Now is the time to gather Soybean Leaves for plant tissue testing.

Del Voight- Penn State Extension

Several growers are considering more high yield management for the soybean crop. There are alot of foliar fertilizer products with ideal nutrient levels for numerous micronutrients. Our research indicates tremendous variation in the response to these products.  Yield enhancement is tied to whether the plant is deficient in micronutrients or not.  Since we cannot test the soil with accurate assessments of micronutrients, the best way to determine hidden hunger is with a simple $24.00 plant tissue test. A few growers last season enjoyed 90 bu/acre plus while managing for high yield soybean crops.  The first step is to gain an accurate soil test an maintain optimum levels of P 150ppm and K 300ppm . The second step is to collect a sample at the R1 to R2 stage(full flower) for plant analysis. The Ag Analytical Lab provides the testing for the results.  Here are the specifics to gather the samples.
Once the plant begins to flower R1 which is occurring at the time of this writing in early planted fields in the next two weeks gather the samples and send them off via overnight mail to gain quick results. This will allow for adequate time to determine a nutrient strategy before peak growth at R3 when pods are being filled.  .

Soybean Specifics  

Interpretive Nutrient Levels for Plant Analysis

Soybeans plant tissue levels