Know your Context
First things first, it’s important to incorporate the context of local conditions into all decision-making about soil health, including for example, soil type, topography, and time of year, land history and regional economics.
Knowledge is information in context. This article describes why focusing on context can help us understand situations that may prevent us from healing our soils.
Principle One - Soil Armor
Soil armor means keeping the soil covered as much as possible.
By: Jay Fuhrer, NRCS Soil Health Specialist
In this first of five articles on soil health, Jay explains the concept of “soil armor” and why it is important for building soil health.
Soil armor or cover, provides numerous benefits for cropland, rangeland, hayland, gardens, orchards, road ditches, and more. Let’s take a closer look at some of the soil armor benefits:
- Controlling Wind and Water Erosion – armor protects soil from wind and/or water as it moves across the soil surface. It holds the soil in place along with valuable soil organic matter and nutrients.
- Evaporation Rates – armor reduces the soil evaporation rates, keeping more moisture available for plant use.
- Soil Temperatures – armor helps soils maintain a more moderate range of soil temperatures, keeping soil warmer in cold weather, and cooler in hot weather. Like us, the soil food web functions best when soil temperatures are moderate.
- Compaction – rainfall on bare soils is one cause of soil compaction. When rainfall hits the armor instead of bare soil, much of the raindrop energy is dissipated.
- Suppresses Weed Growth – limits the amount of sunlight available to weed seedlings.
- Habitat – provides a protective habitat for the soil food web’s surface dwellers.
This picture shows the residual armor after corn planting was completed at the Menoken Farm, located just east of Bismarck, ND. At a minimum, the armor should last until the new crop is fully canopied. How quickly this residue decomposes depends on the carbon/nitrogen ratio of the residue. High carbon residue (eg: wheat at 80:1) decomposes much slower than low carbon residue (eg: pea at 29:1). When we supply the soil surface with a diversity of residues from one year to the next, we can achieve the benefits of soil armor and still maintain a fully functioning nutrient cycle.
Principle Two - Minimize Soil Disturbance
Minimizing soil disturbance is a good start to rebuilding soil aggregates, pore spaces, soil glue, and soil organic matter. This is an essential step for long term soil productivity.
By: Jay Fuhrer, NRCS Soil Health Specialist
In this second of five articles on soil health, Jay explains the concept of “soil disturbance” and why minimizing soil disturbance is important for building soil health.
Soil disturbance can generally occur in different forms:
- Biological disturbance, such as overgrazing, which limits the plants ability to harvest CO2 and sunlight.
- Chemical disturbance, such as over application of nutrient and pesticide, can disrupt the soil food web functions.
- Physical disturbance, such as tillage, which we will focus on in this article.
A typical soil is approximately 45% mineral (sand, silt, and clay), 5% soil organic matter, 25% water, and 25% air. The water and air portions exist in the pore spaces between the soil aggregates. Over time, tillage implements reduce and remove the pore spaces from our soils; restricting infiltration and destroying the biological glues which hold our soils together.
Ultimately tillage results in one or more of the following:
- water erosion; transporting soil, nutrient, and water to offsite locations, which negatively impacts water quality and quantity.
- wind erosion; transporting soil, and nutrient to offsite locations, which negatively impacts air quality, human health, and animal health.
- ponding water; which stays saturated on the surface for long periods of time, a result of reduced infiltration and increased runoff.
- crusting easily, which restricts plant emergence.
- soil organic matter depletion.
Can we reverse the impacts from tillage and improve soil function? Yes, we can. Minimizing soil disturbance is a good start to rebuilding soil aggregates, pore spaces, soil glue, and soil organic matter. This is an essential step for long term soil productivity.
The results of 20+ years of no tillage and crop diversity is a healthy, well aggregated soil.
Click here for a presentation by Regenerative Land Solutions that provides some examples of what soil biology is and why it is important, with some examples of projects to improve soil biology.
Principle Three - Increase Species Diversity
Diverse crop rotations mimic our original plant diversity landscapes. They are important to the long term sustainability of our soil resource and food security.
By: Jay Fuhrer, NRCS Soil Health Specialist
In this third of five articles on soil health, Jay explains the concept of “plant diversity” and why providing plant diversity is important for building soil health.
The Journals of Lewis and Clark describe the northern plains landscape as having abundant plant diversity. Numerous species where observed, working together as a plant community to provide forage for large herbivore populations. Our soils where built over geological time in this environment.
However, settlement of the plains brought agriculture, which resulted in the polyculture perennial landscape being replaced by a monoculture annual landscape. Where the soil food web use to receive carbon exudates (food) from a diversity of perennial plants harvesting sunlight and carbon dioxide; it now receives carbon exudates from only one annual plant at a time.
We can start to mimic the original plant community by using crop rotations which include all four crop types. Diverse crop rotations provide more biodiversity, benefiting the soil food web; which in turn improves rainfall infiltration and nutrient cycling, while reducing disease and pests. Crop rotations can also be designed to include crops which are; high water users, low water users, tap root, fibrous root, high carbon crops, low carbon crops, legumes, and non-legumes to name a few.
The following lists the four crop types with a few common crop examples of each:
- Warm Season Grass – corn, sudan, and millet.
- Warm Season Broadleaf – sunflower, and soybean.
- Cool Season Grass – wheat, oat, barley, and rye.
- Cool Season Broadleaf – flax, pea, and lentil.
Diverse crop rotations mimic our original plant diversity landscapes. They are important to the long term sustainability of our soil resource and food security.
This photo shows harvesting a cool season grass (spring wheat) at the Menoken Farm, August 3, 2016. Previous crops grown on this field include warm season grass (corn), cool season broadleaf (pea), warm season broadleaf (soybean), and cover crops. Supplying the soil resource with the benefits of plant diversity.
Watch this presentation by Robin Kelson of the Good Seed Company sharing why seed saving libraries are important and what an increased seed diversity can do.
Principle Four - Maintain Continual Live Plant/Root
Cover crops can address a number of resource concerns and allow the continuation of the soil food web through the entire growing season.
By: Jay Fuhrer, NRCS Soil Health Specialist
In this fourth of five articles on soil health, Jay explains the concept of “continual live plant/root” and why providing a continual live plant is important for building soil health.
Our perennial grasslands consist of cool season grasses, warm season grasses, and flowering forbs. Consequently, adaptable plants are able to grow during the cool spring and fall weather, as well as the summer heat. Allowing for a continual live plant feeding carbon exudates to the soil food web during the entire growing season.
Our cropland systems typically grow cool or warm season annual cash crops, which have a dormant period before planting and/or after harvest. Cover crops are able to fill in the dormant period and provide the missing live root exudate, which is the primary food source for the soil food web. Cover crops may be incorporated into a cropping system as annuals, biennials, or perennials. Starting on a small acre scale will allow farmers and ranchers to find the best fit for their operation.
Cover crops can address a number of resource concerns:
- Harvest CO2 and sunlight, providing the carbon exudates to the soil food web.
- Building soil aggregates and pore spaces, which improves soil infiltration.
- Cover the soil, controlling wind and water erosion, soil temperature, and rainfall compaction.
- Catch and release of inorganic nutrients, improving water quality.
- Salinity management.
- Pollinator food and habitat.
- Weed suppression.
- Wildlife food, habitat and space.
- Livestock integration.
- Adding crop diversity
- Adjusting the cover crop combination’s carbon/nitrogen ratio, to either accelerate or slow decomposition.
This photo shows an 8-way cover crop combination seeded after spring wheat harvest at the Menoken Farm, benefiting numerous resource concerns. The cover was seeded immediately after harvest.
Read this handout from Integrity Soils which walks us through how weeds and invasive plants are indications or symptoms of a larger problem with our soil health.
Principle Five - Livestock Integration
Animals, plants, and soils have played a synergistic role together over geological time. In recent years, animals are playing a reduced role due to being placed in confinement and fewer farms now include livestock as part of their overall operation.
By: Jay Fuhrer, NRCS Soil Health Specialist
In this fifth of five articles on soil health, Jay explains the concept of “livestock integration” and why animals are important for building soil health.
Animals, plants, and soils have played a synergistic role together over geological time. In recent years, animals are playing a reduced role due to being placed in confinement and fewer farms now include livestock as part of their overall operation.
Why do we want to return livestock to the landscape?
- Fall or winter grazing to convert high carbon annual crop residue to low carbon organic material; balancing the carbon/nitrogen ratio and managing our crop rotation residue for no-till seeding.
- Spring or summer grazing annual and/or perennial plants with short exposure periods followed by long recovery periods; allows the plants to regrow and harvest additional sunlight and CO2.
- Reduce nutrient export from our cropland and hayland fields. In lieu of transporting feed to a feed lot, we can reverse the roles and have the livestock graze the material in place. Recycling the majority of nutrients, minerals, vitamins, and carbon.
- Manage weed pressure by grazing in lieu of an herbicide.
- Grazing cover crops and/or crop residues allow us to take the livestock off the perennial grasslands earlier in the fall. Extending the grass recovery period and providing a higher livestock nutritional diet.
- Grazing reduces livestock waste associated with confinement; helping manage our water quality and nutrient management concerns. Allowing cattle and sheep to be herbivores by securing their energy needs from plants.
How do we return livestock to the landscape?
- Winter and fall grazing cover crops and annual crop residues.
- Summer grazing a full season cover crop, allowing adequate plant recovery, followed by a second grazing during the fall or winter.
- Winter feeding on hayland fields by rolling out bales or bale grazing.
- Seed rotational perennials, graze and manage as part of the crop rotation.
Yearlings and dry ewes grazing rotational perennials; grass plants, legumes, and forbs at the Menoken Farm; diversity in plants and diversity in animals.
Read this resource from the National Center for Appropriate Technology that explains why integrating animals into land management, including grazing animals, birds, and beneficial insects, is beneficial.
