Water Preservation, and Water Stress
There are many variables that come into play when irrigating corn, especially during a year that is dry. When that happens, it is important to be able to grow your crop with the least amount of water possible. To do so, you need to only irrigate crops exactly the amount they need. Finding this magic number is no easy task, but will pay off in the long run. You will be able to preserve the most water by irrigating the root zone to the field capacity. However, the amount will vary due to root depths and the soil type. Like we’ve said before, different soil types will determine how much water can be stored. Most of the time, the water that plants receive comes from the top few inches of soil. So, even if the roots extend fairly deep not much water will be absorbed at this depth.
Water Preservation Tips
In order to keep the root zone at field capacity, you may be irrigating more frequently than you’re used to. The key to saving water is timing, the faster the water gets across the field the better. Speedy irrigation will help with water preservation which is great for droughts or dry years. Here are a few water preservation tips:
Leveling: Uneven fields are much more difficult to irrigate, as you’ll face high or low spots. A great solution is to laser level, significantly decreasing the time it takes to irrigate. However, be wary of steeper grades as it will be much harder to predict water flow.
Higher Flow: In addition, consider putting higher flow into smaller checks. Some people cut back on acreage, and plant their crops closest to the valves. Whatever you can do to get a higher flow will be well worth it.
Pack Soil: Also, a great tip for water preservation is to pack the surface soil. Make sure you do this before pre-irrigating and again after planting for the best results. Most commonly, the first irrigations are the slowest and packing the soil will speed them up. On the other hand, too much compaction slows irrigation and leads to poor root growth.
Weeds: Having weeds present in your fields will slow movement down. Plus, they will use the water that is supposed to be feeding your plants. Take care to remove any weeds quickly when spotted.
Unfortunately, the symptoms of water stress in corn don’t typically appear until it may be too late. The most well-known symptoms are wilting and turning blue. Normally, when plants experience slight water stress it closes it’s stomata as a line of defense. The stomata are like little pores on the leaves that absorb carbon dioxide, which helps with photosynthesis. But, it also happens to be an area where water escapes easily. Therefore, when the stomata close it means no carbon dioxide, no photosynthesis, and no growth.