Detailed Explanation of the Key Technical Steps for High-Yield Cultivation of Plastic-Film Mulched Potatoes
Plastic-film mulched potatoes have the characteristics of early sowing, high yield, early marketing, and high benefit. Developing plastic-film mulched potatoes is of great significance for enriching the vegetable supply of urban and rural people and increasing farmers' income.
1. Deep plowing and land preparation, storing enough subsoil moisture
The formation and expansion of potato tubers require a deep, loose, and moist plow layer.
1. For land selection, it is advisable to choose loam or sandy loam with deep soil layers and medium or above fertility, rotate with legumes and cereal crops, and avoid continuous cropping with solanaceous crops and root-tuber crops.
2. Deep plowing: After the previous crop is harvested, deep plow in time, with 23-25 cm being suitable, and shallow plow 1-2 times before sowing.
3. Moisture storage: After deep plowing, break up soil clods in time, pick up stones and previous crop roots and stems, and harrow and level in early spring to preserve moisture. If subsoil moisture before sowing is insufficient, combine with applying manure water or irrigation to ensure sufficient subsoil moisture.
2. Formula fertilization, applying enough base fertilizer
1. Fertilizer requirement pattern: Potato is a potassium-loving and chlorine-avoiding crop. It mainly uses high-quality organic fertilizer, supplemented by chemical fertilizer. The required ratio of nitrogen, phosphorus, and potassium is 2:1:5.
2. Fertilizer requirement level: For fields generally yielding about 2500 kg per mu, apply 2000-2500 kg of organic fertilizer, 10 kg of urea or 25-30 kg of ammonium bicarbonate, 30-35 kg of superphosphate, and 30 kg of potassium sulfate per mu.
3. Fertilization method: For plastic-film cultivation, adopt a "one-time application." Open a 20-25 cm deep fertilizer ditch in the center of the sowing ridge surface and apply all required fertilizer into it.
3. Selecting good varieties, standardized planting
1. Good varieties: Use virus-free Kexin No. 1, No. 2, Anshu 56, Shaza 15, and other medium-maturing seed potatoes.
2. Carefully selected seed potatoes: Before sowing, select young potatoes with uniform shape, distinct eyes, no pests or diseases, no wounds, and a size of about 50 g.
3. Seed treatment: 20-30 days before sowing, keep them at 15-18°C in a heated hotbed or electric heating wire hotbed for sprouting. When young sprouts grow to the size of mung beans, cut the seed potatoes into pieces, each needing more than 2 eyes, mix with plant ash, and then sow.
4. Standardized planting: Use 80 cm wide, 0.005 mm thick micro-film, plant two rows of potatoes, with a row spacing of 45-50 cm. For pure planting, 6000-6500 hills per mu; for interplanting, 4000-4500 hills.
4. Sowing at the right time and early, ridge cultivation
1. Sowing time: The sowing time for plastic-film mulched potatoes is 20-25 days earlier than open-field potatoes. Use ridge planting and film mulching to prevent freezing and preserve warmth. When the soil thaws and the soil temperature at 10 cm underground stabilizes at about 70°C, sowing can begin. At an altitude of about 800 m, it is in early to mid-February; in high-cold mountainous areas at about 1000 m, it is from late February to early March.
2. Sowing method: For ridge-cultivated potatoes, which produce more tubers and larger tubers, make ridges 20-25 cm high and 55-60 cm wide at the top. Open two sowing ditches 15-20 cm deep on the ridge surface at a distance of 40 cm apart, place seed potatoes along the ridge ditches, then cover with soil and level the ridge surface, cover with film, and press the film edges tightly.
5. Strengthening field management, harvesting at the right time
1. Releasing seedlings: When potato sprouts break through the soil and grow 1-2 leaves, release the seedlings in time. Immediately after releasing the seedlings, seal the openings tightly with fine soil, and carefully prevent high temperatures from scorching the young seedlings.
2. Foliar fertilizer spraying: During the tuber expansion period of potatoes, spray foliar fertilizer with 2% urea solution or 0.2-0.3% potassium dihydrogen phosphate solution. If drought occurs, splash light manure water or irrigate to resist drought.
3. Preventing excessive growth: Plastic-film mulched potatoes have strong growth vigor and lush stems and leaves, so it is necessary to timely control aboveground growth and promote underground growth. For excessively growing fields, spray 0.05-0.1% chlormequat or 30-40 g of paclobutrazol per mu mixed with 50 kg of water on the leaves. Pinching off growing tips and flower buds can also be adopted.
4. Pest and disease control: Potato late blight and the 28-spotted ladybird are the main pests and diseases. While removing the central diseased plants of late blight, spray "Triadimefon" or "Nongkang 120" on affected fields at 0.1-0.2 kg per mu mixed with 50 kg of water. For damage by the 28-spotted ladybird, choose 250% "Shenxing Chuji" 40-45 mL or 48% "Lorsban" 40 mL, mixed with 50 kg of water for spraying.
5. Harvest: When potato plants wither and the middle and lower stems and leaves turn yellow, they can be harvested. They can also be harvested and marketed in time according to market conditions when the market value is best.