How to estimate grass stock (2024)

How do I know how much roughage I actually have in my pasture? What should my inventory percentage be? How do I assess my capacity?

While registering a pasture inventory is quick and easy iGrassland map, to actually calculate the available feed stock per hectare or the carrying capacity of each of your pastures may seem a bit more complicated. Here are four ways to estimate available forage inventory, from a quick estimate to an accurate measurement.

1.How do you calculate inventory days/Acre (SDA) or animal days/Acre (ADA)

This is the grazing inventory method that has become popular by people engaged in adaptive grazing or management-intensive grazing. It's convenient and only requires your boots, eyeballs and some quick math.

• Enter the pasture and start from a square area of ​​pasture that you think can feed one animal unit (AU) per day. For reference, a standard Animal Unit (AU) is a 1,000-pound bull that eats 3% of its body weight per day. This would be 30 kg of dry matter per day. So this place will feed one animal day or one cow day.
• Measure the size of your pasture in steps. Count how many square feet your pace-off patch is. For example, 20x20 meters is 400 square meters.
• Divide to see how many cow days an acre has to get Stock Days/Acre (SDAs). An acre has 4840 square feet per acre.
• In this example, 4840 square feet / 400 square feet = 12.1 storage days/acre.

Stock Days/Acre (SDAs) or Animal Days/Acre (ADAs) is a measure of the amount of grass you have. It is an indication of the feed inventory and carrying capacity. With SDA you can calculate the correct occupancy rate for your animals. Once you train your eye, it will become easier over time to spot SDAs in your pasture.

PastureMap helps you calculate animal days/acre (ADAs)actually the grasson each pasture while keeping track of grazing data, so you can always keep track of the carrying capacity of your pastures. Over time, you will have a much more accurate picture of how many ADAs you have actually removed from your pastures.

Ready to try grass stock? Start a free trial with PastureMap to immediately calculate occupancy and carrying capacity in the field.

Read more about the next step after grazing assessment -how to use ADAs to calculate occupancy and carrying capacity.

2. Eyeball food inventory

If you just want a quick but less accurate estimate of the dry matter of your grass, then all you need is an estimate or measurement of the feed height. Once you have the average height in inches of forage in your pasture, multiply it by 200. This is an average estimate of pounds of dry matter per bushel. hectare per empty feeding height. For example, if your grass is 10 inches tall, multiply 10 x 200 to get 2000 lbs/acre of dry matter. If you want to be a little more precise, you can use the table below to make an estimate. Simply replace 200 with the appropriate number below based on the type and health of forage you have in your pasture.

3. How do you use a grazing stick to measure the pasture pile?

A pasture stick is a tool that allows you to get a more accurate assessment of the dry matter of your pasture. To use this method, you first need a grazing stick. Although the different grazing sticks may be slightly different, the process remains the same.

1. Measure the height of the grass.
2. In addition to your measurement, calculate the percentage of soil covered with roughage. This is usually grouped as coverage <75%, coverage 75%-90% and coverage >90%.
3. Look at the graph on your grazing stick and determine the number of kilos of dry matter per head. acre inches based on your cover percentage group and the type of forage growing.
4. Multiply this by the height of the feed to get pounds of dry matter per feed hectare.
5. Enter this data into PastureMap to track the health of your pasture over time.

Grazing stock estimates on grazing stakes vary by area, so contact your local NRCS for one designed for your region. Try thisclutchto find your own regional grazing stick.

4. How do you measure a very accurate grass supply?

If you want accurate measurements, you can go into the field and use a mower to harvest the forage from a square meter of land mowing just above the ground. Then weigh it and convert it to lbs/acre. If the forage is not dry, multiply the weight by 0.2, assuming the grass contains 20% dry matter. You can also choose to throw the food in the oven or microwave to dry it.

With all of these methods, the more points you sample, the more accurate your inventory will be. In uniform pastures fewer measurements are needed, but in a pasture with varied forage you may need to take five or more sample measurements to get an accurate result.

Likewise: practice makes perfect. Try all the methods and see how they compare in terms of ease and accuracy. Which one works best for you? Remember, the most important part of taking a pasture inventory is to repeat the measurement often so you can see how the productivity of your pasture changes over time.

Do you want to improve your pasture monitoring? Join PastureMap and benefit from grazing inventories to link grazing practices to forage and animal productivity.

Table ofIowa State University, universiteitsuitbreiding.

Subjects:ranchere,occupancy rate,meadows,grazing management