Soil health response to alternative cultivation practices in an organic system

Authors: GRIFFIN, KIMBERLY - UNIVERSITY OF MISSOURI; CLARK, KERRY - UNIVERSITY OF MISSOURI; KREMER, ROBERT - UNIVERSITY OF MISSOURI; VALDEZ, BETZABET - UNIVERSITY OF MISSOURI; Souliere Staples, Jill; Veum, Kristen

Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 12/6/2018
Publication Date: 1/6/2018
Citation: Griffin, K., Clark, K.M., Kremer, R.J., Valdez, B., Souliere Staples, J., Veum, K.S. 2018. Soil health response to alternative cultivation practices in an organic system [abstract]. Soil Science Society of America International Meeting, January 6-9, 2019, San Diego, California. Paper 115667.

Interpretive Summary:

Technical Abstract: Tillage is the dominant practice for weed control in organic agriculture; however, tillage reduces soil organic carbon and can alter soil properties which lead to soil degradation and erosion. This study evaluated soil health indicators for two alternative thermal weed control practices in row-crop grain production: propane flame and hot water spray along with a conventional tillage practice of between-row cultivation for comparison. All treatments were integrated into an organic system that included grain crops consisting of corn (Zea mays L.), soybean (Glycine max L.), and winter wheat (Triticum aestivum L) in a two year rotation. Other organic practices were utilized for a systems approach, such as compost application, crimped winter cover crops, and tillage after harvest. The study site was located in central Missouri in Mexico silt loam soil, and soil heath indicators included aggregate stability (AgStab), bulk density (BD), ß-glucosidase activity (BG), acid phosphatase activity (AP), phospholipid fatty acid (PLFA) biomass, permanganate oxidizable carbon (POXC), and soil organic matter (SOM). Hot water spray in conjunction with a crimped cover crop had the highest overall soil health indicator values and demonstrated a 15% increase of total PLFA biomass compared to cultivation. Propane flame exhibited soil health indicator values similar to cultivation treatment. Hot water spray demonstrated significantly greater soybean yield (2,098 kg ha-1; 22% increase) relative to cultivation, but no differences were detected in corn yield. Propane flame demonstrated a 10% reduction in corn yield (6,643 kg ha-1) compared to conventional cultivation. Overall, both thermal weed suppression practices demonstrated potential to sustain soil health when coupled with crimped cover crops and compost; however, caution must be used when flaming soybeans until improved delivery methods can be employed.