what is leaching in agriculture

Contents

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Leaching

  • Leaching of Soil. Leaching occurs as excess water removes water-soluble nutrients out of the soil, by runoff or drainage.
  • Types of Leaching. The mechanism by which components of a solid material are released into a touching water phase is leaching.
  • Advantages and Disadvantages of Leaching. …

Full
Answer

What is the problem of leaching in agriculture?

In agriculture, leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.

What is leaching in nature?

Leaching means when water washes down something from upper soil layer to lower soil layer. Leaching is washing down of minerals and nutrients from the soil due to heavy rainfall or over-irrigation. Minerals and nutrients move deeper in the soil beyond reach of the plant roots.

How to prevent leaching in soil?

Leaching garden plants grown in containers is the process of washing the salts from the surface of the soil. Pour large amounts of water through the soil until it runs freely from the bottom of …

What is leaching garden plants?

 · Leaching can transport chemical compounds like dissolved substances or larger materials such as decomposing plant materials, fine rock fragments, and microbes throughout …

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What does leaching mean in agriculture?

Leaching can transport chemical compounds like dissolved substances or larger materials such as decomposing plant materials, fine rock fragments, and microbes throughout the Critical Zone. In agricultural ecosystems, leaching is an important balance between preventing salt accumulation and removing nutrients from soil.

What is leaching short answer?

Leaching is the loss or extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). and may refer to: Leaching (agriculture), the loss of water-soluble plant nutrients from the soil; or applying a small amount of excess irrigation to avoid soil salinity.

What do you mean by the leaching?

: to remove or remove from by the action of a liquid passing through a substance Water leaches minerals from soil. The soil was leached by the constant rain. leach. transitive verb.

What is leaching in the soil?

leaching, in geology, loss of soluble substances and colloids from the top layer of soil by percolating precipitation. The materials lost are carried downward (eluviated) and are generally redeposited (illuviated) in a lower layer. This transport results in a porous and open top layer and a dense, compact lower layer.

What is leaching in soil Class 10?

Leaching is a process by which the nutrients in the soil are washed away by heavy rains. Laterite soils develop due to leaching.

What is leaching Brainly?

Leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.

What is leaching of food?

Leaching is a process of soaking raw or frozen vegetables in water for at least two hours before cooking to “pull” some of the potassium out of the food and into the water. You should not eat these vegetables frequently because there is still a lot of potassium in the food after leaching.

What causes soil leaching?

Leaching happens when excess water, through rainfall or irrigation, takes water-soluble nutrients out of the soil. When water carries these nutrients away, they need to go somewhere.

What is leaching and its types?

There are four types of leaching: Cyanide leaching (e.g. gold ore) Ammonia leaching (e.g. crushed ore) Alkali leaching (e.g. bauxite ore) Acid leaching (e.g. sulfide ore)

What is leaching and why is it a problem?

is the movement of contaminants, such as water-soluble pesticides or fertilizers, carried by water downward through permeable soils. Generally speaking, most pesticides adsorb to soil particles (especially clay), become immobile, and do not leach.

Is Leech good for plants?

Leech water turns into perfect fertilizer, and the plants and flowers of your house will love you for it. Leeches, which are blood-eating, have a special quality enzyme, which breaks down blood particles into extremely important and rich compounds to be used in the garden.

What process happens in leaching?

Leaching Process describes the release of organic and inorganic contaminants or radionuclides from a solid phase into a water phase, when influenced by processes such as desorption, complexation, and mineral dissolution.

What is leaching Class 8 Social?

Leaching is the loss of water soluble plant nutrients from the soil due to rain and irrigation. It can also be defined as the process of dissolving a soluble component out of a constituent material at a wet surface.

What is leaching in class 12 biology?

Leaching is a process in which water-soluble substances are washed out from the soil.

What is meant by leaching Class 12?

Leaching is the process of extracting a soluble material from an insoluble solid by dissolving out in a suitable solvent.

What do you mean by leaching Class 11?

Hint: Leaching is a term used in agriculture which means loss of water soluble plant nutrients from the soil which is caused due to rain and irrigation.

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What is the process of removing soluble material from soil?

Erosion is the natural process by which soil / rock are removed from the Earth’s surface by exogenetic processes such as wind or water flow, transported and deposited in other locations. Leaching is the removal of soluble material from soil or other material by percolating water.

What is the term for the loss of soluble substances and colloids from the top layer of soil?

Leaching, in geology, loss of soluble substances and colloids from the top layer of soil by percolating precipitation. The materials lost are carried downward (eluviated) and are generally redeposited (illuviated) in a lower layer. This transport results in a porous and open top layer and a dense, compact lower layer.

What is leaching in water?

Leaching is the natural process by which water soluble substances are washed out from soil or wastes. These leached out chemicals cause pollution of surface and sub-surface water. For example, In the sugar industry for removing sugar from beets (water is solvent).

What is the loss of water soluble nutrients from the soil?

Leaching is the loss or extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). and may refer to: Leaching (agriculture), the loss of water-soluble plant nutrients from the soil; or applying a small amount of excess irrigation to avoid soil salinity.

What is leaching in agriculture?

In agriculture, leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss.

What are the effects of nutrient leaching?

Erosion. While not directly responsible for erosion, the effects of nutrient leaching provide the opportunity for erosion to occur. For example, the acidification of soil can limit the types of plants that grow in a particular area, which leads to poorly developed root systems.

How does mulching affect soil?

Incorporating crop residues or mulching enriches soil organic matter and has a positive impact on soil structure and water retention capacity, which in turn reduces the risk of nutrient leaching.

How to prevent leaching of water from plants?

There isn’t an effective remedial action to prevent leaching, especially from rainwater, since rainfall is a natural and uncontrollable event. Applications of some amendments might be scheduled when minimal rainfall is expected, and spraying of pesticides can be done when weather forecasts are not calling for rain, but if these chemicals stay resident in the soil for an extended period, they will eventually be leached out of the soil anyway. Irrigation leaching can be reduced by making efforts to irrigate without saturating or over-watering, so that the irrigation water doesn’t end up percolating through the soil, rather, that it is taken up by the plant’s root systems.

What is leaching in agricultural soil?

What is leaching in agricultural soil? Rainwater and irrigation water travels through the soil, dissolving nutrients. minerals, and trace elements as it does, taking these valuable materials with it to deeper soil or strata where it is no longer available to the plants. This removal of valuable nutrients decreases the soil fertility and can result in pollution of the groundwater the leached compounds enter in to. Nitrogen, leached out of the top soil enters the groundwater and causes it to become more acidic. Chemicals like pesticides are leached out of topsoil and also end up in the groundwater, another source of pollution. Thus, the problem is two-fold, the plants grown in the soil lose the products that are applied to benefit them, and the groundwater is polluted in the process.

What does “leaching” mean in water?

Leaching means when water washes down something from upper soil layer to lower soil layer.

What is conservation agriculture?

Conservation agriculture is related to conservation of natural resources like water , soil , seed and biodiversity.

What is the government of India encouraging?

Government of India is encouraging to start business ventures in agriculture sector with lot of schemes, subsidies, incentives and financial support.

What is agricultural science?

Agricultural science is a broad-based course that deals with production of food and rearing of farm animals, agricultural extension, rural economy and rural development,etc.

What are the disadvantages of agriculture?

For example, very early agriculture doesn’t produce a notable surplus of food beyond what one could get by hunting and gathering and doesn’t support a larger population. By centralizing production, it allows greater population density, but it’s not clear that hunter-gatherers would particularly want to live closer together. And this comes with a down side of increased exposure to pathogens leading to reduced lifespans. Average life expectancy appears to drop slightly among early farmers.

How to remove crust from garden soil?

Removing this crust with water is the other type of leaching. Leaching garden plants grown in containers is the process of washing the salts from the surface of the soil. Pour large amounts of water through the soil until it runs freely from the bottom of the planter. Leave the container alone for about an hour, then do it again.

What happens when you leach a plant?

Leaching of potted plants. Leaching in plants can happen in potting containers. Once the chemicals have drained down through the soil, they can leave a crust of soluble salts on the surface, which makes it hard for the soil to absorb water. Removing this crust with water is the other type of leaching. Leaching garden plants grown in containers is …

How do pesticides affect the environment?

Once your pesticides have leached from the plants themselves down through your soil into the water table, they begin to affect the environment. This is one reason why many gardeners prefer organic methods of pest control .

What happens when rain falls on a garden?

When rain falls, the soil near the top absorbs as much as possible, keeping the moisture available to the plants growing there. Once the soil is filled with all the water it can hold, the water begins to leak downward through the layers of rock and subsoil beneath your garden. When the water sinks down, it takes soluble chemicals with it, such as nitrogen and other fertilizer components, as well as any pesticides you may have used. This is the first of the types of leaching.

Is sand good for leaching?

The more porous the soil, the easier it is for chemicals to pass through. Pure sand is probably the best leaching type, but isn’t very hospitable to garden plants. In general, the more sand your garden soil has, the more likely it is that you will have excess leaching. On the other hand, soil with more of a clay component presents less …

How does leaching affect agriculture?

In agricultural ecosystems, leaching is an important balance between preventing salt accumulation and removing nutrients from soil. In dry soils of semi-arid regions salts can accumulate in the top horizons of the soil. The Food and Agriculture Organization of the United States estimated 45 million hectares of the 230 million hectares of irrigated croplands are salt-affected. These soils suffer from the accumulation of salts due to limited leaching. Without proper amounts of water to leach these salts (known as the leaching fraction) from the upper soil horizons, the growth of the plants can be slightly to severely impacted. The impact depends on the salt tolerance of the plant and the type of salts accumulating in the soil.

What happens when water moves into rocks?

When water moves into rocks, it commonly carries oxygen with it. The introduction of oxygen to rocks formed under low oxygen conditions causes a cascading chemical reaction allowing for once immobile metals to become rapidly mobilized. This oxidation caused by leaching is one of the main drivers of acid mine drainage!

What are the two ways that water can cause leaching?

As additional water moves into the rock, it can cause the leaching of elements from rocks in two ways: dissolution and oxidation. Subsurface movement of water can cause dissolution of sedimentary rocks, especially calcium carbonate rocks like limestone. This can lead to hazards such as sinkholes and erosion.

What happens to plants without water?

Without proper amounts of water to leach these salts (known as the leaching fraction) from the upper soil horizons, the growth of the plants can be slightly to severely impacted. The impact depends on the salt tolerance of the plant and the type of salts accumulating in the soil.

What happens when water is leached?

Compounds on the surface of minerals can be become dissolved. In addition, the physical movement of water can dislodge and move particles. Leaching can transport chemical compounds like dissolved substances or larger materials such as decomposing plant materials, fine rock fragments, and microbes throughout the Critical Zone.

What does “leaching” mean?

The word “leaching” is believed to have been derived from either late Middle English “leche” or Old English “leccan” meaning to moisten and to allow leaking. Currently, leaching primarily describes the process of water carrying soluble substances or small particles through soil or rock. Although this process seems trivial, …

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How to introduce porosity into a scaffold?

Particulate leaching is one of the first and simplest fabrication techniques used to introduce porosity into the resulting scaffold. This method dissolved a polymer in an organic solvent system. Next, particulates or porogens, which cannot be dissolved in the organic solvent, of a specific size range are added to the polymer solution, and the mixture is then shaped into the desired geometry. Following solvent evaporation, a polymer-particulate composite is formed, which is then immersed in a bath to leach or dissolve the particles leaving behind a porous structure. This fabrication method is very advantageous in that a wide variety of polymers can be used, and the resulting pore size and porosity can be controlled by the size and amount of the particulate, respectively. In addition a variety of porogens such as salt, sugar, macromolecules, and microparticles can be used as a porogen to fit a specific application (Li et al., 2007; Liao et al., 2002 ).

How are PLGA tubes made?

Highly porous PLGA hollow tubes have also been fabricated using a novel particulate-leaching and mold-casting technique ( Li et al., 2007 ). Gelatin microballoons were combined with PLGA solutions and inserted into a custom mold. Following removal of the microballoon porogen, it has been hypothesized that the hydroxyproline residue from the gelatin inside the pore walls can improve cell adhesion onto the PLGA scaffold. Sheet-based techniques have also been used with particulate leaching to produce porous hollow tubes of concentrically smaller dimensions. Porous PCL sheets have been fabricated using PEG macromolecules as the porogen ( Chung et al., 2011 ). The porous PCL sheets were grafted with NGF and Tirofiban (TF), a nonpeptide RGD-mimetic molecule, and rolled into a tube. The rats that were implanted with PCL-NGF/TF conduits regenerated nerves expressed beta-III tubulin (TB), growth association protein-43, and myelin basic protein along their longitudinal axis.

What is the major leaching of biomass?

The major biomass leaching occurred upon the initial acid wash; much smaller losses were observed after the Ca-, Mg-, Na-, or K-hydroxide-based washes. This resulted in major differences in the total concentration of chemically active sites of the treated biomass, as it could be determined by titration with NaOH ( Table 1 ). In brown seaweeds, the ion-binding activity can be correlated with their total carboxyl group content and related to the electronegativity of the elements investigated (Ca, Zn, Cd, Cu, and Pb) [8, 9].

What is leaching in agriculture?

Leaching is the main mechanism responsible for the transport of pesticides in soils. Recognition of soil hydrology, structure, and agroclimatic conditions is critical to characterise the magnitude and frequency of leaching events whether there is concern for groundwater contamination or the potential impact on non-target aquatic organisms in surface waters. There are locations where water resources are known to be vulnerable to leaching and the use of pesticides is banned or restricted. In the future legislation may require that ground and surface water catchments are managed more sensitively with respect to their potential contamination. A wide range of management techniques are being investigated to minimise leaching losses but these are mainly at the research stage and their wider application in agriculture is not yet established.

What is leaching technology?

The leaching technology mainly includes processes such as feeding the raw materials into the leacher, discharging the meal from the leacher, injecting fresh agent, and extraction of thick blending oil, etc. Intermittent leaching is carried out in batches, briefly and periodically, while continuous leaching is carried out continuously. The leaching method of oil production can be categorized into immersion type leaching, spraying type leaching, and mixed type leaching. For immersion type leaching, the raw materials are directly put into the leacher and immersed into the extraction solvent to complete the leaching process. For the spraying type leaching, the solvent is sprayed on the raw materials to achieve sufficient contact and complete the leaching process. The mixed type leaching is a combination of spraying type and immersion type leaching methods, and both the flat-turn leacher and the rotary-turn leacher are representative of the equipment for mixed type leaching.

Why are leaching losses higher in the humid tropics than temperate areas?

Leaching losses are generally assumed to be higher in the humid tropics than temperate areas due to the frequent and intense rain storms, higher temperature, and high carbonic acid content in soil (Ah Tung et al., 2009; Johnson et al., 1975).

How are heavy metals mobilized?

Heavy metals can be mobilized with the microorganism by the processes such as siderophores, methylation, or leaching by the heterotrophic and the autotrophic microorganisms (Fig. 13.2 ). It involves the separation by the formation of the insoluble compound of metals, oxides, sulfides, etc. and desorption of the metal sites over the organic material liberated in the process ( Ag-West Biotech Inc., 1998; Volesky, 1999 ).

How does leaching affect crops?

Leaching in soil can affect your crops because it takes away the essential nutrients that the plants need to grow. But more importantly, leaching has a profound effect on the whole environment. If possible, avoid using harmful chemicals to boost your harvest.

What are the environmental concerns of leaching in soil?

Environmental Concerns of Leaching in Soil. Nitrogen is a common element that you can find in nature and it is essential for plant growth. During leaching in soil, this element is also the most affected. The earth’s atmosphere is composed of 78% nitrogen (N2).

How to prevent leaching in soil?

There is no easy way to prevent leaching in soil. However, you can reduce its impact if you know the level of soil tension (how the soil holds on to the water) and how much water the soil is already holding. Some farmers have a device that measures real-time soil tension and notifies when the tension reaches the saturation level. The farmers can then take precautionary measures to protect their crops. However, without this device, it’s hard to determine when leaching could occur.

Why do plants need organic fertilizer?

Additionally, as the chemicals drain down, they typically leave a crust of soluble salts on the soil surface. With the crust, it will be difficult for the soil to absorb water for the plants. This is one of the reasons why using an organic fertilizer and pesticide is more advantageous. Gardeners normally try to remove the salts by pouring more water until the white covering on the soil is no longer visible.

How does rain affect leaching?

The amount of rainfall also affects the probability of leaching. Heavy rains put too much pressure on the top soil to absorb water. And when the soil reaches saturation and can no longer hold water, leaching will start. Other factors that promote leaching include high temperatures and the absence of protective vegetation.

What happens to the soil during leaching?

During the leaching period, the soil will lose valuable plant nutrients. Sometimes, leaching can even change the soil structure. Knowing this is important as you try to improve the health of your plants.

Why do plants need more water?

Generally, plants with large leaf surfaces or those with glossy dark leaves absorb and use more water. Having these types of plants improves the ability of soil to hold more water before it leaches down. The amount of rainfall also affects the probability of leaching.

What is leaching in science?

Definition • Leaching is a process of mass transfer that occurs by extracting a substance from a solid material that has come into contact with a liquid.

What does “leaching” mean in nutrition?

Leaching as the word indicates extracting water-soluble vitamins and nutrient from foods items through a process. Leaching is thought to drain out excess potassium and phosphorus from the vegetable, thus making it safe for consumption for people with CKD.

What is the difference between leaching and extraction?

Also Know, what is the difference between leaching and extraction? The main difference between leaching and extraction is that leaching is done to extract something from a solid using a liquid whereas extraction can be used to extract something either from a solid or a liquid.

What is the process of extracting a substance from a solid material that is dissolved in a liquid?

Leaching is a process of extracting a substance from a solid material that is dissolved in a liquid. This process is commonly referred to as extraction, particularly in the chemical industry. Three basic steps are involved in the leaching process: contact, separation, and extraction.

What is the problem with leaching?

The Problem of Leaching. Leaching is the movement of contaminants, such as water-soluble pesticides or fertilizers, carried by water downward through permeable so ils. Generally speaking, most pesticides adsorb to soil particles (especially clay), become immobile, and do not leach.

What affects the movement of water through the soil?

Soil texture: The proportions of sand, silt, and clay affect the movement of water through the soil. Coarse-textured soils containing more sand particles have large pores and are highly permeable, allowing water to move through rapidly. Pesticides carried by water through coarse-textured soil are more likely to reach and contaminate groundwater. …

What is the role of clay in soil?

A soil containing large proportions of clay holds more water and adsorbs more chemicals from the water. This slows the downward movement of chemicals, helps increase the chance of degradation and adsorption to soil particles, and reduces the chance of groundwater contamination. Structure: Loosely packed soil particles allow speedy movement …

How does organic matter affect soil?

Organic matter in the soil provides more surface area for adsorption, increases the soil’s ability to hold water and degrade pesticides, and nourishes microorganisms, all of which reduce pesticide leaching into groundwater. Soil organic matter can be increased by incorporating crop residues, adding manure, and growing cover crops.

How does soil move?

Structure: Loosely packed soil particles allow speedy movement of water through the soil. Tightly compacted soil holds water back like a dam, not allowing water to move freely through it. There are several ways that openings and channels can be created for water movement. For example, burrows dug by mammals and earthworms create openings for water to move. Freezing and thawing creates fissures or cracks in soil and rock, breaking up compacted particles. Plant roots penetrate the soil, creating excellent water channels when they die and rot away. These openings and channels may permit relatively rapid water movement, even through, some clay soils.

How does soil protect the ground?

Depth to Groundwater: Varying depths of soil separate the water table from the earth’s surface. Soil protects the groundwater by providing an opportunity for pesticide adsorption and degradation, particularly in those layers at or near the soil surface. The greater the depth to the water table, the more protection the groundwater has from contamination. When the water table is high or close to the surface, it is more vulnerable to contamination.

What is LR in irrigation?

Steady state conditions have been traditionally assumed to exist in the long run when irrigating with brackish water and therefore a concept of leaching requirement (LR) was put forward to control salt balances in the root zone (USSL, 1954; Rhoades et al., 1992 ). Since the alterations of cycles of salt/sodicity build-up with irrigation to winter season crops and their dilution/leaching with monsoon rains do not allow for steady state conditions, the LR’s do not work under the monsoonal climate. Any effort to attain LR’s during winter crops rather results in higher input of salts to mix-with or push the carried over rainwater in soils and thereby reducing its availability to crops ( Minhas, 1996 ). Similarly, various indices like adj.SAR also predict reduced sodification if higher levels of leaching fraction (LF) are attained. Nevertheless, as presented earlier, the ESP build-up is the maximum (2.4 x adj.RNa) under rice-wheat cropping system with LF of almost 0.6–0.8 where as it is about 1.1 times in maize/millet-wheat system ( Minhas and Sharma, 2006 ). Moreover, attempts to achieve leaching requirement (LF 0.5) with additional amount of saline-sodic water (EC 3.2 dS m −1, SAR 21, RSC 4 meq L −1) rather resulted in 1.3-1.5-fold higher salinity to reduce crop yields in both rice-wheat and maize/pearl millet-wheat sequence ( Bajwa et al., 1983 ).

How does saline irrigation affect soil?

Salts in the water and the soil decrease the osmotic potential of the soil water, which combines with effects of matric potential changes to cause stress between irrigations and to make water uptake by crop roots more difficult. For irrigation scheduling purposes, it is possible to consider total available soil water less than that for non-saline soils by correcting the soil water content at the wilting point (Eqs. (16) and (17) ). Thus, frequent irrigation regimes should eliminate both the matric potential effect and minimize the osmotic ( Hillel, 2000 ).

Why should irrigation be more frequent?

On one hand, irrigation events in saline soils should logically be more frequent because they reduce the cumulative water deficits (both matric and osmotic) between the irrigation cycles. On the other hand, small irrigation intervals would be expected to induce water uptake from shallow soil layers, increase unproductive evaporative losses from soil surface and increase the salt load of soils. Moreover, the nonsaline soil water carried over from the monsoon rains may also be displaced beyond the reach of plant roots by the frequently added saline irrigations ( Minhas and Gupta, 1992 ). Extended irrigation intervals usually result in deeper roots and larger proportions of water extractions from deeper zones. Since, under saline conditions, water uptake and thus ET is reduced, higher salinity soils will retain more water than low salinity ones between irrigation events. Thus, overall water stress is moderated and the inhibitory effect of increased solution concentration on growth is reduced. The net results of above counteracting processes still awaits further experimentation, but based upon model predictions Minhas and Gupta (1993b) have shown that depth of applied water should be simultaneously reduced if higher benefits from small intervals are to be accrued. However, it is difficult, nearly impossible, to apply below 40 mm water with surface methods even while using appropriate flow rates and precisely levelled land. The small frequent irrigation events enabled by drip irrigation not only allow efficient salt leaching but would also reduce deep percolation ( Hanson and Ayars, 2002 ). The use of straw mulch to control soil evaporation also helps to control upward transport of salts to the root zone ( Bezborodov et al., 2010; Pang et al., 2010 ).

How to remove salt from soil?

To make leaching an effective method for salt removal, water percolation through soil and eventual drainage should be ensured. In case both requirements are not met, the use of a leaching fraction will unavoidably worsen salinity problems. Enhanced water percolation and drainage are even more necessary for D. lotus rootstocks given the inherent shallowness of their root systems ( Fig. 8.5 ). To ease leaching, soil structure must be improved, and general agronomical recommendations are useful for this aim ( Gardner et al., 1999 ). In case of soil compaction due to machinery traffic across the field, one deep plow (chisel, etc.) is recommended to break the compacted soil layers that will, on the one hand, increase the available soil for root exploration, and, on the other hand, increase water percolation and salt leaching through soil. Once compacted soil layers have been removed, soil porosity must be preserved (1) by frequent organic additions to increase the soil organic matter content, (2) by allowing and/or fostering spontaneous winter meadows to grow on lanes between persimmon rows, and (3) by avoiding as much as possible machinery and people traffic in fields when soils are more compaction prone, i.e., when their water contents are over field capacity.

What is the difference between ECe and LF?

where LF is the minimum leaching requirement fraction , ECe is the average soil salinity tolerated by the crop as measured on a soil saturation extract (dS/m), and ECw is the salinity of the applied irrigation water (dS/m).

What is scheduling irrigation?

Scheduling irrigation is most commonly based on accommodating potential ET (plant evapotranspiration) plus some extra for nonuniform irrigation and leaching purposes. Few if any actually calculate the amount of extra water needed to achieve a desired LF. Some assume that a 20% LF is achieved by applying 20% more water than ET. That is erroneous. The relationship between applied water (AW), ET and LF is

How to determine the leaching requirement of a crop?

The leaching requirement depends on the salt concentration and composition of the irrigation water, on the amount of water extracted from the soil by the crop, and on the salt tolerance of the crop, which determines the maximum allowable concentration of the soil solution in the root zone . Assuming steady-state conditions of throughflow (thus disregarding short-term fluctuations in soil-moisture content, flux, and salinity), and furthermore assuming no appreciable dissolution or precipitation of salts in the soil and no significant removal of salts by the crop or capillary rise of salt-bearing water from below, the following simple equation is obtained:

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