Soil quality indices as affected by long-term burning, irrigation, tillage, and fertility management

Authors: AMORIM, HELEN - University Of Arkansas; Ashworth, Amanda; BRYE, KRISTOFOR - University Of Arkansas; Wienhold, Brian; SAVIN, MARY - University Of Arkansas; Owens, Phillip; SILVA, SERGIO - Universidade Federal De Lavras

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/23/2020
Publication Date: 3/3/2021
Publication URL: https://handle.nal.usda.gov/10113/7709402
Citation: Amorim, H., Ashworth, A.J., Brye, K.R., Wienhold, B.J., Savin, M.C., Owens, P.R., Silva, S. 2021. Soil quality indices as affected by long-term burning, irrigation, tillage, and fertility management. Soil Science Society of America Journal. 85:379-395. https://doi.org/10.1002/saj2.20188.
DOI: https://doi.org/10.1002/saj2.20188

Interpretive Summary: Long-term agricultural practices such as tillage, residue burning, fertilization, and irrigation can affect soil health and crop productivity. Researchers investigated the impacts of long-term management practices on soil health and quality using a framework named "Soil Management Assessment Framework" or SMAF. For 16 continuous years, a wheat-soybean double-crop system was conducted in the Lower Mississippi River Delta region of Arkansas. Researchers measured topsoil compaction, organic matter, and nutrients and then calculated soil quality scores for each management practice. Long-term irrigation and high residue management combined with no-tillage reduced soil quality scores compared to dryland, non-irrigated, and conventional tillage systems. Thus, it is recommended that land managers monitor soil fertility over time to maintain soil health in wheat-soybean systems as best management practices may have diverging soil quality impacts.

Technical Abstract: Understanding the impacts of long-term agricultural management practices on soil quality (SQ) is key for sustaining agroecosystem productivity. This study aimed to investigate tillage, residue burning, residue level, and irrigation effects on soil properties, SQ, and crop yields following 16 years of consistent management in a wheat (Triticum aestivum L.)-soybean [Glycine max (L.) Merr.], double-crop system using the Soil Management Assessment Framework (SMAF). A field experiment was conducted between 2001 and 2018 in the Lower Mississippi River Delta region (AR) on a silt-loam soil. Bulk density (BD), soil organic C (SOC), soil organic matter (SOM), total N, pH, electrical conductivity (EC), and soil P and K from the 0- to 10-cm soil depth were used as SQ indicators, and investigated individually and as an overall soil quality index (SQI). In 2018, residue burning had lower SOC and SOM (1.1 and 2.3%, respectively) compared to non-burning (1.24 and 2.6%, respectively); the high-residue treatment had greater wheat and soybean yields (3.39 and 2.84 Mg ha-1, respectively) compared to the low-residue treatment (2.55 and 2.48 Mg ha-1, respectively); and irrigation had greater soil N (0.12%) compared to dryland (approximately 0.08%). Reduced soil pH and extractable soil P and K were measured under no-tillage (NT), high-residue, and irrigated treatments. Irrigation reduced SQ due to low EC and K scores. High-residue reduced SQ compared to the low-residue treatment within NT systems due to low pH score. The SMAF indices provided an overview of the effects of long-term agricultural practices on SQ and revealed the limiting factors of SQ. Monitoring soil fertility may be needed to maintain SQ in long-term, wheat-soybean systems.