Irrigated Pasture Management: Unlocking the Full Value of Your Irrigated Pasture
Irrigation for pastures is an incredible resource capable of yielding an amazing amount of dry matter. However, proper management is key in achieving high performance on irrigated pastures.
Three Key Areas to Focus on
- Soil health is the foundation for everything else and without it, your pasture can’t reach its full potential. The good news is that proper grazing management combined with proper irrigation can regenerate a pasture’s soil health fairly rapidly. The key principle to keep in mind is that a healthy pasture is the result of healthy soil, and there is an entire soil food web beneath our feet. Periodically testing for Soil Organic Matter (SOM) will help you know if your pasture’s microbial health is trending in the right direction. Generally, a desirable SOM is above 4 or 5, however, most soils across the U.S. have been depleted and are rarely above SOM 2.
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Irrigation management is probably one of the biggest areas of opportunity to improve an irrigated pasture because it is often the most overlooked. A good practice is to fill the soil water table as close to Field Capacity (FC) as possible early in the season and irrigate to maintain 50% Available Water (AW). A good way to achieve this is to irrigate according to your pasture’s Evapotranspiration (ET) rate plus an additional amount related to your irrigation system’s efficiency (ET plus the amount lost in the system). If using a center pivot, frequent light irrigations are usually better than slow heavy watering. This helps avoid runoff, standing water, and waterlogging. The irrigation frequency and duration throughout the year will need to be adjusted to optimize production. Generally, this means you should plan to irrigate with at least one inch per week during the spring and fall, and up to two inches or more during the dead of summer if the goal is to keep the pastures productive during the summer months.
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Grazing management is the other area of opportunity that most operations can improve. A good rotational grazing system is the best way to utilize irrigated pasture if the goal is to maximize productivity while improving soil health. The key principle is to never graze below four inches, and grazing is never started unless the grass has fully recovered, which means under most situations the grass is at least eight to 10 inches tall at the start of grazing. The best way to achieve this is through a well-designed rotational grazing program using the principles of adaptive multi-paddock grazing (AMP) or Management-intensive Grazing (MiG).
A key to successful grazing is consistently monitoring to gauge if changes and refinements need to be made. The first thing to assess is how the grass is responding to grazing. Gauge if it is regrowing quickly or if after grazing it seems dull and lifeless indicating the grass is overly stressed. Second, if your pasture has patches that are both overgrazed and under-grazed, that could be an indication that your stock density isn’t matching your forage availability. This is often a result of too little livestock on too few acres for too long. Third, if there are areas where undesirable weeds and grasses are in your pasture, changes need to be made. Lastly, if there are spots of bare ground showing up in your pasture, this could tell you that there are severe systemic challenges, usually related to the first three, that need to be addressed.
If any of these conditions are present in your pasture, you have an opportunity to make some changes that will greatly improve the productivity of your pasture. Usually, when we see any of these conditions there is an opportunity to increase grazing yields by at least 30% fairly easily by implementing some simple changes:
Putting it Into Practice
1. Implement a rotational grazing program that allows grass to fully recover before it is re-grazed.
2. Confine grazing to a smaller area for a shorter period. This allows a higher percentage of the pasture to be recovering at any given time,
3. Provide a longer recovery period after grazing.
4. Consider if the grasses you are grazing are capable of providing the quality and quantity of forage you desire.
Lastly, one of the best things you can do for your grazing management is to utilize the best forage genetics. Remember, not all grasses are the same, and the modern genetics found in Barenbrug grasses are specifically designed to provide high quality and high yield for irrigated pasture.
