Technical guidance on Spring sowing of Soybean in Northeast China

In autumn and winter last year, the precipitation in Northeast China was less than usual, the soil moisture was insufficient, and the drought was serious. There is more rain and snow this spring, the temperature has risen rapidly since the beginning of April, and the temperature and precipitation are close to year-round. The soybean expert guidance group of the Ministry of Agriculture and the National Agricultural Technology extension Service Center, on the basis of full investigation, put forward the following technical guidelines for spring sowing of soybean: first, strict selection of excellent varieties

Due to the dry climate last autumn, soybean may not mature physiologically during harvest, and mechanical threshing increases the possibility of embryo injury, which will affect the germination rate of seeds. Therefore, it is necessary to strictly select seeds this spring, it is best to use seed selection, remove the injured seeds, and do a good germination test to ensure that the purity and germination rate are up to the standard, and select varieties with high quality, great potential for yield increase and wide adaptability. It is worth noting that due to the influence of Greenhouse Effect around the world, the annual accumulated temperature has increased in recent years, but the ripening period of varieties must be arranged reasonably according to local meteorological conditions, so as to put an end to the phenomenon of cross-area planting, otherwise the seed water content is too high during the autumn harvest. will cause unnecessary losses.

Second, do a good job in seed treatment before sowing. First, dry 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. When the temperature is low or drought occurs, the seeds germinate in the soil for a long time and are vulnerable to diseases and insect pests. Soybean seed coating agent can be used according to the ratio of 1 ∶ 75 to 1 ∶ 100. Soybean root rot can be controlled by 50% mixture of 0.5% seeds or 50% carbendazim with 0.3% seeds. The seriously pest-infested plots should choose coated seeds containing both sterilization and insecticides, and uncoated seeds should be mixed with 35% methyl parathion EC to control underground pests. The seed dressing agent can add ammonium molybdate to improve the seedling emergence rate and nitrogen fixation ability of soybean.

Third, choose a suitable sowing method to freeze the soil moisture before autumn, and there will be more snow this spring than in previous years. It is suggested that live snow measures should be avoided in soybean fields so as to avoid water evaporation prematurely and soil drought during sowing period. 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.

Fourth, scramble for soil moisture sowing and strive for one-time conservation seedlings although there is more snow in spring this year, due to the drought last autumn, the soil moisture is still insufficient, so it is necessary to seize the favorable opportunity of the recovery of ground temperature and make use of the "returning water" in early spring to sow seeds. Sowing can be carried out when the soil temperature of the plough layer passes steadily through 5 ℃, and continuous operation can be carried out to prevent soil moisture loss. 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. Check the fields regularly after sowing. The soil moisture was checked 3-5 days after sowing, and measures were taken 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 the sprouts and bad seed plots in time, check the seedling situation and insect situation after emergence, and replant precocious varieties or chemical control to the plots that lack seedlings and break ridges or suffer from insect pests.

Fifth, promote soil testing formula fertilization for a long time, many places rely solely on experience to apply fertilizer, resulting in the imbalance of soil nutrient elements, production is prone to lack of potassium, lack of trace elements and other phenomena. 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. It is recommended that straw should be returned to the field, nitrogen fertilizer should be applied in stages or slowly, and potassium fertilizer should be increased and magnesium fertilizer should be added appropriately according to the status of soil potassium. Encourage the application of more farm manure, combined with land preparation. When using chemical fertilizer as seed fertilizer, it should be deeply applied to plant 4-5 cm to avoid burning seeds. It is suggested that on the basis of the above fertilization principles, the amount of fertilizer applied at different yield targets is as follows: (1) yield level 250kg / mu: nitrogen fertilizer (N) 2.7kg / mu, phosphate fertilizer (P2O5) 2.3kg / mu, potassium fertilizer (K2O) 2.3kg / mu. (2) yield level 200kg / mu: nitrogen fertilizer (N) 2.3kg / mu, phosphate fertilizer (P2O5) 1.5kg / mu, potassium fertilizer (K2O) 1.5kg / mu. (3) yield level 150kg / mu: nitrogen fertilizer (N) 3kg / mu, phosphate fertilizer (P2O5) 3.7kg / mu, potassium fertilizer (K2O) 3.3kg / mu. Sixth, the safe and efficient use of herbicides should be in accordance with local conditions, according to different grass phases, scientific and rational selection of safe and efficient chemical herbicides and herbicides. In the drought-prone areas of the central and western regions, weeding of stems and leaves after seedlings is advocated. In order to prevent the occurrence of drug damage, it is not suitable to use azinone, 2meme 4murine D butyl ester or the formula containing this kind of herbicides to control weeds in white pulp land, saline-alkali soil, sandy soil and soybean fields with high soil moisture. In view of the fact that it snows heavily and warms up early this year, which is beneficial to the early germination of perennial weeds, glyphosate can be used to control perennial weeds before sowing. Glyphosate can effectively improve the control effect on perennial root weeds such as "borage" and "spinosa". Closed weeding before seedling, if the soil moisture is good, weeding according to the normal dosage of herbicide instructions, soybean fields can use Acetochlor, Metolachlor, Metolachlor, Metachlor, Propargine Fluorachlor (Quick harvest) and other chemicals. If the soil moisture is poor, closed weeding is not recommended. In order to weed the stems and leaves after seedlings, we can use quizalofop, high-efficiency flopyrine (high-efficiency cover grass energy), fluvoflurane (Jing Mingshu), fluorosulfen, dilute grass, bentazon and so on. The stem and leaf control period of "chicory" and "Rhizoma przewalskii" is the full development period of the first compound leaf of soybean, which can not only improve the control effect, but also reduce the drug damage. The control of the stems and leaves of duck toe grass must be used when the weeds have just sprouted. It is best not to use long residual herbicides such as Pushter, Dosulfuron, Huwei, Kuocaoqing, Guangmianling and so on.

7. Scientific prevention and control of diseases and insect pests in a warm winter this year is extremely beneficial to the safe overwintering of soybean bacteria and eggs of diseases and insect pests, and soybean diseases and insect pests may be more serious. According to the harm of local diseases and insect pests and the main objects of prevention and control, seed coating agents should be selected and soybean seed coating should be carried out in an all-round way. In the areas where the occurrence of Liriomyza huidobrensis and Liriomyza huidobrensis is more serious, more than 35% of the seed coating agent (carbofuran content must reach 10%) is used to control the occurrence of root rot caused by insect pests. In areas where the occurrence of underground pests is relatively light, 2.5% Prozac coating can be used to control soybean root rot. In the area where soybean cyst nematode occurs again, rotation or line-resistant varieties should be planted with non-legume crops for more than five years. To control the soybean root velvet scale, it is necessary to grasp the young nymph stage that has not yet been fixed, use 75% imidacloprid 3 grams plus 48% chlorpyrifos 60 ml per mu, and apply twice before the soybean cotyledons are unearthed and after the cotyledons are unearthed. When grubs occur in serious plots, particles such as phoxim and chlorpyrifos should be applied to the field with seed fertilizer to prevent them. This spring, we should increase the prevention of pests such as two-leaf beetle, Mongolian gray weevil, net sand potential, spotted beetle bug and so on. It can be sprayed with 3% acetamiprid 50 ml / mu and 30 ml / mu water. The ground tiger can be trapped and killed by grass in the early seedling stage, cut the grass in piles at an interval of 5 meters, spray 80% dichlorvos 300 times liquid at the bottom of the pile, or carry out manual hunting. In addition, the repeated cropping plots should pay attention to the use of poison bait to control rodent damage after emergence.