Detailed Explanation of Key Points of Potato Double-Mulch Cultivation Technology
Potato double-mulch cultivation technology is a comprehensive cultivation technique combining plastic film mulching with arched sheds, mainly addressing frost damage to early-spring potatoes in northern regions, promoting early sowing and early marketing of potatoes, and increasing farmers' income. Potato double-mulch cultivation generally brings potatoes to market 30 days earlier than plastic-film potatoes, with a per-mu yield of up to 2500 kg and a per-mu income of over 2000 yuan, showing very significant economic benefits. Its main cultivation techniques are:
1. Site selection and shed construction
For double-mulch cultivation, a long strip of land 50-60 m east-west and 6 m north-south is preferable, requiring deep soil layers and medium-to-upper soil fertility; in autumn, plow deeply and prepare the land in time, irrigate in winter as scheduled, break up clods and preserve soil moisture, achieving level ground and sufficient moisture. The specifications for building the arched shed are: width 6 m, center post height 1.7 m, side post height 1.4 m, length determined by the plot conditions, with one upright post every 10 m, three No. 8 iron wires pulled across the tops of the posts, and the wires tightened using the method of anchoring with buried stones as the support for the arched shed. Along the field ridge, punch holes every 80-100 cm and insert bamboo poles about 2 cm in diameter, rest them on the three supporting iron wires, and tie them firmly with plastic rope, keeping the shed surface as level as possible.
2. Selection of improved varieties and seed potato sprouting
The main purpose of potato double-mulch cultivation is early marketing, so early-maturing, high-yielding varieties should be selected, such as "Favorita" and "Zaodabai", and virus-free seed potatoes should be used whenever possible. Sprout the seed potatoes before sowing: about 20 days before sowing, take the seed potatoes out of the storage cellar and spread them indoors under diffuse light, keeping the indoor temperature at 15-18°C, turning them once every few days, and cut them into pieces when the seed potatoes turn green and the young sprouts emerge in a purple-green color. During the sprouting process, eliminate diseased, rotten, and damaged seed pieces.
3. Applying sufficient base fertilizer and formula fertilization
Because double-mulch potato cultivation uses plastic film mulching, hilling and topdressing are generally not carried out, so sufficient base fertilizer must be applied with scientific formula fertilization. Per mu, apply 3-4 cubic meters of farmyard manure, 20 kg of diammonium phosphate, 15 kg of urea, and 10 kg of potassium sulfate, applied all at once before sowing in combination with plowing.
4. Soil treatment and pest and disease control
Per mu, use 500 mL of 50% phoxim emulsifiable concentrate, mix with 5-10 kg of fine sand, and spread evenly into the field, turning it into the soil together with fertilization to control underground pests. To control weeds under the plastic film, after potato sowing and before mulching, use 100 mL of 48% trifluralin emulsifiable concentrate per mu diluted with 30 kg of water, spray evenly on the ridge surface, and then thoroughly mix into the soil 3-5 cm deep. It is strictly forbidden to arbitrarily increase the dosage to avoid phytotoxicity.
5. Timely early sowing and rational close planting
The key to potato double-mulch cultivation technology is to emphasize the word "early", because after the shed is closed, the temperature inside the arched shed rises rapidly and the soil thaws quickly. The sowing period should be from February 25 to March 5, carried out in time on sunny, windless days when the soil has thawed about 15 cm. For potato plastic film mulching cultivation inside the arched shed, single-ridge double-row planting is adopted, with ridge width 60 cm, furrow width 30 cm, and furrow depth 20-25 cm. Plant 6 ridges inside the arched shed, with the ridge direction consistent with the shed direction. After sowing, promptly cover the ridges with a layer of plastic film and press the four edges of the film tightly. Close the shed on the same day as sowing to avoid frost damage.
6. Strengthening field management and timely harvesting
About 25 days after sowing, seedlings emerge. At this time, check at any time and release seedlings promptly to avoid burning the seedlings. When the temperature inside the arched shed reaches 25°C, promptly open the arched shed for ventilation and cooling. In mid-May, open the shed during the day and cover it at night; after hardening the seedlings for 3-5 days, remove the arched shed.
After sowing, water once according to soil moisture conditions to ensure uniform and complete seedlings; water once each at the seedling stage, bud stage, flowering stage, and tuber bulking stage, for a total of 4-5 waterings during the growth period. Flooding over the ridges is strictly forbidden. At the flowering stage, spray a tuber bulking agent once in combination with foliar topdressing to prevent fertilizer deficiency in the late growth period of potatoes, promote tuber growth, and improve the marketable rate.
Harvest promptly in early June and bring to market as early as possible.