Maharashtra HSC Crop Science (Bifocal B4) key terms

The branch of crop science that deals with field crop production and the management of soil, water, and crops to maximise yield. It covers tillage, sowing, nutrition, irrigation, and harvesting practices applied to field crops.

The ratio of total cropped area to net sown area in a year, usually expressed as a percentage. It shows how many times land is cropped annually; a value of 200 percent means two crops are taken from the same land each year.

The pattern in which crops are grown on a farm over a period of years, including their sequence and the management practices used. Examples include monocropping, multiple cropping, and mixed cropping, chosen to suit soil, climate, and market needs.

Growing two or more crops on the same field in a single year, either in sequence or simultaneously. It increases land productivity and income per unit area compared with a single crop, provided water and nutrients are adequate.

Growing two or more crops together in the same field in distinct rows or strips during the same season. It spreads risk, improves use of light and nutrients, and can reduce pest build-up when the crops are compatible.

The relative proportion of sand, silt, and clay particles in a soil, determined by particle size. Texture governs water holding, drainage, aeration, and workability, and is the basis for classifying soil into sandy, loamy, or clayey types.

The arrangement of soil particles into aggregates or peds and the pore spaces between them. Good granular structure improves aeration, water infiltration, root penetration, and resistance to erosion, and is maintained by organic matter.

The total quantity of exchangeable cations a soil can hold on clay and organic matter surfaces, expressed in centimoles of charge per kilogram. Higher values indicate greater ability to retain nutrients such as calcium, magnesium, and potassium against leaching.

A measure of the acidity or alkalinity of the soil solution on a scale from 0 to 14. It controls nutrient availability, microbial activity, and choice of crops and amendments; most crops grow best between pH 6.0 and 7.5.

The mass of dry soil per unit of its total volume, including pore space, usually expressed in grams per cubic centimetre. High values indicate compaction and poor porosity, which restrict root growth and water movement.

The water content remaining in a soil after excess gravitational water has drained away, usually about two days after saturation. It represents the upper limit of water readily available to plants and guides irrigation scheduling.

The soil water content at which plants can no longer extract water and remain wilted even in a humid atmosphere. The difference between field capacity and this point gives the available water holding capacity of the soil.

The portion of soil water held between field capacity and permanent wilting point that plant roots can absorb. It is the practical reservoir a farmer manages through irrigation, and its size depends mainly on texture and organic matter.

A chemical element required by plants to complete their life cycle, whose deficiency causes specific symptoms that only that element can correct. Seventeen elements are recognised, divided into macro- and micronutrients according to the quantity needed.

An essential element needed by plants in relatively large amounts, namely carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur. Nitrogen, phosphorus, and potassium are the ones most often supplied through fertilizers.

An essential element required by plants in very small quantities, including iron, manganese, zinc, copper, boron, molybdenum, chlorine, and nickel. Deficiency or excess of these elements can severely limit yield even when major nutrients are adequate.

The guaranteed percentage of nitrogen, available phosphorus expressed as phosphorus pentoxide, and water-soluble potassium expressed as potassium oxide in a fertilizer, always stated in that order. A grade of 10:26:26 indicates ten percent nitrogen and twenty-six percent each of phosphorus and potassium.

A fertilizer material that supplies only one of the three primary nutrients, nitrogen, phosphorus, or potassium. Urea, single superphosphate, and muriate of potash are common examples, and they are often blended to meet a crop's requirement.

A fertilizer produced chemically so that each granule contains two or more primary nutrients in a definite proportion, such as diammonium phosphate. Unlike a physical mixture, the nutrients cannot separate during handling or transport.

A bulky organic manure made from decomposed cattle dung, urine, litter, and feed residues. It adds organic matter, improves soil structure and water holding, and supplies nutrients slowly, though its nutrient concentration is low.

The practice of growing a leguminous or other quick-growing crop and ploughing it into the soil while still green to add organic matter and nitrogen. It improves fertility and structure, especially on light or degraded soils.

Organic manure produced by earthworms feeding on decomposable waste, resulting in nutrient-rich casts with good microbial activity. It is applied as a soil amendment or in potting mixtures and improves porosity and nutrient supply.

The combined use of chemical fertilizers, organic manures, biofertilizers, and crop residues in balanced proportions to sustain soil fertility and crop yield. It reduces dependence on mineral fertilizers and helps maintain soil health over the long term.

Mechanical manipulation of the soil to prepare a seedbed, control weeds, and manage crop residues. Primary tillage loosens the soil deeply, while secondary tillage breaks clods and levels the surface before sowing.

The quantity of seed sown per unit area, chosen to achieve the recommended plant population for a crop and variety. It depends on seed size, germination percentage, spacing, and the sowing method used.

The distance below the soil surface at which seed is placed. Too shallow a depth risks drying out, while too deep a depth exhausts seed reserves before emergence; the correct depth depends on seed size and soil moisture.

The growth stage at which water shortage causes the greatest reduction in yield, so irrigation must not be missed. In cereals it often coincides with flowering and grain filling; in pulses and oilseeds with flowering and pod formation.

A method of applying water slowly and directly to the root zone through emitters in tubes laid along the crop rows. It saves water, reduces weed growth and foliar disease, and allows fertigation, but requires filtration and maintenance.

The application of soluble fertilizers through an irrigation system, usually drip, so that nutrients reach the root zone with the water. It improves nutrient use efficiency and allows small, frequent doses matched to crop demand.

A strategy that combines cultural, mechanical, biological, and chemical methods to keep pest populations below economic injury levels. Pesticides are used only when monitoring shows they are necessary, reducing cost and resistance development.

The pest population density at which control measures should be started to prevent the population from reaching the level where economic loss occurs. It guides spray decisions so that pesticides are applied only when justified.

A living organism, such as a predator, parasitoid, or microbial pathogen, used to suppress pests or diseases. Examples include Trichogramma egg parasitoids and Bacillus thuringiensis preparations, which are key components of biological control.

The property of a herbicide that allows it to kill weeds without seriously injuring the crop, based on differences in uptake, metabolism, or placement. It depends on correct dose, stage of application, and crop and weed species.

The energy available on a farm for field operations, drawn from human labour, draught animals, tractors, or stationary engines. The level of farm power per hectare strongly influences timeliness and intensity of cultivation.

A machine or tool attached to a power source, such as a tractor or bullock, to carry out a farm operation like ploughing, harrowing, or sowing. Implements are matched to the power source and to the soil and crop conditions.

The horizontal force required to pull an implement through the soil, usually expressed in kilograms or newtons. It increases with depth, speed, and soil moisture content and determines the power needed and fuel consumed.

The quantity of water present in a harvested produce, expressed as a percentage of its weight. It must be brought to a safe level before storage to prevent mould growth, insect attack, and heating of the grain mass.

Keeping harvested produce in conditions of low moisture, cool temperature, and protection from pests so that quality and quantity are preserved. It requires proper drying, clean storage structures, and regular inspection during the storage period.

Sorting harvested produce into uniform lots according to size, colour, shape, or quality standards. Grading improves market acceptability, allows price differentiation, and is a basic step in value addition and packaging.

The total expenditure incurred in producing a crop, including seed, fertilizer, irrigation, labour, machinery, and other inputs. It is used to compute profitability and to decide the minimum price at which the produce can be sold.

The total value of produce obtained from a farm or enterprise, calculated as yield multiplied by price received. It is compared with costs to find net income and is a basic measure in farm planning and enterprise budgeting.

The ratio of gross income to the total cost of cultivation for an enterprise. A value greater than one indicates profit; it allows comparison of alternative crops or technologies independent of the absolute scale of operation.