Soil health indicators and crop yield in a long-term cropping system experiment

Authors: Sainju, Upendra; LIPTZIN, DANIEL - Soil Health Institute; Allen, Brett; Rana Dangi, Sadikshya

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2021
Publication Date: 4/13/2021
Citation: Sainju, U.M., Liptzin, D., Allen, B.L., Rana Dangi, S. 2021. Soil health indicators and crop yield in a long-term cropping system experiment. Agronomy Journal. 113(4):3675-3687. https://doi.org/10.1002/agj2.20673.
DOI: https://doi.org/10.1002/agj2.20673

Interpretive Summary: Long-term continuous cropping enhances soil health indicators and crop yield. Assessment of soil health or quality indicators in agroecosystem involves mostly chemical and some physical properties, but evaluation of biological properties is lacking. Researchers at ARS, Sidney, MT in collaboration with Soil Health Institute evaluated 56 soil health indicators that included soil physical, chemical, and biological properties from a 36-years-old tillage and cropping system experiment and related to crop yield. They reported that physical properties, such as soil aggregation, water holding capacity, and bulk density, chemical properties, such as aluminum, iron, and phosphorus concentrations, and biological properties, such as soil organic matter, microbial community abundance and activity, and enzymes enhanced with long-term continuous cropping compared to crop-fallow rotation and also related to annualized crop yield. Because most of the biological properties responded to tillage and cropping systems and related to crop yield as compared to one-third to one-half of physical and chemical properties, biological properties can be used as robust soil health indicators to include in routine soil test in addition to physical and chemical properties.

Technical Abstract: Soil health indicators that link to ecosystem services, such as water and nutrient cycling, crop yield, environmental quality, and biodiversity, are needed. We measured 56 soil physical, chemical, and biological properties as soil health indicators from a 36-yr-old tillage and cropping system experiment and related to crop yield in eastern MT. Tillage and cropping systems were fall and spring till continuous spring wheat (Triticum aestivum, L.) (FSTCW), no-till continuous spring wheat (NTCW), no-till spring wheat-barley (Hordeum vulgare L., 1984-1999) replaced by spring wheat-pea (Pisum sativum L., 2000-2019) (NTWP), and spring till spring wheat-fallow (STWF, traditional system). Wet soil stability index, average slake aggregate, Al, Cd, Fe, Mn, and P concentrations, soil organic matter, water-extractable C, ß-glucosidase, and autoclaved citrate-extractable protein (ACEPI) were lower, but bulk density and Cu concentration were greater with STWF than other treatments. Annualized crop yield was also lower with STWF than other treatments in most years. Annualized crop yield correlated positively with aggregate stability, wet soil stability index, average slake aggregate, water holding capacity, Al, Cd, Fe, K, P, S, Pb, and Zn concentrations, total C and N, water-extractable C and N, CO2 flush, microbial community and enzymes, but negatively with bulk density. Absence of crops during the fallow period reduced soil health indicators and crop yield with STWF compared to NTCW and NTWP. Because of significant response to management practices and relationship to crop yield, soil biological properties can be used in routine test to measure soil health in addition to physical and chemical properties.