A guest blog by Neal Kinsey
Click here to read Part I of this series.
Like all needed plant and animal products that contribute positively to soil fertility and plant growth, using compost and manures correctly can be of tremendous benefit. The effectiveness and value of applying them to accurately supply the required nutrients for the best in crop production is still greatly misunderstood by so many as to its full effects on the soil. All of the benefits compost and manures provide to encourage the biological life in the soil provides an excellent example. Release of “locked-up” nutrients that are present in soils in unavailable forms by stimulation of biological life in the soil is often completely overlooked or far underestimated in terms of both good and bad effects upon fertility.
Whether using a true compost, or even raw manure, a detailed analysis of both the material to be used and the soil where it will be applied can show how effective these very different materials can be, because either or both may work well in certain situations and yet that very same material can work very poorly or even cause harm in other places.
Moderate amounts of compost would normally be expected to benefit any soil with poor fertility levels. However, even moderate amounts can cause problems for good producing soils, or problem areas that already have the maximum level of one or more nutrients, meaning adding more will possibly tie up other nutrients that are just as necessary, especially the trace elements. Therefore, the consequences of using compost without testing the needs of the soil and the content of the compost to be used to build overall soil fertility can be greatly underestimated in terms of the benefits that compost will actually provide for each individual soil.
For over 15 years we analyzed soil samples every year for one certified organic client on several hundred acres. They built their own composts and had each one analyzed each year before any applications were made. The maximum amount was applied to each different area based on the soil tests and the nutrient content of each compost material. The desire was to use only their own compost to build up their soils. The soil tests indicated this would not be possible based on the soil needs and the nutrient make-up of available compost materials. Tests were set up to measure whether that was true.
After ten years using only compost as the control and applying all the needed nutrients not supplied by the compost in the test area, there was little progress in building deficiencies where only compost was used. Not only were the levels increased in the test area where all nutrients shown to be needed but not sufficiently supplied by the compost had been added, but root systems were 50% greater there as compared to using just the compost. In addition, nutrient levels where only the maximum amount of compost was used without exceeding the amount that would tie up other nutrients were not increased below the first six inches, but when the same amount of needed compost plus the additional nutrients it did not supply were added, nutrient levels were significantly increased to a depth of three feet.
The point here is DO NOT GUESS. Measure what the soil needs. Measure what the compost or manure can supply. Then each year, at least on key fields, measure what the compost has actually done for that soil. We have many clients who send their compost and/or manures to be analyzed along with the soils where they want to apply it. From that information we can recommend where to use these materials to help build maximum fertility without causing the problems that overuse of either may cause.
Is the very best organic compost always good for the land? What are the main drawbacks if you apply too much compost or manure? Part III will consider these questions and some of the others asked in Part I to conclude this series.
And if this information makes sense, how about considering letting us help in receiving the most from the use of manure and compost on your land. Contact us for the information you need to send soils, manure and compost for analysis and recommendations. We have received samples from all 50 states and 75 other countries with pastureland and hay being some of the main crops raised on the land those samples represent. We look forward to the opportunity to help, even if that means beginning with a small acreage to make sure it would work profitably on your land first.
Neal Kinsey owns and operates Kinsey Agricultural Services.