Nutrient Sources and Application Methods

Flashcards covering nutrient sources, fertilizer types, application methods, and the concept of salt indices based on the lecture material.

Fertilizers

Organic or inorganic materials applied to soil or plant tissues to provide essential elements for growing plants, typically absorbed through roots or leaf stoma.

Inorganic Fertilizers

Synthetic or chemical fertilizers synthesized by various chemical treatments that are highly concentrated, easy to handle, and relatively cheap per unit of plant food delivered.

Organic Fertilizers

Natural fertilizers composed of recycled plant and/or animal-derived matter; they are bulky, provide organic matter to aid soil structure, and act as slow-release sources containing micro-nutrients.

Microbial Mineralization

The process through which organic amendments release nutrients over time in the soil.

Broadcasting

The uniform spreading of fertilizers over an entire field, suitable for crops with a dense stand and often involving large doses.

Basal Application

A form of broadcasting where fertilizer is applied at the time of sowing or planting.

Top Dressing

The broadcasting of fertilizers after crop establishment to provide additional nutrients during the growing season.

Placement

The application of fertilizers into the soil at a specific location with or without reference to the position of the seed.

Plough Sole Placement

A method where fertilizer is placed in a continuous band at the bottom of the plough furrow during ploughing, suitable for soils that dry out a few centimeters below the surface.

Deep Placement

The placement of fertilizers deep in the soil, below the seed or in the reduction zone, to prevent nutrient loss by run-off.

Localized Placement

The application of fertilizers into the soil close to the seed or plant to provide adequate amounts of nutrients.

Drilling

A method of applying fertilizer at the time of sowing, where the fertilizer and seed are placed in the same row but at different depths.

Side Dressing

The spreading of fertilizer in between the rows and around the plants.

Band Placement

The application of fertilizers in bands, categorized into hill placement (orchards) or row placement (crops like sugarcane or maize).

Pellet Application

Placement of fertilizer in the form of pellets $2.5$ to $5\,\text{cm}$ deep between the rows of a paddy crop to reduce nutrient fixation and leaching.

Starter Solutions

Liquid application of $N$, $P$, and $K$ in ratios like $1:2:1$ or $1:1:2$ to young plants at the time of transplanting to aid rapid establishment.

Foliar Application

The spraying of fertilizer solutions containing nutrients directly onto the foliage of growing plants, often used for micronutrients like iron, copper, boron, zinc, and manganese.

Fertigation

The application of soluble fertilizers, most commonly nitrogenous fertilizers, through an irrigation system.

Injection into Soil

Directly injecting fertilizer solutions (such as anhydrous ammonia) below the soil surface using specialized equipment like injectors or knives.

Aerial Application

The application of fertilizer solutions via aircraft, typically used in hilly areas, forest lands, grass lands, or sugarcane fields where ground application is impracticable.

Salt Index

A measure of a fertilizer's potential to increase salt concentration in the soil solution compared to sodium nitrate, which has a reference value of $100$.

Osmotic Pressure

The pressure difference required to stop the movement of solvent molecules across a semi-permeable membrane.