 Greetings! I'm Chris Augustine. I'm the Soil Health Specialist at the North Central Research Extension Center in Minot. My contact information is at the bottom of this slide. Be sure to like the Soil Health Group on Facebook at www.facebook.com. This presentation will cover some of the basics of soil fertility. Sound Soil Fertility Management starts with the Soil Test. It saves money and helps to ensure yield goals. Soil testing is commonly done using an average across the field or sampling similar zones in a field. Soil sampling can be easily done with a push probe, shovel, or mechanically powered probe. Soil samples are usually taken at the 0-6 inch depth and 6-24 inch depth. The 0-6 inch depth range is usually tested for nitrogen, phosphorus, potassium, organic matter, electrical conductivity, pH, and various micronutrients. The 6-24 inch depth is usually tested for nitrogen since it can leach. If canola is the crop grown on the field tested, sulfur is recommended to be tested at this depth as it can leach like nitrogen. Soil sample bags are available for most soil testing labs. Soil testing is recommended to be done late in the fall or prior to spring planting as nutrients like nitrogen can change if sampled during the growing season. It is important to soil sample around the same time every year. This makes for a better comparison of a field when looking at a previous fertility report. Here is contact information for the soil labs in North Dakota. The NDSU Soil Science Department tests soils, egg vise in Northwood, North Dakota, and egg soil science in Minot, North Dakota. Averaging a field or also known as central tendency involves taking 20 or more soil samples randomly across a field. Taking 20 samples or more is important because it can account for within one standard deviation of the fertility in 80% of the field. A sampling pattern may look like this, where the field is approximately 40 acres and the red dots signify where a soil sample was taken. The samples can be mixed together in a clean plastic bucket and a composited subsample is taken and sent into a lab. Be sure to fill the soil sample bag to the recommended amount. This method works well in a uniform field. However, if you are sampling a field that varies greatly, you might want to look into sampling the different areas of the field and testing those individually. This presentation will not cover precision agricultural practices like zone sampling. Soil test reports typically display nitrogen in pounds per acre and the other nutrients in PPM or parts per million. Six inches of topsoil in an acre weighs roughly 2 million pounds. Because of this, you can multiply your soil test PPM by 2 to get a rough estimate to how many pounds of a nutrient is in your soil. EC or electrical conductivity will be reported in millimose per centimeter. EC results are usually done with a one part water, one part soil dilution. A saline soil is defined as having an EC over four and a saturated paste extract. Because of the one to one dilution effect, EC can be roughly figured to be two times the reported value. This dilution should be noted on the EC test. Equations that convert one to one dilutions to saturated paste extractions are available in NDSU Extension publication SF-1087 Managing Saline Soils in North Dakota. Organic matter is reported on a percent basis. Before modern agriculture, organic matter was around 5 or more percent. However, due to tillage, soil organic levels have dropped. Organic matter levels can be increased with no till, cover cropping and manure applications. Keep in mind, manure should not be applied above agronomic rates. PH is reported on a scale of 1 to 14. 7 is neutral, below 7 is acidic, while above 7 is basic. PH is important for nutrient availability. Ideal soil PH is around 6 to 7.5. Phosphorus can be tested various ways. To my knowledge, the soil test labs in North Dakota use a phosphorus test called the Olsen. If a lab outside of North Dakota is testing your soil, you should ask them what phosphorus tests they are using, as different phosphorus tests can greatly affect the amount of phosphorus applied. The NDSU publication SF-882 North Dakota Fertilizer Recommendation Tables and Equations based on soil test levels and yield goals is a great tool for determining how much of a specific nutrient should be applied. This table is taken from SF-882 and shows corn fertility recommendations. Let's say we have a yield goal of 150 bushels. According to our soil test, we have 35 pounds of nitrogen, 7 ppm Olsen phosphorus and potassium tested 150 ppm. For nitrogen, we subtract the 35 pounds of soil tested nitrogen from the recommended nitrogen rate of 180 pounds. So it is recommended to apply 145 pounds of nitrogen. The soil test of 7 ppm phosphorus is in the low range and should have 69 pounds applied. The potassium test of 150 ppm is in the high level and requires 22 pounds of potassium. Fertilizations have also been developed for nutrient requirements and are at the bottom of the fertility tables. This publication can be found at the web address at the bottom of this slide. Fertilizer formulations vary. It is important to know how much of a specific nutrient is in a specific fertilizer. The numbering system goes in the order of nitrogen, phosphorus and potassium and is reported as a percent. This picture of a bag of 10-10-10 has 10% nitrogen, 10% phosphorus and 10% potassium. A formulation of 10-52-0 has 10% nitrogen, 52% phosphorus and no potassium. Potash, a common form of potassium, reads as 0-0-60 and has 60% potassium. These formulations will have a fourth or fifth number. The fourth number in the formulation is usually sulfur. These extra numbers should be noted as to what the nutrient is. Thanks for watching this presentation. Here are web addresses for the publications SF-1087 and SF-882. If you have questions, please don't hesitate to contact me. My contact information is at the bottom of this slide. Have a good day.