Potato and scallion multiple cropping can achieve two harvests from one field

I. Cultivation of the preceding potato crop

1. Variety selection The potato variety suitable for potato-scallion multiple cropping in the Xiongyue area is "Dongnong 303", with 15 kg of seed used per mu, maintaining 4500 plants.

2. Deep plowing and fertilization In autumn, plow the soil to a depth of 15-20 cm, harrow the soil in spring, and apply 4000 kg of high-quality organic fertilizer per mu as base fertilizer.

3. Seed potato sprouting In early March, place the selected seed potatoes in a greenhouse or on a heated kang to sprout for about 10 days. Cut the seed potatoes into pieces of 20-30 g, and after cutting, air-dry the seed pieces for 6-12 d, then they can be moved into the shed for seedling raising. Place the potato pieces flat one next to another in the shed with the eyes facing up, cover with fine moist soil or wet sand, and after 10-15 days, when the sprouts grow to 2-3 cm, they can be planted.

4. Ridge formation and timely sowing When the soil temperature at a depth of 10 cm in open field is stable at 7-8 degrees C, transplanting can be carried out, with planting around the end of March. When planting, form ridges 1.2 m wide, break the ridges and open double furrows, apply 15 kg of diammonium phosphate per mu as starter fertilizer, placed between the two ridges. Place the potato pieces at a row spacing of 40 cm and a plant spacing of 25 cm, and firm them with soil. Irrigate to close the soil moisture, cover with soil, and cover with plastic film.

5. Field management 7-10 days after planting, promptly punch holes in the plastic film to guide seedlings out, and earth up around the seedlings. After flowering, the potato pieces begin to expand and require more water. If drought occurs, irrigation can be applied, but each irrigation should not exceed half the ridge height, keeping the soil loose and moist, which is beneficial for the expansion and growth of the potato pieces. For potatoes, attention should be paid to preventing aphids, using 10% imidacloprid wettable powder at 3000-5000 times dilution, or 40% dimethoate emulsifiable concentrate at 1000 times dilution, or 50% pirimicarb wettable powder at 2000-3000 times dilution for spray control. Harvest from late May to early June.

II. Cultivation and management of scallions

Select the excellent variety of scallion "Xianfeng No. 1", with seedling raising time from April 5-10, sowing sparsely to grow strong seedlings. After the potato harvest, promptly prepare the soil and plant at the end of June. To achieve higher yield of scallions, apply more organic fertilizer, and topdress 3-4 times during the growth period, mainly with nitrogen fertilizer in the early stage, phosphorus fertilizer in the middle stage, and potassium fertilizer in the late stage. Spray micronutrient fertilizer 3-4 times.

III. Pest and disease control measures

1. Beet armyworm Before the larvae reach the 3rd instar, spray with 5% Taibao emulsifiable concentrate at 1000-1500 times dilution, or 15% Anda suspension concentrate at 3500-4000 times dilution, or 52% Nongdile emulsifiable concentrate at 1000 times dilution.

2. Onion thrips When the field population reaches 50-100 insects per 100 plants, apply pesticide immediately. Spray with 10% imidacloprid wettable powder at 2500 times dilution or 40% Lucaiibao emulsifiable concentrate at 1500 times dilution, or use 400 times dilution fenvalerate for spraying.

3. Rust disease In the early stage of the disease, spray with 20% triadimefon wettable powder at 2000 times dilution for control. In addition, dithianon sodium at 300 times dilution or 70% mancozeb wettable powder at 1000 times dilution plus 15% triadimefon wettable powder at 20 times dilution, spray once every 10 days, continuously spray 2-3 times, and various pesticides should be used alternately.