Weed Management Strategies in Soybean

Soybean (Glycine max L.), the world’s most important grain legume in terms of production and trade, grows well in tropical, subtropical and temperate climates.

As one of the world’s most adaptable crops, it often encounters severe weed competition during its early growth stages.

Effective weed management is crucial for profitable soybean production, as weeds are a major yield-limiting factor.

However, adverse weather conditions may sometimes limit field operations. On environmental grounds, emphasis has been given to really appropriate mixtures of cultural and chemical techniques of weed control.

Weed of soybean

The primary weeds in soybean are grouped in to two principal classes, broadleaf weeds and grasses and sedges.

- Grasses and sedges

Generally, perennial grasses pose significant challenges of soybeans. They cause large harm and difficult to control.

✘Barnyardgrass                         ✘Crabgrass                        ✘Goosegrass                   ✘Itchgrass

✘Johnsongrass                            ✘Foxtails                          ✘Fall panicum                        ✘Stinkgrass

Sedges are also challenging to control. Apart from competition of moisture, carbon dioxide, light and nutrient; they have allelopathic results on soybeans.

Yellow nutsedge

Perennial weeds are tough survivors. Their underground parts-like rhizomes and tubers-can sprout new shoots and also store plenty of food. This means that even if you cut off the top growth, they can grow back again.

That’s why farmers often use deep plowing to bring these underground parts up to the soil surface, where sun and wind can dry them out and reduce their chance of regrowing.

- Broadleaf weeds

In different geographic regions and cropping practices, broadleaf weeds may still exhibit strong competitiveness at key growth stages. Some produce many seeds making then difficult to manage e.g. lamb’s quarters. Other serious broad-leafed weeds frequent in soybean fields encompass Spiny Amaranth and Morning glory. Annual weeds can be dealt with by repeated shallow cultivation.

✘Spiny Amaranth                       ✘Morning glory                          ✘Eclipta                         ✘Sunflower

Weed Control Methods in Soybeans

- Preventive method

Prevention is the first line of defense. It is easier and more cost-effective to prevent weed introduction than to control established weeds. Farmers should:

✔ Use certified weed-free seeds.

✔ Clean equipment to avoid transferring weed seeds between fields.

✔ Avoid using manure or compost contaminated with weed seeds.

✔ Implement quarantine measures for animals and irrigation water from external sources.

- Cultural practices

Cultural methods reduce weed pressure by enhancing crop competitiveness.

✔ Crop rotation: Alternating soybeans with other crops disrupts weed life cycles and prevents dominance of specific species.

✔ Row spacing and density: Narrow row spacing and optimal planting density help soybean canopies shade out weeds more effectively.

✔ Cover crops: Planting cover crops like rye or millet can suppress weed emergence by occupying ecological niches and reducing light availability for weeds.

- Mechanical control

Manual and mechanical weeding remain effective, especially in smaller fields or organic systems.

✔ Hand weeding or hoeing is useful when weeds are young and the soil is dry.

✔ Mechanized cultivation with tractors can control inter-row weeds but may be less effective under wet conditions or for perennial weeds with deep root systems.

- Chemical control

Herbicides are widely used for efficient and large-scale weed management.

✔ Pre-emergence herbicides: controls weeds at an early stage; hits targets that the hoe or cultivator does not reach, like the weeds in the crop row; reduces or eliminates the risk of damage to the roots and to young plants; reduces the need for labor.

✔ Post-emergence herbicides: targets weeds without damaging soybeans; increases the speed of the control operation per unit area, reducing the cost per treated area; offers unmatched efficiency, especially for in-row weed control and during unfavorable weather.

Combining them with cultural, mechanical, and preventive methods helps prevent herbicide resistance and ensures long-term productivity.

To support farmers in achieving efficient and reliable weed management, King Quenson provides a range of proven herbicide solutions tailored for soybean fields. These products are designed to target both annual and perennial weeds effectively, ensuring flexibility under different field conditions.

Since 2003, King Quenson has been thriving to introduce the latest technologies to agricultural industries and farmers to achieve mutual development and prosperity. With years of dedication and rich experience, King Quenson devotes more than 20 years to crop protection and offers solutions.

If you have a need, you can contact us at any time:

Email: info@kingquenson.com

Tel: 86-755-86612760, 86-755-86612793

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