposed by the soil organisms and decomposed material mix with water, mineral, air and nutrients of the soil. Few centimeters of the top layer of the soil is necessary for the development of the plant. It is necessary to turn and loosen the soil because it brings back the nutrients of soil to the top. So, plants can take nutrients from the top layer of the soil.
(d) Dry soil needs watering before ploughing.
(e) The big piece of soil of ploughed field are known as crumbs. It is necessary to break these crumbs with a plank and leveled for sowing and irrigation purposes.
(f) Agricultural Implements –
Tools which are necessary to break the soils to the size of the grains are called agricultural implements.
(a) It is used by farmers since ancient time.
(b) It is used for tilling the soil, adding fertilizers to the crops, removing the weeds,scarping of soil etc.
(c) It is made of wood or iron. It contains a strong triangular iron strip called ploughshare which is attached to a long wood log called ploughshaft. There is a handle at one hand of the shaft. The other end of the shaft is attached to the beam which is placed on the bulls’ neck.
(d) One pair of bulls and a man can easily operate the plough.
(a) It is used in removing weeds and loosen the soil.
(b) A strong, broad and bent plate of iron which is fixed at the end of the long rod of wood or iron is called blade. This blade is used to till the soil.
(a) It is also used in tilling the soil.
(b) It is made of iron. It has shanks which look like teeth. These shanks till the soil.
(c) It is driven by tractor which saves time and labour of the farmers.
(ii) Sowing –
Sowing is the process in which good quality of seeds are spread over the soil to grow into plants.
(a) Seeds should be sow at equal distance for the proper growth of the plants. It provides sufficient sunlight, nutrients and water from the soil because it prevents overcrowding.
(b) Framers have to be removed some plants to avoid overcrowding of the seeds.
(c) Seeds can be sprinkle by farmers or with the help of machines.
(d) Good quality of seeds which give high yield are selected by the farmers.
Experiment to check quality of seeds-
Take a beaker and fill it half with water. Put some wheat seeds in it and stir it . wait for some time.
- After some time some seeds float on water.
- The seeds which floats on water are lighter than those which sinks in water.
- Floating seeds are lighter because they are damaged seeds. These seeds are hollow. So. These are ligher than sinked seeds.
It is good method to sort out good seeds from the damaged seeds.
Tools for sowing-
(a) This equipment is sow seed in soil traditionally.
(b) It has a funnel which is attached with two or three pipes. These pipes have sharp ends.
(c) Farmer put seeds in funnel. Seeds passes through h the pipes and sharp ends of the pipes pierce soil and put seeds there.
(a) Now, seed drill is used with the help of tractor.
(b)This equipment has many runners. Runners are attached in a series at equal distance. Behind theses runners or drills a series of presses are designed to cut down the trench in which seeds are to place.
(c)This machine also covered seeds with soil after placing them in the soil. It prevents damage caused by birds.
(d) Sowing by machine save time and labour of the farmer.
(iii) Adding Fertillisers-
Fertilisers are those substances which are added to the soil to increase the nutrients of it. These nutrients are helpful in the growth of the plants.
(a) The organic substance which is obtained by the decomposition of plant and animals waste dumped in the open pit is called manure. The decomposition is done by microorganism.
(b)The inorganic substance, full of nutrients, prepared in factories are called fertilisers.
(c) Continuous growing of crop diminishes its nutrients. It can be return to the soil only after adding manure or fertilizers to the soil.
(d) Crop rotation is the method to replenishing the soil with nutrients by growing different crops alternatively.
Eg:- In North farmer used to grow fodder in one season and wheat in other season.
Water is very necessary for proper growth of plants. Plants contain nearly 90% of water.
Importance of water for plants-
(a) Roots of plants absorbed water. They also absorbed minerals and fertilizers with water.
(b) Germination of seeds cannot take place without water.
(c)Nutrients dissolved in water get transported to the each part of the plant.
(d) Frost and hot air current damages plant. Watering plant can prevent damage in winter and summer. In winter water on the surface of plant convert into solid state,ie,snow. The conversion of the water from liquid state to solid state releases energy in the form of heat. This heat keeps plant warm.
In summer plants releases water due to transpiration .So, watering in summer keep plants cool.
Irrigation is the system to supply water in the fields for crops at appropriate intervals.
Intervals of supply water or irrigation depends on-
Sources of irrigation-
Traditional method of the irrigation-
Traditional methods are those methods in which irrigation or watering in fields done manually. Cattles and humans are used in these methods to irrigate fields.
(a) Moat(pully system)-
Moat or pully system is a very old system of irrigation. In India it is popularly known as ‘Ghiri’.In this system, a pully or ghiri is placed on the well with a rope. The one end of this rope is keep free to pull water from the well. A bucket is tied on the other end of the rope to pull water. When we lose the rope, bucket moves into the well. When we pull rope towards us, bucket came out from well with water in the bucket. It is easy to pull bucket through pully because it changes direction of force or load.
(b) Chain pump-
Chain pump is a system to irrigate field with many buckets fixed on a chain or wheel to pull water from water source. In this system, a wheel is fixed on a bottom or other wheel which is always immersed in the water. A chin having many buckets on it, runs on upper wheel to bottom or bottom wheel. A handle or rope is fixed on the upper wheel to move it. When upper wheel starts moving chain also move with it. As bucket reached to water source bucket filled with water, then second bucket filled with water. In this way, all buckets lift water and pour in the field.
Dhekli is a system in which water can be pull with the help of a wood bar. A bucket is tied on the one end of it and a heavy stone is tied on the other end of the bar. To collect water in bucket, it is pulled in the water source and lift water for watering.
Rahat is a system to pull water for irrigation which works on water wheel. In this system, many buckets are fixed on the chain. This chain runs on the wheel. This wheel is attached with other wheels . These wheels are geared with each other at right angle. These wheels are attached with a fulcrum which has a beam for ox. These wheels are under the ground in many systems and ox rotate over it. When ox rotate effort force executed and as a result load force applied at the other wheel. It also rotates and collects water in tied buckets and pours in to fields.
Modern methods of irrigation-
Modern methods of irrigations are those methods which help us to use water economically and use less labour.
(a) Sprinkler System-
Sprinkler system is a system which can be used on water deficient land easily and effectively. Pipes are connected with each other perpendicularly on a main pipe at regular intervals. These pipes have rotating nozzles to sprinkler water in all directions. Water flows through main pipe with the help of pump. This water sprinkled on the crop. It is a very good system for sandy soil.
(b) Drip Irrigation-
It is modern technique watering plants. In this system water reached to the roots drop by drop. Pipes are spread in whole field with small holes or small pipes. Water flows in the main pipe and reached drop by drop to the roots of plants with out wasting water.
(v)Protecting from weeds-
Weeds are undesirable plants which grow along with crop. The process in which weeds are removed are known as weeding. It is very necessary to remove weeds because they compete with the crops for nutrients , water,space and light. Therefore, they affect the growth of plants. We can control weeds by tilling the soil before sowing crops. Weedicides (chemical) can be sprayed on the weeds after diluted with water. Weedicides do not damage the crop.
Harvesting is a process in which crops cut after getting mature.
Threshing- Threshing is a process in which grains are separated from the chaff by thrashing or putting chaff on the floor with force. Thrashing can be done with machines also.
Winnowing – Winnowing is a process in which farmers separate grains with the help of air. Air blows away lighter chaffs and heavier grains fall back down. Winnowing can be done artificially by using fan.
(vii)Storage of grains-
Keeping of dried harvested crop in jute bags or metallic bins are known as storage of crop or grain. It is necessary to dry harvested crop or grains to keep away rats, bacteria and fungi from the grains. If freshly harvested grains are stored they may lose their germination capacity.