Providing pasture recovery | TSLN.com

Providing pasture recovery

Roger Gates

I’ve agreed with a number of folks I’ve visited with recently that, “GREEN is a very restful color!” Compared with the last week of April, it’s been a delight to travel western South Dakota and be greeted with stock dams full of water and pastures full of green vegetation. Even the national drought monitor map indicates South Dakota is free of drought conditions, with the exception “abnormally dry” designation in the extreme southwest corner of the state. It’s the first time in a long time that has been true.

Unfortunately, drought doesn’t recognize state lines and northwest Nebraska and northwest North Dakota are not free of drought conditions. While many can enjoy the relief provided by May and June precipitation, it’s prudent to remember that dry conditions may reemerge at any time.

With adequate to surplus moisture come some management opportunities and challenges as important as managing through precipitation deficits. It is premature to declare the drought “broken,” but there are short term management adjustments that should be carefully considered. Perhaps the most detrimental approach would be to ignore the accumulated stress that pasture and rangeland vegetation has endured for the past six to eight years.

A certain consequence of drought is a reduction in stand density of pasture plants. One result of fewer plants having access to abundant soil moisture is that growth of individual plants increases. Taller plant growth should not be misinterpreted as greater total forage availability. If pasture conditions and stocking rate decisions are based on a “windshield survey,” that primarily reflects plant height, overstocking and overuse may be unpleasant and harmful outcomes.

Rather than exploiting current growth by increasing stocking rates or pushing pastures harder, current growing conditions provide pasture plants the opportunity to begin to recover, to increase stand density and overall vigor. Conservative stocking now will pay dividends in pasture health and productivity in the future.

Another certain outcome following an extended drought is an increase in bare ground. Increased bare ground and ample moisture will certainly provide openings for weed development. A flush of annual plants is a natural protective mechanism and with a few exceptions, such as cheatgrass, is not troublesome if perennial plants are managed so that they can quickly recover and out compete weedy annuals. However, the same open spaces and favorable moisture may also lead to germination and establishment of very undesirable perennial weeds. The worst of these species are classified as “invasive” and pasture vegetation weakened and opened by prolonged drought is subject to invasion.

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While poor pasture management, particularly overgrazing, makes weed invasion a high risk, even the best managed pastures are not immune to development of weed infestations. One consequence of this spring’s heavy rainfall was flooding of low areas adjacent to streams and rivers. Along with the welcome moisture, that overflow likely contained an ample supply of seeds, some of which may be potential new infestations. While it’s always important to observe pastures to identify weed problems, during this growing season, it will be particularly important to watch overflow areas to detect weed development if it occurs.

Three rather obvious questions should be answered in managing to minimize pasture weed problems: “what is it?” “where it” and “why is it there?”

Proper identification is critical to weed management. This becomes particularly important and challenging as areas are examined for new weed development. Make the effort to learn how to identify weeds at the seedling stage. Perennial weeds are much easier to control when they are first developing. Established weeds, with strong root systems, are much more difficult to control.

Making the effort to map weed infestations will provide a valuable management tool. Again a “windshield survey” approach to identifying weed problems is insufficient for careful weed management. When a weed patch is prominent enough to be seen from the pickup seat, it is probably already well established and more difficult and much more expensive to control. Most weeds are best controlled when they are growing rapidly, often in late spring or early summer. If weeds are detected at other times of the year, recording the location on a map, so that it can be easily relocated may be much more effective than attempting immediate control measures. In addition, few weeds can be controlled with a single treatment. An accurate map makes ongoing assessment of control measures possible. Without a map and a plan, control efforts will start over again and again with no opportunity to improve on ineffective procedures.

Finally, understanding why a weedy plant emerges will be essential to ongoing management. Is it appearing in response to overgrazing, long-term drought, and/or recent flooding? Most weeds are opportunistic, “invading” an opening in the vegetation. An infestation resulting from weed seeds introduced by flooding into a pasture stand weakened by ongoing drought may not represent “mismanagement” although overgrazing could make the problem worse. In this case, best management is simply to identify and control the infestation before it expands.

On the other hand, infestations that result from prolonged overgrazing may be reduced by a control treatment in the short term. However, a long term solution must include correcting the overgrazing.

Adequate weed control requires an ongoing effort of observation, identification, treatment and follow-up. Don’t expect success from a “one-shot” approach. A number of valuable herbicides are available for pasture use. Their use should be integrated with other procedures such as biological or cultural control methods and especially proper management of grazing. Check in with advisors such a the Extension Service for help with weed identification and appropriate control measures.

I’ve agreed with a number of folks I’ve visited with recently that, “GREEN is a very restful color!” Compared with the last week of April, it’s been a delight to travel western South Dakota and be greeted with stock dams full of water and pastures full of green vegetation. Even the national drought monitor map indicates South Dakota is free of drought conditions, with the exception “abnormally dry” designation in the extreme southwest corner of the state. It’s the first time in a long time that has been true.

Unfortunately, drought doesn’t recognize state lines and northwest Nebraska and northwest North Dakota are not free of drought conditions. While many can enjoy the relief provided by May and June precipitation, it’s prudent to remember that dry conditions may reemerge at any time.

With adequate to surplus moisture come some management opportunities and challenges as important as managing through precipitation deficits. It is premature to declare the drought “broken,” but there are short term management adjustments that should be carefully considered. Perhaps the most detrimental approach would be to ignore the accumulated stress that pasture and rangeland vegetation has endured for the past six to eight years.

A certain consequence of drought is a reduction in stand density of pasture plants. One result of fewer plants having access to abundant soil moisture is that growth of individual plants increases. Taller plant growth should not be misinterpreted as greater total forage availability. If pasture conditions and stocking rate decisions are based on a “windshield survey,” that primarily reflects plant height, overstocking and overuse may be unpleasant and harmful outcomes.

Rather than exploiting current growth by increasing stocking rates or pushing pastures harder, current growing conditions provide pasture plants the opportunity to begin to recover, to increase stand density and overall vigor. Conservative stocking now will pay dividends in pasture health and productivity in the future.

Another certain outcome following an extended drought is an increase in bare ground. Increased bare ground and ample moisture will certainly provide openings for weed development. A flush of annual plants is a natural protective mechanism and with a few exceptions, such as cheatgrass, is not troublesome if perennial plants are managed so that they can quickly recover and out compete weedy annuals. However, the same open spaces and favorable moisture may also lead to germination and establishment of very undesirable perennial weeds. The worst of these species are classified as “invasive” and pasture vegetation weakened and opened by prolonged drought is subject to invasion.

While poor pasture management, particularly overgrazing, makes weed invasion a high risk, even the best managed pastures are not immune to development of weed infestations. One consequence of this spring’s heavy rainfall was flooding of low areas adjacent to streams and rivers. Along with the welcome moisture, that overflow likely contained an ample supply of seeds, some of which may be potential new infestations. While it’s always important to observe pastures to identify weed problems, during this growing season, it will be particularly important to watch overflow areas to detect weed development if it occurs.

Three rather obvious questions should be answered in managing to minimize pasture weed problems: “what is it?” “where it” and “why is it there?”

Proper identification is critical to weed management. This becomes particularly important and challenging as areas are examined for new weed development. Make the effort to learn how to identify weeds at the seedling stage. Perennial weeds are much easier to control when they are first developing. Established weeds, with strong root systems, are much more difficult to control.

Making the effort to map weed infestations will provide a valuable management tool. Again a “windshield survey” approach to identifying weed problems is insufficient for careful weed management. When a weed patch is prominent enough to be seen from the pickup seat, it is probably already well established and more difficult and much more expensive to control. Most weeds are best controlled when they are growing rapidly, often in late spring or early summer. If weeds are detected at other times of the year, recording the location on a map, so that it can be easily relocated may be much more effective than attempting immediate control measures. In addition, few weeds can be controlled with a single treatment. An accurate map makes ongoing assessment of control measures possible. Without a map and a plan, control efforts will start over again and again with no opportunity to improve on ineffective procedures.

Finally, understanding why a weedy plant emerges will be essential to ongoing management. Is it appearing in response to overgrazing, long-term drought, and/or recent flooding? Most weeds are opportunistic, “invading” an opening in the vegetation. An infestation resulting from weed seeds introduced by flooding into a pasture stand weakened by ongoing drought may not represent “mismanagement” although overgrazing could make the problem worse. In this case, best management is simply to identify and control the infestation before it expands.

On the other hand, infestations that result from prolonged overgrazing may be reduced by a control treatment in the short term. However, a long term solution must include correcting the overgrazing.

Adequate weed control requires an ongoing effort of observation, identification, treatment and follow-up. Don’t expect success from a “one-shot” approach. A number of valuable herbicides are available for pasture use. Their use should be integrated with other procedures such as biological or cultural control methods and especially proper management of grazing. Check in with advisors such a the Extension Service for help with weed identification and appropriate control measures.