Moisture was an issue in many fields this year in the area. There are fields that were too wet at seeding time and caused yield reductions. There were fields that were too dry at seeding time and were seeded too deep and reduced yield. There were fields that had excess rain in big summer storms (fortunately less than last year). There are fields that got dry in July and reduced yield because of the lack of moisture. There are now fields out there that have excess moisture and are very soft and fields that do not have the ideal amount of moisture to give us the best opportunity for maximum yield next year. Because of this variability, growers need to get out and check their fields to see what level of sub-surface moisture that they have. Checking for sub-surface moisture is easy. What you need is a Brown soil moisture probe. This sounds like a high tech piece of equipment but it is not. What it is a 4 foot steel rod attached to a handle that allows a grower to push the probe in the ground. On the end of the rod that is being pushed into the ground, there is a ball bearing welded on. This ball bearing needs to be a bigger diameter than the shaft of the rod. This simple tool allows a producer to estimate what level of soil moisture there is in his soil available for next year’s crop. The tool works because it allows us to see how far the moisture is in the ground. Soil water always wants to run down in the soil once its concentration is above soil capacity. When we get a rain, the water starts to percolate through the soil. What is left is what is available to the plants next year for growth. What determines exactly how much is left is the soil texture. One foot of wet sand hold the equivalent of 1 inch of rainfall. One foot of clay holds 2 inches of moisture. If you have a 4 foot rod and you can push it 4 feet into the soil, you have a full moisture profile. Annual plants root 4 feet so this represents what the crop will have to use even if it doesn’t rain. Depending on the amount of crop, this number tells a producer how much moisture will be needed to hit next year’s target yield. The issue that we have this year is that we have soils that are wet in some areas and soils that could use more moisture in other areas. It is important to know what moisture is in the fields when deciding how to manage fields this fall. Fields that are short of moisture need to have management practices applied that conserve moisture. Fields that are extremely wet should have significantly different management practices applied. The Brown soil moisture probe is an excellent tool to determine moisture in your fields. If you want to know more on how you can use it, give me a call.
By Dave Cubbon, P Ag