Detailed Explanation of High-Yield Soybean Cultivation Techniques in the Northern High-Cold Region

The scope covered by this model includes the vast areas of the northern part of the third accumulated temperature zone and the fourth accumulated temperature zone in Nehe, Keshan, Yi'an, Kedong in northern Qiqihar, Heilongjiang, and Wudalianchi, Nenjiang, Bei'an, Xunke, Aihui, Sunwu and other counties (cities and districts) of Heihe City.

The soybean planting area in this region is about 10 million mu, which has a decisive influence on soybean production in the entire province and even the whole country.

This region has a large cultivated land area, a high degree of mechanization, and a commodity rate as high as 70%. It is an important soybean export base for the province and the country.

This region has a cold and cool climate, little pollution, and mild pests and diseases. The use of chemical fertilizers and pesticides is relatively low, and it is a recognized green food soybean production base.

This region has fertile soil, rain and heat occurring in the same period during crop growth, a large temperature difference between day and night, and sufficient sunlight, which is relatively favorable for soybean growth and development. However, because this region is located in a high-cold area with a short frost-free period, low temperature and early frost are important factors affecting soybean production; this region also has many windy days in spring. The relatively low precipitation in spring and early summer also has a major impact on soybean growth and development.

Because the soybean planting proportion in this region is as high as 40-70%, and continuous and alternating cropping is 50-95%, the problem of continuous and alternating cropping is a prominent issue in soybean production.

In response to the climatic characteristics and production problems of this region, after six years of experiments and demonstrations of large-area high-yield comprehensive supporting soybean technology, we have summarized the large-area high-yield soybean cultivation techniques that use machinery as the carrier, early cultivation as the basic tillage form, and early maturation promotion as the central link:

"Early plowing and harrowing in summer and autumn on normal (alternating) stubble, carefully selected coated improved seeds; layered application of nitrogen, phosphorus, and potassium fertilizer, sowing at the right early time with uniform plant distribution; weed control, disease treatment, and pest prevention, timely harvest and careful threshing with strict checks."

Technical Regulations for Engineering-Based High-Yield Soybean Cultivation

1. Crop rotation

Implement 2-3 year crop rotation to avoid continuous cropping; the previous crop should mainly be @#@245@#@, corn, potatoes, etc.

2. Tillage and land preparation

Plow and harrow the land in summer and autumn. The topsoil is required to be fine, loose, and level, with no more than 3 soil clods with a diameter of 5 cm per square meter in the plow layer; autumn-ridged fields must reach a state ready for sowing.

3. Fertilization

(1) Increase potassium fertilizer application and rationally combine nitrogen, phosphorus, and potassium. Generally, apply 10-12 kg of diammonium phosphate, 3 kg of urea, and 4-5 kg of potassium sulfate per mu, with a nitrogen:phosphorus:potassium ratio of 1:1.4:0.6. Also apply a small amount of micronutrient fertilizer.

(2) Apply 1-2 cubic meters of well-decomposed farm manure per mu before autumn plowing; it can also be applied to the previous crop to fertilize the previous stubble.

(3) Chemical fertilizer used as seed fertilizer should be applied in layers. Apart from a small amount applied in the upper layer, most should be applied 7-10 cm below the seed, with seed fertilizer separated to strictly prevent seedling burn.

4. Carefully select improved seeds

(1) Select improved varieties

Select improved varieties according to local climate and soil conditions, and strictly prevent planting beyond the suitable zone. In the northern part of the fourth accumulated temperature zone, Heihe 18 and others are the main varieties, with Heihe 17, Beifeng 15, and Heihe 22 as companion varieties; in the southern part of the fourth accumulated temperature zone, Heihe 19, Beifeng 11 and others are the main varieties, with Heihe 18 as a companion variety; in the third accumulated temperature zone, Beifeng 14 and Heihe 23 are the main varieties, with Beifeng 9 and other varieties as companions. Seed purity must be above 98%, cleanliness above 99%, and germination rate above 95%.

(2) Seed treatment

After mechanical selection or manual screening, the seeds should be manually selected once more to remove diseased, insect-damaged, and mixed seeds; after seed selection, use seed coating agents such as "Keduofu" or "Weifu Yaofei No. 1" for seed coating.

5. Sowing

(1) Sowing time. It is advisable to begin sowing when the ground temperature stably passes 8°C. Locally, in order to seize accumulated temperature and soil moisture, sowing generally starts after May 1 and is completed before May 10.

(2) Sowing method. For wide-ridge cultivation, use 60-70 cm with precision double-row hill sowing on the ridge; for narrow-ridge cultivation, use 45-50 cm with precision double-row hill sowing on the ridge; for flat cultivation with narrow-row dense planting, use 15 cm, 30 cm, or 45 cm.

(3) Density. For seedling retention per hectare, about 300,000 plants for wide ridges, 350,000-400,000 plants for narrow ridges, and 450,000-550,000 plants for narrow-row dense planting.

(4) Sowing quality. The total sowing rate error is 42%, the single-outlet discharge error is 43%, seeding is uniform, without overlap or omission, sowing depth is 4-5 cm, and pressing follows immediately after sowing.

6. Management

(1) Chemical weed control. After sowing and before emergence, Pursuit and Command are generally commonly used, and acetochlor plus chlorimuron can also be used for closed weed control. The general principle is to select suitable herbicides for weed control according to the weed situation.

(2) Deep loosening or one pass of plowing before hoeing. The depth is 10-20 cm to increase temperature and release cold.

(3) Hoe and ridge 2-3 times, and pull large weeds once.

(4) Prevent and control pests and diseases

a. Control soybean frogeye leaf spot and purple seed stain. In early August, spray 1-2 times with 40% carbendazim or 70% thiophanate-methyl wettable powder at 400-500 times dilution.

b. Control aphids, red spiders, and thrips. When spot infestations occur, spray with 40% dimethoate emulsifiable concentrate at 800 times dilution.

c. Control soybean pod borer. In early to mid-August, when pod borers are found flying in groups, use 0.1-0.13 kg of 80% dichlorvos emulsifiable concentrate made into toxic sticks for targeted control, or spray with Kung Fu for control.

d. Foliar topdressing and early maturation promotion. Apply 0.7-0.8 kg of urea plus 0.1 kg of potassium dihydrogen phosphate mixed with 30-40 kg of water per mu for foliar spraying at the flowering stage.

7. Harvest

(1) Harvest time. It is advisable to harvest when soybeans are in the yellow-ripe stage, with 80% of leaves fallen, beans turning yellow, most pods turning yellow, and a small portion turning brown.

(2) Harvest quality. The stubble height should be based on leaving no pods. During harvest, do not lose branches, shatter pods, or scatter grains.

Brief explanation of the technical model

The 42-character model "Early plowing and harrowing in summer and autumn on normal (alternating) stubble" contains two meanings. First, in view of the very serious current situation of continuous and alternating soybean cropping locally, it emphasizes that high-yield soybean production must follow a virtuous cycle path. In addition to selecting normal stubble, according to local production realities, alternating stubble is also a relatively good stubble. Second, in response to the early cultivation agriculture of this region and the characteristic of "spring drought in nine out of ten years," it proposes early summer and autumn land preparation and fine land preparation to store autumn rainwater, achieve autumn prevention of spring drought, and give full play to the role of the "soil reservoir." "Carefully selected coated improved seeds," in addition to emphasizing the role of improved varieties and careful selection, mainly targets the reality of very serious continuous and alternating cropping in production and emphasizes seed coating to reduce yield loss caused by continuous and alternating cropping. "Layered application of nitrogen, phosphorus, and potassium fertilizer," in addition to normal application of nitrogen and phosphorus, also emphasizes the application of potassium fertilizer based on experimental results showing that potassium fertilizer has a relatively good effect under continuous and alternating cropping. Layered application refers to the method of applying chemical fertilizer to improve its fertilizer efficiency. "Sowing at the right early time with uniform plant distribution" targets the region's susceptibility to low-temperature late spring frost damage, which affects yield and quality, and emphasizes sowing early at the right time to seize accumulated temperature and soil moisture. Uniform plant distribution mainly refers to the sowing method, focusing on uniform seed distribution and emphasizing precision hill sowing. "Weed control, disease treatment, and pest prevention" is proposed mainly because this region has a large cultivated land area, is prone to weed infestation, and has an increasing trend in pest and disease occurrence. "Timely harvest and careful threshing with strict checks" emphasizes timely and careful harvest, reducing losses, doing a good job at the final stage, securing the fruits of a good harvest, and achieving both high yield and a good harvest.