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Jan
At more than 95 of those sites when we applied various foliar fertilizer products at R3 we saw no impact on soybean yield in yield environments averaging 20 to 80 bushels per acre. Therefore it is important to apply foliar nutrition during optimal temperature ranges when plant photosynthesis and respiration are not inhibited.
Growers have appreciated that the technology has increased soybean yields and are a bit reluctant to go back to the old ways of not investing in soybeans.
Foliar fertilizer soybeans timing to spray. Treatments involved single or double applications spaced about 10 days of 2 to 6 galacre sprayed during the V5 to V7 growth stages. This early-season foliar fertilization resulted in statistically significant yield increases usually more than 2 buacre in about 15 percent of. The foliar fertilizer mixtures were based on composite soil samples collected from the trial areas.
Foliar fertilizers were applied at V4 when the row spacing was 15 inches or less and at R1 when the rows were wider than 15 inches. The prescription foliar fertilizer mixture increased soybean yields at three of the 20 sites 15 of the time. In 2019 we participated in a study with 13 States across the US for a total of 20 sites.
At more than 95 of those sites when we applied various foliar fertilizer products at R3 we saw no impact on soybean yield in yield environments averaging 20 to 80 bushels per acre. The best timing is R2 full flower to R3 first pod if you are only spraying one time. If you are after white mold spray twice about 2 weeks apart starting immediately.
Also spraying Cobra will help reduce white mold issues but spray that separate from fungicide. Foliar fertilizer has been hit and miss in soybeans. Therefore it is important to apply foliar nutrition during optimal temperature ranges when plant photosynthesis and respiration are not inhibited.
Ideal temperature range for corn and soybeans is 70-85 F. High humidity delays the drying of spray droplets from application giving the plant a longer time for optimal absorption. While it is okay to apply P or K directly ahead of the soybean crop research has demonstrated that soybean is less sensitive to application timing within a two-year cropping system and will provide maximum yield as long at the rate of P or K applied to the preceding crop.
We have evaluated spray-grade AMS finer particles and purer product 21-0-0-24S in foliar applications to soybean at V4 R2 R4 and R6 plus various combinations at 5 lb S per acre 21 lb of spray-grade AMS dissolved in 15 gallons per acre. This mix will take time to dissolve so slowly mix and agitate the mixture. What makes a good formulation for foliar feeding soybeans.
There has been a lot of interest in foliar feeding soybeans since the runup in soybean prices a decade ago. Growers have appreciated that the technology has increased soybean yields and are a bit reluctant to go back to the old ways of not investing in soybeans. However there is no single perfect product out there.
In fact several university studies have confirmed little difference in yield when foliar applying macronutrients to corn and soybeans. Micronutrients on the other hand can prove beneficial as a foliar feed but only if deficiency symptoms exist Figure 3 and Figure 4. Intensively grown crops like cereals are routine sprayed several times during the season for different purposes like pesticide treatment and growth regulation.
In such cases foliar fertilizer may be combined with pesticide application provided that the foliar fertilizer formula is compatible with the pesticide. As part of Becks Practical Farm Research program theyve tested time of day of application of foliar nutrition products across multiple locations for the past three years. At each location we are seeing anywhere from a 4-9-bushel increase by.
Time of the day. The best time to foliar feed is early morning or late evening when the stomata are open. Foliar feeding is not recommended when the temperature exceeds 80F.
Smaller droplets cover a larger area and increase efficiency of foliar applications. However when droplets are too small less than 100 microns a drift might occur. Questions often arise in June about emergency or catch-up fertilization for soybean.
Most producers are not worried about this because they typically apply adequate amounts of phosphorus P and potassium K fertilizers before planting soybean or apply sufficiently large amounts before the previous years corn for both the corn and soybean crops. But that was when soybeans were 13 15 and even 17 per bushel. But now you may be able to sell your crop for 10-11 if you still have any in storage and the future prices are reflecting record acreages.
So it seems that Ive been asked Should I apply a foliar feed to my soybeans more this year than in the past few years. However liquid boron fertilizer can be applied with post-emergence herbicide applications. To avoid leaf burn foliar boron application rates should be less than 05 pounds per acre and do not spray when temperatures are high and the crop is under moisture stress.
Boron fertilizers applied near the seed have been shown to reduce germination. Understanding the soybeans nutrient uptake can lead to the correct timing of nitrogen application. The translocation of nitrogen is at its peak in around 8 weeks after the planting.
In any case the fertilizer program has to be based on a reliable yield. Foliar feeding corn and soybeans remains a controversial subject in some corners of agriculture but not to an increasing number of farmers who are using the practice to fine-tune fertilization strategies to maximize yields. Most university research indicates that because only small amounts of nutrients can enter leaves foliar feeding cant provide adequate nutrition to positively impact.