Spring sowing techniques of soybean in the year of severe drought in Northeast China

Current drought situation in Northeast China and Technical guidance on Spring sowing of Soybean:

I. precipitation and temperature in last winter and this spring

Last autumn and winter, the drought in Northeast China was serious, the precipitation was less than usual, and the soil moisture was insufficient. From January to October 2007, the average precipitation in Heilongjiang Province was 402 mm, which was 20% less than that in the same period of previous years. In addition, the general "dry enclosure" in winter this year was not conducive to soil moisture conservation. Since the beginning of winter, the precipitation in some counties and cities in southern Qiqihar, most of Daqing, Hegang and Jiamusi is more than 90% less than that in the same period of previous years, and that in other areas is 10% less than that in other areas. In January 2008, the average precipitation in Heilongjiang Province was only 0.1 mm, which was 97% less than that in the same period of previous years, among which most of Songnen Plain and the western Sanjiang Plain had no precipitation throughout the month. After entering February, the precipitation continues to be on the low side. The snow depth in various parts of Heilongjiang Province has also decreased significantly. Compared with the same period in previous years, the depth of snow in most parts of the province is about 25 centimeters less. In 2008, the area of cultivated land affected by drought in the early stage of sowing in Heilongjiang Province may reach 50 million mu. In addition, the continuous warm winter is extremely beneficial to the safe overwintering of soybean pathogens and disease and insect eggs, and soybean diseases and insect pests may occur more seriously this year. The situation of spring drought in Inner Mongolia is similar to that in the west of Heilongjiang Province.

The general meteorological situation of Jilin Province last winter and this spring is that the temperature is slightly higher and the precipitation is slightly less. Among them, the temperature in October last year is 0.6 ℃ higher than that in the same period of normal year, and the precipitation is 20.7mm, which is 29% less than that in the same period of normal year. The temperature in November is 0.6 ℃ higher than that in the same period of normal year, and the precipitation is 9.3mm, which is 39% less than that in the same period of normal year. In December, the temperature was 2.9 ℃ higher than that of the same period of the year, and the precipitation was 8.7mm, 24% more than that of the same period of the year. In January this year, the temperature was 0.9 ℃ lower than that of the same period of the year, and the precipitation was only 0.4mm, 92% less than the same period of the year. The precipitation in the eastern region was 76% and 98% less than that in the same period of the year, and there was basically no precipitation in the central and western regions. The temperature in the first ten days of February is 0.7 ℃ higher than that in the same period of normal year. In the middle of February, the temperature is 0.5 ℃ lower than that in the same period of normal year. There is no precipitation in the first and middle of February, which is 100% lower than that in the same period of normal year. It is expected that there is little precipitation in most areas of Jilin Province in the spring of 2008, especially in the central and western regions. The average precipitation in Liaoning Province since the beginning of winter is only 34 mm, which is 20% less than that of the same period of the normal year. Especially since the middle of winter (January 11), only Huanren, Kuandian, Donggang and Lushun have precipitation of 1 to 3 mm, while there is no precipitation in other areas. the average precipitation in the province is more than 90% less than that in the same period of the year. According to the forecast that the general trend of precipitation this spring is slightly less, spring drought is more likely to occur in most parts of western Liaoning, the south of Dalian and the north of Shenyang this spring, which will affect the spring sowing work.

II. Supply and preparation of soybean seeds

In the spring of 2008, soybean prices reached a record high, planting efficiency was significantly improved, soybean production showed a good momentum of development, and the planting area will show restorative growth. Soybean planting in Heilongjiang Province is expected to reach 58 million mu this year.

Last year, due to late drought in some areas, the quality of soybean seed reproduction was seriously affected, the number of "stone beans" increased, the germination rate decreased, coupled with the uncertainty of the soybean market in autumn, seed preparation was obviously insufficient. Due to the recent improvement of the soybean market and the rebound of farmers' willingness to plant, the supply of soybean seeds can not meet the market demand, which may need to be temporarily transferred or started to prepare for famine. Through the normal channel @ # @ 136 seeds, the overall quality is good, and the purity and germination rate are basically up to the standard. However, due to the insufficient number of seeds, some places may have the problem of substandard seed quality, and it is difficult to guarantee the quality of farmers' own seeds.

III. Technical guidance

In view of the current production situation and the main problems, the experts put forward the following technical guidance:

(1) strict selection of fine varieties

Due to the dry climate last autumn, first, the seeds did not mature normally physiologically, and second, mechanical threshing of soybean increased the possibility of seed embryo injury, affecting the germination rate of seeds, so it is necessary to strictly select seeds, and it is best to use seed selection to remove the injured seeds. and do a good germination test. The selected varieties should be of high quality and high potential for yield increase, with strong adaptability and no cross-regional planting. It is necessary to transport seeds in an organized manner, help farmers buy seeds through normal channels, and ensure that the purity and germination rate are basically up to standard.

(2) do a good job in seed treatment

One is to sow the seeds before sowing. Generally, seed drying can increase the germination rate by about 13%, and seedling emergence 2-3 days earlier. The second is seed dressing or seed coating. Low temperature and drought, seeds in the soil for a long time, vulnerable to diseases and insect pests, soybean seed coating agent can be used according to the drug seed ratio of 1 ∶ 75 100. Soybean root rot can be controlled by 50% mixture of 0.5% seeds or 50% carbendazim with 0.3% seeds. In the plots with serious insect pests, coated seeds containing both sterilization and pesticides should be selected, and uncoated seeds should be mixed with 35% methyl thiocyclophos EC to control underground pests, and ammonium molybdate can be added to the seed dressing agent to improve the emergence rate and nitrogen fixation ability of soybean. In addition, attention should be paid to the prevention and control of rodent damage with poison bait after emergence.

(3) choose appropriate sowing methods according to local conditions

The original ridge sticking seeds were adopted in the plots that were not turned over in autumn, ridging or flat planting in narrow rows were adopted in the ridging plots in autumn, deep trenching, shallow covering and heavy suppression were adopted in the plots with poor soil moisture, and the sowing method of film mulching between rows was adopted in the plots with serious drought, and continuous operation was carried out to prevent the loss of soil moisture.

(4) adopt "early sowing" technology to make good use of "return water" and strive for one-time preservation of seedlings.

Scramble to sow seeds to protect the whole seedling. It is necessary to seize the favorable opportunity of the rise of ground temperature and make use of the "returning water" in early spring to grab moisture and sow seeds. Sowing can be carried out when the soil temperature of the plough layer passes steadily through 5 ℃, and continuous operation can be achieved to prevent the loss of soil moisture. The sowing methods of deep trenching, shallow soil cover and heavy suppression can be adopted. Deep trench to ensure that the seeds are sown on wet soil, covering soil evenly, up to 2 cm after suppression, and ensuring consistent sowing depth. Suppress and conserve soil moisture after sowing. When the soil moisture is suitable, it should be suppressed 2-3 hours after sowing; when the soil moisture is poor, it should be sowed and pressed; the land with high soil moisture (water content > 25%) or rain after sowing needs to be suppressed when there is a 2 cm dry soil layer on the surface.

(5) inspecting land to replenish seedlings

Check the fields regularly after sowing. Check the soil moisture 3-5 days after sowing, take corresponding measures to replenish the soil moisture in the plots with serious loss of soil moisture, check the bud situation before emergence, sit in the water to replant in time for the dry buds and bad seed plots, check the seedling situation and insect situation after emergence, and replant precocious varieties or chemicals to the plots that lack broken seedlings or suffer from insect pests.

(6) promoting soil testing and formula fertilization

For a long time, many places rely solely on experience to apply fertilizer, resulting in the imbalance of soil nutrient elements, and the phenomenon of lack of potassium and trace elements in production. Combined with the soil testing formula fertilization project implemented by the Ministry of Agriculture, scientific fertilization should be adhered to, and nitrogen, phosphorus and potassium fertilizers should be applied according to a certain proportion according to the results of soil testing. Encourage the application of more farm manure, combined with soil preparation; chemical fertilizer as seed fertilizer, deep application of 4 cm to 5 cm to avoid burning seeds.

(7) using non-long residual herbicides to prevent and control drug damage

Due to the serious continuous cropping of soybean, the use of long residual herbicides in soybean fields is more, and there are no land files, which brings a lot of trouble to the structural adjustment, so we advocate the use of non-long residual herbicides. The main long-residual herbicides are Pustilon, Dosulfuron, Huwei, Kuocaoqing, Guangmianling and so on.

Two situations may occur in 2008: 1. The area of sugar beet and potato in Sanjiang Plain should be expanded, and special attention should be paid to the sensitivity of these two crops to long-residual herbicides, which can only be planted at intervals of 3 to 4 years. 2. With the expansion of soybean area, the pre-planting crop is basically corn, but if atrazine is applied to 2000g/hm2 in corn field, drug damage may occur in planting soybean, which should be paid attention to.