Sunday, November 27, 2011

Fern Road Farm - Riparian Restoration Project

Soil...

The main soil type at the Fern Road Farm is a well-drained Malabon made of clayey and loamy alluvial parent material. This soil is a fine, mixed, super active, mesic Pachic Ultic Argixeroll in the order Mollisol.  The texture classification of Malabon is 14.2% sand, 49.9% silt, 35.8% clay, and 2.55% organic matter content. It has a saturated hydraulic conductivity of 5.9 micrometers per second. A detailed report of this information, produced by the USDA, can be found by clicking here. The report has information for all of the soils in the Area of Interest from the map with details including texture components, available water capacity, and parent material names. There are some cool maps generally outlining each characteristic and charts at the end summarizing the given information.
 
Malabon Soil Series Description
The Malabon series consists of very deep well drained soils formed in mixed alluvium. Malabon soils are on stream terraces. Slopes are 0 to 3 percent. The mean annual precipitation is about 45 inches and the mean annual temperature is about 52 degrees F.

Taxonomic Class: Fine, mixed, super active, mesic Pachic Ultic Argixerolls

Typical Pedon: Malabon silty clay loam, cultivated (colors are for moist soil unless otherwise noted).

Ap--0 to 7 inches; very dark brown (10YR 2/2) silty clay loam, dark grayish brown (10YR 4/2) dry; strong very fine granular structure; hard, friable, slightly sticky and slightly plastic; many very fine roots; many irregular pores; moderately acid (pH 5.6); clear smooth boundary (6 to 11 inches thick).

AB--7 to 12 inches; dark brown (7.5YR 3/2) silty clay loam, dark grayish brown (10YR 4/2) dry; weak fine subangular blocky and strong very fine granular structure; hard, friable, moderately sticky and moderately plastic; many very fine roots; many very fine and few fine tubular pores; very dark brown (10YR 2/2) coatings on peds; slightly acid (pH 6.1); clear wavy boundary (0 to 15 inches thick.

Bt1--12 to 19 inches; dark brown (10YR 3/3) silty clay, dark grayish brown (10YR 4/2) dry; moderate medium subangular blocky and moderate very fine granular structure; hard, firm, moderately sticky and moderately plastic; common very fine roots; common fine and very fine and few medium tubular pores; many prominent very dark grayish brown (10YR 3/2) clay films on faces of peds and along pores; slightly acid (pH 6.3); clear wavy boundary (6 to 20 inches thick.

Bt2--19 to 29 inches; dark brown (10YR 3/3) silty clay, brown (10YR 5/3) dry; moderate medium and very fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common very fine roots; common very fine and few medium tubular pores; many prominent dark brown (7.5YR 3/2) clay films on faces of peds and along pores; slightly acid (pH 6.5); clear wavy boundary (8 to 20 inches thick).

BCt--29 to 42 inches; brown (10YR 4/3) silty clay loam, brown (10YR 5/3) dry; weak coarse subangular blocky structure; very hard, firm, slightly sticky and moderately plastic; common very fine roots; common fine and medium tubular pores; common prominent dark brown (7.5YR 3/2) clay films on faces of peds and along pores; neutral (pH 6.8); clear wavy boundary (0 to 20 inches thick. 
2C--42 to 60 inches; brown (10YR 4/3) clay loam, brown (10YR 4/3) dry; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; few fine tubular pores; neutral (pH 6.9). 

Below is a visual representation of our project's soil description. The colored circles correlated to the colored boxes which describe a specific soil on the farm.


How Does Soil Make this Project Work? 

Soil's major role in this particular project is providing the trees we planted with the nutrients they need to thrive. As we have learned in class, nutrient uptake by plants is accomplished by ion exchange between a plant's growing roots and the soil particles themselves. Recall this image from lecture...
Here we see the mechanism for nutrient availability consists of H+ ions from the root hairs replacing nutrient cations on the exchange complex, and therefore forcing the nutrients into the soil, where they can be assimilated by adsorptive surfaces of roots or lost to drainage. 

Other soil variables are considered when determining if a plant will thrive, such as soil aggregation, water holding capacity (OM content), pore size and distribution, texture, ect. 

In a more broad sense, the reason we plant in a riparian zone is to preserve the nutrient rich soils from eroding into the water flow, thus causing water pollution, and wildlife habitat destruction. The long roots associated with the trees help stabilize the structure of the soils to prevent these destructive activities. Planting trees also shades the water, which decreases water temperature fluctuations. 

The largest enforcer to soil erosion is agriculture (74%). This is mostly due to the tillage method used on such farms.

In Northern Laos, it was found that on a slope of 60%, the soil losses due to tillage was the same as the soil losses due to water erosion. Soil clods that are broken from tillage tend to accumulate at field boundaries, and as slope increases, those soil losses from tillage increase as well (shown below). This is one reason why planting on the slopes near the water banks in a riparian area is important.

What we Learned...

One of the biggest stand out features related to soils is the amount of work it takes to reverse human mistakes. We worked hard in the riparian zone of the Fern Road Farm in order to help it recover from one such mistake; a recovery that has only just begun. The riverbanks along the Marys River was overtaken by Himalayan blackberry (Rubus discolor) many years ago. This human introduced invasive plant has plagued landowners of the Pacific Northwest for many years.  Without a doubt the riparian zone before anthropogenic interactions was composed of native grasses and trees. Much like the Black Cottonwood (Populus trichocarpa), Red Alder (Alnus rubra) and Oregon Ash (Fraxinus latifolia) we planted in the freshly cleared riparian zone.  The mismanagement of the past is affecting the land managers today. The financial cost is one issue, ecosystem deterioration is another.  Issues like these stand in the way of managers like Jason Bradford at the Fern Road Farm. Transitioning to an organic farm while also increasing the distribution of native species on site has proved to be a challenging endeavor.

One of the more surprising discoveries we made while digging in the soil was the significant gradient in soil texture. The soil in the riparian zones textured out to a variety of different soils from loamy sands, to loamy clays. For the most part the soil at the farm was high in clay, very sticky and compacted to the point where it was difficult to get a shovel through it.  However, just a few feet toward the river the sand content prevailed. A number of us noticed this trend as we moved around turning up the soil. One thing became increasingly clear, soil surveys do not depict soil type change on such a micro scale and that each soil needs to be examined in person before making management decisions.

There were a number of other personal realizations we came to while working. With the help of Mr. Bradford most of our questions were answered expertly.  The entirety of our experience can be summed up as informative and surprisingly enjoyable. Although, it is safe to say that none of us envy our local farmers on a rainy Saturday in the Pacific Northwest.



How Soil Management Could Improve this Project…


For many decades now agriculture has incorporated big machinery and massive chemical applications to save time and boost crop yields.  Since WWII, these were thought to be the most efficient farming methods.  Unfortunately, these methods have neglected what really matters….THE SOIL!  Fern Road Farm incorporates sustainable farming practices which avoid using massive chemical applications, and avoid the use of large machinery when possible. To be a certified organic farm, many chemicals and fertilizers are prohibited. The task of rehabilitating the soils from years of misuse is the task Jason Bradford, the manager of Fern Road Farm is tasked to do on more than 150 acres.

One management goal of Bradford’s is to rebuild the soil in a manner that is more sustainable.  Bradford recruits OSU students to help with projects around the farm to help with soil management. Our group helped Jason plant native trees in riparian areas that were being invaded by species including the Himalayan black berry. One goal as the result of planting the tree is to prevent the resprouting of black berries, which do not grow well in shaded areas.  Planting trees will also help with the overall soil structure along the river banks.

Jason also had some of us cut up some small branches from local willow and dogwood tree and stick them in the ground.  These two species of trees are also native to the area and should start growing a root system on their own given some time. The root capacity for willows and dogwoods are high and improve bank stability, shade out invasive species, and improve overall watershed health.

Fern Road Farm is like a laboratory; Jason experiments with different management regimes including planting combinations of cover crops and keeping those crops in rotations throughout the farm. Certain grasses or cover crops penetrate the soil differently and give back different amounts of nutrients. The rotation of crops helps to distribute nutrients across the farm and decrease the risk for pests and disease. Some grass root systems have shallow root systems while some grass roots, mostly perennials, penetrate deep into the soil. As a result, Jason is patiently figuring out the best management program for this particular farm giving the wet/dry season, temperatures etc.


In addition to crop rotations, livestock was utilized as a management tool.  At Fern Road Farm, sheep, chicken, pig, cattle, and goat grazing rotations are used throughout the farm.  As the animals graze, they give back nutrients to the soil in the form of manure (natural fertilizer).   Free Labor!!!!!



Overall, Fern Road Farm has implemented good management practices and is on track to be a sustainable, organic farm.  Jason is consciously thinking about the soil quality and native habitats with his every move.  He has brought in a lot of biodiversity and a self-sustaining approach to this 150-acre farm that will start to pay off for Fern Road Farm in the next couple of years.  He knows that this renovation will not be an overnight change but a more gradual change.  We can’t wait to go back out there next year to see how things are going.
Broader Impact of this Project…

This project has been an educational experience and a way to connect soils in the classroom to soils in the real world. Soil is a 4-dimentional, self-organizing, complex habitat, and a living thing! It is hard to grasp that in the classroom; a hands-on experience with soils is essential in order to really understand what soil is all about. We know that humans have been contributing to environmental degradation e.g. global warming for thousands of years. As the unintended consequences of our influence on the planet unfold, understanding the relationship between soil and our existence on Earth has become increasingly important.

Organic farming is an example of the relationship between soil and humans. If we protect our soils from anthropogenic inputs like chemical pesticides and herbicides, and operate a farm that is self-sustaining, we are moving towards a more livable future. Our efforts at the Fern Ridge Farm were small, but were an important contribution to the health of the soil as a whole. Soils are important and we need to manage them better for the future.





Check out our video on youtube. Think about the soil!