Tilth and Tillage – Effects of Tillage on soil & Plant growth
Effects of Tillage on soil & Plant growth:
A) Effect on soil:
1) loosens the soil which favors the germination & growth of crop,
2) Improves the soil structure due to alternate drying and cooling,
3) Improves soil permeability, soil aeration & soil inversion,
4) Facilitates the movement of water in soil,
5) Results in soil & water conservation through higher infiltration, reduce run-off & increase depth of soil for moisture storage,
6) Holds more water in the soil,
7) Increased soil aeration helps in multiplication of micro-organisms,
8) Org. matter decomposition is hastened resulting in higher nutrient “availability,
9) Increase aeration helps in degradation of herbicide and pesticide residues & harmful allelopathic chemicals exuded by roots of previous crops or weeds.
Tillage operations also influence the physical properties of soil like:
1) Pore space: Tillage increase the pore spaces i.e. space between the soil particles, due to equal amount of capillary & non- capillary (Macro & microspores) pores. This facilities free movement of air & moisture in the soil & increases infiltration.
2) Soil structure: Soil with crumble & granular clods are considered as soil with good structure which can be achieved by proper tillage operations at optimum moisture. This reduces the soil loss due to erosion.
3) Bulk density: when soil is loosened, the soil volume increases without any effect on weight. Therefore, bulk density of tilled soil is less than untilled soil which is favorable in many ways for crop, micro organisms, etc.
4) Soil colour: Tillage increases oxidation and decomposition resulting in fading of colour The org. matter is mainly responsible for the dark brown to dark grey colour of soil.
5) Soil water: Tillage improves soil water in different ways which depends on soil porosity, soil depth & roughness. also increases rate of infiltration, water holding capacity (WHC) & hydraulic conductively.
6) Soil temperature: Tillage creates up to soil temperature for seed germination & seed establishment. Tillage loosens the soil surface resulting in decrease of thermal conductivity (rate of heat transfer at which the heat penetrates) and heat capacity (heat storage / unit area)
B) Effects on crop growth:
1) Tillage loosen the soil thereby favors the germination & establishment of seeding.
2) Tillage helps in maintaining the optimum plant stand,
3) Increases depth of root penetration,
4) Roots proliferate profusely in loose soil & increase the growth of seminal & lateral roots.
5) Reduce the competition within crop & weeds for light, water, nutrients & space thereby helps in better growth of crop,
6) Tillage reduce the pest attack on succeeding crop,
7) Tillage helps in availability of nutrients to crop in proper amount.