When is the latest planting time for black beans?
Black beans are the black seeds of the soybean, a plant in the legume family, also known as lubdou, black soybean, etc. The outer skin is black, and the inside is yellow or green. They have the characteristics of high protein and low calories, prefer warmth, and tolerate high temperatures. The suitable growth temperature is 18 to 30 degrees. For propagation by sowing, those with large, plump grains and a glossy black color are best. Now let us take a look at when black beans are planted!
Seed Treatment
1. Variety selection: According to the local production and ecological conditions and market demand, select high-quality varieties with a suitable maturity period, high yield, good quality, and strong stress resistance according to local conditions, such as Black Pearl No. 1.
2. Seed selection: Before sowing, the seeds are selected and graded to remove diseased seeds, damaged seeds, shriveled seeds, grass seeds, and debris. After that, the seed purity reaches 99%, the varietal purity reaches 98%, and the germination rate reaches 95%.
3. Seed treatment: Use 0.75 liters of rhizobia per hectare to evenly coat the seeds under light-protected conditions. After seed coating, do not mix with fungicides, and sow within 24 hours after coating.
Planting Time
1. Precision sowing at the right time: The sowing time for black beans is generally from May 15 to 20. When the ground temperature at a soil depth of 5 cm stably passes 8 to 9°C, monitor soil moisture and use a precision seeder to sow precisely in double rows on the ridge at equal spacing at the right time, and press as you sow.
2. Sowing depth: The sowing depth for black beans is generally 3 to 4 cm. If the soil in the sowing plot is clayey or has good moisture, it should be shallower; if there is spring drought, much wind, loose soil, or poor moisture, it can be slightly deeper.
3. Sowing density: The cultivation density of black beans should be determined according to varietal characteristics, natural conditions, soil fertility, and cultivation methods. The seedling retention density is 200,000 to 260,000 plants per hectare, and the sowing rate is 70 to 90 kg per hectare.
4. Deep application of seed fertilizer: When sowing black beans, use a precision seeder to apply compound fertilizer deeply in layers at 8 cm and 12 cm below the seeds, with a fertilization rate of 100 to 120 kg per hectare.
Land Selection and Preparation
1. Crop rotation selection: Black bean cultivation uses a 3-year rotation system of wheat-corn-black beans or corn-wheat-black beans, using wheat stubble or corn stubble to plant black beans.
2. Land selection and deep plowing: For black bean cultivation, choose plots with good drainage, fertile soil, and irrigation conditions. Wheat stubble is shallow-plowed 15 to 18 cm in summer and autumn. Corn stubble is stubble-cleared and deep-plowed in late autumn, with stubble clearing at 12 to 15. cm and deep plowing ≥30 cm.
3. Land preparation and fertilization: Black bean cultivation is mainly based on spring land preparation. It should be finely plowed and harrowed, and ridges should be formed promptly after harrowing to conserve moisture, with a ridge width of 60 cm. Before land preparation, evenly apply 30 tons per hectare of fully decomposed high-quality farmyard manure, and bury it into the plow layer while harrowing.
Field Management
1. Cultivation, ridging, and topdressing: In order to increase ground temperature, store water and conserve moisture, eliminate weeds, enhance soil microbial activity, and promote healthy seedling growth, after full emergence, the furrows should be loosened deeply in time, with two hoeings and three ridgings, and a pass of large weeds should be pulled before grass seeds form. Combined with the second intertillage and hilling, apply 60 kg per hectare of urea as topdressing.
2. Foliar topdressing: For black bean cultivation, at the early flowering stage and the pod-filling stage, spray the leaves once each with a 1% urea solution and a 0.2% potassium dihydrogen phosphate aqueous solution.
3. Timely irrigation: During black bean cultivation, in order to promote full subsequent black bean seeds, if drought occurs during the flowering and pod-setting stage, irrigate 1 to 2 times in time. Generally, each irrigation is 400 cubic meters per hectare, and 45 kg of urea is applied with the water.
4. Pest and disease control: For black bean cultivation, use a 1500-fold dilution of 10% imidacloprid spray to control aphids, and at the early stage of gray leaf spot, use a 300-fold dilution of 40% carbendazim spray for control.
5. Harvest and storage: Black beans mature in stages. To reduce labor, generally harvest all at once when more than 70% of the subsequent pods have matured. After harvest, dry for 5 to 7 days, and use manual threshing on the threshing floor, ensuring separate harvest, separate transport, separate threshing, and separate bagging.