Soil compaction can lead to yield reduction in a number of ways. A common misconception is that soil fertility loss on pipeline construction rights-of-way cause significant crop losses. Reduction in crop productivity after pipeline construction is more commonly due to compaction, drainage issues, and changes in the characteristics of the upper soil. During pipeline construction soil structure is destroyed and compaction resulting from the use of heavy equipment may occur throughout the ROW. Even when de-compaction efforts are made during restoration, compaction can continue to be a significant yield limiting problem that will have on-going costs to a pipeline for many years. Research has shown that root growth can be limited at a soil strength greater than 180 PSI and is restricted to the point of no root penetration at a soil strength greater than 300 PSI. A corn crop requires a minimum of at least 30 inches of uncompacted soil to achieve 100% yield potential.
Soil compaction can negatively impact reclamation success
The impact of soil compaction can include:
- Crop root growth – When crop roots are prevented from exploring the entire rooting zone the newly planted crop can become nutrient deficient, droughty, lodged and experience yield loss.
- Waterlogging – Compacted soils tend to have layers in the profile that have a slower permeability on which an artificial water table can form. This might lead to drowning out of the crop especially, in high rainfall, humid climates.
- Decreased microbial activity – Most soil microbes require oxygen to be successful. Soil compaction decreases the oxygen diffusion rates therefore decreasing microbial activity. The decrease in soil microbe activity can decrease reclamation success due to lowering nutrient cycling with in the soil system.
Soil compaction can be avoided
Moisture conditions during construction as well as equipment weight, distribution of weight, and the frequency of traffic, will greatly affect the depth and severity of compaction and the level of difficulty involved to reduce or remove the compacted zone. Due to equipment size and continued work during wet conditions, compaction created during construction often can reach depths of 18 inches below the work surface. The degree of soil compaction is usually measured in the field during construction using a handheld penetrometer. Although handheld penetrometers are good field tests during the construction process they have many inherent problems and measurements are often collected at inappropriate times. An alternative testing procedure, if compaction is a concern post-construction, is a constant rate cone penetrometer, GPS mapped; and with graphs of the compaction profile in 2 inch increments are created to aid in determining the depth and thickness of the compacted layer. Spring time, prior to planting, is the most appropriate time of the year to obtain defensible and accurate constant rate cone penetrometer data.
If you think compaction might be limiting your reclamation success you should test both on and off-ROW to determine if your construction activity is the cause because not all compaction is due to project related activities. An accurate soil compaction assessment can be done cost effectively which will allow the pipeline to prepare proper decompaction plans and save money by only decompacting those areas where they are responsible. Proper and timely decompaction allows the farmer to return to full productivity more quickly and limits costly crop loss payments beyond the pre-construction negotiated terms. Duraroot has the right equipment and professional staff to efficiently identify the compaction problem, determine if it is due to previous construction activities and establish an effective and efficient reclamation plan.
About the Author
Aaron DeJoia is a board Certified Professional Soil Scientist (#33232), Certified Professional Agronomist (#33232), and Certified Crop Advisor (#33232) with 16 years of experience as a soil science consultant for both international and domestic clients. He currently works as an environmental soil scientist/agronomist providing permitting, operational, reclamation and salinity remediation assistance to varying clients in both the private and public sectors. Aaron has served on the National Soils Certification Board and is currently serving on the Council of Soil Science Examiners and Soil Science Society of America Board of Directors. He was also the March, Soils Support Agriculture International Year of Soil Chairman for the Soil Science Society of America.
Aaron’s technical strengths are in soil science, weed management, water resources, and agronomy. His specific technical experience includes reclamation, crop and weed management plans, facility water management strategies to manage nutrient and salinity impacts, land application of biosolids, wastewater land application, NPDES permitting and soil chemistry. He has particular expertise in the reclamation of pipeline ROWs and oil and gas facilities throughout the United States. Aaron has assisted in the reclamation of over 15,000 acres of drastically disturbed lands from New Jersey to Wyoming.
Aaron can be reached at email@example.com