Detailed Explanation of Key Points of Water-Saving Potato Cultivation Technology

The furrow-ridge water-saving potato cultivation technique increases the contact surface between soil and air, ensures a good aeration environment for the underground stems, intensifies the variation in diurnal temperature difference, reduces surface runoff, and enables the soil to more fully absorb precipitation. Through the implementation of the project "Integration and Demonstration of Water-Saving Agricultural Technology Systems in Semi-Arid Rainwater Harvesting and Supplementary Irrigation Dryland Areas of Northern China (Pengyang, Ningxia) - Research, Screening, Integration and Demonstration of High-Efficiency Rainwater Harvesting Agricultural Supporting Technologies," the water-saving potato cultivation technique has been summarized for use in production.

(1) Variety Selection

Use virus-free microtuber seeds or first-generation foundation seed of Ningshu No. 4, which can increase yield by more than 30% compared with self-saved seed potatoes.

(2) Site Selection and Land Preparation

Select a plot where potatoes or Solanaceous crops (eggplant, pepper, tomato, flue-cured tobacco, etc.) have not been grown for three years, with fertile soil, deep soil layer, and where herbicides such as chlorsulfuron and clethodim have never been applied, in a shady and moist sandy loam soil with certain irrigation conditions. The plot should be deep-plowed in autumn or plowed in early spring, with a depth of more than 25cm. Before sowing, break up clods, pick out roots and stubble, and achieve fine land preparation. Around the virus-free potato plants, do not plant non-virus-free potatoes or crops with yellow flowers such as rapeseed, to prevent the spread and proliferation of viral diseases that cause yield reduction.

(3) Formula Fertilization

Apply 1000kg of farmyard manure, 15-20kg of diammonium phosphate, 10kg of urea, and 10kg of potassium sulfate per mu. Mix all chemical fertilizers and apply as base fertilizer. Note that when applying ammonium bicarbonate, it must absolutely not come into contact with seed potatoes. For chemical fertilizers, it is best to use 100 jin of compound fertilizer with a nitrogen-phosphorus-potassium ratio of 15:15:15 (never use ammonium nitrate as seed fertilizer, to avoid rotting of potatoes caused by contact between ammonium nitrate and wounds on seed potatoes). At the budding and hilling stage, apply 10kg/mu of ammonium nitrate as a top dressing.

(4) Timely Sowing

① Sowing time: Begin sowing when soil temperature is stably above 7°C, approximately in early to mid-April.

② Seed potato treatment: 20 days before sowing, pile virus-free microtubers or cut seed potatoes in a solar greenhouse, cover with a layer of straw curtain or black plastic film, and maintain dark conditions for sprouting. After sprouts emerge uniformly, place in a ventilated, dry area with scattered light to strengthen the sprouts. Once the small sprouts turn green, they are ready for sowing. Note that the apical bud must never be knocked off, otherwise yield will be reduced by 10%. Remove any bad potatoes that have not sprouted.

③ Density: 4500-5000 plants per mu for sole cropping, 3500-4000 plants per mu for intercropping. Appropriate close planting can increase yield. Form ridges at 90cm intervals, with ridge height of 20cm, ridge width of 60cm, and furrow width of 30cm. Plant in double rows in a staggered pattern, with plant spacing of 30-33cm.

④ Control of underground pests: Apply 2kg of phorate (3911 granules) per mu, broadcast along the furrow.

⑤ Sowing method: Open a furrow 12-14cm deep on the ridge, sprinkle in chemical fertilizer and pesticide, then apply farmyard manure, preferably covering the chemical fertilizer and pesticide. If not covered, add some soil. Finally, place the seed potatoes, then form the ridge. After sowing, the seed potatoes should be 10-12cm below the ridge surface.

(5) Field Management

① 12-15 days after sowing, use a rake to gently rake away 3-4cm of ridge soil, which can preserve moisture, raise temperature, eliminate weeds, and promote early emergence. If not raking soil, sow shallower, approximately 8-10cm.

② When 80% of the field has emerged, carry out the first cultivation and hilling. During the operation, bury all seedlings completely, which can increase stolons, thicken underground stems, and prevent excessive above-ground plant growth.

③ When seedlings are 15-20cm tall, carry out the first hilling to thicken and widen the ridge platform. When irrigation conditions allow watering, do not wet the ridge; water up to half the ridge height. Ensure one watering during the budding and flowering stage.

(6) Strict Pest and Disease Control

Based on the characteristics and damage patterns of potato pests and diseases, and on the basis of actual investigation and careful summarization, it is proposed to primarily promote high-yield, virus-free, disease-resistant potato varieties. In areas where conditions do not allow the promotion of virus-free potatoes, strict attention must be paid to seed potato cutting. Combined with corresponding agricultural control technical measures, and then applying chemical control, the goal of controlling pest and disease occurrence and increasing potato yield is achieved.

① Strengthen plant quarantine: Some potato diseases mainly spread with seed potatoes. Therefore, when exchanging and introducing seeds, special attention must be paid to preventing the exchange of diseased seeds, and strictly control the planting of diseased seed potatoes.

② Whole-tuber sowing: For example, in areas where potato ring rot occurs and causes damage, if cut-tuber sowing is adopted and the cutting tools have no disinfection measures, it will cause the spread and proliferation of the disease.

③ Clean up the field: After the previous crop is harvested, deep plow to reduce the number of pathogens overwintering in the soil. Before sowing the next year, plow again, then carefully prepare the land, break up soil, and remove plant residues, weeds, volunteer seedlings, etc., thereby reducing infection sources and alleviating the occurrence of pests and diseases.

④ Rational fertilization: Apply 1000-1500kg of farmyard manure per mu and 25kg of phosphate fertilizer as base fertilizer. At the budding stage, combine with cultivation and weeding, and apply appropriate amounts of nitrogen and potassium fertilizer as top dressing according to soil fertility conditions, to enhance plant growth and improve plant resistance to pests and diseases.

⑤ Improve the cropping system: For heavily affected plots, implement crop rotation, and use quicklime for soil treatment to reduce infection sources. After 2-3 years, the occurrence and severity of pests and diseases will be significantly reduced.

⑥ Chemical control: In response to the characteristics of major potato disease occurrence and damage, chemical control should focus on aphids and late blight.

Aphids are the main transmission vector of potato viral diseases. From the seedling stage to the budding stage, spray with 5% pirimicarb 2500x solution or 10% imidacloprid 2500x solution to control aphid damage and reduce the occurrence of viral diseases. In areas where potato late blight occurs severely, chemical control should be carried out early to control the center of infection. Spray once at the beginning of budding, then treat again after 10-15 days. Chemical agents can be selected from 58% metalaxyl-mancozeb 400x, 72% cymoxanil-fosetyl 800x, or 72% DuPont Curzate 600x, all of which can achieve good control effects.

(7) Harvesting and Selling

① 15 days before harvest, thoroughly remove virus-diseased plants (wrinkled leaves, leaf roll, mosaic, etc.) and their tubers, and inspect and verify, then kill the vines. There are two methods: spray herbicide, such as 20% paraquat, using 200ml diluted in 40-50kg of water, sprayed evenly; or manually cut the vines.

② Harvest is expected from September 15 to 20. At harvest, tubers must be dried in the sun for half a day to age the skin, facilitating transportation without scratching the skin.

③ Pick out diseased potatoes, damaged potatoes, and foreign potatoes. Qualified potatoes above 50g should be sent to designated locations for weighing and sale.