Soil Test or Tissue Test or Both?

How do you know if you need a soil sample or maybe a tissue sample?  What is a tissue sample?  Do I need both?

Most people are familiar with soil samples and we literally take hundreds every year.  Soil samples are very important where we are growing any annual crop like cotton, wheat, sorghum, etc.  And they are important if we are growing perennial crops like bermudagrass for hay, especially where we take multiple cuttings.

So what is a tissue sample?  Tissue samples are usually leaves but can be other plant parts that are taken or pulled during the growing season.  For instance, in pecans we would pull mature leaves from about the middle of the tree canopy.  These leaves are taken from several trees to make up a sample to send in to the lab.  These samples tell us if the plant is getting all the nutrients it needs from the soil and/or our fertilizer applications.  Sometimes we can supply a nutrient in the soil and the soil properties keep it from being available to the plant.  Or in the case of perennial plants like trees they may be getting nutrients from deeper down than the soil sample was taken.  The tissue sample along with a soil sample is a great way to make decisions  about crop fertility and know you are making a difference in crop yield.  As with soil samples it is important to take  tissue samples for several years to compare results from year to year.