Agronomy 1. “ the science of growing plants from creating on-farm opportunities to environmental protection and ecosystem management ” 2. “ the science of utilizing plants for food, fuel, feed, and fiber ”

3. “ Science of agriculture that deals with all aspects of field crop production and soil management ” 4. “ The word derived from Greek word “ agros ” meaning fields and “ nomos ” meaning management indicating crop production and soil management on scientific approach ”

Principals of Agronomy/Crop Production 1. Cultural practices 2. Seed and variety 3. Irrigation 4. Manuring 5. Plant protection 6. Post harvest management

Cultural Practices 1. Tillage i. Primary tillage (preparatory tillage) ii. Secondary tillage (seed bed preparation) iii. Tertiary tillage (Interculture)

2. Sowing Method i. Ridge sowing ii. Line sowing iii. Pit planting

Seed and Variety Varieties according to sowing time Varieties according to sowing time Seed rate Seed rate Depth of sowing Depth of sowing

Irrigation Irrigation requirement Irrigation requirement Method of irrigation Method of irrigation

Manuring Rate Rate Method of application Method of application Green manuring Green manuring Crop rotation Crop rotation

Plant Protection Weed management Weed management Insect management Insect management Disease management Disease management

Post Harvest Management

How plants grow Requirements Light Light Water Water Air Air Essential minerals Essential minerals Anchorage Anchorage Favorable climatic conditions Favorable climatic conditions

Plant utilizes raw material for food manufacture through photosynthesis CO 2 + H 2 OC 6 H 12 O 6 proteins, fats, starch, cellulose

Essential nutrients (C, H, O) 18% of plant weight Water 80% Mineral constituents 2%

16 essential nutrients Primary nutrients, N, P, K Secondary nutrients, Ca, Mg, S Micro-nutrients Fe, Zn, Co, Cl, Mn, B

The soil that feeds plants Soil composition Mineral constituents (45-49%) + Organic matter (1-5%) Water (25%) Air (25%)

Physical properties of soil to regulate productivity Water holding capacity Nutrients retention capability Movement of air and heat Mechanical impedance to root development and seedling emergence Ease with which the soil can be tilled Soil texture Soil texture Soil structure

Soil chemical properties Organic matter Organic matter Cation 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 soil  Bacteria  Algae  Protozoa  Fungi  Insects  Earthworms  Azotobactor  Clostridium

Fertilizer-food for the hungry plant 30-50% contribution toward yield 30-50% contribution toward yield Improve quality of the produce Improve quality of the produce Resistance to cold/water stress Resistance to cold/water stress Increase/decrease plant resistance to diseases/insects Increase/decrease plant resistance to diseases/insects

What is fertilizer Plant foods Plant foods Supplement the soil supply of essential nutrients Supplement the soil supply of essential nutrients Defined as a substance used for the purpose of supplying one or more of the elements essential for growth. Defined as a substance used for the purpose of supplying one or more of the elements essential for growth.

Fertilizer terms Straight fertilizer; contain single nutrient, examples are Urea, SSP, TSP, SOP, MOP Straight fertilizer; contain single nutrient, examples are Urea, SSP, TSP, SOP, MOP Compound fertilizer; contain two or more elements, examples are DAP, NPK Compound fertilizer; contain two or more elements, examples are DAP, NPK

Expression of nutrients N= elemental form, N on %age by weight basis N= elemental form, N on %age by weight basis P= P 2 O 5, P= P 2 O 5, Px2.29= P 2 O 5 Px2.29= P 2 O 5 P 2 O 5 x0.44=P P 2 O 5 x0.44=P K=K 2 O K=K 2 O Kx1.2=K 2 O Kx1.2=K 2 O K 2 Ox0.83=K K 2 Ox0.83=K

Fertilizers available in Pakistan Urea Urea DAP DAP SSP SSP TSP TSP Potassium sulphate Potassium sulphate Potassium chloride Potassium chloride NPK NPK Ammonium Nitrate Ammonium Nitrate

Special fertilizers Polyphosphates Polyphosphates Slow release fertilizers: concept based on 2 imp. points Slow release fertilizers: concept based on 2 imp. points 1. Certain nutrients particularly N and S can leach beyond root zone, slow release increase their efficiency 2. Certain crops require to be fertilized frequently — reduce their requirement e.g.

Super coated urea (SCU)-for rice Super coated urea (SCU)-for rice Urea super granule (USG) Urea super granule (USG)  Liquid fertilizers  Fertilizer pesticide mixtures

Mechanism of nutrient uptake Diffusion Mass flow Root interception