Type of Hydrogen- Green Hydrogen Brown Hydrogen Grey Hydrogen Blue Hydrogen

Types of Hydrogen on the basis of production

Green Hydrogen

It is produced by electrolysis of water using renewable energy like wind, solar energy. India is front runner for production of green hydrogen.

Brown Hydrogen

It is hydrogen produced by using of coal. Emission gases are released in atmosphere.

Grey Hydrogen

It is hydrogen produced by using natural gas. Emission gases are released into atmosphere.

Blue Hydrogen

In this hydrogen is produced by using natural gas, and emission gases are absorbed and not to be released into atmosphere.

CLASS – 7 : CHAPTER – 1 NURITION IN PLANTS KEY WORDS, SUMMARY AND FACTS

CLASS – 7 : CHAPTER – 1 NURITION IN PLANTS

LESSON NOTES – KEY WORDS, SUMMARY AND FACTS    

KEYWORDS:

·       Autotrophic nutrition: mode of nutrition in which organisms prepare their own food.

·       Chlorophyll: green pigment present in the leaves of plants.

·       Heterotrophic nutrition: mode of nutrition in which organisms do not prepare their own food; they derive their food from plants, or animals, or both.

·       Host: the living organisms from which a parasite derives its food.

·       Insectivorous plants: insect-eating plants.

·       Nutrition: the process, of obtaining, and utilising, food by a living organism.

·       Nutrients: Carbohydrates, proteins, fats, vitamins and minerals are components of food. These components of food are necessary for our body and are called nutrients.

·    Parasitic nutrition mode: of nutrition in which non-green plants live on other living organisms and obtain their food from them.

·       Photosynthesis: the process through which green plants prepare their own food.

·       Saprotrophic nutrition: mode of nutrition in which some plants feed on dead and decaying matter.

·       Stomata: tiny pores that are present on the surfaces of leaves; useful for exchange of gases.

·       Vessels: channels, to transport water and minerals, to different parts of the plant.

    SUMMARY:

·       All organisms need food and utilise it to get energy for growth and maintenance of their body.

·       Green plants synthesise food for themselves by the process of photosynthesis. They are autotrophs.

·       Plants like Cuscuta are parasites. They take food from the host plant.

·       Plants use simple chemical substances like carbon dioxide, water and minerals for the synthesis of food.

·       Chlorophyll, water, carbon dioxide and sunlight are the essential requirements for photosynthesis.

·       Complex chemical substances such as carbohydrates are the products of photosynthesis.

·       Solar energy is absorbed by the chlorophylls present in leaves/plants.

·       Oxygen is produced during photosynthesis.

·       Oxygen released in photosynthesis is utilised by living organisms for their survival.

·       Many fungi derive nutrition from dead and decaying matter. They are saprotrophs.

·       A few plants and all animals are dependent on others for their nutrition and are called heterotrophs.

    FACTS:

 ·    Euglena is an organism that shows both autotrophic and heterotrophic modes of nutrition. It has both plant and animal-like features.

·    Some plants have leaves that are not green in colour. Such leaves contain chlorophyll but the green colour is masked due to the presence of other coloured pigments. The presence of additional pigments causes other leaf colours, such as red in coleus and purple in red cabbage.

      However, such leaves can still perform photosynthesis. However, some variegated leaves have yellow patches. Such yellow areas on the leaf do not contain any chlorophyll and hence, cannot perform photosynthesis.

 Hence, solar energy is the ultimate source of energy for all living organisms.

·       Both deer and lion depend on plants. If there were no plants, deer would not survive and if there were no animals, like deer, the lions, too, would die. Plants, in turn, depend on solar energy.

·       You must have observed

(i)          A white cottony growth on leather articles in humid weather

(ii)          Mushrooms growing on rotting wood and

(iii)         Greenish-blue patches on rotting fruits. A cottony growth, developing into coloured patches, is a common occurrence on stale bread.

These organisms belong to the group of fungi and bacteria, and they exhibit the saprotrophic mode of nutrition.

Crop production and management

 Notes

Crop

Plants of the same kind that are grown and cultivated as a source of food in a large cultivable land is called crop.

Types of Crops

1. Kharif Crops : The crops which are sown in the rainy season are called kharif crops. The rainy season in India is generally from June to September.

Example-Paddy, maize, soyabean, groundnut and cotton are kharif crops.

2. Rabi Crops : The crops grown in the winter season (October to March) are called rabi crops. 

Examples -wheat, gram, pea, mustard and linseed.

3.Zaid crops- are summer season crops grown on the sub-continent on dry lands which do not have to wait for monsoons. They grow in the long duration between Rabi and Kharif crop season, mainly from March to June. Example- Cucumber, Watermelon, Bitter gourd (Karela) 

Agricultural practices-

Cultivation of crops involves several activities undertaken by farmers over a period of time are called agricultural practices. These are as-

(i) Preparation of soil

(ii) Sowing

(iii) Adding manure and fertilisers

(iv) Irrigation

(v) Protecting from weeds

(vi) Harvesting

(vii) Storage

i) Preparation of soil-

·       Preparation of soil is the first step in cultivating crop for food production.

·       The soil is prepared for sowing the seeds of the crop.

·       This is carried out using various processes and tools.

     Tilling or Ploughing

The process of loosening and turning of the soil is called tilling or ploughing and is done by using a plough.

 

Plough

·       Plough is a device that is used by farmers for different purposes such as adding of fertilizers, tilling and loosening of the soil.

·       It is also used for adding fertilizers to the soil, removing weeds, scaping of soil etc.

·       The ploughshare is the triangular iron strip.

·       A plough-shaft is the main part of the plough which is made using a log of wood.

·       The other end of the shaft has a handle.

·       The other end is attached to a beam which is placed on the bull’s necks.

·       A wooden, traditional plough can be operated by a pair of an ox and a man.

·       Nowadays these wooden ploughs are being replaced by the iron ploughs.

 

 Hoe

A hoe is a tool that used to dig up soil to remove weeds and also loosen up the soil before planting a sapling.

Cultivator

·     A cultivator is attached to the tractor and helps in loosening soil.

·   Cultivators are used instead of ploughs since they are faster.

 

 Importance preparation of soil-

a. The loosened soil helps in the growth of earthworms and microbes present in

the soil. 

b. These organisms are friends of the farmer since they further turn and loosen the soil and add humus to it.

ii) Sowing

·       Sowing the process of planting the seeds in the soil.

·       The seeds are sowed in the soil that is loosened by cultivator or plough.

 

Quality of the Seeds

·   Quality of the seed is an important factor that determines the crop yield.

·    Selection of good seeds is done by putting the seeds in water.

·    The dead and damaged seeds become hollow and float on water whereas the good seeds sink.

 

Traditional Tools

·       Before the advent of modern agricultural machinery, traditional tools were used by farmers.

·       These include ploughs, shovels, scythes and pickaxes.

·       The traditional tool used to sow the seeds was like a funnel.

·       Once seeds put into this funnel, they would go to 2-3 tubes having sharp ends.

·       The ends will pierce into the soil and place the seeds there.

Seed Drill

·   Seed drills are used for sowing with the help of tractors.

·   It ensures that seeds are sown uniformly, at a particular depth and are covered by soil after sowing.

Germination of Seeds

·    Germination of the seed happens when the seed is sowed in the land and watered.

·    A plant starts to emerge from the seed and starts to grow.

iii) Adding Manure and Fertilizers- it is method to replenish to soil with nutrients 

 ·   Manures and fertilizers are the substances that are added to the soil to increase their fertility.

·    While manures are made by decomposition of organic substances, fertilizer is made of inorganic chemicals.

Difference between Manure and Fertilizers

S.No.	Fertilizer	Manure
1.	Fertilizer is an inorganic salt	Manure is prepared from organic matter such as human waste, cow dung and farm waste
2.	Fertilizers are manufactured in factories	Manures can be prepared in farms
3.	Fertilizers are added in comparatively smaller quantities	Fertilizers are added in comparatively smaller quantities
4	Fertilizers do not provide any humus to the soil	Manures provide a lot of humus to soil

Advantages of Manure :

a. it enhances the water holding capacity of the soil.

 b.it makes the soil porous due to which exchange of gases becomes easy.

c. it increases the number of friendly microbes.

d. it improves the texture of the soil.

Disadvantages of Using Fertilizers

· Excess use of fertilizers decrease the soil fertility. 

·  decreases the porousness of soil, responsible for frequent floods 

· Excessive use of fertilizer can cause pollution.

·   It can also change pH of the soil in certain rare cases.

Leaving the Land Fallow

·       When land is left fallow for a certain period of time, the land replenishes its nutrients by itself.

·    This land can be used for agriculture again.

Crop Rotation

·       Crop rotation ensures that the same crop will not grow continuously and lead to the erosion of the soil fertility.

    ·  By growing crops that require different sets of nutrient, we can ensure the soil fertility is restored.

iv) Irrigation - supply of water to crops.

it is by two way -

a). tradition methods- well, river, drains,ponds,dekully,water pump  etc

b). Modern methods - sprinkler system and Drip system (adapted from Israel country)

(v) Protecting from weeds

Weeds

Weeds are undesirable plants that may grow naturally along with the crop.

 

·  Weeds compete with the crops by absorbing all the water, nutrients, space and light.

Tilling

·       Tilling is a process done before sowing of crops that helps in uprooting and killing of weeds.

Manual Removal

·       Manual removal includes physical removal of weeds by uprooting them from the soil or chopping them off to ground level periodically.

     Weedicides

·       Chemicals used to kill the weeds are known as weedicides. Weedicides as 2,4-D

·       They usually don’t damage the crop.

(vi) Harvesting

·       Harvesting is the process of cutting the crop after it is mature.

Methods of Harvesting

·       Harvesting is done by 2 methods.

·       First is the manual method where a sickle is used.

·       Second is the mechanical method where a huge machine called harvester is used.

Threshing

·       Threshing is the process of loosening the grains from the chaff.

·       While it can be done manually, these days a machine is used that separates all the grain seeds.

 

Winnowing

·   Winnowing is the process of separation of grain seeds from the chaff using the help of the wind.

·   Due to the wind, the lighter chaff flies away and the heavier grains fall down.

vii. Storage

·       Storage of the grains is an important step in agriculture.

·       After harvesting steps, the ready grains are stored in granaries or silos.

·       The grains have to stored in a dry place that does not have a rodent or fungal infestation.

·       Fumigation of storage places is carried out to make it free from microbes.

Granaries

·       Granaries are the place where the freshly obtained food grains are stored.

Animal Husbandry

·       Animal husbandry is the management and care of farm animals for milk, egg or meat.