Basic concepts in crop production

AGRONOMY

Scientific crop production is called Agronomy.

CROP

Community of plants to produce yield, which are economically important, called Crop.

OBJECTIVES OF CROP

To provide the food to the human beings and also useful to animals.

GENOTYPE

Genotype are the new varieties and cultivars.

• Poor yield    =      poor genotype +         good environment
• Poor yield    =      poor genotype +         poor environment
• Poor yield    =      good genotype +         poor environment
• Good yield   =      good genotype +         good environment

FACTORS EFFECTING GENOTYPE

These are the factors effecting genotype

• Vulnerability of seed.
• Viability of seed.
• Poor storability.

SOIL

It is a layer of lithosphere. Soil is composed of aluminium and silica is 1:1 or 1:2 ratio.

Soil is the basic medium for plant growth.

PHYSICAL PROPERTIES OF SOIL

Physical properties of soil are

• Bulk density
• Porosity
• Soil texture and structure.

CHEMICAL PROPERTIES OF SOIL

Chemical properties of soil are

• Cation (-), Anion (+) exchange capacity
• Soil ph.
• Soil salts or electrical conductivity
• Soil types.

CROPING SEASONS

We have two cropping seasons

• Rabi
• Kharif.

RABI CROPS

Those crops which growing season starts in winter

For example; Wheat, Barley etc.

KHARIF CROPS

Those crops which growing season starts in summer

For example; Cotton, Rice etc.

TYPES OF PLANTS ON THE BASIS OF PHOTOSYNTHETIC SYSTEMS

There are two types of plants on the basis of photosynthetic systems

• C₃ Plants (Mesophyllous photosynthetic system)
• C₄ Plants (PEP carboxyl’s photosynthetic system)

DISTINGUISHING CHARACTERISTICS OF C₃ AND C₄ PLANTS

• C₄ are tropical plants.
• C₄ plants productivity is greater than C₃ plants.
• C₄ plants are Sugar cane, Sorghum, Milit, Maize, and Weeds.
• C₄ plants does not utilize its own chloroplast whether C₃ plants does use it.

SOIL COMPOSITION

Soil is the basic medium for plant growth.

Soil contain

• 25% moisture
• 25% Airspace
• 5% Organic matter
• 45% Minerals.

ESTIMATED NUMBER OF COMMON MICROORGANISMS PER GRAM OF SOIL.

• Bacteria                           3,000,000 to 500,000,000
• Actinomycetes                  1,000,000 to 20,000,000
• Fungi                               5,000 to 1000,000
• Protozoa                          1,000 to 500,000
• Algae                               1,000 to 500,000

CN RATIO (CARBON TO NITROGEN RATIO)

CN ratio indicates the decomposition of organic matter. Number of carbon units utilizes to produce nitrogen unit.

Crop Name	C	:	N
· Green Legumes	12	:	1
· Compost (decompose form of O.matter)	15	:	1
· Garbage	25	:	1
· Sugar Cane thrash	50	:	1
· Weeds	80	:	1
· Rice straw	80	:	1
· Saw dust	500	:	1