By Kable Thurlow and Kim Cassida
Often you hear someone say that they have a pasture that is worn out, but what does that really mean? In this article, we hope to shed some light on what that means and provide suggestions beef producers can use on their farm to determine if a pasture is really worn out, and how grazing can be used to improve the situation. The main focus of this article will be utilizing grazing management as a pasture renovation tool for those worn out or unproductive pastures.
In most cases, a pasture is labeled worn out because the yield has dropped below desired levels. There can be many reasons for that and multiple options to resolve those issues. Good record keeping will help you notice when the yields have dropped. Knowing how many animal units and days you are grazing will allow for comparison to previous years. This is where a well thought out grazing plan comes in handy.
Assessment
The first step in dealing with worn out pastures is to determine if you can renovate the existing stand or whether a full replacement may be better. Below is a list of questions and tools to help gain a better understanding of the current situation that exists in a hayfield or pasture you are considering making changes to.
- Is the stand mostly desirable forage species, but not performing up to expectations?
- Is the stand mostly weeds?
- Is the stand near the end of its planned lifespan?
- Can I afford a year of reduced productivity during establishment of a new stand?
If you answered yes to question one, this favors renovation. If you answered yes to questions 2-4 then your pasture might be a good candidate for a full replacement. There are several tools available online that will be helpful when making this determination. The USDA Natural Resources Conservation Service (NRCS) Guide to Pasture Condition Scoring provides a systematic scoring system for evaluation and comparison of individual pastures and will help you determine which pastures are in most need of improvement. The NRCS Web Soil Survey provides information on the productive potential of the soil types on your farm, or you can connect directly with the NRCS by visiting the USDA Service Center covering your county. The NRCS also has a website that explains how to get started with the Web Soil Survey and you can access that by clicking here.
Identify the causes for the inadequate production and make the needed changes to avoid repeating mistakes and heading right back to a place of poor results. Then, decide how much you can afford to spend on improvements. Prioritize which pastures to renovate or replace first by determining the best return on your investment. Those areas that can have the highest gain in yield with the least amount of investment are the places to start.
Consider the time frame for reaching the improvement goals that you set. Ideally you would do the assessment and planning 6-12 months ahead of when you want to start implementing the changes. You will need to decide whether you can afford slow gradual progress, or whether you need a faster turnaround time. Keep in mind that faster returns will likely require more upfront cash.
Improve pasture management
It is entirely possible that you can renovate your pastures simply by changing or improving the management of the existing stand. These types of changes will not provide instant results, but if you have some flexibility to wait one or two years, the payback can be significant. Management changes such as implementing a managed rotational grazing system or improving soils using bale grazing allow continued use of the field while these changes are being implemented, whereas brand new seedings mean the pastures will produce little forage in the seeding year and the livestock will need to be fed elsewhere for two months or longer Simply splitting a pasture into two sections is a start; that one change will allow 50% of your pastures to be in the recovery/rest mode.
Managed grazing
When a forage plant is grazed, a harvest occurs. Perennial forages rely on two things to support regrowth after harvest. The first is nutrients that are stored in the crowns or rhizomes of legumes and in the lower part of stems for grasses. The second is the amount of green leaf that is left to conduct photosynthesis after a grazing event (harvest) has taken place, referred to as the post-grazing residual forage. Think of the stored nutrients as a bank account that is replenished by the photosynthetic activity. For the bank account to be adequately replenished, we must allow enough photosynthetic activity to take place before leaves are eaten again. The more green leaf that is left after the grazing event, the faster the plants can recover because the surviving leaves continue to make the carbohydrates that are needed for regrowth and the plant does not have to dip into the savings account. Desirable plants disappear under continuous stocking where cattle have access to all the grazing acres because they are the ones favored by the cattle and get eaten so often that the bank accounts are depleted. Just like your bank account, if you keep withdrawing and not putting anything back, eventually the balance will be zero. A zero in this case means no nutrients for the plants and the loss of that plant. Do that enough times and most of the desirable plants will be gone. This leads to a dominance of undesirable plants (i.e. weeds) in the pasture.
Soil Improvement
Another item to consider is improving the soil through soil fertility; and the best place to start is with a soil test to check for soil pH and the availability of the major nutrients phosphorus (P) and potassium (K). Checking soil organic matter (SOM) can also provide a benchmark for measuring the improvement of soil health. Greater SOM generally indicates a healthier and more productive soil. Soil fertility does not just pertain to chemical fertilizers. Remember that all feedstuffs brought onto the farm contribute to soil fertility if the manure is deposited on the pastures, because growing, pregnant or lactating livestock excrete approximately 50% of N, and 85% of P and K that is eaten. Winter bale grazing is also a method that can be used to bring in fertility if you purchased the hay. If you grow your own hay, bale grazing can be used to move soil nutrients from highly fertile areas where the hay is harvested to less fertile areas where bales are fed.
A little bit of effort in planning, soil improvement and grazing (harvest) management can go a long way toward improving the forage resources on your farm. For a deeper dive into pasture and hay field renovations, get a copy of the MSU Extension Bulletin E-3310 Low-Cost Renovation Practices for Perennial Pastures and Hayland in Michigan. For more information, contact Michigan State University Extension forage specialist Kim Cassida at cassida@msu.edu or beef and grazing educator Kable Thurlow at thurlowk@msu.edu.
Source : msu.edu