Soil Active Herbicides: A Boon for Weed Management

Weeds have always been a cause of concern for farmers across the globe. They compete with crops for resources like water, nutrients and sunlight, thereby reducing crop yields. Traditional methods of weed control like mechanical weeding or manual weeding are time consuming and labor intensive. With the introduction of soil active herbicides a few decades back, weed management has become much more efficient. Soil active herbicides have revolutionized agriculture by providing long term pre-emergent weed control.

What are Soil Active Herbicides?

Soil active herbicides, also known as pre-emergent herbicides, work by forming a chemical barrier in the soil which prevents weed seeds from germinating and emerging as seedlings. They are applied to the soil surface before the weeds emerge. These herbicides are absorbed by the root systems of germinating weeds and disrupt their growth. Some common active ingredients in soil active herbicides include Diuron, Oryzalin, Pendimethalin, Prodiamine etc.

Modes of Action

Soil Active Herbicides work via different modes of action:
– Mitosis Inhibitors: These herbicides like Diuron interfere with cell division in plants by inhibiting microtubule assembly in the mitotic spindle.
– Root Growth Inhibitors: Herbicides like Oryzalin and Pendimethalin inhibit cell elongation and division in the root tip region, thereby stunting root growth.
– Cell Membrane Disruptors: Herbicides containing Prodiamine disrupt membranes of plant cells.

Advantages of Soil Active Herbicides

– Provide broad spectrum and long term weed control: With a single application, these herbicides can control many annual grasses and broadleaf weeds for several months.
– Economical: By eliminating the need for multiple cultivations or hand weeding operations, soil herbicides prove to be cost effective in the long run.
– Convenient to apply: They can be easily mixed with soil during seedbed preparation or applied as spray solutions.
– No harmful residues: Once the herbicidal action is over, they degrade into non-toxic components without leaving any injurious residues.

Areas of Application

– Agriculture: Soil herbicides are widely used in fields of major crops like corn, soybeans, cereals, vegetables, orchards etc. for pre-plant or pre-emergent weed control.
– Non-Agriculture: They also find use in non-crop areas like industrial sites, rights of way, landscapes etc. to keep weeds under check.

Crop Safety Considerations

– Compatibility with various soils needs to be tested, as certain soils may rapidly degrade the herbicide.
– Application should be made only at labeled rates and during suitable weather conditions.
– Care must be taken while applying near recently planted crops as young crop plants are also susceptible especially during early growth stages.
– Tank mixing with certain fertilizers or other agrochemicals can cause phyto toxicity, so compatibility is important.

Future Prospects

– With rising labour costs and shortage of farm workers, demand for soil herbicides is expected to grow further in coming years.
– Development of new formulations and mixtures enabling application through various techniques will make their usage more convenient.
– Use of GIS and satellite imagery for zone-specific custom application may enhance their efficacy while reducing costs.
– Biodegradable polymers for controlled release over an extended period are being researched to minimize residual issues.

Soil applied herbicides have revolutionized agriculture by providing broad spectrum and long term weed control in a cost effective manner. With continuous research towards improved formulations and application techniques, their usage will certainly increase manifold in future for sustainable weed management. Though compatibility and safety aspects need monitoring, soil herbicides have undeniably become a boon for efficient weed control when used judiciously.

Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it