Learning to Love Litter in Your Pastures

Learning to Love Litter in Your Pastures

 

Spring is here after a long, hard Saskatchewan winter and before we know it, creeks will be running and grass will be greening up! Spring is a great time to start assessing the health of your pastures and rangelands. If you have ever worked with an agrologist or range land technician they may have used the term “litter cover” when evaluating pasture and range condition. But what exactly is litter? It’s not that random plastic bottle in a ditch but rather the dead plant material from the previous grazing seasons and it can be standing or lying and slightly decomposed. Litter can be an important indicator of pasture health and previous management.

Leaving an appropriate amount of litter for the next year can help protect the soil surface, increase moisture availability and improve nutrient cycling when litter breaks down into organic matter. Retaining adequate amounts of litter can even improve a pasture’s resiliency in the event of drought.

The amount of litter in an area is closely related to overall plant growth and the ability for the soil to retain water. It acts as a physical barrier from heat and helps to keep the soil temperature cooler, reducing evaporation while increasing water filtration. When litter amounts are reduced due to overgrazing more soil surface is exposed. This makes it more vulnerable to erosion by wind and water runoff. Litter protects the soil from the wind, and slows the flow of water over the landscape, keeping the nutrient rich topsoil in place.

In addition to protecting existing topsoil, litter also helps to build the topsoil.  Plant material decays and is broken down by microbes, and the nutrients are returned to the soil. This builds the organic layer of the soil. As organic matter increases, so does water infiltration and the ability of the soil to hold moisture. This can become especially important in times of drought, when every drop of moisture counts.

Overall, the effect of litter can have major impacts on pasture productivity, and the reliability of your forage base, particularly when rainfall is limited. When there is enough litter, less water is lost through evaporation or runoff, and the soil is able to hold more moisture.  Managing for a healthy level of litter can be an important tool for “drought proofing” your ranch, and is ideally done before droughts occur. It is much easier to accumulate litter when growing conditions are good, rather than when plants are stressed and availability has started to decline. If litter levels are lost due to heavy grazing, drought or fire then it may take years to build it back up to healthy levels and will need to be monitored more closely. Appropriate stocking rates and periods of rest after grazing are important components of creating a sustainable grass management strategy that ensures adequate litter is left on the pasture.

Measuring litter can be a simple but effective tool to determine if current stocking rates or rest periods are appropriate for your pasture. You may need to get a little down and dirty for this! The first step is to measure out a plot that is 0.25 m2 and begin hand raking all plant debris within that area into a pile. Be sure to leave any new growth from this year behind. Once you have the litter collected, place it all in your hand and you can cross reference it to the charts below. Please note that part of this is subjective, so there is always going to be some variation from person to person but this estimate will give you a general idea of whether or not your litter levels are appropriate for your pasture.

 

 

The expected, or healthy, amount of litter varies from site to site. Soil type/ecosite, and soil zone/ecoregion impact the potential of the site to produce litter. For example, what is deemed healthy cover in a thin ecosite is unhealthy in a loam ecosite. It is important to compare your litter amounts to the appropriate category (If you have a Loam ecosite, and are in the Dry Mixed Grasslands, make sure that you’re comparing your litter levels to the Loam ecosite in the Dry Mixed Grasslands). Each ecosite has a different capacity to produce forage and litter, so knowing what your site is capable of is a good starting place when evaluating your litter.

Working with a professional agrologist or range technician can help to explain what the amount of litter in your native grasslands means for your grazing patterns moving forward into the months ahead. They can also help put together a management strategy to maximize the overall health of your grasslands.

 

 

Authors: Marika Sherman and Mindy Hockley