How to Use Plastic Mulching Technology in Sweet Potato Fields

Mulching and planting sweet potatoes with plastic film can raise low temperatures, preserve soil moisture, prevent soil compaction and reduce weed damage. So how do you mulch sweet potatoes with plastic film? How do you use plastic mulching technology in sweet potato fields?

1. Mulching methods

There are two methods: mulching after transplanting seedlings and planting after mulching, with planting after mulching being more widely used. Generally, after ridging, herbicide is sprayed and then the plastic film is applied; after covering, it can be left for a few days to raise the soil temperature, and then planting is carried out.

At present, domestic rotary tillage, ridging and film mulching all-in-one machines have been developed, which can greatly reduce labor intensity and facilitate field operations, especially in spring when the wind is strong and manual film covering is quite laborious.

2. Benefits of mulching sweet potato fields

1. The advantage of mulching sweet potatoes is that it keeps them warm and moist, which is good for rooting; rooting is fast and the root system is well developed and thick.

2. Above ground, this shows up as fast seedling recovery, robust plants and well-developed leaves, improving photosynthesis and oxygen production, thereby increasing yield.

3. Another benefit is weed control, effectively saving manpower and material resources.

3. Key technical points of mulching

Choose the soil: mulch good soil, not poor soil

Increase fertilizer: apply enough, not too little

Select strong seedlings: mulch strong ones, not weak ones

Mulch with sufficient soil moisture: mulch wet soil, not dry soil

Plant early at the right time: mulch early, not late

Increase density: mulch densely, not sparsely

4. Mulching cultivation procedures and operating standards

1. Choose a suitable film:

Sweet potato mulching mostly uses transparent film; transparent plastic film has a lower cost and warms the soil quickly. However, high-quality black film is beneficial for high yields and controls weed growth.

2. Fertilize, irrigate, prepare the land and apply pesticide:

Since it is inconvenient to fertilize and apply pesticide after sweet potato planting and mulching, sufficient base fertilizer should be applied before land preparation, preferably more organic fertilizer; in dry years, irrigation should be used to build up soil moisture so as to keep the soil moisture suitable.

Using high-potassium compound fertilizer together with biological organic bacterial fertilizer achieves a combination of organic and inorganic nutrients, with comprehensive nutrients; it can both meet the sweet potato's demand for nitrogen, phosphorus and potassium and improve the soil, enhance the sweet potato's disease resistance, and produce sweet potatoes that are high-yielding, high-quality, delicious and sweet.

Before ridging, broadcast pesticides such as:

6% phoxim · phorate granules can effectively control underground pests such as white grubs, wireworms and cutworms, at 5-8 kg per mu;

Spraying herbicides such as 50% propisochlor emulsifiable concentrate before mulching can control grassy weeds and some broadleaf weeds (spraying after weeds emerge is ineffective), 220-250 ml per mu, mixed with 40 kg of water and sprayed evenly.

3. Ridging and film covering:

For sweet potato cultivation with plastic mulching, high beds or high ridges should be used, with a ridge spacing of 80-90 cm and a height of more than 30 cm. The ridge surface should be slightly arched, and the film should be stretched tight when covering.

4. Planting sweet potato seedlings after mulching:

When planting sweet potato seedlings after mulching, a hole-setting watering device can be used to water; when planting, leave three leaves at the top, and avoid getting soil on the seedling tips when covering with soil.

5. Precautions for mulching cultivation:

After ridging and applying pesticide, cover with film promptly to help the soil maintain moisture and reduce water evaporation.

If the film is applied immediately after spraying herbicide, the spray concentration can be appropriately reduced to prevent burning the sweet potato seedlings.

When covering with film, pull it tight and spread it flat, completely adhering to the ridge surface, and press the film firmly in the furrow with soil.

Why does plastic mulching reduce sweet potato yield?

These situations mainly occur in particularly dry areas in spring; if the soil is too dry when mulching, it is also easy for the sweet potatoes to fail to get sufficient water in the early stage. This can be improved by watering more when planting to increase soil moisture. In addition, if full mulching is used, the soil can receive little rainwater, and most rainwater runs off, which can also cause artificial drought, but generally it will not cause serious effects.