Eight key technical measures for increasing soybean yield

First, applying flower-and-pod fertilizer. The flowering and pod-setting stage is when soybean grows and develops most vigorously, and it is the period of greatest fertilizer demand in the soybean's entire life. Applying flower-and-pod fertilizer can reduce flower and pod drop, promote full grains, and improve quality. Flower-and-pod fertilizer should be applied at the early flowering stage, preferably as a combined application of nitrogen and phosphorus fertilizer, with 3-5 kg of urea and 7.5-10 kg of phosphate fertilizer per mu, applied in holes opened 5 cm to the side of the soybean roots, and after application, soil should be hilled up to cover the fertilizer.

Second, spraying foliar fertilizer. In addition to the three major elements nitrogen, phosphorus and potassium, boron, zinc and molybdenum are indispensable trace elements for soybean. Therefore, spraying a multi-element compound nutrient solution from the flowering to the seed-filling stage of soybean has the effect of increasing pods, increasing grains and raising yield. The method is: add 500 g of urea, 100 g of monopotassium phosphate, 50 g of zinc sulfate, 100 g of borax (first dissolve it in hot water) and 25 g of ammonium molybdate to every 50 kg of water, and stir thoroughly to prepare the solution. Spray evenly on both the front and back of soybean leaves, spraying 2-3 times in succession, with 75 kg of fertilizer solution sprayed per mu each time.

Third, topping and pinching out the growing tip. Timely topping and pinching out the growing tip can control excessive growth and has a significant effect on preserving flowers and increasing pods. For soybean varieties with indeterminate pod-setting habit, reasonably removing the growing tip can also control apical dominance and reduce flower and pod drop. The method is to remove the apical growing point on a clear day from the full flowering stage to the late flowering stage.

Fourth, spraying paclobutrazol. Spraying paclobutrazol can control plant height and shorten internode length, and the yield increase is greater for indeterminate pod-setting varieties than for determinate pod-setting varieties. Application method: from 5 days before soybean flowering to 7 days after the beginning of flowering, use 50-100 g of 15% paclobutrazol wettable powder per mu, add 50-75 kg of water to dilute, then spray evenly on both the front and back of the leaves, without spraying twice over the same area or missing any area.

Fifth, spraying triiodobenzoic acid. This is a multi-effect plant hormone that can inhibit apical dominance and promote axillary bud development. The plant becomes dwarfed, branches increase, and stems become thicker, which is conducive to ventilation and light penetration and prevents lodging. Spray once each at the early flowering stage and the full flowering stage, which can advance maturity by 5-7 days. Spray concentration: 100×10 at the early flowering stage

Sixth, before spraying, first dissolve the pure product in alcohol at a ratio of 1:100, then add water to dilute and spray evenly, with 50 kg of spray solution per mu each time. It should not be used on early-maturing varieties or soybeans with poor growth.

Seventh, spraying chlormequat can make plants short and sturdy, enhance lodging resistance, reduce flower and pod drop, improve quality, and increase yield by 10%. Application method: when the fourth compound leaf has grown, spray once with a 0.1% chlormequat solution, and at the early flowering stage spray once more with a 0.05% chlormequat solution. Spraying should be even, with 50 kg of spray solution per mu each time.

Eighth, spraying sodium sulfite, a photorespiration inhibitor, can increase dry matter accumulation. Spray once each at the early stage and full flowering stage of soybean, using 10 g of sodium bisulfite plus 75 kg of water per mu each time, diluted and sprayed evenly, preferably in the afternoon. For spraying photosynthetic micro-fertilizer, spray once each at the early flowering stage and full flowering stage of soybean, using 100 g of photosynthetic micro-fertilizer per mu each time, plus 50 kg of water, diluted and sprayed evenly.