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 farms can operate profitably and preserve environmental quality for decades to come.
Consider the valuable services that soil provides both on farm and in all of our gardens at home:
|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?||Filtering water – Healthy soil can filter and decompose organic substances such as manure, agricultural chemicals, and other compounds that can pollute air and water.|
|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?||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.|
Back to Basics
Slope, texture, climate, and other critical soil factors cannot be controlled, but tillage, crop rotations, soil amendments, and other management choices can be. These choices affect the structure, biological activity, and chemical content of soil, as well as influencing erosion rates, pest populations, nutrient availability and crop production. Improving soil performance requires different actions on each farm, but here are a few examples of what farmers are already doing:
Adding organic matter
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.
Avoiding excessive tillage and soil compaction
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 minimises 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.
Keeping the ground covered
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 helps to reduce 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 the farm.
Monitoring soil performance
Nothing can replace the value of “casual” observations of how the 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, systematic observations of the soil are also required.