Sampling Procedures

Tissue Sampling

Denele Labs recommends starting tissue sampling in the spring, post bloom so there will be ample time to remediate a deficiency prior to harvest.  For micro nutrients such as Boron and Zinc, you should submit leaf blades for testing. 

Petiole testing is a very good method for determining nitrogen and nitrogen movement.  If nitrogen is your primary concern, a petiole test is recommended.

Some growers will pull both samples then we will split them and base the report on the micro nutrients of the blade and the nitrate nitrogen of the petioles.  This allows the best of both methods for a small increase in fees.

Pull tissue opposite the fruit on the vine trying to pick the average knowing that your eye will be attracted to the abnormal.  A sample size should consist of a large handful, typically 25-35 leaves or 40-50 petioles are optimal.

Pod vs. Random
Many growers are switching to pods for their soil and tissue testing.  A pod is where there are a few known locations in a block with known vines that are an average representative of the block and all the tests are from these vines.  Each year for example, pod 7-10 equals block 7-10 tenth tractor row from the south west vines 10-11-12 on the left and right side for a total of 6 vines.  The benefit of this method is that since one returns to the same vines each time they test, they eliminate the intra-vineyard difference and allow for a closer analysis of cultural factors as well as yearly weather influences.

Soil Testing

Soil tests are recommended to be taken to a depth of 1-2 feet with a minimum of 10 sub samples combined to make one lab sample with the exception of pod testing where there would be one sub sample per vine/tree so 6 to 8 sub samples per pod.  When sampling sites on berms, placement should be 12-18 inches from vine/tree towards middles rotating as needed to stay on berm and 2-4 inches from shoulder.  If drip irrigated, always sample in irrigated areas.

At Denele, our lab samples are research grade so we weigh our soils and wash our tissue samples so that we can tell you what is in the vine, not on the vine.  This is different than most labs so a difference can be expected from previous tests.  This attention to quality in the lab and the vineyard is what separates the quality wines from the rest.

Happy Sampling,

Joe Mullinax

Taking a Good Feed Sample

An analysis is only as good as the sample submitted.  Taking a good representative sample of your feed is the first and most critical step of the analysis process, yet it is often the step that is the most taken for granted.  Following good sampling procedures will help insure that your analytical results truly reflect the nutrient composition of your sample and will be useful in developing your feeding program.  Poorly taken samples can result in decisions that lead to either over or under feeding.  Both of these can be costly in terms of money and/or lost production.

The key to submitting a good sample is to collect several subsamples to form a composite.  Remember that the one pound sample that you submit for analysis is going to represent several tons of feed.  Thus, you want to be sure that it represents a good cross-section of the feed, not just one bale.  There can be a great variability between bales in the same lot.  For example, if you sampled the worst bale in the lot, feeding recommendations based on this information would result in overfeeding and increased feed cost.  Studies have been done demonstrating that compositing multiple subsamples is the best way to get an accurate picture of the forage in question. 

Guidelines
 
Hay- hays of different types, cuttings or lots should be sampled separately.  Using a suitable hay probe, bore 12-20 bales selected at random through the small square end.  Combine all core samples and submit for analysis.

Silage- collect only fresh unloaded material.  Grab handfuls of silage from 12-20 locations in the unloaded silo pile, feed bunk, or from in front of 12-20 cows.  For bunker or trench silos, collect 12-20 samples from across the face of freshly exposed material.  Sampling locations should vary from top to bottom and left to right.  All subsamples should be combined and mixed thoroughly in a clean plastic bucket to form a composite sample.  Submit one pound (0.5 kg) of the composite for analysis.

Another option is to load a mixer wagon with silage, blend for a few minutes, and then grab a sample from the discharge.

Total Mixed Rations- collect only freshly blended rations.  Grab 12-20 handfuls of the mix from different locations in the feed bunk or from in front of 12-20 cows.  All subsamples should be mixed in a clean plastic bucket to form a composite.  Submit a one pound (0.5 kg) sample of the composite for analysis.