CROP PRODUCTION AND MANAGEMENT [ CLASS-8 ]

 

 SCIENCE             CLASS-VIII

CROP PRODUCTION AND MANAGEMENT

1.CROP

• Same kind of plants cultivated at one place on a large scale is called a crop.


• Variety of crops depends on different conditions like temperature, humidity and rainfall.


• Types of crops :-

A. KHARIF CROPS[Rainy season crops]:- These are sown in June/July and harvested in September/October. Examples- Paddy, Maize, Soyabean, Groundnut, Cotton etc.

paddy	maize	soyabean	ground nut

 B. RABI CROPS[Winter season crops] :-These are sown in October and harvested in March.Examples- wheat, gram, pea, mustard, linseed etc.

wheat	gram	pea	mustard

2.AGRICULTURAL PRACTICES

Several activities or tasks related to the cultivation of crops are called agricultural practices.

1. Preparation of soil
2. Sowing
3. Adding manure and fertilisers
4. Irrigation
5. Protecting from weeds
6. Harvesting
7. Storage

(i) PREPARATION OF SOIL

• This is the first step before growing a crop.
• Tilling or Ploughing:- The process of loosening and turning of the soil is called tilling or ploughing.
• How tilling is done ? - Tilling is done by agricultural implements-Plough , Hoe and Cultivator.
• What benefits from the tilling ? -
  (a)This allows the root to penetrate deep into the soil and to breathe easily.
  (b)This helps in the growth of earthworms and microbes present in the soil. They further turn and loosen the soil and add humus to it.
  (c) Soil contains minerals, water, air, and some living organisms. Dead plants and animals get decomposed by soil organisms and various nutrients in the dead organisms are released back into the soil. These nutrients are absorbed by the plants.
  (d)Tilling brings the nutrient-rich soil to the top so that plants can use these nutrients.

plough	cultivator connected with tractor	hoe

(ii) SOWING

• Sowing is an important part of crop production.
• Farmers prefer to use good quality ,clean and healthy seeds which give high yield.
• Selection of seeds:-How to separate good-healthy seeds from damaged seeds ? - If a handful of seeds be put in water taken half in a beaker and be left for some time then we find the damaged seeds float on water because they are hollow and lighter whereas good quality seeds sink in water.
• Seeds sowing tools:- (a) Traditional tool - This is a funnel-shaped tool. In this tool, seeds are filled into the funnel, passed down through two or three pipes having sharp ends.These ends pierce into the soil and place seeds there.
  (b)Seed drill:- This is used for sowing with the help of tractors.This sows the seeds uniformely at equal distance and depth.It ensures that seeds get covered by the soil after sowing.This protects seeds from being eaten by birds. This tool saves time and labour.
• Appropriate distance between the seeds is necessary. Why? :-
  (a) To avoid overcrowding of plants.
  (b)This allows plants to get sufficient sunlight, nutrients and water from the soil.

traditional tool for sowing seeds	seed drill connected with a tractor	seed drill

(iii) ADDING MANURE AND FERTILISERS

• Manure and Fertilisers:- The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilisers.
• Soil supplies mineral nutrients to the crop plants. These nutrients are essential for the growth of plants.
• Continuous cultivation of crops makes the soil poor in nutrients. Therefore, farmers have to add manure to the fields to replenish the soil with nutrients.
• Manuring:- The process of adding manure to the soil to replenish the nutrients in it, is called manuring.
• Improper or insufficient manuring results in weak plants.
• Manure:- It is an organic substance obtained from the decomposition of plant or animal wastes.
• Use of manure improves soil texture as well as its water retaining capacity.
• Crop rotation also replenishes the soil with nutrients.
• Rhizobium bacteria, present in the nodules of roots of leguminous plants, fix atmospheric nitrogen.
• How the manure is prepared ? :- Plant or animal wastes are dumped in pits at open places and are allowed to decompose. The decomposition is caused by some microorganisms. The decomposed matter is used as organic manure.
• Fertilisers :- These are chemicals which are rich in a particular nutrient.These are produced in factories. Examples - (a) urea (b) ammonium sulphate (c) super phosphate (d) potash (e) NPK [Nitrogen, Phosphorus, Potassium ].
• Fertilisers increase productivity of crops but their excess use make the soil less fertile.
• Fertilisers are water pollutant.

Difference between Fertiliser and Manure

S.No.	Fertilisers	Manure
1.	It is a man - made inorganic salt.	It is a natural substance obtained by the decomposition of cattle dung and plant residues.
2.	It is prepared in factories.	It can be prepared in the fields.
3.	It does not provide any humus to the soil.	It provides humus to the soil.
4.	These are very rich in plant nutrients like N , P , K.	These are relatively less rich in plant nutrients.

Organic manure is considered better than fertilisers. why ?

Reasons are :-
(i) Manure increases the water holding capacity of the soil.
(ii) Manure makes the soil porous which makes easy exchange of gases.
(iii) Manure improves the texture of the soil.

(iv)IRRIGATION

What do you mean by irrigation ?
Supplying water to crops at regular intervals is called irrigation.

How are the irrigation intervals and frequency vary ?
This varies from -

(i) crop to crop

(ii)soil to soil

(iii) season to season
What are the different sources of water for irrigation ?
Different sources of water for irrigation are :- wells , tubewells, ponds, lakes, rivers, dams, and canals.

What are the different methods of irrigation ?
methods of irrigation can be classified as the following:-
(A) Traditional methods:-

1. moat (pulley - system)
2. chain pump
3. dhekli
4. rahat (Lever system)

(B)Modern methods :-
Modern irrigation methods have been designed to minimize water waste and maximize crop yield.

1. Sprinkler irrigation:-
   This method is similar to natural rainfall. Water is distributed through a system of pipes usually by pumping.It is then sprayed into the air through sprinklers so that it breaks up into small water drops which fall to the ground.
2. Drip irrigation:-
   
3. Subsurface irrigation
4. Surface irrigation