First, the soybean needs fertilizer characteristics (a) soybean nitrogen nutrition. The nitrogen nutrition needed by soybean seedlings can be supplied by the dissociation of proteins stored in the cotyledons. After the seedlings emerge, they quickly absorb the available nitrogen compounds from the soil. Generally, when the first compound leaves appear in soybean seedlings, although nodules have been formed, the nitrogen fixation capacity has not been fully exerted. At this time, although the amount of nitrogen needed is not large, the deficiency of nitrogen in the soil often causes the symptoms of nitrogen deficiency. Affect normal growth. During the period of flowering and scabbing of soybean, it is the period with the most amount of nitrogen. At this time, the nitrogen-fixing ability of rhizobia is very strong, but it can not meet the needs. Therefore, nitrogen fertilizers in the soil must be used to supplement their needs at this stage. The amount of nitrogen supplied during this period is closely related to the accumulation of dry matter. Plants that obtain more nitrogen have more dry matter accumulation. There are two sources of nitrogen in soybeans, namely nitrogen fixed by rhizobia and nitrogen absorbed by the root system from the soil. Applying large amounts of nitrogenous fertilizers does not increase the yield of soybeans, and sometimes even fertilizes without increasing production. Under the following two conditions, nitrogen can be used as a soybean seed fertilizer: First, the soil fertility is low, and it is not guaranteed that soybeans can achieve normal flourishing degree; second, soybean varieties with early-maturing culms need to promote vegetative growth at the seedling stage. Soybean plants accumulated nitrogen up to the fastest time during the flowering stage. Therefore, the effect of topdressing during flowering is better. (b) Phosphorus nutrition of soybeans. Soybeans require high levels of phosphorus nutrition throughout their growing period. Phosphorus requirement is most urgent from emergence to full flowering, especially at seedling stage. Phosphorus deficiency will severely inhibit the growth of soybean vegetative organs. Soybean plants get enough phosphorus in the first eight weeks, and even if there is a lack of phosphorus, there will be no significant reduction in production. Because the phosphorus of soybean meal can be met by the phosphorus input in the vegetative organs, this shift is particularly strong in the absence of phosphorus in the soil. Phosphorus application of soybean is often closely related to the available phosphorus content in soil. (3) Potassium nutrition of soybeans. Potassium compounds in the organic fertilizer content, the general is not lacking in the soil potassium, soybean fertilizer technology (a) base fertilizer. Increasing the use of farmyard manure as base fertilizer is an important condition for ensuring high yield and stable production of soybeans. Fertilizer is a complete fertilizer, minerals, high nutrient content, but also contains more organic matter, the nature of relaxation, long-term fertilizer, very beneficial to the cultivation of land. Organic fertilizer produces organic acids after maturity, which can dissolve all kinds of non-supplyable nutrients in the soil and give it to soybeans in time for absorption and utilization. At the same time, organic fertilizer can also improve the physical and chemical properties of the soil, increase the degree of looseness, make the soil water, fertilizer and enhance the insulation capacity, forming a good environment for the growth of soybean. In farm manure, pig manure had the best effect on soybean yield, followed by horse dung and compost with more organic matter, and the effect of soil manure was poor. The amount of basal fertilizer applied depends on the specific conditions such as the quality of manure, soil fertility, and the amount of fertilization in the previous crop. General high-quality manure, apply 1000--1500kg per mu, poor quality, 2000--3000kg per mu. For soils with low soil fertility and small amount of fertilization, pay attention to applying organic fertilizer. (b) Fertilizer. In most cases, superphosphate is used as a soybean seed fertilizer to achieve significant yield increase. Use 10-15kg per acre. Thin application of fertilizers often need to add a small amount of nitrogen fertilizer, applied per acre urea 10kg or ammonium nitrate 10-15kg mixed application, nitrogen, phosphorus ratio of 1:3 or 1:2 as well. When applying fertilizers, special attention should be paid to the isolation of fertilizers and seeds to avoid contact with seed fertilizers so as to avoid burning seedlings. Deep application of fertilizer can significantly increase production. (c) Dressing. Local production tests have shown that a top-dressing crop during the branching period to the initial stage of flowering has a good yield increase effect. Soil fertility is low or the growth of soybean seedlings is thin. The more difficult ridged land should be topdressed. When the soil is relatively fertile, the basal and seed fertilizers are sufficient, and the soybeans grow robustly. When the plants are flourishing, it is not necessary to top-dress, so as to avoid causing lodging. When soybean topdressing, it is necessary to consider the adaptation of nitrogen and phosphorus. The amount of topdressing fertilizer is 10kg of urea, 20- to 30kg of ammonium bicarbonate, 10 to 15kg of ammonium nitrate per mu, and 15 to 20kg of superphosphate. The tests showed that during the formation of soybean seeds, liquid fertilizers with the same proportion of N, P, K, and S contained in soybean seeds were sprayed, and the yield increased by more than 50%. The first spray of fertilizer can be carried out when the top pods are able to touch the beans, spraying once every 10-14 days, using a liquid volume of 2.3L per acre. (d) Apply molybdenum fertilizer. Molybdenum can promote the formation and growth of root nodules, increase the number of root nodules, increase the volume, and increase the amount of nitrogen fixation; it plays an important role in nitrogen metabolism of soybean; it can increase the nitrogen content of soybean tissues and increase the protein content; Chlorophyll content; promotes the absorption, distribution and transformation of phosphorus in soybean plants; enhances the respiration intensity of soybean seeds and increases seed germination power. In acidic soils, due to the action of available molybdenum and free iron and aluminum precipitation, the leguminous crops are particularly prone to molybdenum deficiency and affect yield. Therefore, molybdenum fertilizer should be applied in an appropriate amount. There are two methods to apply molybdenum: seed dressing: use ammonium molybdate 20--30g, add a small amount of warm water first, make it dissolve, then add water 2.5--1kg, make a 1% - 2% solution, with a sprayer Spray on 50kg seeds, stirring while spraying, until the solution is fully absorbed by the seeds and dried. Pay attention to not drying seeds after seed dressing, so as to avoid seed coat rupture and affect seed germination. Spraying: spraying in the flowering period of soybean, usually 50kg of water plus ammonium molybdate 20-25g, made into a solution, spray 25--30kg per acre. Molybdenum fertilizer and phosphorus fertilizer spray, the better. Phosphate fertilizer is best to use ammonium phosphate, ammonium per acre spray solution of ammonium molybdate 30g ammonium phosphate, stir evenly to use.