Define Agronomy & write the scope and importance of Agronomy.
Agronomy
‘It is the branch of agricultural science that deals with the principles and practices of field
management for the crop production.’
Scope
scope means at which things or places we can apply the knowledge of Agronomy. We can get all
possible things (production, yield) which the basic farmers or producers need. We can study of
the following contents.q
- Crop production – by maximizing our yield.
- Soil management – by improving soil fertility & productivity.
- Proper method of tillage – by using modern concept of tillage (Minimum tillage, Zero
tillage). - Suitable time of sowing – most important for seed germination & stability of plants.
- Proper method of sowing – (Drilling, Dibbling etc) for maintaining plant population.
- Maintaining farm implements & machineries in proper shape.
- Management of livestock including their feeding, management & disposal of farm and
animal products like milk and eggs etc.
Importance
For getting higher yield, agronomy benefits in…
– Organic farming
– Sustainable agriculture
– Forestry
– Mixed farming
– Poultry production
– Sheep & Goat rearing
– Mixed & Inter Cropping etc.
Explain the relationship of agronomy with other sciences & Role of agronomists in short.
Relationship with other sciences –
agronomy has a deep relation with the following sciences these are…
– Soil science & agriculture chemistry
– Genetics & plant breeding
– Horticulture
– Crop physiology
– Animal husbandry & dairy science
– Agro meteorology
– Agriculture extension
– Agriculture engineering
– Agriculture economics
– Agro-forestry
– Statistics
– Basic science like Mathematics, Zoology, Ecology etc
Role of agronomist- are…
– He should know the deep knowledge of agronomy.
– He should have the ability to convert his theoretical knowledge into practical.
– He is the co-ordinator of different SMS. (subject matter specialist)
– He is the consultant for the farmers.
– He should have mastery in agriculture production through research.
– He has well information of conducting experiments on different aspects like sowing time,
seed rate, spacing, fertilizer requirement, weed management, cropping systems etc.
Define Tillage & write Objectives of Tillage.
Tillage- ‘The manipulation of soil with tools & implements for loosening the surface crust and
bringing conditions favorable for the seed germination & crop growth.’
Objectives-
– To make the soil loose and porous (friable).
– To remove weeds.
– To mix manures and fertilizers.
– To destroy insects and their eggs.
– To aerate the soil.
– To increase the soil temperature.
– To remove stubbles.
– To break hard pan (big stones).
– To incorporate organic manures.
– To have repeated exchange of air & gases. Etc.
What is Soil tilth or Tilth ? Explain the characteristics of good soil tilth & how soil tilth
is measured.
Tilth – ‘It is the physical condition of soil resulting from tillage & said to be good when the soil
is soft, friable and properly aerated.’
Characteristics of good soil tilth –
– It should have higher % of larger aggregates (more than 5 mm diameter) for irrigated
farming.
– It should have higher % of smaller aggregates (1-2 mm diameter) for dry-land farming.
– Good soil tilth should be porous & has free drainage up to water table.
– Micro-pores (capillary) & Macro-pores (non-capillary) should be in equal proportion.
– The soil particles should not be easily eroded by water or wind.
– Soil should not be sticky when moist.
– Soil should permit easy infiltration of water.
Note (Aggregate means Different sized soil particle)
Measurement of soil tilth –
It can be measured by following methods
– 1) Feel and appearance method
– 2) Pore space content – equally divided in micro & macro pores.
– 3) Measuring size of soil aggregates – best size of soil aggregates ranges from 1 to 6 mm.
5) What are the Types of Tillage ? write the names of tools & implements used in different
tillage operations.
Types of tillage operations.
A) Preparatory tillage
‘Tillage operations which are carried out from the time of harvesting of the previous crop
to the sowing of the next crop are known as preparatory tillage/cultivation.
i) Primary tillage – Ploughing (cutting & inverting the soil)
ii) Secondary tillage – Clod crushing, Land leveling, Discing (Disking), Manure mixing.
B) Seedbed preparation
After preparatory tillage the land is to be laid out properly for irrigating crops if irrigation
is available for sowing or planting seedlings which is known as seedbed preparation.
i) Harrowing
ii) Preparation of irrigation layouts – Ridge & Furrow, Flat beds, BBF etc
iii) Sowing & covering of seeds
C) Intercultural operations / Inter-tillage / Inter-cultivation
The tillage operations which are carried out in the standing crops. Viz.
i) Thinning ii) Gap filling
iii) Weeding iv) Hoeing
v) Top dressing of fertilizers vi) Earthing up etc.
- Tools & implements used in tillage operations
- Plowing – MB plow, Chisel plow, Desi plow, Disc plow, Sub soil plow etc.
- Clod crushing – Norwegian harrow, Plank, etc.
- Land leveling – Bulldozer, Keni, Plank-leveler, etc.
- Manure mixing – Manually, Disc harrow, country plow, cultivator etc.
- Harrowing – Blade harrow, Disc harrow etc
- Irrigation layout – Ridger, Bund former (Sarayantra), Blade harrow etc
- Inter-tillage – Weeding hook (khurpi), Hoe, Japanese hoe.
- Harvesting – Combine harvester etc.
Explain the Modern Concept of Tillage.
The main aim of the modern concept of tillage is to minimize the cost of cultivation by reducing
some tillage operations.
Need of modern concept of tillage is very necessary today. In India maximum farmers are
marginal according to area & cost of cultivation is also increasing day by day, so the generation
of Minimum & Zero tillage is helpful.
The modern concept includes.
1) Minimum Tillage
2) Zero Tillage
3) Stubble Mulch Tillage
Modern Concept Preparatory Tillage Seedbed Preparation
Primary Secondary
Minimum Tillage Carried out Reduced
(1 instead of 2
harrowings etc)
Reduced by combining
Agril. Operations like
(seeding & fertilizer
application)
Zero Tillage Avoided Avoided Row zone only
&
Stubble Mulch Tillage –
Clean cultivation and unnecessary plowing lead to soil erosion due to heavy rains and
wind in the arid lands. A new approach has been developed for protecting soils all the time either
by growing crops or spreading of crop residues.
‘Covering the soil surface with crop residues or stubbles during the fallow periods for
protecting soil is known as stubble mulch tillage or stubble mulch farming.
Define a Seed and write the qualities/characteristics o a good seed.
Seed – ‘Any material used for sowing or planting or propagation of a crop is called a seed. It
maybe in the form of seed or seedlings or tubers or bulbs or rhizomes or roots or cuttings or graft
or any other vegetatively propagated material.’
Characteristics/Qualities of good seed…
– It should be genetically pure.
– It should have high germination percentage.
– It should be free from any insect pests.
– It should be free from disease-bearing organisms.
– It should be free from any admixture, dirt & inert material.
– It should be free from noxious, objectionable & satellite weed seeds.
– It should be clean, dry, bold, uniform in size & shape, etc.
Define Seed Treatment & write the objectives of seed treatment.
Seed Treatment – ‘It is the process in which the seeds are treated before sowing to overcome
heavy losses due to natural & unforeseen infections.’
Healthy seed materials, free from pests & diseases and having high viability is essential
for the establishment of the crop.
Objectives of seed treatment.
– Convenience in sowing.
– Disease control includes seed born, soil born & air born diseases.
– Insect control like white ants and other ants, termites.
– Quicker germination.
– Better yield.
– Protection against insects.
– Increasing nitrogen fixation.
– Inducing earliness (Vernalization).
Note- (Vernalization – is the treatment in which the seeds are soaked in water for inducing
germination. By giving this treatment, the maturity period of long durational crop is
shortened.)
- Name of crops Seed treatment Diseases
- Sorghum 300 mesh fine sulfur dust @ 3gm/kg of seed. Grain smut
- Bajra 20 % brine solution (NaCl or common salt solution) Ergot
- Rice 3 % brine solution. Blast
- Wheat Thirum (Fungicide) @ 2.5 gm/kg of seed. Smut
Define Seed Dormancy. Write down the causes of seed dormancy.
Seed Dormancy- ‘It is an internal condition of viable seed which does not allow its actual
germination, although suitable temperature, moisture and aeration etc are provided.’
Causes of seed dormancy-
– Inadequate supply of oxygen due to poor soil aeration.
– Excess or deficiency of moisture in the soil.
– Lower or higher soil temperature than the requirement of the crop.
– Attack of insects pests, diseases and birds on seed or newly emerging seedlings.
– More or less depth of sowing than the optimum depth of sowing.
– Rough or poor seedbed preparation.
– Faulty seeds – seeds with poor germination, diseased seeds, damaged seeds etc.
Short notes on
A) Types of Dormancy.
B) Methods of breaking dormancy.
C) Types or Stages of Seed multiplication.
Types of Dormancy – there are 3 types.
i) Innate dormancy – occurs due to the genetical characters of the seed or due to hard seed coat,
immature embryo etc.
ii) Enforced dormancy – due to conditions of deficient oxygen, excess CO2 & deep placement of
seed in the soil etc.
iii) Induced dormancy – due to sudden physiological change in seed by unfavorable climatic
conditions.
Methods of breaking seed dormancy – by
i) Scarification- hard seed coat is broken by chemical (by dipping seeds in dilute solutions of
HNO3, HCl or H2SO4) Or by mechanical means (by filling the seeds in gunny bags & beating
them to rupture the seed coat).
ii) Exposure of seed to light.
iii) Gas treatment.
iv) Soaking seeds in hot water – deep seeds in boiling water for 2-3 minutes.
C) Stages of seed multiplication –
– Seed viability is the ability or capacity of the soil to germinate.
There are five stages of seed multiplication
1) Nucleus seed 2) Breeder’s seed
3) Foundation seed 4) Certified seed 5) Truthful seed.
Enlist different methods of sowing & explain them in detail.
Sowing of crop is done by following methods
1. Broadcasting
2. Drilling or line sowing.
3. Dibbling
4. Transplanting
5. Planting
6. Putting the seeds in plough furrow.
12) Define plant population. What are the effects of plant population on crop growth and
yield.
–
Plant population- ‘It is defined as the number of plants per unit area’. Eg. Optimum plant
population of kharif hybrid sorghum is 1,37,000 to 1,50,000 plants/ha. ( plants pe hectare).
Effect of plant population plant growth & yield – Plant densities influence the crop growth
considerably….
1. High density is conducive for building up of pests diseases.
2. At very high density, seedling mortality is common.
3. High plant density may decrease protein & oil content.
4. At high plant density lodging is more.
5. With increasing density, competition for light, plant height increased.
6. Widely spaced plants have circular root distribution.
7. There is interpenetrated root growth at high density.
Define Crop/Planting geometry. Explain it.
Crop geometry or plant geometry is the pattern of distribution of plants over the ground or the
shape of the area available to the individual plant.
It includes – 1) Solid planting 2) Paired planting & 3) Skip Row planting
1) Solid planting – sowing of crop on a solid basis by drilling or dibbling method at same
spacing. (Eg. Groundnut at 30 cm × 10 cm)
2) Paired planting – sowing of crop on a given area in a specific paired arrangement.
(Eg. Soybean at 45 cm × 15 cm, but skip the one or two rows).
3) Skip Row planting – sowing of a crop in a specific row pattern and add the other one row
of different crop in it.
Define manures & Fertilizers. Write the importance of manures and fertilizers.
Manures – it is a well decomposed refuse from stable and barn yards including both animal
excreta and straw or other litter.
Fertilizers – these are industrially manufactured chemicals containing plant nutrients which
when added to the soil makes it productive and promotes plant growth.
Importance of manures and fertilizers –
– Manures and fertilizers are the main source of essential plant nutrients.
– Application of manures & fertilizers overcomes the deficiency symptoms of nutrients.
– Manures increase the physical condition of soil thereby productivity increases
– Manures increase the fertility of the soil.
– Fertilizers increase the per hectare yield of crop.
– Fertilizers help in giving maximum output (yield) than manures.
– Application of some fertilizers is helpful in different climatological calamities like in
excess rainfall, in drought condition. Etc.
Give the classification of manures & fertilizers with suitable examples.
Mainly three basic types…
A) Organic (Natural) – includes
Bulky organic manures Concentrated organic manures
FYM Groundnut cake
Compost Linseed cake
Vermi–compost Neem cake
Green manure cotton seed cake
Sheep manure Bone meal
Sewage waste Meat meal
Sludge Slaughter house refuse etc
B) Inorganic (Artificial) – includes
Nitrogenous Phosphatic Potassic Others
Urea SSP MOP Gypsum
Calcium nitrate DSP Sulphate of potash Lime
Ammonium sulphate Rock phosphate Potassium nitrate Complex fertilizers
Ammonium nitrate Basic slag – Micro–nutrients
Etc Row bone meal – Etc
C) Biofertilizers –
1. Rhizobium 2. Azotobacter 3. Azospirillum
4. PSB 5. Blue green algae
Enlist the methods of fertilizer application & explain any one. Write the time of
fertilizer application in short.
Methods of fertilizer application are…
1. Broadcasting
2. Drilling
3. Band placement
4. Point placement
5. Injection into soil
6. Fertigation
7. Root dipping
8. Foliar application
Time of fertilizer application…
1. Before sowing
2. At sowing
3. After sowing
4. Slit application
Define Green Manuring, write types of green manuring with an example, write advantages
& disadvantages of green manuring.
‘Green manuring is a practice of ploughing or turning the undecomposed green plant tissues into
the soil for the purpose of improving soil fertility.’
Types of green manuring Crops used in green manuring
1) Green manuring in situ Sunhemp, Dhaincha, Guar beans, Kulthi, Senji etc.
2) Green leaf manuring Glyricidia, Sesbania, Karanj etc.
Advantages of green manuring –
1. It increases the fertility of soil.
2. Being a legume, it fixes atmospheric nitrogen in the soil.
3. Being a quick growing crop, it helps in suppressing the weed growth.
4. It improves the soil structure, water holding capacity & decreases run off.
5. It adds organic matter & stimulates activities of soil micro-organisms.
Disadvantages of green munuring –
1. It may increase the incidence of pests & diseases.
2. There is loss of one season especially kharif.
18) Define Weed & explain the characteristics of weeds.
Weed – Any plant not sown in the field by farmer is out of place called weed.
Weed is an unwanted plant growing where it is not wanted & it is extremely noxious, useless and
poisonous.
Characteristics of weeds…
1. Weeds have high reproductive capacity.
2. They thrive well under adverse climatic condition.
3. They have morphological similarities with associated crops.
4. They can protect themselves from animal and human being.
5. They are harmful to crops, cattle and human being.
6. Weed seeds have similarities with crop seeds.
7. Weeds have competitive in nature. Etc.
19) Give the classification of weeds. & explain any one
–
Classification
A) Based on Life cycle.
B) Based on Habitat or place of occurrence.
C) Based on Dependence on other hosts.
D) Based on Soil type.
E) Based on plant family.
A) Based on Life cycle –
1. Annual – weeds complete their life cycle within a year. In kharif season or in winter season.
Ex. Aghada, Hazardana etc
2. Biennial – weeds require two years for completion of their life cycle.
Ex. Wild carrot etc.
3. Perennials – weeds continue their life cycle for years together.
Ex. Lavala, Hariyali etc.
20) Write Advantages (benefits) & Disadvantages (damages/losses) occurred by weeds.
– advantages disadvantages
Weeds add nutrients & organic matter into the
soil.
Reduction in crop yield.
Weeds control soil erosion. It increases the cost of cultivation.
Weeds are useful as fodder for animals. It reduces the quality of produce.
Weeds have medicinal value. Harm to animal and human being.
Weeds are used as vegetables. Check the flow of water in irrigation water.
Weeds serve as ornamental plants. Harbour insects & diseases.
Weeds are used in reclamation of alkali land. Depreciate the land value. Etc
21) Enlist the methods of weed control. Explain any one.
Classified in two groups.
A) Preventive – it consists of…
– Use clean seed.
– Use well decomposed FYM/Compost.
– Cut the weeds before seeding.
– Remove weed growth or keep irrigation & drainage channels clean or free from seeds.
– Clean all the farm implements before using it. Etc
B) Curative – it includes
1) Mechanical/Physical methods
2) Cultural methods
3) Biological methods
4) Chemical methods
Explanation-
1) Physical
i) Hand weeding ii) Hoeing iii) Hand pulling iv) Burning
v) Flooding etc
2) Cultural
i) Crop rotation ii) Kind of crops
iii) Use of fertilizers iv) Date & seed rate of sowing etc
3) Biological
Using of living organisms (insects) for controlling the weeds.
Ex.
Bio-Agents (insects) Host weeds
1. Cochineal scale (insect) Prickly pear (Nagphana)
2. Moths Lantana camara (Ghaneri)
3. Zygograma bicolorata (beetle) Parthenium (Gajar gavat) etc
4) Chemical
Using of different types of chemicals for the control of weeds.
Ex.
2,4-D, MCPA, Atrazine, Simazine, Glyphosate, Alachlor, Diuron, Pendamethalin
