•Tillage is the process of removing the surface crust and creating germination-friendly conditions by manipulating the soil using tools and equipment.
•Tilth refers to the soil’s physical state in relation to plant development.
• Buck scraper (or) levelling plank – for substantial field levelling.
• “Porosity” refers to the percentage of soil volume filled by porespace.
• A healthy soil structure is a crumb and granular structure.
•Bulk density is the mass of dry soil per unit volume.
• “Puddling” is the mechanical manipulation of soil at high moisture content.
•Heavy plough, Peddamadaka, utilised for heavy ploughing in black cotton soils.
•Buck scraper is a levelling tool.
• Seed bed layout ridges plough bund former; broad bed furrow previous
• Weed control using a star weeder in groundnut.
• A rotating weeder used in lowland rice cultivation in Japan.
• Gorru = seed dril, Guntaka = blade harrow.
• The device known as the “Pallamanu” is used to level puddled dirt.
• Humus is the end (or) ultimate result of the breakdown of organic materials. Green manure should be applied during the blossoming stage of the crop.
•The depth of sowing is determined by the seed size.
• Due to the high temperature of Indian soils, it is unable to accumulate substantial levels of organic matter.
• When there is dew on the leaves, it is not a good idea to broadcast fertiliser. • Diancha is a green manure crop that is used to reclaim salty and alkaline soils.
• Drilling, seeding behind a country plough is a method of sowing that ensures consistent spacing for all plants.
• The Earth spins in a clockwise direction from west to east.
• “Thermoperiodism” is the response of living organisms to a regular shift in temperature, either day (or) night.
• Hydrometers are a type of precipitation metre.
• Mountain- caused rainfall (orographic rains).
Solistice → It’s the shortest distance between the sun and the earth. During the yearly passage of the earth around the sun, it happens twice, once in the south and once in the north of the celestial equation.
June – 21st
Dec – 22nd
Equinox : The astronomical day when the sun is directly above of the equator and light and darkness are equal.
March – 21st
Septermber – 22nd
• Surface emmission that isn’t a perfect black body is always less than one.
• Winter has the greatest albedo levels, as well as dawn and sunset.
• S.No. : Surface % of albedo
1. Fresh snow : 75 – 95%
2. Dry Sand duke : 35-45 %
3. Clay Soil : 20-35%
4. Wet sand : 20-30%
5. Deciduous forests : 10-20%
6. Human Skin bloude : 43-45%
7. Dark soil : 5-15%
•Heat capacity of between 0.3 and 0.6 cal/cm3
•Minerals have a specific heat of 0.18 to 0.20 cal/gm.
0 – 45 calories per gramme of humus
•”Chola King” built the “Grant Anicut” over the Cauvery River in Tamil Nadu.
•In South India, there are a lot of tanks, while in North India, there are a lot of inundation canals.
• First irrigation commission – 1901.
• Total geographical area – 328 m ha
• Average Rainfall – 1200 mm
• Total Precipitation – 400 m ha
• Major source of irrigation in Andhra Pradesh is Canals.
•Anicut – Embankment across a river.
•Ayacut – Irrigation area under a project.
•A soil with little structure causes water to percolate too quickly (or) too slowly.
•”Warabandi” is a suitable resorting technique for water distribution among farmers.
•In India, growing plants get access to around two-thirds of capillary water.
•Musi Project –
Nalgonda, Kaddem – Adilabad, Yerralakawa – East Godavari Rayalabanda
diversion scheme – Mahaboobnagar, Vamsadara – Srikakullum and Gajuladinne – Kurnool.
•The quantity of water a soil can store is determined by its texture.
•A platy structure can obstruct water flow downhill.
•2.65 g/cc particle density, 1.25 to 1.70 g/cc bulk density
Porasity = [(1-B.D/P.D) X 100]
•The soil is considered to be saturated and at its “Maximum retentive capacity” when all of the pores, large and tiny, are filled.
•Gravitational water (or free water) moves downhill via big pores.
•Capillary water is water that moves through tiny holes due to capillary force. It has a greater range of motion than free water. It can travel in any direction, but it will always increase the strain.
•”Hygroscopic water” is a thin coating over soil particles that plants cannot utilise.
•Adhesive and cohesive forces drive capillary migration.
•Water travels from saturated to unsaturated layers of the soil.
•Water circulation is more consistent in moist soils than in dry soils.
•Capillary movement is fastest in sandy soils and slowest in clay soils at saturation. Capillary movement is quick in clay and sluggish in sandy soils when the soil is unsaturated.
•Adhesion refers to the attraction of soil particles to water.
•Cohesion is the bonding of water molecules.
•Soil moisture tension is a measurement of the tenacity with which water is maintained in the soil and depicts the force per unit area required to extract water from the soil. It frequently manifests itself in the form of an atmosphere.
•The amount of water in the soil is not indicated by the moisture tension. To demonstrate how much moisture a particular soil can keep under varying tensions.
•It is necessary to develop “moisture extraction curves” (soil moisture characteristic curves).
•The logarithm of height in a column of water is defined as PF. The saturated soil’s Pf value is ‘O’.
•P.W.P – 4.2 soil moisture tension – 15 bars at Field capacity pF 2.54
•Irrigation circulation “Water intake = percolation + infiltration” refers to the flow of water from the surface into the soil via the soil.
•The downward movement of water from the surface into the soil is known as infiltration.
•The passage of water through the soil profile is known as percolation.
•The permeability (or) hydraulic conductivity of the soil determines the rate of percolation.
•Permeability refers to the ability of soil to convey air and water.
•The co-efficient ‘K’ represents hydraulic conductivity (Proportionality factor).
• Darcy’s law = V = Ki
V = Effective flow velocity
i = Hydraulic gradient
‘K’ depends on the properties of fluid as well as the soil.
•The lateral flow of water in the soil is known as seepage.
•Leaching is the process of removing soluble salts from soil by passing water through it.
•A well-drained soil’s field capacity is the quantity of water it can hold after free water drains against gravity.
•F.C – PWP = available water
•The field capacity of the soil is commonly considered to be 1/3 of the atmospheric tension.
•The soil moisture required to meet transpiration requirements is known as the permanent wilting point.
•Ultimate wilting point – At this point, even with water, the plant will die.
•Root development is limited by a higher water table, and roots may die as a result.
•The typical water extraction pattern is 40% moisture from the top quarter, 30% moisture from the second quarter, 20% moisture from the third quarter, and 10% moisture from the fourth quarter.
•The soil depth from which the crop collects the majority of the water required for “evapo transpiration” is known as the effective root zone depth.
•Cotton has a deep root system, while safflower has a deep root system.
•Infiltration is reduced by soil crusting.
- Basics of Silviculture
- Agriculture History of India
- Silvicultural System of Concentrated Regeneration
- Coppice System of Silviculture
- Branches of Horticulture