What are the benefits of planting autumn potatoes in rice fields?
"There is a lot of rain in autumn, and the humidity in the field is high, which makes seed rot most likely, and has the greatest impact on emergence and yield." Recently, Fang Diduan, head of the agricultural technology station of the Luxian Agriculture Bureau and a senior agronomist, led technicians from the county agriculture bureau to Yanyan Village Group 2, Zhaoya Town, Luxian, to guide farmers in planting autumn potatoes.
"Autumn potatoes are the focus of late-autumn production and an effective way to make up for the major spring grain production. Making full use of the stubble advantage after the hybrid rice harvest, when there is a certain gap before planting minor spring crops, to grow autumn potatoes is an effective measure for achieving the annual grain production target under the new situation this year, in which summer drought followed by dog-day drought caused serious reductions in major spring grain production," Fang Diduan said.
Years of planting in Luxian have proven that growing autumn potatoes in fields after harvesting hybrid rice has advantages such as simple planting, improving soil fertility, regulating temperature and preserving moisture, suppressing weeds, saving labor, and increasing yield and income. After years of multi-site trials and demonstrations by the agricultural department, the yield per mu is 1000 kg, with an output value of more than 4000 yuan.
Key technical points
Select good varieties. Autumn potatoes have a short growth period, generally only 80—90 days; varieties with a relatively shorter maturity period, short dormancy, and high yield, such as "E Shu No. 5", "Hui—2", "Mira", "Favorita", "Chuan Yu Zao", and "Chuan Yu 56", should be selected as seed potatoes.
Sow at the right time. Potatoes are cool-loving crops, and the sowing time is generally best when the daily average temperature is stable below 30℃.
Because this year has experienced prolonged high temperatures and dog-day drought, most rice fields lack water and have cracked dry. Before sowing, deep furrows and high beds must be made to drain water and prevent waterlogging, reducing wet damage.
Sow with sprouts
Sowing with sprouts is a key technical measure to promote early and uniform emergence of autumn potatoes and to strive for more tubers and larger tubers. Potatoes generally have a dormancy period of 2-3 months, and seed potatoes should be treated according to different situations.
Soak seeds with "920". Before sowing, cut the seed potatoes with one eye as one seed piece, then soak them for 5—10 minutes in a solution of 1 gram of "920" mixed with 2000 jin of water. Cut while soaking to break dormancy and shorten the emergence period.
After soaking, place them indoors with moist straw spread above and below and the seed potatoes in the middle, and sow after sprouts are forced out; or 10—15 days before sowing, cover them indoors only with moist straw to preserve moisture and force sprouts.
For seed potatoes that need to be cut before sowing, after cutting the seed potatoes, soak them in a 1:800 dilution of carbendazim for 30—60 seconds, then quickly remove them. They must be sown after the seed potatoes are dried.
Plant on ridges
Choose plots with higher terrain and good drainage for ridge planting. Rice fields should have high beds and deep furrows to drain water and prevent waterlogging, and to prevent seed rot and dead seedlings.
If sowing encounters drought, water the holes with clear manure water and sow in the morning and evening to prevent sprout burning. Because autumn potatoes have a short growth period, the planting density should be greater than that of spring potatoes. Generally, for pure autumn potato planting, open beds at 0.85 m and plant double rows, with a hole spacing of 0.25 m, planting 6000—7000 holes per mu, with about 20 g—30 g of whole seed potatoes per hole, which helps cultivate full and strong seedlings.
Manage early
Apply heavy base fertilizer, apply seedling fertilizer early, and increase phosphorus and potassium fertilizer.
At sowing, apply 1000 kg—1500 kg of farmyard manure, 100 kg of plant ash, and 20 kg—30 kg of phosphate fertilizer per mu as base fertilizer. When about 70% have emerged, apply human and livestock manure or nitrogen fertilizer per mu as a topdressing to promote seedlings. After the seedlings are 15 cm high, begin intertillage and hilling to facilitate drainage and cooling.
Where conditions permit, spray 1—2 times with 0.1% potassium dihydrogen phosphate to promote tuber expansion. In the early growth stage, pay attention to drought resistance and seedling protection. After heavy rain, intertill and loosen the soil in time to prevent soil compaction and promote deep roots and luxuriant leaves. In the later stage, promptly control late blight to ensure more planting and more harvest.
No-till straw mulching
For fields where the previous crop is middle-season rice and rice-stubble autumn potatoes are grown with no-till straw mulching cultivation, choose fields with low rice stubble and no ratoon rice retained; open furrows and make beds in the rice field along the drainage direction by using a line.
For low-lying wet fields, open furrows and make beds at a width of 6.8 chi per furrow and bed, of which the bed surface width is 6 chi and the furrow depth is 1—1.2 chi. For general rice-stubble fields, open furrows and make beds at 12.8 chi per furrow and bed, of which the bed surface width is 12 chi, the furrow width is 0.8 chi, and the furrow depth is 1—1.2 chi. Open border ditches 3 chi from the field ridge around the field, with a ditch width of 0.8 chi and a ditch depth of 1—1.2 chi.
Break up the soil dug from the furrows evenly and spread it over the bed surface, so that the bed surface across the whole field is level and the bed surface does not accumulate water.
For rice-stubble autumn potatoes, each mu of potatoes needs straw from 1.5—2 mu of rice field for mulching, and the straw mulching thickness should reach about 0.3 chi.