Crop rotation is the practice of growing a range of different or different plant species in the same area in successive seasons. This is done so that farmland is not used for only one set of nutrients. It helps in reducing soil erosion and improves soil fertility and yields.
Growing the same plant in the same place for many years in a row (Monocropping) disproportionally drains the soil from certain nutrients. With rotation, plants that leach ground from one type of nutrient followed during the next growing season by different plants that return the nutrients to the soil or draw different nutritional ratios. In addition, crop rotation reduces the accumulation of pathogens and pests that often occur when one species continues to be trimmed, and can also improve soil structure and fertility by increasing the biomass of various root structures.
The crop cycle is used both in conventional and organic farming systems.
Video Crop rotation
Histori
Agriculturalists have long acknowledged that appropriate rotation - such as growing spring crops for livestock in the grain for human consumption - makes it possible to recover or maintain productive land. Middle Eastern farmers practiced crop rotation in 6000 BC without understanding chemistry, alternately planting legumes and cereals. In the Bible, chapter 25 of the Book of Leviticus instructs the Israelites to observe the "Land Sabbath". Every seventh year they will not arrive, prune or even control the insects.
Two-field system
Under a two-field rotation, half the ground is planted within a year, while the other half is abandoned. Then, the following year, the fields were reversed. From the time of Charlemagne (d. 814), peasants in Europe shifted from a two-field rotation of crops to crop rotations of three planes.
Three-field system
From the late Middle Ages to the 20th century, European farmers rotated three fields, dividing the available land into three parts. One part is planted in autumn with wheat or winter wheat, followed by spring oats or wheat; the second part planting crops such as peas, peanuts, or nuts; and the third field is left empty. Three fields are rotated in this way so that every three years, a field will rest and become empty. Under a two-field system, if a person has a total of 600 acres (2.4 km km 2 ) of fertile soil, one will only plant 300 hectares. Under the new three-field rotation system, one will plant (and hence harvest) 400 hectares. But additional plants have a more significant effect than mere quantitative productivity. Since the spring crop is mostly peas, they improve the overall nutrition of the people of Northern Europe.
Rotate four fields
Farmers in the area of ​​Waasland (now northern Belgium) pioneered the rotation of four fields at the beginning of the 16th century, and the English farmer Charles Townshend (1674-1738) popularized this system in the 18th century. The order of four plants (wheat, turnips, barley and clover), including cattle and grazing crops, allows cattle to be raised throughout the year. The four-field crop rotation became a key development in the British Agricultural Revolution. The rotation between arable and ley is sometimes called ley farming.
Modern developments
George Washington Carver (1860-1943) studied the method of crop rotation in the United States, teaching farmers in the south to rotate soil-like crops with soil-rich plants such as beans and peas.
In the Green Revolution of the mid-twentieth century, the traditional practice of crop rotation gave way in some parts of the world to practicing chemical supplies to the soil by fertilizing with fertilizers, adding (for example) ammonium nitrate or urea and restoring soil pH with lime. Such practices aim to improve yields, prepare land for specialist crops, and reduce waste and inefficiency by simplifying planting and harvesting.
Maps Crop rotation
Options crop
A preliminary assessment of reciprocity can be found in how each plant: (1) contributes to soil organic matter content, (2) provides for pest management, (3) manages nutritional deficiencies or overload, and (4) how to contribute or control for soil erosion.
The choice of plants is often associated with the objectives that farmers want to achieve by rotation, which can become weed management, increase available nitrogen in the soil, control erosion, or improve soil and biomass structures, to name a few. When discussing crop rotation, plants are classified in different ways depending on what quality is being assessed: by the family, by nutritional needs/benefits, and/or with profitability (ie food versus cover crops). For example, giving sufficient attention to the plant family is essential for reducing pests and pathogens. However, many farmers manage the rotation by planning the sequence and covering the plants around the desired crop. The following is a simplified classification based on the quality and purpose of the harvest.
Plants line
Many of the important crops for the market, such as vegetables, are line crops (ie, growing in tight ranks). Although often the most profitable for farmers, these plants are more taxing the land. Line plants usually have low biomass and shallow roots: this means the plants donate low residues to the surrounding soil and have limited effects on the structure. With so much land around the plant exposed to disturbance by rainfall and traffic, fields with row crops are experiencing faster parse of organic matter by microbes, leaving less nutrients for future crops.
In short, while these plants may be profitable for agriculture, they are nutrient depletion. The practice of crop rotation exists to achieve a balance between short-term profitability and long-term productivity.
Legum
The great advantage of crop rotation comes from the linkage between a nitrogen-fixing plant and a plant that requires nitrogen. Nuts, such as alfalfa and clover, collect available nitrogen from the ground in the nodules on their root structure. When the crop is harvested, the biomass from the unfiltered root is damaged, making stored nitrogen available for future crops. Nuts are also a valuable green manure: plants that collect nutrients and fix them in depths of land that can be accessed for future crops.
In addition, nuts have heavy tap roots that dig deep into the soil, raising soil for better til and water absorption.
Grass and cereals
Cereals and grasses often become cover crops because of the many advantages they provide for soil quality and structure. Roots and extensive root systems provide sufficient structures for the surrounding soil and provide significant biomass for soil organic matter.
Grasses and cereals are key in weed management as they compete with undesirable plants for soil space and nutrients.
Green Fertilizer
Green dirt is a plant that is mixed into the soil. Nitrogen-fixing legumes and nutrient scavengers, such as grass, can be used as green manure. Green manure from nuts is an excellent source of nitrogen, especially for organic systems, however, the legume biomass does not contribute to soil organic matter that is as lasting as grass.
Plotting rotation
There are many factors to consider when planning a crop rotation. Planning an effective rotation requires the weighing of a fixed and fluctuating production situation: market, land size, labor supply, climate, soil type, growth practices, etc. In addition, crop rotation should consider under what conditions one plant will leave the soil for the next crop. and how one plant can be seeded with other plants. For example, a nitrogen-fixing plant, such as a legume, should always precede a nitrogen depleting; Similarly, low residue crops (ie plants with low biomass) should be offset by high biomass cover crops, such as mixtures of grass and legumes.
There is no limit to the number of plants that can be used in rotation, or the amount of time it takes to complete the rotation. Decisions about rotation were made a few years earlier, previous seasons, or even in the last minute when opportunities to improve the profitability or quality of the land came into being by themselves. In short, there is no single formula for rotation, but many considerations to consider.
Implementation
The rotation system of plants can be enriched by the influence of other practices such as the addition of livestock and manure, intercropping or many crops, and low organic management in pesticides and synthetic fertilizers.
Merge cattle
Introducing animals makes the most efficient use of soil plants and critical cover crops; livestock (through feces) is able to distribute nutrients in this plant throughout the soil rather than removing the nutrients from the farm through the sale of straw.
In Sub-Saharan Africa, as farms become less than nomadic practice many pastoralists begin to integrate crop production into their practice. This is known as mixed farming, or the practice of cultivating crops with the incorporation of cattle, sheep and/or goats farms by the same economic entity, increasingly common. This interaction between animals, soil and plants is done on a small scale throughout the region. The rest of the plant provides animal feed, while animals provide manure to replace plant nutrients and draft power. Both of these processes are very important in this region of the world because they are expensive and logistically unfeasible to be transported in synthetic fertilizers and large-scale machinery. As an added benefit, cattle, sheep and/or goats provide milk and can act as cash crops in times of economic difficulty.
Organic farming
Crop rotation is a necessary practice in order for a farm to receive organic certification in the United States. "Standards of Plant Rotation Practices" for National Organic Programs under the Federal Regulations of the US Regulations, section Ã,§205.205, states that:
Farmers are required to apply crop rotations that maintain or build soil organic matter, work to control pests, manage and preserve nutrients, and protect against erosion. Unpotled annual plant producers can use other practices, such as cover crops, to maintain soil health.
In addition to decreasing input requirements by controlling pests and weeds and improving the available nutrients, crop rotation helps organic farmers increase the amount of biodiversity in their land. Biodiversity is also a requirement for organic certification, however, there are no rules to regulate or strengthen this standard. Increasing plant biodiversity has a beneficial effect on the surrounding ecosystem and can host a greater diversity of fauna, insects, and beneficial microorganisms in the soil. & Lt; Several studies have shown increased availability of nutrients from crop rotation under organic systems compared to conventional practices because organic practices are less likely to inhibit beneficial microbes in soil organic matter.
While many of the intercropping and intercropping benefits of many principals are similar to crop rotations, they do not meet the requirements under NOP.
Intercropping
Multiple cropping systems, such as intercropping or companion planting, offer more diversity and complexity in the same season or rotation, such as three sisters. Examples of companion planting are intercropping of corn crops with peas and pumpkin or pumpkin. In this system, the seeds provide nitrogen; corn provides support for nuts and "screens" against pumpkin grape borer; squash vining provides a canopy of weed suppression and a hungry raccoon of maize.
Double plants are common where two plants, usually from different species, are planted sequentially in the same growing season, or where one plant (eg vegetables) is planted continuously with cover crops (eg wheat). This is beneficial for small farms, which are often unable to leave cover crops to fill the soil for long periods of time, such as larger farms. When many crops are implemented on small farms, these systems can maximize the benefits of crop rotation on available land resources.
Benefits
Agronomists describe the benefits of producing plants that are rotated as "Rotation Effects". There are many benefits to be found from the rotation system: however, there is no special scientific basis for yield improvement of 10-25% occasionally in plants grown in rotation versus monoculture. Factors associated with the increase were only described as mitigating the negative factors of the monoculture cropping system. Explanation for the improvement of nutrition; pests, pathogens, and weed stress reduction; and soil structure improvements have been found in some cases to be correlated, but causes have not been determined for most planting systems.
Other benefits of the rotation cropping system include production cost advantages. The overall financial risk is more widespread in the production of more diverse plants and/or cattle. Lack of dependence is placed on purchased inputs and over time crops can maintain production goals with fewer inputs. This along with shorter and longer term results makes the rotation of a powerful tool for improving farming systems.
Soil organic matter
The use of different species in rotation enables an increase in soil organic matter (SOM), larger soil structure, and improved environmental soil chemical and biological for crops. With more SOM, water absorption and retention increased, providing increased drought tolerance and decreased erosion.
Soil organic matter is a mixture of decomposing material from biomass with active microorganisms. Plant rotation, naturally, increases biomass exposure from soil, green manure, and various other plant remnants. The reduced requirements for intensive processing under crop rotation allow biomass aggregation to lead to greater retention and nutrient utilization, reducing the need for additional nutrients. With land preparation, soil disturbance and oxidation create an environment that is less conducive to the diversity and proliferation of microorganisms in the soil. These microorganisms make nutrients available to plants. Thus, where organic matter soil is "active" is the key to productive soils, soils with low microbial activity significantly provide fewer nutrients for crops; this is true even though the quantity of biomass left on the ground may be the same.
Soil microorganisms also decrease the activity of pathogens and pests through competition. In addition, the plant produces root exudates and other chemicals that manipulate their soil environment as well as their weed environment. Thus rotation allows increased yields of nutrient availability but also alleles of allelopathy and competitive weed environments.
Carbon sequestration
Research has shown that crop rotation greatly increases the organic carbon content (SOC) of soil, the main constituent of soil organic matter. Carbon, together with hydrogen and oxygen, is a macronutrient for plants. A very diverse rotation over a long period of time has proven to be more effective in improving SOC, while soil disturbance (eg from preparation) is responsible for the exponential decrease in SOC levels. In Brazil, conversion to a groundless method combined with intensive crop rotation has shown an absorption rate of SOC of 0.41 tons per hectare per year.
In addition to increasing crop productivity, carbon uptake in the atmosphere has major implications for reducing climate change by removing carbon dioxide from the air.
Nitrogen tightening
Rotating plants adds nutrients to the soil. Legum, the Fabaceae family, for example, has nodules in their roots that contain a nitrogen-binding bacteria called rhizobia. During a process called nodulation, rhizobia bacteria uses nutrients and water provided by plants to convert atmospheric nitrogen into ammonia, which is then converted into organic compounds that plants can use as their nitrogen source. Therefore it makes sense for agriculture to alternate them with cereals (Poaceae family) and other plants that need nitrates. How much nitrogen is available for the plant depends on factors such as the type of legume, the effectiveness of rhizobia bacteria, soil conditions, and the availability of the elements necessary for plant foods.
Pathogens and pest control
Plant rotation is also used to control pests and diseases that can form on the ground over time. Successive plant change decreases pest population by (1) disrupting pest life cycle and (2) disrupting pest habitat. Plants in the same family of taxonomies tend to have the same pests and pathogens. By regularly changing plants and maintaining the soil occupied by cover crops as a substitute for unplanted crops, pest cycles can be damaged or limited, especially useful cycles of winter surplus in residues. For example, root node nematodes are a serious problem for some plants in warm climates and sandy soils, where it slowly builds up to a high level in the soil, and can severely damage the productivity of plants by cutting circulation from plant roots. Growing a non-host plant for the node node for one season greatly reduces the nematode level in the soil, making it possible to grow vulnerable plants next season without the need for ground fumigation.
This principle is a special use in organic farming, where pest control should be achieved without synthetic pesticides.
Weed management
Integrating certain plants, especially cover crops, to crop rotation is of particular value to weed management. These plants get rid of weeds through competition. In addition, soil and compost from cover crops and green manures slows down what weed growth can still make through the soil, giving crops further competitive advantage. By eliminating the growth slowdown and the proliferation of weeds while cover crops are cultivated, farmers greatly reduce the presence of weeds for future crops, including rooted and shallow crops, which are less resistant to weeds. Crop cover, therefore, is considered as a conservation plant because they protect unplanted land to be flooded with weeds.
This system has advantages over other common practices for weed management, such as cultivation of land. Tillage is intended to inhibit weed growth by overturning the soil; However, this has the effect of exposing the weed seeds that may have been buried and burying valuable plant seeds. Under the rotation of the plant, the number of seeds eligible in the soil decreases through the reduction of weed populations.
In addition to its negative impact on quality and yield, weeds can slow the harvest process. Weeds make farmers less efficient at harvest, because weeds such as bindweed, and knotgrass, can become tangled in the equipment, resulting in a kind of stop and go harvest.
Prevent soil erosion
Crop rotation can significantly reduce the amount of soil lost due to erosion by water. In areas highly susceptible to erosion, agricultural management practices such as zero and reduced cultivation can be supplemented by certain crop rotation methods to reduce the impact of rain, sediment detachment, sediment transport, surface runoff, and soil loss.
The protection of ground loss is maximized by the rotation method leaving the largest remaining plant stump (residual crop remaining after harvest) above the soil. The stump cover in contact with the soil minimizes the erosion of the water by reducing the flow rate of land, electricity, and thus the ability of water to release and transport the sediment. Soil and Cill Erosions prevent disturbance and detachment of soil aggregates causing macropores to clog, decreased infiltration, and increased runoff. This significantly improves soil resistance when experiencing periods of erosion and stress.
When forage crops break down, binding products are formed that act like adhesives on the ground, which make the particles stick together, and form aggregates. The formation of soil aggregates is important for erosion control, as they are better able to withstand the impact of rain, and water erosion. Soil aggregates also reduce wind erosion, because the particles are larger, and more resistant to abrasion through soil practices.
The effect of crop rotation on erosion control varies according to climate. In areas under relatively consistent climatic conditions, where annual rainfall and temperature levels are assumed, rigid plant rotation can produce sufficient plant growth and ground cover. In areas where climatic conditions are less predictable, and unanticipated periods of rain and drought may occur, a more flexible approach to cover land with crop rotation is required. The cultivation system of opportunity promotes an adequate layer of soil under these uncertain climatic conditions. In an opportunity planting system, plants are planted when ground water is sufficient and there is a reliable sowing window. This form of cropping system tends to produce better soil closure than rigid plant rotation because plants are planted only under optimal conditions, whereas rigid systems are not always planted under the best available conditions.
Crop rotation also affects time and length when a field is subjected to fallow. This is very important because depending on the climate of a particular region, a field can be the most vulnerable to erosion when under fallow land. Efficient fallow management of land is an important part of reducing erosion in crop rotation systems. Zero tillage is a fundamental management practice that promotes retention of crop straw under unplanned land when plants can not be planted. Such management practices that successfully maintain suitable land cover in the areas below fallow will ultimately reduce the loss of soil. In a recent study lasting a decade, it was found that common winter cover crops after potato harvest such as falling grain could reduce soil runoff by as much as 43%, and this is usually the most nutritious soil.
Biodiversity
Increasing plant biodiversity has a beneficial effect on the surrounding ecosystem and can host more diverse faunas, insects, and beneficial microorganisms in the soil. Several studies have shown increased availability of nutrients from crop rotation under organic systems compared to conventional practices because organic practices are less likely to inhibit beneficial microbes in soil organic matter, such as arbuscular mycorrhiza, which increases nutrient uptake in plants. Increased biodiversity also increases the resilience of agro-ecological systems.
Agricultural productivity
Crop rotation contributes to improved yields through improved soil nutrition. By requiring planting and harvesting different crops at different times, more land can be cultivated with the same number of machines and labor.
Risk management
Different plants in rotation can reduce the risk of bad weather for individual farmers.
Challenges
While crop rotation requires a lot of planning, the choice of plants should respond to a number of permanent conditions (soil type, topography, climate, and irrigation) in addition to conditions that can change dramatically from year to year (weather, market, labor). provide). In this way, it was not wise to plan the plant many years before. The improper implementation of the crop rotation plan may lead to an imbalance in the composition of soil nutrients or the accumulation of pathogens that affect important crops. The consequences of incorrect rotation can take years to become real even for experienced soil scientists and can take a long time to improve.
Many challenges exist in practice related to crop rotation. For example, green manure from nuts can cause snail or snail invasion and decay of green manure can sometimes suppress the growth of other plants.
See also
- Organic farming
- Nitrogen installation
- Agroecology
- Shmita
- Carbon cycle
Note
References
External links
- Medieval technology
- Ã, "Plant Rotation". New International Encyclopedia . 1905
Source of the article : Wikipedia
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