Glossary category : Management practices

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3 - Farms

3.2 - Management practices

   

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  • Bearing capacity

    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.

  • Biological control

    The use of biological agents (intact organisms, components derived from organisms) to destroy or deter pests and diseases or to promote natural enemies.

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  • 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.

  • Evaporation

    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.

  • Evapotranspiration

    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.

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  • Fallow

    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

    Substance used in agriculture to provide crops with vital nutrients to grow (such as Nitrogen (N), Phosphorus (P), Potassium (K) and lime).

  • 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.

  • Field capacity

    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.

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  • Green manure

    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.

  • Groundwater

    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.

  • Growing season

    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.

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  • 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

     

     

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  • Nitrogen (N)

    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.

  • Nurse crop

    Main crop under which an undersowing is established which accompanies the main crop during at least a part of its growing season.

  • Nutrient recovery

    Fraction of plant-available nutrients from fertilizers and manures taken up by the crop in harvestable fraction(s) and above ground residues, usually excluding roots and stubbles.

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  • Vadose zone

    The aerated region of soil above the groundwater table. The unsaturated zone is characterized by a downward movement of leachate.

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  • Water deficit

    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.

  • Water table

    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.

  • Wilting point

    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.

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  • Zero tillage

    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.