Introduction to soil management
Soil: A farmer's "silent partner"
Soil is the basis of farming. It delivers water and nutrients to crops, physically supports plants, helps control pests, determines where rainfall goes after it hits the earth, and protects the quality of drinking water, air, and wildlife habitat.
The goal of soil management is to protect soil and enhance its performance, so you can farm profitably and preserve environmental quality for decades to come.
Why learn more about soil management?
Consider the valuable services your soil provides:
- Growing crops. Soil delivers nutrients and water and gives plants structural support. Could your soil cycle nutrients more efficiently so you save on input costs and your crops are healthier? Could your soil store more water so crops do better during dry spells?
- Controlling water flow. Soil helps control how water moves over and through the earth’s surface. Does rainfall quickly fill waterways rather than moving slowly through your soil? Could you reduce the amount of organic matter, nutrients, and soil you are losing to erosion?
- Filtering water. Healthy soil can filter and decompose organic substances such as manure, agricultural chemicals, and other compounds that can pollute air and water.
- Storing carbon. Soil is a storehouse of carbon. As concern grows about increased atmospheric carbon dioxide, farmers may receive financial benefits for increasing the amount of carbon (organic matter) stored in their soil.
You determine how soil performs.
You cannot control slope, texture, climate, and other critical soil factors. But you can control tillage, crop rotations, soil amendments, and other management choices. Through these choices you change the structure, biological activity, and chemical content of soil, and you influence erosion rates, pest populations, nutrient availability, and crop production.
Six practices that improve soil performance
Improving soil performance requires different actions on each farm. Most soil-friendly farm practices fall into one of six groups. Each of these practices is further explained in other publications in the series.
- Adding organic matter
- Avoiding excessive tillage and soil compaction
- Managing pests and nutrients efficiently
- Keeping the ground covered
- Increasing diversity
- Monitoring soil performance
Regular additions of organic material may be the most important way to enhance soil quality. Organic matter improves soil structure, enhances water and nutrient holding capacity, protects soil from erosion and compaction, and supports a healthy community of soil organisms. Organic matter includes residue and roots from the previous crop, animal manure, cover crops, or amendments from off the farm.
Tillage is valuable for loosening surface soil, preparing the seedbed, and controlling weeds and pests. But tillage can also break up soil structure, speed the decomposition and loss of organic matter, increase the threat of erosion, destroy the habitat of helpful organisms, and cause compaction. Reducing tillage minimizes the loss of organic matter and increases the residue protecting the soil surface. Compaction reduces the amount of air, water, and space available to roots and soil organisms. Compaction is caused by traveling on wet soil or by heavy equipment.
In this century, pesticides and chemical fertilizers have revolutionized U.S. agriculture. In addition to their desired effects, they can harm non-target organisms and pollute water and air if they are mismanaged. Nutrients from organic sources also can become pollutants when misapplied or over-applied. Efficient pest and nutrient management means applying only the necessary chemicals, at the right time and place to get the job done; testing and monitoring soil and pests; and adding non-chemical approaches to your management toolbox (such as crop rotations, cover crops, and manure management).
Bare soil is susceptible to wind and water erosion, and to drying and crusting. Groundcover protects soil, provides habitats for larger soil organisms (such as insects and earthworms), and can improve water availability. Farmers often leave crop residue on the surface to cover the ground between growing seasons.
Living cover crops create new organic matter and help feed soil organisms. Groundcover must be managed to prevent problems with delayed soil warming in spring, diseases, and excessive build-up of phosphorus at the surface.
Diversity is beneficial for several reasons. Each crop contributes a unique root structure and type of residue to the soil. A diversity of soil organisms helps control pest populations, and a diversity of cultural practices reduces weed and disease pressures. Diversity across the landscape can be increased by using buffer strips, small fields, or contour strip cropping. Diversity over time can be increased by adding crops to the crop rotation or by varying tillage practices. Changing vegetation across the landscape or over time not only increases plant diversity, but also the types of insects, microorganisms, and wildlife that live on your farm.
Nothing can replace the value of "casual" observations of how your land is changing from day to day and year to year. Yet, to fine-tune management practices and promptly determine whether changes in soil or crops are significant, you also need to make systematic observations of the soil.
How do I keep soil records?
Soil records should allow you to assess your soil, identify problem areas, and track changes in management practices and soil condition. A record-keeping system could consist of:
The soil scientist
This section gives background information about how soil works. Understanding the basics will help you apply management recommendations found in this and other publications in this series.
What is soil made of?
It takes thousands of years for rock to develop into soil, and hundreds of years for rich organic layers to build up. Soil is made of air, water, mineral particles, organic matter, and organisms. Half of soil is pore space. Generally, pores are about half filled with water and half air, though the proportion varies greatly depending on weather, plant water use, and soil texture. Most of the solid portion of soil is mineral particles. Organic matter may make up only 5% to 10% of the volume of soil (less than 5% of the weight), but it is critical in holding soil particles together, storing nutrients, and feeding soil organisms.
Mineral particles are divided into three groups based on their size: clay, silt, and sand. Soil texture depends on the proportion of particles from each of these groups. (See the texture triangle below.) For example, a loam has similar proportions of all three classes of particles. A sandy loam is higher in sand; a clay loam is higher in clay.
Soil structure, or how soil is put together, can be as important as what it is made of. Most soil particles are held together in aggregates of many particles. The size and stability of these aggregates determine the size of pores. Soil texture is difficult to change, but farming does impact soil structure.
Soil texture triangle particle diameters
clay: < 0.002mm
silt: 0.002mm to .05mm
Sand: .05mm to 2mm
Your Farm #2
How well do you know the differences in texture, organic matter, and terrain across your land? Get this information onto paper, so you can use it as a base map. A base map shows the permanent features of your land. Make many copies of your base map, and use them to record changes in soil condition, and to keep management records (see Rodney Rauk’s story). By looking at maps of soil types, management practices, and problem areas side-by-side you can identify patterns that give you clues for better soil management.
Start your base map by copying or tracing a Soil Survey map or aerial photos. Today, you might just sketch a portion of your farm with a pencil so you can learn what you want to include in your base map. Some of the features you might include are:
Soil types. Draw boundaries between soil types and label the texture, slope, and any other important characteristics (such as depth). This information is available in the county Soil Survey. Ask at your Soil and Water Conservation District office for help.
Terrain. Mark low spots and hill tops.
Water flow. Draw dotted arrows showing the direction and path of water flow. Note where it comes from before reaching your farm and where it goes after it leaves your farm. Include streams, wetlands, drainage ditches, sinkholes, and waterways that are only wet during a storm.
Wind patterns. Note prevailing wind direction(s).
Organic matter. Note areas of high and low amounts of organic matter. High organic matter areas appear darker in an aerial photo.
Permanent structures. Mark the location of terraces, tile lines, buffer strips along waterways, windbreaks, etc. Mark field boundaries, buildings, and livestock yards.
Former structures. Mark locations of former fence lines, buildings, lanes, and livestock yards.
Public areas. Are there parts of your fields visible to others that you want to keep "looking nice"?
How does soil work?
Regardless of the kind of farming you do, the rules of soil chemistry, physics, and ecology are the same. Four processes make your soil what it is: formation of soil structure, nutrient cycles, water cycles, and life cycles of soil organisms.
- Soil structure
- compaction or hardpans?
- soil that is difficult to work?
- Nutrient cycles
Soil particles range in size from gritty sand particles as large as 2 mm (1/16 inch) to microscopic clay particles 1000 times smaller. These particles rarely exist separately in the soil. They normally combine into clumps called aggregates or peds. A few particles bind into tiny microaggregates. Microaggregates, in turn, combine to form larger aggregates. Ideally, soil will have a wide range of aggregate sizes and pore sizes. Aggregates in healthy soil will be stable and resist breakage when tilled, hit by rain, or otherwise disturbed.
How soil structure develops
How do aggregates form?Several biological, physical, and chemical processes interact to form aggregates and then stabilize them. Microbes decomposing organic matter create compounds that cement soil particles together. Synthetic polymers ("soil conditioners") and sugars excreted from roots can have a similar cementing effect. Humus - the stable organic compounds - also binds soil particles together.
Fungal hyphae and fine roots surround and stabilize aggregates. This is why surface residue and other organic matter improve soil structure - the residue is food for fungi and bacteria that in turn help form and stabilize soil aggregates.
Larger organisms (such as insects and earthworms), enhance soil structure when they burrow through the soil and deposit fecal pellets that become stable soil aggregates.
Physical and chemical processes are also important to the formation of soil aggregates - especially smaller aggregates. Particles are physically pushed closer together by freezing and thawing, wetting and drying, and roots pushing through the soil.
At the molecular level, electrochemical charges bond clay particles together. In arid areas, this process may be disrupted by large amounts of sodium (Na+) ions. In tropical and semitropical soils, iron oxides can cement together aggregates.
How do surface crusts form?Rain drops break apart soil aggregates and then fine clay particles clog the spaces between aggregates and form a crust on the soil.
Improving soil structure
Several of our six soil-friendly practices impact soil structure:
Organic matter management. Regular additions feed the organisms that build soil structure.
Tillage practices. Over time, tillage increases the decomposition of soil organic matter and breaks up aggregates - especially when tillage is done in wet soil. Residue left at the surface protects surface aggregates from rain and encourages the growth of fungi that help stabilize aggregates.
Compaction prevention. Compaction pushes aggregates together and eventually breaks them down.
Crop choices. The dense roots of grasses, small grains, and pastures stabilize soil aggregates and improve structure.
Where are my soil structure problems?
Mark on your base map or make a list of where the tilth of your soil is not as good as you would like. Where do you have problems with:
Soil is the storehouse for the nutrients that plants need. It is a dynamic environment in which soil organisms, chemistry, and physics are continually acting to change the form of plant nutrients.
Plant roots draw most of the nutrients they need from the soil solution - the water and dissolved minerals in soil pores. The amount of nutrients in the soil solution at any one time is just a fraction of that needed by plants over the course of the year. The soil solution must be continually replenished from the store of nutrients in minerals and organic matter. Many farmers also contribute nutrients to the soil solution by adding readily available fertilizers once or more each year.
Soil particles and plant residue are made of large quantities of nutrients that are unavailable to plants. Eventually, the soil (mineral) particles weather into sand, silt, clay molecules, or mineral ions. Plant residue eventually decomposes into mineral ions or reforms into humus.
Adapted from Brady and Weil, 1996, p. 22.
Plant nutrients exist in several forms
Clay and humus are not absorbed by plants, but they hold nutrients (mineral ions) on their surfaces. The amount of places available on clay and humus to hold nutrients is called the "exchange capacity" of the soil.
Cation exchange capacity is the number of places available - the storage capacity - for positively charged ions, including calcium, magnesium, sodium, and potassium ions (Ca2+, Mg2+, Na+, and K+). Nutrient ions attached to the exchange sites on clay and humus are released into the soil solution for use by plants and soil organisms such as bacteria and fungi.
As plants draw nutrients out of the soil solution, more may be released into solution from exchange sites on clay and humus. Fertilizers added to the soil solution do not remain unchanged, waiting to be used by plants. Like minerals from other sources, they become attached to exchange sites, are used by microorganisms, and are transformed.
Roots get nutrients in three ways: 1) the root grows into an area where the soil solution has not been depleted of nutrients; 2) after a root depletes the nutrients near it, nutrients will diffuse into the deficient area; and 3) water flows towards the root and carries nutrients. This means that prolific root growth and adequate water are essential to plant nutrition.
What is soil fertility?
Where is the most fertile land on your farm? What makes it more productive than other fields? The soil may test high in nutrients, but it probably has additional characteristics that make it your best land. Soil fertility is not just the amount of nutrients, but whether plants can get the nutrients when they need them. In other words, a fertile soil will have:
- Good rooting environment. To grow and find nutrients, roots (and mycorrhizal fungi) need well-drained soil with a crumbly, uncompacted structure.
- Adequate water. Soil with good "tilth" will have good water infiltration and water-holding capacity.
- High organic matter. Organic matter is a source of many nutrients, improves the rooting environment, and helps hold water in the soil.
- Active soil community. Soil organisms release and retain nutrients, protect plants from pests, and even enhance plant growth. Their activity depends on food availability, pH, and moisture and temperature levels.
- Appropriate pH. When pH changes, many nutrients can become either more or less available to plants, depending on the nutrient. pH also affects microbial activity. For example, Rhizobia form nitrogen-fixing nodules poorly in acid soils.
Improving nutrient cycling
Several of our six soil-friendly practices are important to nutrient cycling:
- Organic matter management. Organic matter supplies nutrients for plants and feeds the soil organisms responsible for cycling nutrients. It is a "slow release" fertilizer.
- Tillage practices. Tillage triggers the decomposition of organic matter and the release of nutrients, and mixes nutrients throughout topsoil. Excessive tillage reduces organic matter and the nutrient-holding capacity of your soil.
- Compaction prevention. Preventing compaction improves the ability of roots to grow through soil to reach available nutrients.
- Fertilizer management. You have choices about which form and how much of a nutrient to use, and when and how to apply it.
- Crop choices. Each crop affects nutrient cycling differently and encourages a different mix of soil organisms. Deep-rooted crops draw up nutrients that other crops cannot reach. Legumes can add nitrogen to the soil.
Where are my fertility problems?
Make a list of where your soil is not working as well as you would like. Mark problem areas on a base map. Note where:
If you have watched crops suffer through a drought or have seen yields jump after installing drainage tiles, then you understand that water is a fundamental factor for good crop yields. Like animals, plants need large amounts of water every day. Yet, too much water deprives roots of air and makes soil susceptible to compaction. Water carries soil, nutrients, and other substances, so water management is essential to controlling erosion and pollution.
Three major water processes occur in soil: water gets into the soil (infiltration), is held by the soil, and drains out of the soil. How these processes occur depends on soil type and management.
Infiltration is the rate at which water gets through the surface and into the soil. With higher infiltration, more water will be available to plants and less will run off the surface, erode soil, and wash away nutrients. Crop residue, living plants, or a rough soil surface will slow down the flow of water so more can infiltrate. A soil crust reduces infiltration and can be minimized by leaving surface residue, improving organic matter levels, and enhancing biological activity.
Available water holding capacity is the amount of water soil can hold for plant use. After water gets into the soil, the surface tension of water holds it in soil pores against the pull of gravity. Because of surface tension, small pores in fine-textured soils such as silt and clay loams hold more water than the large pores in sandy soils. Organic matter also holds large quantities of water. The maximum amount of water that a soil can hold against the pull of gravity is called the field capacity. Generally when a soil is at field capacity, half the pores are filled with water.
Plants cannot use all of the water in soil. As water evaporates and is drawn out of soil by plants, the water content gradually declines until plants can no longer extract the small amount of remaining water held tightly to soil particles. This remaining amount of soil water is called the wilting point. Clays have a high wilting point. They hold water more tightly than coarser-textured soils and so less of the water is available to plants. Thus, although silt loams hold a bit less water (have a lower field capacity) than clay loams, more of it is available to plants. Salts prevent roots from absorbing water and thus increase the wilting point.
Drainage or percolation is excess water that soil cannot hold that moves out of the rooting zone so roots and organisms can get air. After a heavy rain, the soil will be saturated (all the soil pores are filled with water). Many roots and soil organisms will die if the excess water does not quickly percolate out and allow air into the pores again.
Changes in Soil Water. Field capacity minus wilting point is the amount of water available to plants.
Improving the availability of water
Several of our six soil-friendly practices increase field capacity and improve infiltration:
- Organic matter management. Organic matter significantly increases the water-holding capacity of soil in two ways. It absorbs and holds large amounts of water, and it improves the structure of the soil - increasing the total volume and size of pores that can hold water and preventing soil crusting.
- Tillage practices. Leaving residue on the surface slows runoff and prevents crusting. Residue encourages populations of earthworms and other burrowing organisms and water infiltrates rapidly into their burrows.
- Compaction prevention. Compaction reduces water holding capacity by reducing the number and size of soil pores.
- Erosion control. Erosion reduces the depth of your soil and its water-holding capacity.
Where are my water problems?
Review this section on water cycling and list (or mark on your base map) where your soil is not working as well as you would like. Where do you have problems with:
Soil organisms were mentioned in connection with all three of the previous soil processes. Their life cycles are an integral part of the formation of soil structure and nutrient cycles, and their activity is highly dependent on the water status of soil. Temperature, food supply, and pH are other factors that determine what lives in your soil and when they are active.The food web of organisms living underground is at least as diverse and complex as the ecosystem of plants and animals living above ground. Practically all the energy for the food web comes from the sun. Plants and other photosynthesizers convert the sun’s energy and carbon dioxide into the carbon compounds used by other organisms. Plant-eaters create compounds that other organisms need. As bacteria, fungi, earthworms, microscopic insects, and other organisms consume and transform carbon compounds, they release carbon dioxide back into the atmosphere and make nutrients available to plants. Farmers depend on these life cycles for their livelihood.
Improving the soil ecosystem
Several of our six soil-friendly practices can improve your soil’s ecosystem:
- Organic matter management. Soil organisms need a regular supply of organic matter for food.
- Increase diversity. It is generally beneficial to increase the diversity of organisms in the soil. Diversity is increased by using different management practices, including long crop rotations, changing tillage practices from year to year, supplying several types of organic matter, or creating buffer strips or other vegetation that adds variety to the landscape.
Where are my biology problem areas?
Are desired plants and animals thriving, or do weeds and pests dominate in some areas? On your base map or on a list, note the locations of:
A year in the life of your soil
Dates are approximate for Minnesota and vary each other.
(Late April through early June)
(June through August)
(Late August through September)
|Structure & Temp.||Saturated soils have a weak structure and are prone to compaction. Spring soil is highly susceptible to wind and water erosion, because soil is often bare and soil structure is weak. By late spring, bacterial and fungal activity will help stabilize soil aggregates, and plant growth will begin to protect the soil surface.||Even healthy soil is difficult to penetrate when it gets very dry.||Risk of soil compaction increases again as soil moisture levels rise and heavy harvest equipment enters the fields.|
|Nutrients||Bacteria and fungi are becoming active, but not necessarily enough to provide nutrients to young plants. Side-dressing of nutrients may be useful.||If a young (high N) forage is plowed down, soil organisms quickly release N and other nutrients to the next crop. A low-N amendment, such as straw, may trigger N deficiency in a crop, as soil organisms use soil nitrate to decompose the high carbon amendment.||Fall is a good time to test soil - leaving all winter to use test results for planning the next cropping season. Cool season cover crops can take advantage of nutrients (and water and sunlight) not being used by the main-season crop, and can prevent nitrogen losses.|
|Water||Compacted soils drain slowly. The loose, rough surface of newly tilled soil readily allows rain water to infiltrate into the soil - unless a crust forms.||High temperatures in July and August cause high water loss through evaporation and transpiration from plants. Soil water stores are at their lowest.||Soil water levels begin to recharge as temperatures drop and evaporation and transpiration slow.|
|Organisms||Warming temperatures, air from tillage, and food from a plowed-down crop trigger a high level of activity. Organisms give off heat, carbon dioxide, and nutrients as they consume residue.||Any change in environment - new food, hot spell, heavy rain - will change microbial activity. In late summer, organisms from bacteria to earthworms are less active and reproduce less because of the lack of water.||Microbial activity increases in response to greater soil moisture and new food in the form of roots and residue from harvested crops.|
|Plants||Tillage triggers weeds to sprout. As crop roots begin to grow, they continually contribute organic matter to the soil. They exude organic compounds and slough off dying cells.||Root growth slows as plants produce flowers and other reproductive growth. By this time, roots may have extended deep into subsoil in search of water and nutrients. Warm season plants such as corn and some grasses flourish in the heat (if they have enough water).||Over the course of the year, 40% of the photosynthetic energy captured by a plant is used by the roots, and enters the soil system. Most of this carbon is released from the roots as CO2.|
A year in the life of your soil (continued)
|Freezing (October through mid-November)||Winter (Mid November through February)||Thawing (March and April)|
|Structure & temp.||Both surface residue and the irregular surface left by rough fall tillage protect the soil from winter wind erosion and spring water erosion.||A January thaw affects the structure of the top inch or so of soil.||Bare soils warm more quickly than residue-covered soils.|
|Nutrients||In late fall nitrate leaching increases as plant uptake and microbial activity decline.||Few changes occur in nutrients during the winter. Freezing temperatures prevent biological and chemical activity, or water movement.||Microbes and plants are not active and using nitrate, so soil nitrate is prone to leaching in early spring. Cool temperatures prevent denitrification losses.|
|Water||If an early heavy snow insulates the soil, the ground may not freeze deeply.||Surface soil may freeze and thaw several times each winter, but subsoil only freezes once. Any water from thawed snow or surface-applied manure cannot soak in and will run off.||Soil ice does not thaw evenly. Cracks and openings in the ice begin to allow water to flow down into subsoil and recharge water supplies.|
|Organisms||If it is warm, fall plowing triggers a final flush of microbial activity and organic matter decay.||There is little or no biological activity, except from a few species adapted to living in snow and cold soil.||A few organisms are becoming active. Root nodules on some perennial legumes have survived the winter and begin to fix nitrogen. When the soil fully thaws, some arthropods and earthworms move toward the surface from deep in the soil where they have been dormant.|
|Plants||As perennials "harden off" they send energy down to the roots for storage. If perennials such as alfalfa are protected by a continuous snow cover, they may stay green and perform some photosynthesis well into winter.||The soil environment is steeply stratified: Little or no root activity occurs near the frozen surface, while deep down, temperatures may be in the 40°s. Even when all above-ground growth is dead, deep perennial roots are alive and growing. They get energy from stores in the thicker roots.||Root activity (growth and uptake of water and nutrients) gradually increases as soil warms, but does not become very active until soil temperatures pass 50 degrees. Perennials such as alfalfa take energy from the roots to start growth of a new crown.|
Making a soil management plan
Now that you have reviewed how soil works, and how it is working on your farm, it may be time to begin clarifying which soil management changes would be beneficial on your farm. Whole farm planning includes four steps which can be modified for use in developing a soil management plan:
- Setting goals
- Inventory and assessment
What do you want to get from your soil? On page one is a list of services or functions that soil performs. Look at these for ideas as you write your soil management goals. Think about them in relation to the overall goals you have for your farm.
Inventorying and assessing soil
What kind of soil do you have? What problems are of greatest concern? To begin answering these questions, look at the problem areas you identified in "Your Farm #3, 4, 5, and 6." Also consider areas where erosion or loss of organic matter is a problem, where crop performance is consistently poor, or where crops are highly susceptible to less-than-ideal weather conditions. You will probably find that many of the areas on each list will overlap.
Which areas are costing you the most money, causing the most environmental damage, or threatening the long-term productivity of your farm? After you narrow down your major soil management concerns, make a detailed description of the problem areas: How severe is the problem? What are its boundaries? What is the condition of the soil? You can come back to this description periodically to track improvements.
Inventorying and assessing practices
What are the effects of your current management practices? Listing your current soil management practices will help you examine their effects and will give you a baseline for tracking changes.
You might develop this list by going through the six soil-friendly practices for improving soil health, and describing your current practices in each category. For example, for the first item (adding organic matter), you might write:
- Soybean roots and residue are added every other year.
- Corn roots and residue are added every other year.
- Only corn stubble is left on field X, when we harvest silage.
- Liquid manure is applied to field A and B every year.
Leave room for comments and move on to the next category.
What are your management alternatives? What information do you need to decide how each alternative could address your problems and goals? Review the six soil-friendly practices and ask which ones might address your problem areas. Examine the other publications in this series for more ideas.
Label a sheet of paper as your "preliminary management plan" and jot down possible management changes to consider and learn more about.
What changes do you expect to see in your soil, water, and crops? Are they occurring? If your soil/crop ecosystem works well, it provides essential services: high crop yields, quality crops, water control, and pollution control. If the system is not working well, the land is less productive, pollution is more likely, and the soil shows signs of degradation, such as erosion, salinization, or compaction. The purpose of monitoring and record keeping is to find the link between soil quality and the management practices you use.
The table on page 17 lists items you might include in your soil management record-keeping system. When deciding what to measure and monitor, think about what information would convince you either that your soil is improving or that your practices are not having the desired effect. Keep in mind that some soil properties might not change significantly until a few years after changing a practice.
To monitor changes in soil quality, you can measure 1) how you are treating the soil (management practices, such as residue cover or length of crop rotation), 2) the condition of the soil (e.g., nutrient levels or compaction), or 3) how the soil is performing (e.g., yield, water quality, or erosion). All three provide different clues about how to modify management practices.
Information on how to monitor each of these is available in other publications in this series and from soil and crop advisors such as Extension educators, NRCS conservationists, private consultants, and dealers.
One part of monitoring may be on-farm trials. Before changing a practice on the entire acreage, many farmers test a small area to see if it is beneficial, how the technique needs to be modified, and what new problems are created. Take time before testing a new practice to make sure the trial will give you the information you need. On-farm trials are only informative if they make a valid comparison between the old and new practice. Ask your local Extension educator for help setting up a trial, and check the list of on-farm trial information in the Further Resources section at the end of this publication.
Pulling it together.
By now you should have:
These five items are the start of your soil management plan. Use this information to decide which publication in this series to read next. Keep your plan handy as you read the other publications, and revise it as you go.
Ann Lewandowski, Soil Quality Institute, Natural Resources Conservation Service, United States Department of Agriculture
Deborah Allan, professor, Department of Soil, Water, and Climate, University of Minnesota
Phill Arnold, Farmer, Long Prairie
Jay Dorsey, (former) research associate, Department of Soil, Water, and Climate, University of Minnesota
Thomas Hansmeyer, graduate student, Department of Soil, Water, and Climate, University of Minnesota
David Huggins, (former) professor, Department of Soil, Water, and Climate, University of Minnesota
Maggie Jones, consultant, Blue Earth Agronomics
Tim King, Farmer, Long Prairie Bob Olson, Washington County Extension, University of Minnesota Extension Service
Jean Peterson, farmer, Delano
Carl Rosen, Department of Soil, Water, and Climate, University of Minnesota
Mark Zumwinkle, Energy and Sustainable Agriculture Program, Minnesota Department of Agriculture
Debra Elias Morse, Minnesota Institute for Sustainable Agriculture
Kathleen Cleberg, copy editor, Press 1 Production
Roxanne Madison, product manager, Communication and Educational Technology Services, University of Minnesota Extension Service
John Molstad, Studio 31 Graphics, Inc., designer
Deborah Allan, Department of Soil, Water, and Climate, University of Minnesota
Jim Anderson, Department of Soil, Water, and Climate, University of Minnesota
Barb Bakken, farmer, Alden
Carmen Fernholz, farmer, Madison
Dennis Gibson, farmer, Montevideo
Ken Matzdorf, Natural Resources Conservation Service, United States Department of Agriculture
Steve Potter, farmer, Sauk Centre
Linda Schroeder, Schroeder Communications
Russ Severson, West Polk County Extension, University of Minnesota Extension Service
Funding for this project approved by the Minnesota Legislature, 1995 Minnesota Laws, Ch. 220 Sec. 7, Subd. 2.
Additional funding provided by the Soil Quality Institute, Natural Resources Conservation Service, United States Department of Agriculture
Copyright © 2013 Regents of the University of Minnesota. All rights reserved.
FO-02331 Revised 2001