AgronomyAgronomy

1. “the science of growing plants from 1. “the science of growing plants from creating on-farm opportunities to creating on-farm opportunities to environmental protection and environmental protection and ecosystem management”ecosystem management”

2. “the science of utilizing plants for 2. “the science of utilizing plants for food, fuel, feed, and fiber” food, fuel, feed, and fiber”

3. “Science of agriculture that deals 3. “Science of agriculture that deals with all aspects of field crop with all aspects of field crop production and soil management” production and soil management”

4. “The word derived from Greek word 4. “The word derived from Greek word “agros” meaning fields and “nomos” “agros” meaning fields and “nomos” meaning management indicating meaning management indicating crop production and soil crop production and soil management on scientific approach” management on scientific approach”

Principals of Agronomy/Crop Principals of Agronomy/Crop ProductionProduction

1.1. Cultural practicesCultural practices

2.2. Seed and varietySeed and variety

3.3. IrrigationIrrigation

4.4. ManuringManuring

5.5. Plant protectionPlant protection

6.6. Post harvest managementPost harvest management

Cultural PracticesCultural Practices

1. Tillage1. Tillage

i.i. Primary tillage (preparatory tillage)Primary tillage (preparatory tillage)

ii.ii. Secondary tillage (seed bed Secondary tillage (seed bed preparation)preparation)

iii.iii. Tertiary tillage (Interculture)Tertiary tillage (Interculture)

2. Sowing Method2. Sowing Method

i.i. Ridge sowingRidge sowing

ii.ii. Line sowingLine sowing

iii.iii. Pit plantingPit planting

Seed and VarietySeed and Variety

• Varieties according to sowing timeVarieties according to sowing time

• Seed rateSeed rate

• Depth of sowingDepth of sowing

IrrigationIrrigation

• Irrigation requirementIrrigation requirement

• Method of irrigationMethod of irrigation

ManuringManuring

• RateRate

• Method of applicationMethod of application

• Green manuringGreen manuring

• Crop rotationCrop rotation

Plant ProtectionPlant Protection

• Weed managementWeed management

• Insect managementInsect management

• Disease managementDisease management

Post Harvest ManagementPost Harvest Management

How plants growHow plants grow

RequiremenRequirementsts LightLight

WaterWaterAirAirEssential mineralsEssential mineralsAnchorageAnchorageFavorable climatic Favorable climatic

conditionsconditions

Plant utilizes raw material for Plant utilizes raw material for food food manufacturemanufacture through through photosynthesisphotosynthesis

COCO22 + H + H22OO CC66HH1212OO66

proteins, fats, starch,proteins, fats, starch,

cellulosecellulose

Essential nutrients (C, H, O) 18% of plant Essential nutrients (C, H, O) 18% of plant weightweight

Water Water 80% 80%

Mineral constituentsMineral constituents 2% 2%

1616 essential nutrientsessential nutrients

Primary nutrients,Primary nutrients,

N, P, KN, P, K

Secondary nutrients,Secondary nutrients,

Ca, Mg, SCa, Mg, S

Micro-nutrientsMicro-nutrients

Fe, Zn, Co, Cl, Mn, Fe, Zn, Co, Cl, Mn, BB

The soil that feeds plantsThe soil that feeds plants

Soil composition

Mineral constituents(45-49%)

+Organic matter

(1-5%)

Water(25% )

Air(25%)

Physical properties of soil to Physical properties of soil to regulate productivityregulate productivity

Water holding capacityWater holding capacity

Nutrients retention capabilityNutrients retention capability

Movement of air and heatMovement of air and heat

Mechanical impedance to root development Mechanical impedance to root development and seedling emergenceand seedling emergence

Ease with which the soil can be tilledEase with which the soil can be tilled

Soil textureSoil texture

Soil structureSoil structure

Soil chemical propertiesSoil chemical properties

Organic matterOrganic matterCation exchange capacity (CEC)Cation exchange capacity (CEC)Soil reaction (pH)Soil reaction (pH)C:N ratio (Carbon to Nitrogen)C:N ratio (Carbon to Nitrogen)Salinity (EC)Salinity (EC)

The living part of soilThe living part of soil

BacteriaBacteria AlgaeAlgae ProtozoaProtozoa FungiFungi InsectsInsects EarthwormsEarthworms AzotobactorAzotobactor ClostridiumClostridium

Fertilizer-food for the hungry Fertilizer-food for the hungry plantplant

• 30-50% contribution toward yield30-50% contribution toward yield

• Improve quality of the produceImprove quality of the produce

• Resistance to cold/water stressResistance to cold/water stress

• Increase/decrease plant resistance to Increase/decrease plant resistance to diseases/insectsdiseases/insects

What is fertilizerWhat is fertilizer

• Plant foodsPlant foods

• Supplement the soil supply of Supplement the soil supply of essential nutrientsessential nutrients

• Defined as a substance used for the Defined as a substance used for the purpose of supplying one or more of purpose of supplying one or more of the elements essential for growth.the elements essential for growth.

Fertilizer termsFertilizer terms

• Straight fertilizer; contain single Straight fertilizer; contain single nutrient, examples are Urea, SSP, TSP, nutrient, examples are Urea, SSP, TSP, SOP, MOPSOP, MOP

• Compound fertilizer; contain two or Compound fertilizer; contain two or more elements, examples are DAP, more elements, examples are DAP, NPKNPK

Expression of nutrientsExpression of nutrients

• N= elemental form, N on %age by weight N= elemental form, N on %age by weight basisbasis

• P= PP= P22OO5,5,

• Px2.29= PPx2.29= P22OO55

• PP22OO55x0.44=Px0.44=P

• K=KK=K22OO

• Kx1.2=KKx1.2=K22OO

• KK22Ox0.83=KOx0.83=K

Fertilizers available in Fertilizers available in PakistanPakistan• UreaUrea• DAPDAP• SSPSSP• TSPTSP• Potassium sulphatePotassium sulphate• Potassium chloridePotassium chloride• NPKNPK• Ammonium NitrateAmmonium Nitrate

Special fertilizersSpecial fertilizers

• PolyphosphatesPolyphosphates

• Slow release fertilizers: concept based on Slow release fertilizers: concept based on 2 imp. points 2 imp. points

1.1. Certain nutrients particularly N and S can Certain nutrients particularly N and S can leach beyond root zone, slow release leach beyond root zone, slow release increase their efficiencyincrease their efficiency

2.2. Certain crops require to be fertilized Certain crops require to be fertilized frequently—reduce their requirement frequently—reduce their requirement e.g. e.g.

• Super coated urea (SCU)-for riceSuper coated urea (SCU)-for rice

• Urea super granule (USG)Urea super granule (USG)Liquid fertilizersLiquid fertilizersFertilizer pesticide mixturesFertilizer pesticide mixtures

Mechanism of nutrient Mechanism of nutrient uptakeuptake

DiffusionDiffusion

Mass flowMass flow

Root interceptionRoot interception