Weeds compete with crops for sunlight, nutrients, and water in an agricultural field. They are tough, have a deep root system, and produce numerous seeds that sleep and persist for several years in some cases.
Non chemical methods of weed management are used to remove weeds without using chemicals.
They reduce crop yields and cause severe damage to crop quality. Generally, herbicides effectively control weeds when added with other weed control methods.
In recent years, several factors have increased the importance of the non chemical method of weed management. Of these environmental problems resulting from excessive pesticide use, growing demand for organic food, and the development of herbicide resistance in weeds are some.
Non-chemical methods of weed management methods are available to farmers. Biological and mechanical control practices are widely used on organic farms and can enable regular farmers to reduce herbicide use and risk.
Mechanical Weed Control Method
Mechanical weed control is one of the non chemical methods of weed management. Mechanical weeding is a physical activity that prevents the growth of unwanted plants.
This weed management manages a population of weeds by physical methods that remove, damage, kill or worsen growing conditions. Some mechanical methods cause direct damage to weeds by their complete removal or fatal injuries. [1]
Weed control by mechanical means involves the physical destruction of weeds or the creation of barriers to weed removal.
Although weed control through the mechanical way can limit the use of herbicides, it should be borne in mind that mechanical weed control measures also require external inputs (for example, fossil fuels).
These are not necessarily friendlier to the environment than using responsible herbicides.
There must be a balance between weed control methods that depend on different inputs and minimizing the environmental impact.
Tillage in Weed Control
Among non chemical methods of weed management, tillage is one of them. Tillage refers to the mechanical treatment of soil and the remaining crops to prepare a seedbed for plant cultivation. This practice is an essential part of traditional farming systems.
Tillage has many benefits. It removes weeds, loosens the soil, increases the release of nutrients from the ground for plant growth, and regulates the water and air circulation in the soil.
In organic farming, tillage is a vital tool to control weeds. Careful use of specific tillage procedures in crop systems can lower the need for a chemical to control weeds without increasing soil erosion.
Methods that increase organic matter in the soil and cover as much soil as possible (for example, covering crops) can minimize the potential adverse effects of tillage on the farm soil.
Weed control by tillage depends on the environmental conditions conducive to their success. Good soil moisture and temperature are necessary for tillage for germination and weed emergence. On the other hand, tillage operations aim to remove weeds best in dry conditions.
Spring Tillage Practice
Spring tillage (plowing) operations have two purposes, seedbed preparation, and second weed control. This method is one of the non chemical methods of weed management in agriculture.
Pre-planting and pre-emergence tillage can provide a good crop start by removing weeds that precede the crop.
In competitive crop cultivation, this head start can help to less herbicide. Although single-stage sowing with a high degree of disturbance can kill weeds and seeds simultaneously, this practice may not be effective for some combinations of soil type and moisture.
Tillage is usually practiced to control early weed germination. For some crops, delaying seed sowing will prevent the initial fluid of the weeds. The type of tillage applied in spring operations will depend on the need to save soil water, the number of crop residues, and the type of weeds present.
Also Read: Pest and Disease Control in Agriculture
In-Crop Tillage
This tillage within the crop eradicates weeds without damaging the crop selectively. Potential is there in In-Crop Tillage to replace or reduce herbicide use in crops in traditional systems, and this tillage is common practice among organic farmers.
Post-emergent harrowing included in In-Crop Tillage can be used on solid seeding and intra-row planting crops, commonly used on in-row crops.
The success of in-crop harrowing to control weeds in crops hangs on the crop type and weed species’ presence. Deep seed crops with large seeds are internally more resistant to in-crop harrowing than tiny seeds.
It is less likely that harrowing practices will uproot large seed crops as these are more resistant to being buried by soil. Likewise, the in-crop harrowing practice most affects weeds with tiny seeds; they grow from shallow depths.
Fall Tillage
Fall tilling is a good head start for several farmers to begin planting in the spring. Fall tillage is also one of the non chemical methods of weed management.
It can help manage residues, faster decomposition, and improve contact between seeds and soil. Also, prepare a seedbed, which is helpful for farmers dealing with wet springs that delay sowing dates.
Fall tillage help control several pests of vegetables and incorporates soil changes. However, it can lead to soil loss of nutrient loss, degradation, and unnecessary costs in some cases.
Fall tillage can be very important for controlling perennial and winter weeds. But, fall tillage may contribute to weed problems in the future. Weed seeds are buried and added to the weed bank by fall tillage. These seeds can be dormant and therefore raise issues in the future crop. [2]
Mulches
Mulching is one of the most straightforward and valuable procedures you can use in the garden. Mulch is a protective layer of material spread over the soil.
This method can be organic materials like grass clippings, straw, bark chips, and the like, or inorganic materials like brick chips, stone, and plastic. Organic and inorganic mulches have many benefits.
Live or killed mulch is a physical barrier to the appearance of weeds. Using mulch to control weeds can lower dependence on herbicides and tillage and can be beneficial in developing organic conservation tillage systems.
Live mulch is also referred to as cover crops or smoother crops. A good cover crop for live mulch will have a fast establishment, field traffic tolerance, drought tolerance, low fertility, and low maintenance costs.
Other Methods of Mechanical Weed Control
Cutting weeds above the crop canopy is a method that organic farmers use to prevent the spread of weeds. This practice can work on shorter plants such as lentils and flax.
Although weed clipping can offer a specific aesthetic value, it is unknown whether this method affects crop yields or the return of weeds to the soil seed bank.
Flaming, steaming, freezing, and application of plastics or particular mulches are other non-chemical methods of weed management and are included in mechanical weed control methods.
Some mechanical weed control methods can potentially be used on high-quality crops but are generally not valuable for field crops.
Conclusion
In the future, non chemical weed control methods are likely to gain market traction for new and novel weed control methods. Organic farmers are conscious of the role of weed management in producing high-quality products.
They employ several non-chemical methods to comply with organic farming rules and regulations. They choose to use organic methods because pesticides and herbicides are banned in organic production and handling.
