3 - Farms
3.2 - Management practices
Yield increase of a crop per unit of nutrient applied (kg per kg) in addition to the yield of an unfertilized control.
Fraction of an applied nutrient (kg per kg) recovered in above ground or harvested crop parts in addition to the amount of that nutrient taken up in an unfertilized control.
Underground reserve of freshwater usually contained in a discrete layer of water-permeable rock or other material (such as gravel, sand etc.) from which water can be extracted using a well or other appropriate extraction technology.
Available soil water
The weight a soil can withstand before severe damage occurs to the structure of the soil. Bearing capacity varies throughout the year, based upon the moisture content of the soil. For instance a very heavy tractor that causes no damage on dry soils may cause a lot of damage to the soil structure of wetted soils.
The use of biological agents (intact organisms, components derived from organisms) to destroy or deter pests and diseases or to promote natural enemies.
CaO Ca x 1.39 = CaO
An agricultural crop grown to provide revenue from an off-farm source (‘the market’).
Aerobic microbial decomposition and transformation of organic materials. It is usually achieved by regular turning and aeration of a stored organic product in piles with a geometry that can favour aeration. With this transformation, the chemical composition, particularly the C to N ratio comes closer to values needed for the net release of N once the product is land-applied. Concomitantly, the product may become less bulky due to the loss of water and also more manageable due to homogenisation. Additional benefits of composting involve the decrease in the initial phyto-toxicity of organic materials used, reduction in weed and pest infestation, and potential biocontrol effects.
Conservation agriculture (CA)
Ploughing in a direction that follows the contour, maintaining the same elevation.
Contour strip cropping
Growing crops in strips that follow the contour line. Strips of grass or close-growing crops alternate with strips of clean-tilled crops or summer fallow.
Using the same traffic lanes for machinery used for different applications within one year and the same traffic lanes across years, usually supported by a sat-nav system, in order to reduce soil compaction.
Full width tillage that disturbs the entire soil surface which is generally performed prior to planting. It usually involves a primary operation by depth ploughing or chiselling (commonly to 20-30 cm depth), followed by secondary operation such as rotavating or harrowing that pulverizes, flattens, and firms the surface.
The temporal alternation of different crop types (mown vs. lifted, monocots vs dicots, annual vs perennial) on a piece of farm land.
The period after which a crop type returns to a field in the course of years, commonly expressed as a percentage of the number of years needed for a full crop rotation cycle.
Liquid or solid residues produced by fermentation of biomass (anaerobic digestion) in a biogas plant.
Direct sowing, direct drilling
Planting crops in a non-inverted soil without seedbed preparation (i.e. under no-tillage).
Man-made adjustments to a field directed at the removal of excess water by ditches, subsoiling, pipes.
Refers to the capacity of unaltered soils to drain water through percolation, as opposed to artificial drainage, which is commonly the result of artificial drainage or irrigation but may be caused by the sudden deepening of channels or the blocking of drainage outlets.
Application of water under low pressure through a piped network in a pre-determined pattern, applied as a small discharge close to each plant and adjustable by irrigation nozzles or droppers. Usually called “high frequency irrigation” since irrigation rates are usually very small and intended to compensate crop evapotranspiration during one or a few days.
Effective rooting depth
The soil depth from which a fully grown plant can easily extract most of the water needed for transpiration. It can be limited by physical (e.g. cemented pan) or chemical (e.g. saline horizon) properties.
The rate of water loss from liquid to vapour (gaseous) state from an open water, wet soil or plant surface, usually expressed in mm day–¹.
The process by which water passes from a liquid to a vapour (gaseous) state through transpiration from vegetation, and evaporation from soil and plant surfaces. The rate of evapotranspiration is usually expressed in mm day-¹; a distinction can be made between the potential evapotranspiration under unlimited availability of water and the actual evapotranspiration under limited availability.
Cropland left idle in order to restore productivity through accumulation of moisture or organic matter. Summer fallow is common in regions of limited rainfall where cereal grains are grown. The soil is tilled for at least one growing season for weed control and decomposition of plant residue.
Fertilizer replacement value
The extent to which a nutrient (N, P) in a manure or in a compost is as plant-available as that nutrient in a common mineral equivalent applied according to good agricultural practices, usually expressed as kg per 100 kg applied = fertilizer equivalency = ratio of apparent recoveries* (or of apparent efficiencies**) of a nutrient (often N) from manure and from a commonly used mineral fertilizer equivalent.
The moisture condition where a soil contains the maximum amount of water that it can hold against gravity, and where further wetting will result in drainage. Following saturation, soils typically return to field capacity, when the rate of downward movement of water has substantially decreased, usually 1-3 days after rain or irrigation after the gravitational, or free, water has drained away. It is typically expressed as a mass or volume fraction of soil water or as a soil moisture deficit (SMD) of zero.
Non-harvested crop grown in between two main crop seasons, intended to improve the soil fertility, generally not growing under N limitation due to the use of fertilizers and manures, or the ability to fix atmospheric N.
Ground Cover (GC)
The most widely used agronomic practice in Conservation Agriculture (CA), whereby the soil surface between rows of annual or perennial crops remains protected against erosion. With this technique, at least 30% of the soil is protected either by sown cover crops, spontaneous vegetation or inert covers, such as pruning residues or tree leaves. For the establishment of sown cover crops and the spread of inert covers, farmers must use methods in coherence with CA principle of minimum soil disturbance.
Freshwater found beneath the earth’s surface that fills the cavities of the earth’s crust (pores, crevices, etc. in soil, sand and rock) contiguously, – and that supplies wells and springs, excluding the water in the vadose (unsaturated) zone. The definition applies to all permanent and temporary water deposits, formed both artificially and naturally, of sufficient quality for at least seasonal use. Groundwater supplies are replenished, or recharged, by rain and melting snow, depending on climate conditions. They can usually be recovered from, or via, an underground formation.
The portion of the year when soil and air temperature allow biological activity; this period can be approximated by the number of frost-free days.
The maximum rate at which water can infiltrate into a soil under a given set of conditions.
The speed at which water can pass into the soil, being typically lower in wet clay than in dry sand (unless sand has become hydrophobic).
Mineral, synthetic, industrial, artificial or manufactured fertilizers.
A crop grown amidst a main crop or in between the planting rows of that main crop and intended to be harvested or to be supportive to the harvest of the main crop.
Application of water to soils to assist in production of crops.
Livestock Unit (L(S)U)
A reference unit which facilitates the aggregation of livestock from various species and age as per convention, via the use of specific coefficients established initially on the basis of the nutritional or feed requirement of each type of animal (see table below for an overview of the most commonly used coefficients).
The reference unit used for the calculation of livestock units (=1 LSU) is the grazing equivalent of one adult dairy cow producing 3 000 kg of milk annually, without additional concentrated foodstuffs.
LU’s as derived from the LUCAS land use nomenclature (http://ec.europa.eu/eurostat/ramon/other_documents/lucas/index.htm):
Bovine animals Under 1 year old 0,400 1 but less than 2 years old 0,700 Male, 2 years old and over 1,000 Heifers, 2 years old and over 0,800 Dairy cows 1,000 Other cows, 2 years old and over 0,800 Sheep and goats 0,100 Equidae 0,800 Pigs Piglets having a live weight of under 20kg 0,027 Breeding sows weighing 50kg and over 0,500 Other pigs 0,300 Poultry Broilers 0,007 Laying hens 0,014 Ostriches 0,350 Other poultry 0,030 Rabbits, breeding feemales 0,020
MgO Mg x 1.66 = MgO
Livestock excrements, as such or including bedding material.
The use of machines to bury, cut or uproot the weeds.
A tillage system that limits tillage operations to those essential to crop production and prevention of soil damage, generally leaving about 30% crop residues on the surface, often executed with specific machines (e.g. harrow, cultivator with rigid tines or a rotavator), only once a year.
The growing of a single arable crop species on a field year after year, for at least 10 years.
Organic residues left on top of the soil or in the first few cm of soil.
Leaving organic residues (or plastic sheet) on top of the soil or in the first few cm of soil.
NO3 N x 4.43 = NO3
NH4 N x 1,29 = NH4
No tillage (NT)
An agronomic practice in Conservation Agriculture (CA) for annual crops, and is defined as a way to farm without disturbing the soil through tillage. NT must leave at least 30% of area covered by plant residues right after crop establishment, and crops are sown using machinery which is able to place seeds through plant residues from previous crops. The agronomic practice that best characterizes CA for annual crops is NT, which has the highest degree of soil conservation in annual crops, since the mechanical tillage of the ground is completely suppressed. Also, in arid climates it enhance water retention in soils through decreasing evaporation losses from the soil surface which is usually enhanced by tillage involving soil invert.
Main crop under which an undersowing is established which accompanies the main crop during at least a part of its growing season.
Terms describing permeability are:
Very slow: 0.15 cm/hr
Slow: 0.15-0.5 cm/hr
Moderately slow 0.5-1.5 cm/hr
Moderate 1.5-5 cm/hr
Moderately rapid 5.00-15.00 cm/hr
Rapid 15-50 cm/hr
Very rapid >50 cm/hr
Synthetic biocide directed at destroying insects, nematodes, molluscs, mammals, plants, fungi or bacteria.
P2O5 P x 2.29 = P2O5
Plastic sheet covering the soil surface to increase the temperature, reduce evaporation or suppress weeds.
K2O K x 1,20 = K2O
Water flow through macro-pores (e.g., cracks, root channels) in the unsaturated/ vadose zone.
Any organic product generated during the production, processing or consumption of crops, ranging from roots, stubbles, straw and leaves, to industrial and urban ‘wastes’.
The part of the soil that can be penetrated by plant roots.
Subsurface area below unsaturated/ vadose zone that is permanently water-saturated.
A liquid mixture of livestock urine and faeces, with or without some water and or bedding material.
The extent to which a soil is covered (in space and/or time) by a vegetation, including crops, or dead crop residues on the surface of the soil, directed at reducing soil erosion and the loss of particulate pollutants (i.e. those attached to soil) including nutrients, plant protection products and fecal microbes. Measures directed at increasing the soil cover may also increase soil organic matter.
Application of water to the field by a sprinkler system which mimics a high intensity rainfall, can be mobile of fixed.
Growing crops in a systematic arrangement of strips or bands which provide vegetative barriers to wind and water erosion.
The process in which only a narrow strip of land needed for the crop row is tilled.
Application of water to the field that flows over the land surface or in narrow channels (e.g.furrow or basin sprinkler).
Water bodies flowing over or resting on the surface of a land mass, natural waterway (rivers, streams, brooks and lakes) or artificial waterway, including irrigation, industrial and navigation canals, drainage systems and artificial reservoirs.
The mechanical cultivation of a soil profile for any purpose. Tillage can be performed to accomplish a number of tasks including: breaking compactions, incorporation of crop residues, manures, fertilizers or weeds, seedbed preparation, weed control.
The capacity of soil to carry machinery without significant damage to the soil or the vegetation growing on it.
The process whereby plants lose water by evaporation of liquid water at the surface of the stomatal cells, the water vapour diffusing out through the leaf via the stomata openings.
A crop grown under a nurse crop and intended to become either a non-harvested crop grown in between two main crop seasons or become a main crop itself in a next season.
The aerated region of soil above the groundwater table. The unsaturated zone is characterized by a downward movement of leachate.
Amount of water (mm) needed to return moisture conditions of a soil back to field capacity.
Water holding capacity
The capacity of soils to hold water that is available for use by most plants. It is commonly defined as the difference between the amount of soil water at field moisture capacity and the amount at wilting point. It is commonly expressed as mm of water per m of soil.
The upper surface of groundwater or that level in the ground where the water is at atmospheric pressure. Different horizons can be recognized, such as the highest and lowest average height of the groundwater level in summer or winter.
Soil moisture content where the rate of absorption of water by plant roots is too slow to maintain plant turgidity and permanent wilting occurs. The average moisture tension at the outside surface of the moisture film around soil particles when permanent wilting occurs is 1500 kPa.
An agronomic practice in Conservation Agriculture (CA) for annual crops, and is defined as a way to farm without disturbing the soil through tillage. Zero tillage must leave at least 30% of area covered by plant residues right after crop establishment, and crops are sown using machinery which is able to place seeds through plant residues from previous crops. The agronomic practice that best characterizes CA for annual crops is Zero Tillage, which has the highest degree of soil conservation in annual crops, since the mechanical tillage of the ground is completely suppressed. Also, in arid climates it enhance water retention in soils through decreasing evaporation losses from the soil surface which is usually enhanced by tillage involving soil invert.