 |
 |
|
 |
|||
 |
Soil
Testing For years, agronomists and soil scientists have encouraged farmers to regularly sample and analyze the soil in their fields. Regular soil sampling is important for developing a successful fertility management program. In the past, soil sampling was often overlooked and fertilizer was frequently over-applied in order to ensure nutrient levels were adequate. It has been proven that soil testing is the single most important guide to the profitable application of fertilizers and lime. When soil test results are combined with information about the soil types within a field, you have a reliable basis for planning the fertility program on a field. Traditionally, soil testing had been used to determine how much fertilizer and lime needs to be applied; However, with an increase in economics and environmental concerns, soil tests are also a logical tool in determining areas where adequate or excessive fertilization has taken place. In addition, soil tests are used to measure the impact of past fertility practices or changes in a fields nutrient status. Which Sampling Scheme is the best method? There have been many people voicing there opinion on which sampling method is best for the most accurate and reliable results. Some feel that grid sampling gives a very good representation of the variable fertility, while others feel that sampling by zones (soil type, EC maps, past yield) is a smarter approach. We feel, depending on the individual field or the individual operator, there is a definite place for both methods. What works best for one field may not be the best option for another. If the topography of a field is relatively non-variable and there are only a few large soil types within the field, or if the field has had non-uniform applications of manure or commercial fertilizer, sampling by the Grid Method is an excellent approach. Click HERE for a map that shows high fertility around a building site where manure was frequently applied. If there is no knowledge of the past history of the field, grid sampling is a good place to begin. Since soil characteristics affect the productivity and nutrient holding capacity of the soil, if the field in question has variable topography and several different soil types, sampling by the Soil Type Method is usually a better approach than the grid method; However, past management practices such as manure application, crop rotations, or fields that have been combined into one larger one may affect the results of zone/soil type sampling. It is important to have knowledge of the field’s soil characteristics as well as the past history of the farm to achieve the most effective zone sampling program. How often should I sample? There are several factors to consider when determining how often to sample a particular field. Some of these factors include the field’s soil type characteristics, previous soil test levels, cation exchange capacity (CEC), and crop rotations. Fields typically receive re-test recommendations varying from every two to every four years. As a general guideline, if previous soil test levels are considered high, soil sampling and analysis may not be needed for three to four years. If fertility levels are low, testing should be done more frequently to monitor the field’s activity. Since yield goals, soil types, management practices, and weather vary from region to region, no single recommendation for the frequency of soil sampling should exist. When should I have my field sampled? Since tillage and weather conditions alter soil nutrient availability, sampling should be done close to the same date each year. Sampling each year at the same seasonal time minimizes year to year variability, allowing easier tracking of the fields fertilizer applications and fertility levels. A big advantage to sampling in the spring is the opportunity to have the data to analyze over the course of the growing season, as well as having an excellent tool for scouting. Please click on the following links for more information...
Precision Management
Services (515) 885-0330
|
||
|
|
© 2005 Precision Management Services. All Rights Reserved. GPS Soil Testing |
Data
Processing | Manure/Nutrient Management Plans |
Crop Scouting |