Do you know the difference between P and P2O5 or K and K2O? Understanding fertilizer forms can be key in interpretation of the peer reviewed literature and making decisions based on your own reports. Reminder:  Fertilizer grade shows % N – % P2O5 – % K2O. The three percentages are always in this order. I...Read More

We often hear that someone has a low salt fertilizer that is liquid. Many people associate salt with table salt. However, we know fertilizers do not contain sodium chloride. So what is a liquid fertilizer low in salt and what implications does that have? Defining Salt Let’s start by defining salt. A salt is a...Read More

Over the past year, our soil experts have added the Soil Health Assessment test. Soil health is the overlapping areas of the chemical, physical and biological properties of the soil. Previously, the chemical or nutrient status of the soil has been the main focus of soil testing laboratories. Recent addition of biological properties have become...Read More

Ward Laboratories uses soil test methods developed and calibrated by land grant universities.  Standard methods are published in several manuals.  We prefer to use standard methods that have performed well for many years. Soil pH & EC: We use a 1:1 water pH.  This means we measure 10 grams of soil and 10 mL of...Read More

Available Water Holding Capacity (AWC) of soil is the amount of water held in the soil for crop growth and yield. Field capacity is the amount of water a soil will hold against gravity at a water tension of 1/3 atmosphere. Permanent wilting point is the point where plants cannot obtain more water and remain...Read More

Reprint From June 2003 Ward Letter. Ward Laboratories professionals often get questions about surface urea application and UAN solutions. Urea is a dry fertilizer that dissolves with water after application creating urease enzyme activity that is naturally present in all soils at some level. Urease enzyme converts urea to ammonia (NH3) and bicarbonate (HCO3) in...Read More