Know The Future
Sap testing can detect nutrient excesses and deficiencies weeks ahead of a lab test allowing immediate monitoring and management of your crops.
Benefits of Sap Testing:
What is plant sap?
The sap is the blood of the plant coming from the guts of cells when they are pressed as well as the fluid in the plants veins, xylem and phloem.
Tissue vs Sap
Plant tissue is akin to an arm, containing the blood as well as all of the bones and muscle of the plant. Bones and muscles keep nutrients locked up and stored for the long-term where as nutrients in the sap show what is happening right now in the plant. A typical lab tissue test dissolves the entire leaf in an acid and is a total measure of the elements in the leaf. Sap testing is a measure of just the elements in the blood, the nutrients that are readily available to a plant right now.
Hand held meters for assessing plant sap are available for Brix (total dissolved solids), Calcium, Nitrate, Potassium, Electrical Conductivity and pH. Unlike a lab test where every nutrient can be read, hand held meters create a picture of numbers and are analyzed looking at rations as well as environmental factors. Electrical conductivity, Brix and pH are only available to sap testing and provide valuable insights.
Plants Are Smart
Tissue or sap, testing and comparing the upper and lower leaves of a crop provide details well worth their while. Depending on how the element or nutrient is used in the plant determines it's behaviour in times of excess and shortage. For example, Calcium is difficult for the plant to remobilize when it experiences a shortage from the soil as it is bound in plant tissue making a protective barrier against disease. Typically lower leaves on a plant will have higher Calcium levels as it slowly accumulates through transpiration. Potassium on the other hand is the transporter of the plant and extremely mobile constantly moving and shuttling nutrients throughout the plant. If the soil cannot supply enough Potassium, levels will drop in the lower leaves and in times of excess, the plant will store these excesses in the lower leaves.
Comparisons Are Everything
Within the same crop, different varieties have been shown to have different elemental compositions. Different soils, fertilizer programs, timing and even tillage all impact the balance of the plant. This is where sap testing excels in providing detailed insight unique to your crop and your farm. By comparing upper and lower leaves the plant provides many clues about what is happening and where it's headed.
Sap test your crops
On-farm plant sap analysis for immediate crop management
o Find crop deficiencies weeks before a lab based test
o Get access to cost effective analysis of 20+ elements
o Take action the same day with on-farm testing of your crop
o Learn to perform basic and advanced crop testing yourself
o Harness cost effective specialist and global expert advice
$200 / visit
On-farm assessment and recommendations for three crops
+ Additional travel costs may apply
Sap Testing PResentation - ACRES USA
Presentation provides an excellent overview in an hour on the potential of plant sap testing.