Rural Conservation

RURAL CONSERVATION

Connecting Iowa's agricultural and natural resource needs.

Our Polk County farmers and landowners in the rural areas play a key role in preserving our natural resources. Whether you own a small residential acreage or make a living farming there are plenty of ways that you can help the earth, while helping yourself, too.

Rural areas, like residential acreages and crop fields, make up a little over half of the landscape in Polk County. This has drastically changed from the past landscape of prairie and woodlands.

Because of this, most of the rainfall does not infiltrate into the ground and instead quickly runs off into nearby water bodies.

Fertilizers, chemicals, and other pollutants are often carried with this water causing degraded water quality. In some cases, exposed soil is also carried with the water leading to erosion.

Current management practices are also leading to decreased amounts of organic matter, causing less productive soils.

There are many conservation practices that can help solve some of these issues. Farmers and landowners are currently working with one another as well as local agencies to try and implement these solutions.

THE PROBLEM:

Prior to the settlement of Iowa, the state was almost completely covered by tallgrass prairie. These prairies maintained soils with high organic matter content and a lot of pore space. This is what created most of the dark, rich topsoil seen on Iowa’s landscape today! All of the pore spaces also allowed the landscape to absorb rainfall while shedding little runoff. Most rainfall infiltrated the soil, where it recharged groundwater flow.

Iowa’s soil resources have been significantly altered by tillage based agricultural practices as well as land development in urban areas. Because of this, less rainfall infiltrates into the landscape leading to more surface runoff.

Along with prairie, many wetlands also covered Iowa’s landscape. These wetlands allowed water to pool in areas and provided essential wildlife habitat. Unfortunately, most of these areas have now been drained for farming or development purposes.

Because of the vast changes in the Iowa, many problems that are negatively affecting our environment have become evident. Below you will learn about some of the problems seen in the rural areas of the state. To learn about our urban problems, visit the “urban” page.

Erosion

Erosion of topsoil has been a prominent environmental concern since the dust bowl of the 1930s. During this time, so much degradation was happing on the landscape due to intense tillage practices and exposed soil that the wind picked up and carried topsoil creating large dust storms. Following the dust bowl, the government and farmers realized how important it was to start putting measures in to place to protect our essential topsoil and not have a repeat of the dust bowl. Even though we have made positive advances to combat erosion since then, soil loss is still occurring across Iowa.

Movement of topsoil, or erosion, can happen in two main ways; water and wind. Wind erosion occurs when strong winds pick up small soil particles and carries them away from their current location. This is especially evident during the winter months when accumulated snow is black from the eroding topsoil.

Even though wind does play a significant role in loss of topsoil, most of erosion in Iowa occurs by water. When it rains, soil is carried from fields and open lots and discharged into streams, rivers, and lakes. Sometimes, the flow of the water across the landscape is concentrated along one path causing large gullies and drop offs. These areas can be hazardous to machinery if not taken care of. Water erosion also causes the loss of banks along streams and rivers. During storm events, a surge of water rushes across the landscape and through the stream and river channels. This happens at such a quick and sudden rate that unstable soil is picked up and carried with the water. In some cases, 10 feet of stream bank can be lost in one storm event!

Water Quality

There are two main sources of water quality pollutants in Iowa; nonpoint and point. Point sources can be traced back to a single location of pollution and are often easy to fix. Non-point sources are harder to treat because they originate from multiple points on the landscape. In the rural areas, most of the pollutants come from nonpoint sources such as stormwater runoff from farm fields and lawns as well as discharge from tile lines and septic tanks.

Due to the vast change in Iowa’s landscape, rain water is not able to infiltrate into the soil like it used to. This, paired with our increased heavy rains, leads to more water running quickly across the surface picking up pollutants and sediment along the way. This water is then discharged directly into our rivers, lakes, and streams.

Increased nitrogen and phosphorus in our surface waters is having a negative impact on our environment. While these nutrients are essential to many natural processes, too many can be detrimental. The negative affects are being seen on both a local and nationwide scale. Harmful algal blooms leading to fish kills and beach closures are a common site throughout the Iowa summer and increased nitrogen in our drinking water is causing health concerns. On a national scale, Iowa’s excess nutrients are contributing to the creation of a large hypoxic or “dead zone” in the Gulf of Mexico where nothing can live for portions of the year.

Along with excess nutrients, excess sediment from stormwater runoff is also having a negative impact on our water sources. Too much sediment can lead to declining aquatic species habitat by causing low visibility, decreased light penetration, and increased sediment deposition in our lakes and ponds. Harmful pollutants such as metals and bacteria can also attach to sediment particles, increasing their transport in our water systems.

Soil Health

Degradation of the soil that is still in place on the landscape is also a problem seen in our rural areas. This degradation is mainly due to current farming practices and changes in the landscape. Healthy soils are needed in order to continue to produce crops. When the quality of these soils is degraded, more fertilizers are required to maintain crop productivity. This increases farmers expenses and the risk of excess nutrients in our waterways.

Most of these problems seen today are directly related to human sources. Luckily, there are many ways we can all work to fix these issues and improve our environment. Visit the “solutions” section to learn what you can do.

THE SOLUTION:

In most cases, the problems seen throughout the rural landscape can be solved with management changes and conservation practices. The Polk SWCD works hand-in-hand with landowners and farmers to work to make these changes in order to solve erosion, water quality, and soil health problems. Some of these solutions are “quick fixes” and others are complete changes to the way someone manages the land. Below we have highlighted some common solutions to our environmental problems.

Yearly Management Changes

These solutions involve changing the way producers and landowners manage their property or farm year-to-year.

Cover Crops – Turnips, cereal rye, and snow peas are all types of cover crops used across farm fields in Iowa. Cover crops are seeded after the cash crop (corn and soybeans) are harvested, covering the soil until the next years planting season. They have multiple benefits including reduced soil erosion, increased organic matter, lessened nutrient leaching, and decreased compaction. Erosion, Water Quality, Soil Health.

Reduced Tillage – Tilling a farm field can destroy the soil structure, creating compaction and reducing microbial activity. In many cases, tillage is not necessary to produce a profitable cash crop. By reducing tillage, or removing tillage all together (no till), the soil structure will recover leading to greater infiltration and increased soil health. Not tilling also decreases the input costs that are associated with farming, saving the producer some money!

Nutrient Management – Managing the source, amount, and timing of nutrients is a great management change that can decrease the chance of excess nutrients reaching our water sources. Determining the proper amount of nutrients to apply can also save the producer from applying too much, saving them money! Water Quality

Conservation Crop Rotation – Conservation crop rotation involves growing multiple crops in succession on the same field. Most of the time, one soil conserving crop such as hay is inserted into a normal rotation of corn and beans. This management practice has the potential to break up the disease and pest cycles leading to less use of chemicals. The third crop also decreases erosion potential and adds biological diversity to the soil. Erosion, water quality, soil health.

Prescribed Grazing – Prescribed grazing (or rotational grazing) is the management of the harvest of perennial vegetation using grazing animals such as cattle. This is a great way to avoid over grazing and has potential to extend the grazing time of pastures. Preventing the vegetation from becoming overgrazed also provides more ground cover reducing the chance of erosion and helping water quality. Erosion, water quality

Permanent Landscape Changes

These conservation practices are “one-time” fixes and usually don’t require changes to the land management. In many cases, these are structures or plantings that are placed on the ground and kept there indefinitely requiring only occasional maintenance.

Terraces – Terraces are earthen embankments placed across the slope of a hillside. They intercept surface runoff and reduce erosion. Erosion, Water Quality

Water and Sediment Control Basins – A Water and Sediment Control Basin (WASCOBS) is an embankment of soil placed across (perpendicular to) an area of concentrated water flow. This embankment intercepts the water flow, slowing it down and allowing the sediment and pollutants to be removed. Erosion, Water Quality

Grasses Waterways – Grassed waterways are installed along areas of concentrated water flow and are designed to convey water off the field during rain events. They are seeded down to grass that holds the soil in place, preventing erosion. Erosion, Water Quality

Filter Strips – Filter strips are planted between fields and surface waters (streams, lakes, rivers…etc) to protect water quality. The vegetation the strip is planted to (usually grasses or prairie plants) slows down the surface water as it flows from the adjacent fields, settling out nutrients and sediment before it reaches the water sources. Water Quality, Erosion

Contour Buffer Strips – Contour buffer strips are narrow strips of perennial vegetation planted along the slopes of hillsides between wider strips of crop. They are placed strategically to slow down surface waters and prevent erosion. Prairie STRIPS are contour buffers strips that are planted to prairie plants and can have a secondary benefit to pollinators! Erosion, Water Quality.

Saturated Buffer – Saturated buffers are specifically designed to remove nitrates from farm field tiles. Normally, these tiles run underneath a filter strip and dump directly into a river or stream, dumping nitrogen directly into the stream. A water control structure box is placed on this tile line directing water out laterally through new perforated along the filter strip. The water then seeps through the filter strip before it enters the stream or river. This allows for the nitrogen to be removed from the water by the plants and soils. Once installed, the saturated buffer is barely visible on the landscape. Water Quality

Bioreactor – Bioreactors are another practice that is designed to improve water quality, specifically removing nitrates. A large pit is dug adjacent to a tile line and filled with wood chips. Tile water is then directed from the original tile into the bioreactor and allowed to flow through the woodchips before exiting back into the tile. The microbes in the woodchips remove the nitrate from the water before it is discharged into the stream or river. Water Quality

Wetlands – There are two main tops of wetlands in Iowa; constructed and restored. Constructed wetlands usually involve placing an embankment across an area of high volume of concentrated flow. The water is then slowed down and stored in the wetland allowing the pollutants to settle out. Restored wetlands involve digging out an old wetland, usually identified by an area that is consistently wet, a few feet and allowing water to intermittently pool. Oxbow restorations are another from of wetlands that can even be used as livestock watering areas in pastures! Water Quality, Erosion

Wind Break – Windbreaks can be planted on residential properties or along field borders. They usually consist of multiple sizes and types of trees and shrubs designed to slow down the wind. This reduces the potential of wind erosion, cuts down on energy bills by providing shade, and provides wildlife habitat. Some windbreaks can even be planted with berry producing shrubs! Erosion

Conservation Cover – Planting areas of the landscape to prairie grasses or other perennial vegetation is the implementation of conservation cover. Conservation cover is suited for areas of a farm field that shouldn’t be farmed such as steep hillsides, wet areas, or portions with poor soils. This is usually done through the Conservation Reserve Program (CRP) and has the potential to receive a yearly incentive payment! Erosion, Water Quality, Soil Health

As you can see, many of the solutions to our rural problems have multiple environmental benefits. Along with water quality and soil health, many of them provide essential wildlife habitat that is missing from our landscape. Recreational benefits also arise when we talk about wetlands and any of the practices that improve the quality of our lakes, rivers, and streams. Contact us today if you are interested in implementing any of these solutions on your property.