LCA Agriculture/Horticulture key terms

The systematic recording of existing site conditions such as topography, soils, drainage, utilities, vegetation, and access before design begins. It provides the factual baseline that later decisions about grading, planting, and construction depend on.

The interpretive step that turns collected site data into conclusions about opportunities and constraints, such as where to place a patio, which slopes need retaining, or where drainage must be redirected.

A field measurement of how quickly water moves through saturated soil, usually expressed in minutes per inch of drawdown. Results determine whether a site can support a septic system or infiltration feature.

The relative proportions of sand, silt, and clay particles in a soil. Texture governs water holding, drainage, aeration, and nutrient retention, and it cannot be permanently changed by ordinary cultivation.

The arrangement of soil particles into aggregates or peds, creating pore space for air and water. Good structure supports root growth and infiltration and is damaged by compaction and excessive tillage.

The soil's capacity to hold positively charged nutrient ions such as calcium, magnesium, and potassium on clay and organic matter surfaces. Higher values generally mean greater nutrient retention and less leaching loss.

A measure of soil acidity or alkalinity on a 0 to 14 scale. It controls nutrient availability, so pH outside a crop's preferred range causes deficiencies even when nutrients are present.

The compression of soil that squeezes out pore space, restricting root growth, water infiltration, and air exchange. It is commonly caused by construction traffic, stockpiling, and working soil when wet.

The mass of dry soil per unit volume, including pore space. Rising bulk density signals compaction, and values above crop-specific thresholds indicate conditions that limit rooting and drainage.

The speed at which water enters the soil surface, usually reported in inches or millimeters per hour. It determines irrigation application limits and the risk of runoff and erosion.

The water content remaining in soil after excess water has drained away by gravity, typically one to three days after saturation. It represents the upper practical limit of stored plant-available water.

The soil moisture level below which plants can no longer extract water and remain wilted even after watering. The gap between this point and field capacity defines available water.

The amount of water a soil can store that plants can actually use, calculated as the difference between field capacity and permanent wilting point. It guides irrigation scheduling and plant selection.

A grouping of plants with similar water needs that are irrigated together on one valve or circuit. Hydrozoning lets each area receive appropriate water without over- or under-irrigating neighboring plantings.

The combined loss of water from soil evaporation and plant transpiration. Reference values are adjusted by crop and climate coefficients to estimate irrigation demand for a specific planting.

The percentage of applied water that actually reaches and is used by the target plants. Losses come from evaporation, wind drift, runoff, deep percolation, and leaks in the delivery system.

A low-pressure system that delivers water slowly through emitters directly to the root zone. It reduces evaporation and foliar wetting, and it suits hydrozones with differing water needs.

A device or assembly that stops contaminated water from reversing flow into the potable supply. Local codes typically require approved protection on irrigation systems and must be tested regularly.

Temporary storage of runoff on site so it infiltrates or is released slowly rather than discharging quickly. Features include basins, rain gardens, and permeable paving that reduce peak flows and erosion.

A decision framework that combines monitoring, cultural, mechanical, biological, and chemical controls, using pesticides only when thresholds justify them. The goal is effective, economical suppression with minimal harm to people and the environment.

The pest population level at which the cost of control is justified by the value of damage prevented. It prevents unnecessary spraying and is a core trigger for action in integrated pest management.

Regular, systematic inspection of plants to detect pests, diseases, and weeds early and to estimate population levels. Findings drive threshold decisions and reveal patterns such as recurring hotspots or resistant populations.

Managing pests by encouraging or releasing natural enemies such as predators, parasitoids, and pathogens. Success depends on habitat, timing, and avoiding broad-spectrum pesticides that kill beneficial organisms.

The inherited ability of a pest population to survive a pesticide dose that once controlled it. It develops fastest with repeated use of one mode of action, so rotation and non-chemical tactics are essential.

The specific biochemical or physiological process by which a pesticide or herbicide kills its target. Grouping products by mode of action and rotating among groups slows resistance and guides appropriate selection.

A herbicide that injures certain plant groups while leaving others largely unharmed, such as grass-only or broadleaf-only products. Selectivity depends on plant physiology, rate, timing, and application method.

A product applied to soil before weed seeds germinate, forming a barrier that prevents seedling establishment. Timing and incorporation are critical, and it generally will not control existing weeds.

A layer of organic or inorganic material spread over the soil surface to suppress weeds, conserve moisture, moderate temperature, and reduce erosion. Depth and material choice affect aeration and plant health.

The amount of liming material needed to raise soil pH to a target level for a given crop. It depends on current pH, soil texture, and buffer capacity, and is determined by laboratory testing.

Laboratory analysis of a soil sample for pH, nutrients, organic matter, and sometimes texture or salinity. Results underpin fertilizer and amendment rates, though they reflect only the sampled area.

The guaranteed percentage of nitrogen, available phosphate, and soluble potash stated on a fertilizer label, always in that order. It allows calculation of the product weight needed to supply a target nutrient rate.

A fertilizer whose nutrients become available gradually through coatings, chemical forms, or low solubility. It reduces leaching and burn risk and matches nutrient supply more closely to plant uptake.

The downward movement of dissolved nutrients, especially nitrate, below the root zone with drainage water. Over-irrigation and excessive fertilizer rates increase losses and can contaminate groundwater.

A drawing showing existing and proposed ground elevations, slopes, and drainage directions. It communicates how water will move across the site and coordinates finish grades with hardscape and planting.

A structure built to hold back soil where a slope change is needed. It requires proper base preparation, drainage, and, above certain heights, engineering design and permits.

The prepared native or compacted soil layer beneath a pavement, wall base, or planting bed. Its strength and drainage determine how much base material and reinforcement the finished structure needs.

Gear worn to reduce exposure to workplace hazards, such as gloves, eye protection, hearing protection, respirators, and boots. Selection follows a hazard assessment and equipment-specific labels and standards.

A document supplied with a hazardous product that describes its hazards, safe handling, required protective equipment, first aid, and spill response. Current equivalents are often called safety data sheets.

A procedure that isolates energy sources and applies locks and tags before servicing equipment, preventing accidental startup or release of stored energy. It protects workers from entanglement and electrical hazards.

The legally binding instructions and warnings on a pesticide container, covering approved uses, rates, protective equipment, and re-entry intervals. Applying contrary to the label is a violation of law.

A written, signed amendment to a contract that alters scope, price, or schedule after work has begun. It protects both parties by documenting agreement before the changed work proceeds.

A documented list of incomplete or defective items identified near project completion that the contractor must correct before final acceptance and final payment. It supports a clear closeout process.

A written statement defining exactly what work, materials, and deliverables a contract includes and excludes. Clear scope reduces disputes and is the reference point for change orders.