Key Technical Points for No-Till Potato Cultivation and Management
No-till potato cultivation is a cultivation method in which, after the late rice or single-crop middle rice is harvested, the soil layer is not plowed, fertilizer is applied directly to the soil surface, potato tubers are planted, and then rice straw is spread as mulch. This method can save the labor of plowing and reduce labor intensity, and because the rice straw and potato stems and leaves are returned to the field, it plays a role in fertilizing the soil. It is a sustainable agricultural farming model that saves labor, saves effort, reduces costs, and increases income, and it is also a good approach for making full use of winter fallow fields in the limestone mountainous areas of northern Guangdong. The key technical points of its cultivation are introduced as follows:
I. Sprouting
Seed potatoes should be high-quality improved varieties, such as Atlantic and Favorita. Before planting, potatoes should be treated for sprouting. Generally, cut seed pieces are soaked in a 5-10 mg/L gibberellin solution for 15 minutes, and whole tubers are soaked in a 10-15 mg/L gibberellin solution for 20 minutes. After soaking, remove them and place them in moist sand under diffused light to sprout. Once the sprouts turn purple and grow thick and strong, they can be planted. When planting cut pieces, the cutting knife must be disinfected. Each cut piece should weigh 30-50 g, and each seed piece must have an eye, and be mixed with plant ash for seed dressing.
II. Digging Trenches and Making Beds
Make beds every 3 m including trenches, with a trench width of 30 cm. Spread the trench soil evenly over the bed surface and shape it into a turtle-back form to facilitate drainage, then dig the field-edge drainage trenches well.
III. Planting and Straw Mulching
The planting spacing is 25 cm between plants and 30 cm between rows, with 9 rows per bed, and the eyes facing upward when placing the seed potatoes. After planting, apply base fertilizer evenly between the rows, using 2000 kg of decomposed manure and 50 kg of potassium sulfate per mu, then cover with rice straw to a thickness of about 10 cm. After covering with straw, pour once with decomposed human manure and urine.
IV. Field Management
1 Topdressing: After emergence, use 200 kg of decomposed human manure and urine per mu, or 5 kg of urea diluted with water, and pour it on to strengthen the seedlings. At the budding stage, use 2.5 kg of urea plus 10 kg of potassium sulfate per mu, diluted with water, and pour it on. At the tuber bulking stage, apply 15 kg of potassium sulfate per mu, and afterward spray the leaves with 60 kg of a 0.2%-0.3% potassium dihydrogen phosphate solution, once every 7-10 days for a total of 2-3 times, to prevent premature aging of the plants and promote tuber expansion.
2 Water management: When there is a lot of rain, clear the trenches and drain water in time. If drought occurs, water once in the evening, but the frequency should not be too high.
3 Plant control: After the rows close, spray 15% paclobutrazol diluted with 60 kg of water per mu to inhibit leaf growth.
4 Pest and disease control: For potato late blight, spray 200 g of carbendazim or 350 g of mancozeb or 167 g of metalaxyl-mancozeb per mu diluted with water. If plants with bacterial wilt, ring rot, viral disease, and other diseases are found, remove them in time, and use agents such as plant disease spirit for prevention. The main potato pests include aphids, potato tuber moths, and 28-spotted ladybirds. Aphids can be killed by spraying with a 2500-fold solution of imidacloprid, potato tuber moths can be controlled by spraying with a 2000-fold solution of phoxim-cypermethrin emulsifiable concentrate or a 1500-fold solution of Kewobao emulsifiable concentrate, and 28-spotted ladybirds can be killed by spraying with a 700-fold solution of trichlorfon or a 1000-fold solution of dimethoate emulsifiable concentrate.