Detailed Explanation of Key Techniques for Mulched Cultivation of Spring Potatoes

When cultivating spring potatoes, selecting good varieties, applying sufficient fertilizer, sowing at the right time, and controlling pests and diseases well can achieve a yield of 2000 kg per mu, with a marketable rate above 80%.

For careful variety selection, it is best to use virus-free seed potatoes, and varieties such as Zhengshu No. 6, Dongnong 303, Jinyan No. 8, and Zhongshu No. 3, which are early-maturing and strongly disease-resistant, can be chosen.

For good crop rotation selection, choose slightly acidic sandy loam soil with deep soil layers and loose, fertile texture for planting. The previous crop should be vegetables of the Liliaceae and Cucurbitaceae families, as well as rice, soybeans, etc., and planting should be avoided as much as possible in plots where the previous crop was solanaceous fruits and peanuts, so as to reduce damage from scab, cancer, wireworms, and white grubs.

For increased fertilizer application, producing every 1000 kg of potatoes requires 5 kg of pure nitrogen, 2 kg of phosphorus pentoxide, and 11 kg of potassium oxide. For a yield above 2000 kg per mu, each mu requires 2000 kg of decomposed organic fertilizer, 10 kg of urea, 70-80 kg of sulfur-based compound fertilizer, and 15-20 kg of potassium sulfate. For plastic film mulching cultivation, the above fertilizers can be applied all at once as a base fertilizer.

For cutting seed potatoes and promoting sprouting, cut the seed potatoes into pieces 20-25 days before sowing, with each piece weighing about 40 grams and each carrying 1-2 buds, and soak the seeds in a 500-fold dilution of 25% carbendazim for 10 minutes, then remove and dry them in the sun. After the cut surfaces are air-dried, pile the seed potato pieces in a wind-sheltered, sunny place to promote sprouting, with a pile height of 60-80 cm, cover with 10 cm thick rice straw, then cover with a layer of plastic film, and seal the film tightly around the edges. Sow when the sprouts are 0.5-1 cm long.

For timely early sowing, mulched cultivation should be sown from late January to early February, while open-field cultivation can be postponed to mid-February. Ten days before sowing, spread organic fertilizer, urea, and potassium fertilizer, then plow, and then apply compound fertilizer to form ridges, with a ridge spacing of 85-90 cm and a ridge height of 30 cm. Sow on a sunny day, with a sowing depth of more than 10 cm, using 180-200 kg of seed per mu, and about 4500 basic seedlings. After sowing, use 100 ml of 50% acetochlor or 100 ml of 33% pendimethalin per mu, add 50 kg of water, and spray for chemical weed control, then cover with film 30 minutes after spraying.

For proper pruning, after the seedlings emerge fully, keep one robust main stem growing per plant, except for plants on both sides of gaps, so as to increase yield and improve the marketable rate.

For pest and disease control, the main diseases are late blight, blackleg, scab, etc., and prevention should use disease-resistant varieties and crop rotation. The main pests are white grubs, cutworms, aphids, etc. To control white grubs, apply 1.8 kg of 3% Dichongshaxing per mu by broadcasting before sowing; before budding in early April, use 300 ml of 50% phoxim per mu, add 1500-2000 kg of water, and pour at the base of each plant. To control aphids, from late April to early May, use 15 g of 10% imidacloprid per mu, add 50 kg of water, and spray, then apply the pesticide once more after 70 days.