There’s more to soil than what meets the eye. As the basis for life on Earth, soil is a big deal!
Soil health is part of the bedrock of agriculture. In the last decade, interest in soil health has increased as a focus on sustainability and the benefits of healthy soils have become more mainstream. In honor of Soil Health Day, we’re breaking down the facts about soil, soil health, taking care of soil, and making sure it’s healthy for generations to come.
What is soil made of?
As every farmer knows, what covers the Earth and grows crops isn’t ‘just dirt.’ But what is soil made up of? While it may look like a single, dusty brown substance, soil is a combination of minerals, organic matter, living organisms, gas, and water. These give soil unique, location-dependent characteristics.
Soil has been studied since the 1800s when soil scientists began looking into what soil is made of. Scientists have classified soil horizons, or layers within the soil, as well as soil age, soil minerals, and more! Soils are diverse due to differing parent materials and formation conditions.
Major contributions were made by Hans Jenny introducing the CLORPT concept: soil formation is affected by Climate (CL), Organisms (O), Relief (R), Parent material (P), and Time (T). This conceptual model for understanding soil geography and geomorphology has had many impacts on soil science. It’s been a global foundation for understanding soils as a function of combined environmental factors.
Around the world, soil reflects various factors, including geologic events, organisms, climate, topography, and time. These five factors impact soil from the surface to its lowest depths. A change in one of the five soil forming factors results in “soil genesis”, creating a new soil.
Geologic Events
Soil parent material is a result of geologic events, such as volcanic eruptions or glaciers. Volcanic ash is a lightweight parent material with high water-holding capacity and compaction susceptibility. Glaciers have ground up rocks and pushed glacial till to the soil surface, generating a different parent material entirely. And in swampy areas, peat is a common soil parent material generated from decaying plants and animals.
Organisms
All living plants and animals can impact soil formation. Soil horizons often reflect the types of plants that grow on a site, with residue like needles, twigs, and roots incorporated into the soil. Organisms in the soil break these plant residues down. Microorganisms are present in all soils, though the types of microorganisms will depend on the plants that are present on the site. Other organisms, like worms, voles, and moles, impact the soil by creating channels in the soil or mixing it, which helps move water and air throughout the soil.
Climate and soil
Climate, including temperature and annual precipitation, can have massive impacts on soil formation. Wetter climate can support richer vegetation, which decomposes and in time affects soil formation and its characteristics. Too much water in soil can reduce soil air, and impact what types of plants can grow on that site. Documenting annual precipitation and average soil temperature is important for understanding the climate of a given site.
Topography
Topography refers to the type of landscape the soil is in. Landscape location includes elevation, shape, and compass direction. All of these factors change soil drainage, runoff, deposition, and erosion. For example, south-facing slopes dry out faster and are warmer from high solar heat, which speeds up chemical reactions and water evaporation. This influences soil genesis.
Time
Soil landscapes are continuously building and degrading throughout time. Soils can be young or old. Climate can impact how quickly soils form; in hot, wet climates, soil horizons form more quickly than in cold, dry environments. Young soils have little horizon development, while older soils have many well-defined soil horizons.
Understanding soil characteristics and what it is made of is important because of all the ways soil contributes to life on Earth. Soil plays a part in regulating water, sustaining plant life, and cycling nutrients. Soils provide nutrients and water for most of the plant life on Earth.
They also filter pollutants and transform nutrients into biologically available forms that are prevented from leaching. All in all, soil contributes ecosystem services that microorganisms, plants, animals, and the environment all depend on.
Is Your Soil Healthy?
Because soil is a living natural resource, it’s possible for it to be in different states of health. Soil health is the “continued capacity of soil to function as a vital living ecosystem that sustains plants, animals, and humans,” according to the U.S. Department of Agriculture’s Natural Resources Conservation Service.
In agriculture, soil health is of particular importance. Agriculture fundamentals require plant and animal life to be sustained. Soil’s ability to regulate water, filter pollutants, and stabilize and support plant roots are critical puzzle pieces to growing plants and raising animals for agricultural purposes.
And for agriculture to be productive, plants need nutrients from the soil to grow and produce high-quality food. Because of this, soil fertility and soil productivity are of high importance. Nutrients like carbon, nitrogen, and phosphorus are cycled, stored, and transformed in the soil, fueling plant growth and productivity.
When soil health is degraded, it can’t complete these critical functions. In short, there are many benefits of soil health that have importance in agriculture!
It’s possible for stewards of the land to protect and restore soil health, guided by soil health principles. Soil health principles include maximizing the presence of living roots, minimizing disturbance, maximizing soil cover, and maximizing biodiversity.
Farmers can use soil health principles to focus on improving soil health. Some ways to improve soil productivity include composting, cover crops, crop rotation, and soil assessments.
Composting
Composting organic material can drive soil health improvement. It can supply organic nutrients which can substitute synthetic fertilizer and it can build up the soil organic mater, which helps stabilize aggregate stability and help the soil withstand soil erosion and gullying. Composting can promote a slow release of nitrogen, too.
Cover Crops
Cover crops, like rye or crimson clover legumes, are grown to protect the soil during times it is normally fallow. Cover crops are one of many ways to improve soil productivity and restore soil health. There are many benefits to cover cropping, including increasing organic matter, suppressing weeds, reducing erosion, managing compaction and soil structure, and increasing water infiltration. Cover crops do a great job of addressing all four soil health principles!
Crop Rotation
Rotating planted crops has many benefits for yield, drought tolerance, and plant disease. Crops with different rooting depths can be used in crop rotation to improve soil structure. Cover crops can be used in crop rotation to increase diversity, improve organic matter, and prevent erosion.
Soil Assessments
Collecting data to understand the current status of soil is a critical step to determining the best course of action to protect or restore it. Soil testing and field observations can help determine the health of the soil, including physical and biological properties.
Automate Plant Nutrition
Because of the importance of soil health in agriculture, taking active steps towards soil health improvement is important. Beyond production practices like cover crops and composting, farmers can find ways to improve soil productivity by streamlining plant nutrition with soil health and sustainability in mind.
Soil may not naturally have the right composition or rate of nutrients for a given crop. Or, the nutrients may not be in a plant-available form. In these situations, farmers must balance applying the right type and rate of fertilizers, because over-applying can impact soil health and negatively impact the environment.
Soil health decreases when you underapply nutrients, and soil organic matter gets depleted. Using an adaptive approach to nutrient management and regular soil testing enables tracking of nutrient levels. Armed with this knowledge, it’s possible to re-supply adequate nutrients as needed, either through manure or synthetic fertilizers.
Adaptive approaches to nutrient management take into consideration the current state of the field and its variability. Within a field, variability in soil texture, organic matter, nutrients, fertility, compaction, soil depth, and drainage is present. Planning for all of these factors is difficult, if not impossible, with a one-size-fits-all solution. A decision support system tool, like Agmatix’s Digital Crop Advisor, makes it easy to adopt an adaptive approach to nutrient management.
Agmatix’s Digital Crop Advisor
Digital Crop Advisor is a data-driven decision support system that automates plans and makes the best of crop nutrients for a specific site. Because of the importance of soil productivity and soil fertility, a tool like Digital Crop Advisor can help assess and meet a field’s nutritional demands with environmental sustainability and soil in mind. With Digital Crop Advisor, it’s easy to meet crop nutrition needs.
The Digital Crop Advisor map interface uses two types of satellite imagery – Sentinel-2 and Landsat 8 – with a 5-day revisit time frame to ensure accuracy. Site-specific recommendations are created using various parameters that can be customized. Yield uptake, previous crop performance, removal rate, soil characteristics, and environmental impact are just a few of the possible parameters that can build a precise, customized, optimized plan.
Digital Crop Advisor also connects to soil analyses to enable integrated crop nutrient management. This allows adjustments to the nutrition plan to be made as needed. Lab analysis results can be used in-season and pre-season to adjust for seasonal nutritional demand.
In a specific sustainability section, a detailed carbon footprint assessment helps farmers understand the impact of a specific nutritional plan recommendation on the environment. The sustainability section also provides a benchmark for future recommendations. Farmers can continue to improve production practices and enhance inputs with sustainability in mind. Ultimately, meeting nutritional needs with a low environmental impact leads to high yields and productive crops that enable continued growth well into the future.
Ensuring Your Soil’s Future
The future of the world’s food production depends upon the health and productivity of agricultural soils. Farmers have a big job in protecting and restoring soil health while feeding a growing, hungry world.
With a global population projected to reach close to 10 billion by 2050 and the challenges of a changing climate, food security relies on the capability of current soils under production to continue to produce well into the future.
At Agmatix, we support agriculture professionals in improving sustainable food production. Food production is both impacted by and impacts soil health, and Agmatix is dedicated to providing data and decision support for farmers and industry professionals as they navigate sustainable food production and crop nutrition. With tools like Digital Crop Advisor, Agmatix is helping pave the way to a sustainable, healthy soil future.