| Soils are the source of thirteen of the | | | | |
| sixteen essential plant nutrients and can be | | | | Soils usually contain much higher amounts of |
| viewed as suppliers of nutrients to plants. | | | | nutrients than what we see in the reports, |
| Plants absorb available nutrients, which can | | | | because lab results describe only the |
| be replenished by adding fertilizers. | | | | available nutrients to plant. To estimate the |
| | | | amounts of nutrients which are actually |
| To achieve good yield and quality, nutrient | | | | available to plants, different testing |
| balance has to be maintained. Nutrient | | | | methods were developed. Some of these methods |
| imbalance may result in deficiencies, | | | | give empirical values or measures. |
| toxicities or interference of one nutrient | | | | |
| with the absorption of others. | | | | 4. Don't look only at the numbers in the |
| | | | report |
| This may result in stress to the crop, | | | | |
| causing a decrease in quality and/or yields. | | | | It's true, lab reports can be confusing: |
| Soil analysis is an important tool for | | | | different labs use different testing methods, |
| evaluating or avoiding problems of nutrients | | | | resulting in different results for the same |
| balance. | | | | sample! They may even use the same methods, |
| | | | but express the results in different units. |
| Why is soil analysis important? | | | | |
| | | | To correlate the numbers in the soil analysis |
| You can roughly estimate just how much | | | | report with crop response to added nutrients, |
| fertilizers you need to apply according to | | | | numerous field experiments are required. The |
| general growing recommendations for your | | | | reason is that the same numbers may lead to |
| crop. But is it too much, or maybe too | | | | different recommendations in different soils, |
| little? This is where soil analysis comes in. | | | | different areas and under different |
| | | | conditions. The numbers in the report, |
| Soil analysis eliminates at least one unknown | | | | coupled by the description of the nutrient |
| from the "equation": when adding nutrients to | | | | content in the soil, can indicate if the |
| the soil, knowing the starting point is a | | | | predicted crop response to fertilizers will |
| very valuable piece of information. | | | | be favorable or not. |
| | | | |
| Here are the basics of how to make sense of | | | | 5. Choose the right lab |
| soil analysis reports. | | | | |
| | | | Good labs, with good experience, use their |
| 1. Take the soil sample correctly | | | | regional database to give a description of |
| | | | each nutrient (indicating if its level is too |
| Taking the sample correctly is the number one | | | | high, too low or adequate) and even |
| step for any reliable soil analysis result. | | | | fertilization recommendations. |
| The soil sampling should be well planned and | | | | |
| preformed. For example, the sample site | | | | Don't take these recommendation as |
| should be far from roads, fences, tree | | | | "instructions". Remember that no one knows |
| groups, piles of fertilizers and manure or | | | | your crop better than you do. You are the |
| any other object that can locally affect the | | | | best judge of your crop needs and specific |
| soil properties and content. | | | | conditions. |
| | | | |
| The sample should represent the entire field | | | | 6. Use your experience |
| as closely as possible. If the field is not | | | | |
| uniform, and consists of different areas with | | | | The soil analysis report, together with your |
| different properties, each area should be | | | | close familiarity with your crop and field |
| sampled. Compiling results from completely | | | | conditions, give you the starting-point to |
| different areas and averaging them into one | | | | tackle the next question: how much |
| report, will obviously give us a very | | | | fertilizers to apply? |
| misleading result. | | | | |
| | | | First thing to remember is that different |
| 2. Consider all growing conditions | | | | crops remove from the soil different amounts |
| | | | of nutrients. So knowing your crop needs is |
| Keep in mind that there are many factors that | | | | essential. Next is your crop target yield. |
| affect the plant growth. The soil analysis | | | | Generally speaking, higher fertilization |
| will not supply answers to poor or inadequate | | | | level gives higher yields, but only up to a |
| conditions, such as critically low or high | | | | certain point. Beyond that, adding |
| temperatures, inadequate drainage, wrong | | | | fertilizers will not increase yields and may |
| application of fertilizers, accumulation of | | | | even reduce them as a result of salts |
| salts, plant diseases, pests damage, | | | | accumulation in the root zone. |
| competition with weeds etc. | | | | |
| | | | Bottom line is that soil analysis lab reports |
| Assuming you took samples correctly and you | | | | give us a good starting point for making |
| acknowledge the many factors that may affect | | | | better fertilization-management decisions. |
| you crop, how do you proceed to interpret the | | | | They should be put in context and their |
| numbers in the soil analysis lab reports? | | | | interpretation should be adjusted to the |
| | | | individual crop behavior and specific field |
| 3. What do the numbers in the report stand | | | | conditions. |
| for? | | | | |