UPMSP Intermediate Agronomy key terms

The branch of agricultural science that studies field crop production and soil management, combining crop physiology, soil science, and management practices to raise yield and quality per unit area.

The ratio of total cropped area to net sown area in a year, usually expressed as a percentage; it measures how many crops are harvested from the same land annually.

The pattern and sequence of crops grown on a farm over time and space, together with the management practices applied, determined by climate, soil, water supply, and the farmer's needs.

Growing two or more crops on the same field in one year, either in sequence (sequential cropping) or simultaneously (intercropping), to raise total production per unit of land.

Growing two or more crops simultaneously in the same field in definite row arrangements so that their periods of peak demand for light, water, and nutrients differ, reducing competition.

The total land area needed under sole cropping to produce the same yield as one hectare of an intercrop, calculated as the sum of the component crops' relative yields; values above one indicate an intercrop advantage.

Growing different crops in a planned sequence on the same field over successive seasons, used to break pest and disease cycles, manage weeds, and balance soil nutrient use.

The relative proportions of sand, silt, and clay particles in a soil, which govern water holding capacity, drainage, aeration, and ease of tillage.

The arrangement of soil particles into aggregates or peds, together with the pore space between them, which controls aeration, infiltration, root penetration, and resistance to erosion.

The total quantity of exchangeable cations a soil can hold per unit weight, usually expressed in centimoles of charge per kilogram; it reflects the soil's ability to retain nutrient cations such as potassium, calcium, and magnesium.

The percentage of the cation exchange capacity occupied by basic cations (calcium, magnesium, potassium, sodium) rather than acidic ones, used as an indicator of soil fertility and lime requirement.

A measure of the acidity or alkalinity of the soil solution on a logarithmic scale; it controls nutrient availability, microbial activity, and the choice of crops and amendments.

An element required by plants to complete their life cycle, whose absence causes specific deficiency symptoms that only that element can correct; classified as macronutrient or micronutrient by the amount needed.

The principle that crop growth is limited by whichever essential factor is in shortest supply relative to need, so adding other nutrients or inputs cannot raise yield until that limiting factor is corrected.

Supplying crop nutrients through a planned combination of chemical fertilizers, organic manures, biofertilizers, and crop residues to sustain yields while maintaining soil health and reducing environmental loss.

Well-rotted mixture of cattle dung, urine, bedding, and feed waste used as a bulky organic manure; it supplies organic matter and several nutrients but in low concentration.

A crop grown specifically to be ploughed into the soil while still green, adding organic matter and nitrogen, especially when the species is a legume with root nodules.

Nutrient-rich organic material produced by earthworms digesting organic wastes, used as a manure and a component of organic farming systems.

Mechanical manipulation of soil to prepare a seedbed, control weeds, incorporate residues, and manage compaction, achieved through primary and secondary operations.

The first, deeper soil-opening operation after harvest, such as ploughing, which breaks compacted layers and inverts or loosens soil to a considerable depth.

Shallow operations such as harrowing, cultivator passes, and levelling carried out after primary tillage to break clods, level the surface, and create a fine seedbed.

Any tillage system that leaves a substantial proportion of previous crop residue on the soil surface, reducing erosion and moisture loss compared with clean cultivation.

Sowing a crop directly into undisturbed soil with a specially designed drill, avoiding ploughing; it conserves soil moisture, saves fuel and time, and reduces erosion.

The prepared surface soil layer in which seed is placed, judged by its tilth, moisture, levelness, and freedom from clods and weeds for uniform germination.

Covering the soil surface with crop residues, straw, plastic film, or other material to reduce evaporation, suppress weeds, moderate soil temperature, and protect against erosion.

The resumption of growth by a viable seed under suitable moisture, temperature, and oxygen conditions, ending with emergence of the radicle and plumule.

The proportion of seeds in a lot that are alive and capable of germinating under favourable conditions, usually tested by germination percentage.

Application of fungicides, insecticides, or bioagents to seed before sowing to protect germinating seeds and seedlings from soil-borne and seed-borne problems.

The quantity of seed sown per unit area, adjusted for seed weight, germination percentage, and the plant population required for the crop and sowing method.

An implement that places seed in rows at a controlled depth and rate, often with fertilizer placement, giving more uniform stands than broadcasting.

The number of plants of a crop established per unit area, which determines competition for light, water, and nutrients and strongly influences final yield.

The yield-forming components of a crop, such as number of effective tillers or branches, grains or pods per plant, and grain weight, that together determine final economic yield.

Deciding when and how much water to apply to a crop, based on soil moisture status, crop water requirement, and growth stage, to avoid both water stress and waste.

The water content remaining in a soil after excess free water has drained away under gravity, generally two to three days after saturation; it is the upper practical limit for irrigation storage.

A growth stage at which water stress causes a disproportionately large reduction in yield, so irrigation must be assured; examples include crown root initiation in wheat and flowering in most crops.

A plant growing where it is not wanted, competing with the crop for water, nutrients, light, and space, and often reducing produce quality and acting as a pest host.

The combination of cultural, mechanical, biological, and chemical methods used to keep weed populations below the level at which they reduce crop yield or quality.

A chemical used to kill or suppress weeds, applied either before weed emergence (pre-emergence) or after (post-emergence), with selectivity depending on crop, dose, and timing.

A pest control strategy that combines resistant varieties, cultural practices, biological agents, monitoring, and judicious pesticide use, applying chemicals only when pest populations cross economic thresholds.

The pest population density at which control measures are justified because the value of the crop loss prevented would exceed the cost of treatment.

A production system that relies on organic manures, biofertilizers, crop rotation, and biological pest control while excluding synthetic fertilizers and pesticides, with certification required for marketing.

Suppression of pest or pathogen populations using their natural enemies, such as predators, parasitoids, or antagonistic microorganisms, released or conserved in the field.

Separating grain or seed from the harvested ear, pod, or panicle by impact, rubbing, or beating, done manually or with a thresher, followed by winnowing and cleaning.

A machine that cuts, threshes, and cleans the crop in one pass, reducing labour and turnaround time but requiring grain moisture and crop condition to be suitable.