UPMSP Soil Conservation (Vocational) key terms

A vertical section through soil from the surface down to the parent material, showing distinct layers called horizons. Each horizon differs in colour, texture and organic matter, and together they reveal how the soil formed.

A layer within the soil profile that differs from the layers above and below in properties such as colour, structure and organic content. Horizons are usually labelled O, A, B, C and R from top to bottom.

The underlying geological material, such as rock, alluvium or wind-blown deposit, from which a soil develops through weathering. Its mineral composition strongly influences the texture and nutrient supply of the resulting soil.

The physical, chemical and biological breakdown of rocks and minerals at or near the earth's surface. It produces the loose mineral fragments that become the mineral skeleton of a developing soil.

The long-term process by which weathered mineral material is transformed into soil under the combined influence of climate, organisms, relief, parent material and time. These five factors control how deep, fertile and stable the resulting soil becomes.

The relative proportions of sand, silt and clay particles in a soil sample. Texture governs water holding capacity, drainage, aeration and how easily the soil can be worked or eroded.

The way individual soil particles are bound together into aggregates or clumps, described by shape and size such as granular, blocky or platy. Good structure improves aeration, root growth and resistance to erosion.

The decomposed and decomposing plant and animal residues present in soil, together with living soil organisms. It improves structure, holds nutrients and water, and gives soil its dark colour and biological activity.

The dark, stable, fully decomposed fraction of soil organic matter that resists further rapid breakdown. It improves aggregation, water retention and nutrient exchange capacity, and is a key indicator of long-term soil health.

The detachment and removal of topsoil particles by the action of water, wind or gravity, often accelerated by human land use. It reduces soil depth, fertility and productivity and causes sedimentation downstream.

The uniform removal of a thin layer of topsoil across a sloping surface by raindrop splash and shallow overland flow. It is easily overlooked because no channels form, yet it steadily strips the most fertile layer.

Erosion in which small, shallow channels form on a slope where concentrated runoff cuts into the soil. Rills are typically a few centimetres deep and can be smoothed by ordinary tillage operations.

Advanced erosion where concentrated runoff cuts deep, wide channels that cannot be removed by normal tillage. Gullies fragment fields, lower water tables and require structural treatment such as check dams and reshaping.

The first stage of water erosion, in which raindrop impact detaches soil particles and throws them into the air. These particles then seal surface pores and are carried away by surface flow.

The portion of rainfall or irrigation water that does not infiltrate the soil and instead flows over the land surface. Its volume and speed determine the erosive power of water on a slope.

The planned set of practices used to protect soil from erosion and degradation while maintaining its productive capacity. It combines mechanical structures, agronomic measures and careful land-use decisions suited to the site.

Ploughing and cultivating along lines of equal elevation rather than up and down the slope. The furrows trap runoff and sediment, reducing sheet erosion and improving moisture retention on gentle slopes.

An earth embankment built along a contour across a slope to intercept runoff and hold it long enough to infiltrate. Bunds are spaced according to slope and soil type and are common on medium-rainfall agricultural land.

The construction of level or gently sloping platforms on a hillside, each supported by a riser, to reduce slope length and trap water and soil. Terraces allow cultivation on steep land while limiting erosion.

A crop grown mainly to protect and improve the soil rather than for harvest, often between main crops. Its canopy shields the surface from raindrop impact, and its roots bind soil and add organic matter.

Spreading a layer of crop residues, straw or other material over the soil surface to protect it. Mulch absorbs raindrop energy, reduces evaporation, suppresses weeds and adds organic matter as it decomposes.

The entire land area that drains its rainfall runoff to a single common outlet such as a stream, lake or reservoir. It is the natural unit for planning soil and water conservation measures.

The integrated planning and treatment of all land within a watershed to conserve soil and water, reduce peak runoff and improve productivity. It combines vegetative, agronomic and structural measures with community participation.

The collection and storage of rainwater from a catchment surface for later productive use, such as irrigation or livestock. Systems range from small field pits to lined tanks and farm ponds.

A small excavated or embanked water storage structure built on a farm to capture runoff from its catchment. It provides supplemental irrigation, groundwater recharge and often fish or livestock water.

The ability of a soil to supply essential nutrients in adequate amounts and suitable proportions for healthy plant growth. It depends on nutrient reserves, organic matter, pH and biological activity.

The continued capacity of soil to function as a living system that supports plants, animals and water quality. It integrates physical, chemical and biological properties rather than nutrient supply alone.

A laboratory or field analysis of a soil sample to measure properties such as pH, organic carbon and available nutrients. Results guide balanced fertiliser recommendations and reveal deficiencies or excesses.

The combined use of organic manures, chemical fertilisers and biological inputs, matched to soil test results and crop demand, to sustain yields and soil health. It reduces waste and dependence on any single nutrient source.

A crop grown specifically to be incorporated into the soil while still green, adding organic matter and nutrients such as nitrogen. Legume species also fix atmospheric nitrogen through root nodules.

The downward entry of water through the soil surface into the soil body. The infiltration rate determines how much rainfall is absorbed in place and how much becomes erosive runoff.

The water held within soil pores, available to plants to varying degrees depending on how tightly it is bound to particles. Managing it is central to irrigation scheduling and drought resilience.

Deciding when and how much water to apply to a crop, based on soil moisture status, crop water demand and weather. Good scheduling avoids both waterlogging and yield-limiting moisture stress.

A method that delivers water slowly and directly to the root zone through emitters along tubes. It saves water, limits evaporation and surface runoff, and reduces soil erosion compared with flood irrigation.

The pattern of crops grown and their sequence on a given piece of land, including rotations, intercropping and fallow periods. The choice of system strongly affects erosion risk, soil fertility and water use.

Growing different crops in a planned sequence on the same field over successive seasons. Rotation interrupts pest cycles, balances nutrient use and improves soil structure compared with continuous monocropping.

A land-use system in which trees or shrubs are deliberately grown together with crops or livestock on the same land. Trees reduce wind and water erosion, add organic matter and diversify farm income.

A row or belt of trees and shrubs planted across the direction of prevailing winds to reduce wind speed near the ground. It protects soil from wind erosion and shields crops from wind damage and moisture loss.

The detachment and transport of loose, dry soil particles by wind, most severe on bare, smooth or overgrazed land in arid regions. It removes fine fertile material and can bury crops and infrastructure.

Field measurement to locate and mark points of equal elevation on the ground, used to lay out bunds, terraces and channels. Levels and pegs guide construction so that structures follow the land's contours.

A permanently fixed point of known elevation or position used as a reference for surveying and construction work. All levels taken on a site are related back to it so structures are built to the correct grade.

A small barrier built across a drainage channel or gully to slow runoff, trap sediment and allow water to infiltrate. It helps stabilise gully beds and can recharge groundwater upslope.

The practices that prevent injury when operating, maintaining or moving tractors and implements, such as using guards, shutting off power before clearing blockages and wearing protective equipment. It also covers safe transport on roads and safe storage of fuel.

The clothing and gear worn to protect the body during farm or conservation work, such as boots, gloves, goggles, helmets and dust masks. Correct use reduces injury from tools, chemicals, noise and flying debris.

The safe storage, mixing, application and disposal of agricultural chemicals according to label instructions. It includes protective clothing, avoiding spray drift and preventing contamination of water sources and soil.

Understanding how farm and conservation activities affect soil, water, air and biodiversity, and acting to reduce harm. It covers preventing pollution, conserving vegetation and protecting habitats while meeting production goals.

Starting and running a farm-based or service enterprise around soil and water conservation, such as a nursery for planting material, custom terracing services or a farm pond for fish and irrigation. It converts conservation skills into income while improving land.