Believe it or not, even with all the quality control process that labs have in place...mistakes can happen!!
I know some of you may be falling out of your seat right now, because getting a lab to admit that a mistake happens is not easy. Prior to starting our lab, our agronomy group sent 1000's of samples off each month and we called labs for re-testing often. In all those situations we never had a lab admit that the sample results were incorrect or that a mistake had happened!! Not even one single time! Never!!
Well, it doesn't take a rocket scientist to figure out that there is an unwritten rule in the lab business....do NOT admit mistakes!! Its a simple matter of liability and the fear of being sued. Many labs also think that if you admit a mistake then you introduce doubt into the clients mind regarding your ability to do the job properly. Its a policy made from fear and ignorance. People make mistakes, computers pull corrupted files, emails don't go out when they should, data gets mishandled, equipment malfunctions, etc. No matter how many control checks that we have, sooner or later a mistake happens (note: At the end of these comments I will list some of the QC methods that we have in place at our lab.), the overall question is what is the policy or philosophy about how to handle these situations.
Our policy is that if we make a mistake we own up to it. Its that simple. We realize that growers depend on us to give them good information and we take that responsibility very seriously. We trust our growers to understand that when we admit a mistake that we can find a way to work together to fix it and it has been our experience that this has been the case.
In our mind, there is a difference between responsibility and Liability. Liability, is a legal term that all labs have created an "out" for. In other words, we are not liable for applications or mistakes that happen at the farm level for any amount over and above what the sample cost and value is. Most labs have a disclaimer somewhere that says something like: We give recommendations only and not guarantees or assurance of yield or performance based on our data. Our liability for any errors in our results will be limited to the cost and value of the soil sample that was sent in. Our lab accepts no liability in the performance of a crop grown based on our recommendations or using our data! Technically This is our "liability policy" as well. However, our "Responsibility Policy" is more like: "If we screw up, and we 100% know its our fault then we will do everything in our power to help make it right!"
Thankfully, these situations do not happen often but when they have in the past we have always worked with the growers toward a resolution that satisfies each party. We trust growers to understand that a $6-$10 soil sample doe not obligate us to $10,000 worth of lime or potash, but we also understand that there are times when refunding the cost of a soil sample just doesn't cut it.
The fear of having to do this often is a very motivating force to make sure we do things correctly in the laboratory. In my opinion, based on numerous visits and conversations with other laboratory personnel in various regions, we do as good, if not better job of QC than most. I will go into some details regarding these procedures below:
1. Certified samples: We test 2 certified samples from the North American Proficiency Testing Service on each run of 60 samples: This is in addition to our calibration standards and our internal laboratory control standards and blanks. A certified sample has a guaranteed analysis that comes with the sample so that you know what those values are supposed to be. We run one at the start of the run and one toward the end of the run of 60. Again, this is in addition to the lab control standard that are also within that run. So the idea is that if you test 60 samples and all the certified samples hit their parameters then you can be assured that the samples in between are correct. Various labs have similar methods, but I am not aware of any that are doing this level of certified sampling, most have many more samples in between these checks.
2. Software flags: We have invested a lot time and money with programmers to build our lab the ability to automatically flag samples that are our side of specific ranges that we can set for each crop and nutrient. We are just introducing these abilities with the release of our newest software updates, but a lot of work that was being done manually by looking over reports for inconsistencies withing the data will now be done automatically. These flags, although technically happen after samples have passed the original QC checks, will then be flagged for further analysis. The managers and techs decide if the sample need to be retested at this point and verified. The same software also handles the certified samples listed above and allows for documentation of issues with the samples and measures taken.
3. Sample Integrity measures: When samples come in the door at our lab they never leave their original container/bag. Many labs, will dump the sample into a separate container and place a label on that container to track it through the lab. When this happens the original handwriting on the bag is lost (unless the bag is kept), the sample integrity chain has been broken because errors happen when transferring and re labeling.
4. Sample Tray System: The samples do not leave their original container but they also are assigned a physical position on a tray as soon as they are take from boxes and assigned to a run. These trays take up a lot of laboratory space but also assure that a sample location can be verified at all times all the way until the sample is disposed of several weeks after testing. We currently have space to store about 25,000 samples at once so during busy season a sample may only be held in storage for a week or two. Our goal is to continue sample storage space.
5. Bar codes/ QR Codes: Our new software program has a web portal that clients can go to and create the lab submission sheets electronically or print them off to send in. The sheets, regardless of if they are emailed or sent with samples have QR codes on them that allow for samples to be pulled into our system without having to retype them and make clerical errors.
These are just some of the main procedures that we have in place to make sure that your samples are treated with integrity! The main thing we want to convey here is the fact that your samples are VERY IMPORTANT to us and that we spend a LOT of time and resources each year thinking of ways to make them better!!!!