Tissue Testing Values

A couple of weeks ago I attended theInternational Ag Labs field day. Dr. Skow had a great presentation on tissue testing soybeans for high yields. Tissue testing is becoming a very hot item. I thought I’d share with you a few high lights from this presentation.

Nutrient	Normal	Current Ag Labs Average of tests	Notes
Phosphorus	0.25% - 0.5%	< 0.73%
Nitrogen	4% – 5.5%	3% -4.2%
Potassium	0.35% - 2 %	?	High nitrogen and potassium can lead to increased insect damage
Calcium	0.35% - 2%	Often below 1%	First line of defense against disease
Iron	50 – 250 ppm	?	Affects leaf thickness, need iron for a thick leaf, if you double the leaf thickness you increase its ability to produce chlorophyll by 4 times
Manganese	20 -100 ppm	?	Keep it in a 2:1 ratio with iron, w parts iron, 1 part manganese
Copper	10-30 ppm	?	Low values increase plants susceptibility to molds
Zinc	20-50 ppm	?	High zinc levels keep insects at bay, high plant zinc cause insects to defecate themselves to death often after the first bite!
Sap Ph	6.4 pH	Many times it is lower	Low sap pH points to a lack of calcium or Potassium
Magnesium	0.15% - 1%	?	If value is low sap doesn’t flow, if it is high plant sap flows too quickly
Boron	10 -55 ppm	?
Sulfur	0.2% -0.4%	?
Molybdenum	1 – 5 ppm	?	Moly affects nitrogen utilization, shows as leaf chlorosis similar to nitrogen deficiency
Nickel	0.1 -1 ppm	?	Need to fix nitrogen
Lithium	0.2 – 1 ppm	?
Selenium	.05 – 2 ppm	?
Cobalt	0.01 -0.3 ppm	?
Chromium	0.1 – 0.5 ppm	?	Affects sugar formation

I will be working to add more information to this chart over the winter. In the mean time review this past years tissue tests to see what your low on and work to incorporate those nutrients into next year fertility plan.

Yield Starts Here is a blog for farmers, focusing on increasing yield and profitability by focusing on the soil. It is managed by Craig Dick, a Blogronomist and Sales and Marketing Manager at Calcium Products. Find other articles by Craig and guest writers at http://blog.calciumproducts.com/ .