Pasturing Oxbows: Optimizing Benefits to the Farm, Water and Wildlife

Jan 05, 2024

By Elizabeth Ripley

Iowa Learning Farms, in partnership with the Iowa Nutrient Research Center and the Conservation Learning Group, is hosting a free virtual field day on pasturing oxbows, Thursday, Jan. 18, at 1 p.m. Central time. Join for a live discussion with Sara McMillan, professor of agricultural and biosystems engineering at Iowa State University, and Karen Wilke, associate director of Freshwater at the Nature Conservancy.

Iowa Learning Farms is a conservation program with Iowa State University Extension and Outreach.

The virtual field day will explore an oxbow in Kossuth County, including how it naturally formed and the restoration process to date. Located within an actively used pasture, the restoration process took into consideration factors like livestock safely accessing the water. These pastured oxbows help improve overall forage production by providing a place for water to collect and reduce flooding within the pasture. Additionally, by providing a water source out of the stream, these systems improve water quality through the reduction of direct contributions of bacteria from livestock in the stream and the maintenance of streambanks that help retain sediment and phosphorus.

“When we are designing these pastured oxbows, we want to be sure that we are doing a seeding plan that will be successful for livestock and the wetland,” noted Wilke. “We’re looking for something quick to establish and stabilize those banks and that is hardy as well. When possible, we also use natives as they can be as nutritious and palatable to livestock as other types of pasture grasses.”

Virtual field day access instructions

To participate in the live virtual field day at 1 p.m. CT on Jan. 18,

Click this URL, https://iastate.zoom.us/j/98608335082, or visit https://www.iowalearningfarms.org/events-1.
Or, join from a dial-in phone line. Dial 309-205-3325 or 312-626-6799; meeting ID, 986 0833 5082.

The field day will be recorded and archived on the ILF website so that it can be watched at any time. The archive will be available at https://www.iowalearningfarms.org/virtual-field-day-archive.

Participants may be eligible for a Certified Crop Adviser board-approved continuing education unit. Information about how to apply to receive the CEU (if approved) will be provided at the end of the event.

About Iowa Learning Farms

Established in 2004, Iowa Learning Farms is building a Culture of Conservation by encouraging adoption of conservation practices. Farmers, researchers and ILF team members are working together to identify and implement the best management practices that improve water quality and soil health while remaining profitable. Partners of Iowa Learning Farms include the Iowa Department of Agriculture and Land Stewardship, Iowa State University Extension and Outreach, Leopold Center for Sustainable Agriculture, USDA Natural Resources Conservation Service, and Iowa Department of Natural Resources (USEPA section 319) and GROWMARK Inc.

Source : iastate.edu

Video: Turning Plant Defense Into a Management Strategy

Turning Plant Defense Into a Management Strategy

Understanding how a plant responds to stress is one thing.

Using that knowledge to make better management decisions is another.

Systemic acquired resistance, or SAR, is the plant's more direct defense response. When stress or infection occurs, the plant begins signaling throughout its system and preparing defensive compounds.

But if we know that response exists, can we help prepare the plant before the stress arrives?

The answer starts with understanding what triggers the response and what the plant needs to carry it out.

The Trigger and the Fuel

Salicylic acid plays an important role in triggering the SAR pathway.

Think of it as turning the truck on.

The engine may be running, but it still needs fuel to do the work.

In this case, manganese plays an important role in supporting the enzyme systems involved in the plant's defensive response.

This makes manganese status an important part of the conversation. Whether a producer is using tissue testing, sap analysis, or simply scouting for visible deficiency symptoms, the goal is to make sure the plant has adequate manganese available.

Manganese is required in relatively small amounts, but that does not make its role small.

If the plant receives a signal to defend itself but lacks the nutrition needed to support that response, it may struggle to carry out the process efficiently.

The trigger matters.

The fuel matters too.

Prepare Before the Stress Arrives

The best time to think about stress management is before the plant is overwhelmed.

Once a crop is already struggling, management can quickly turn into a game of catch-up.

This is similar to nitrogen management. Once a plant becomes severely deficient, correcting the problem does not necessarily erase the time and yield potential already lost.

Plant defense can work the same way.

Low-rate, targeted approaches designed to support the SAR pathway may fit best ahead of an expected stress event rather than after significant damage has already occurred.

That requires producers to think about predictable stress.

We may not know exactly what the weather will do tomorrow, but we generally know summer heat is coming. We know certain field conditions increase disease pressure. We know a herbicide application can temporarily stress a crop as the plant processes the chemistry.

Even a properly timed and labeled herbicide application can create a temporary response in the plant.

That does not mean the herbicide is bad.

Weeds can create significantly more yield loss than the temporary stress caused by controlling them.

The question is not whether we should eliminate every stressor.

The question is whether we can better prepare the plant to manage necessary and predictable stress.

Not All Stress Is Bad

Stress is a normal part of plant growth.

A perfectly stress-free environment does not exist in the field.

In fact, some stress is necessary for normal plant development. A plant responds to wind, temperature, moisture, sunlight, and countless other environmental signals throughout the season.

The environment is stress.

The plant's job is to manage it.

Problems begin when the stress load becomes greater than the plant's ability to respond.

Extreme heat, drought, high salt concentrations, disease pressure, and even certain management practices can add to that load.

This is where understanding SAR becomes useful.

Instead of waiting until the plant is visibly struggling, producers can begin identifying periods when stress is likely and make management decisions around those windows.

ISR Starts With the Soil

While SAR is a more direct defense response, induced systemic resistance, or ISR, brings the conversation back to soil health.

The longevity of a farm is closely connected to the health of its soil.

Carbon plays a major role because it supports biological life within the soil. Bacteria, fungi, and other organisms interact with plant roots and influence how the plant grows, accesses nutrients, and prepares for stress.

This is why soil health cannot be reduced to one product or one application.

It is a system.

Keeping living plants in the field longer can support biological activity. Cover crops may fit some operations. Better water management can improve soil conditions.