Organic Matter and Water Stability of Field Aggregates Affected by Tillage in South Dakota

Abstract

Tillage has been associated with soil organic matter (SOM) decline. A case study of two adjacent farms was conducted in eastern South Dakota. One farm used no‐till (NT) and the other used chisel tillage (CT). We hypothesized that soil under NT, compared with tillage, would have both greater quantity and greater quality of SOM and that this improved SOM condition would result in increased water stable aggregation (WSA). A rotary sieve was used to sort dry field aggregates into six size groups: <0.4, 0.4 to 0.8, 0.8 to 2.0, 2.0 to 6.0, 6.0 to 19.0, and >19 mm. Water stable aggregation, soil organic C (SOC), N, glomalin, and basidiomycete fungi were measured. Fine particulate soil organic matter (fPOM, 0.5–0.053 mm) and coarse particulate organic matter (2.0–0.5 mm) were isolated by sieving. Quantitative solid‐state 13C nuclear magnetic resonance was used to determine C type in humic acid, humin, and whole soil. The fPOM/SOM ratio was greatest in <0.4‐mm aggregates and 24% greater in NT than CT. Soil organic C was greatest in 0.8‐ to 2.0‐mm aggregates and 11% greater in NT than CT. Average WSA was 63% greater under NT than under CT. Aggregate wettability was less under NT than CT. Slower water uptake under NT might be attributed to a greater abundance of wax‐type C under NT than under CT. We conclude that NT, compared with CT, resulted in better SOM quality during the course of 10 yr. Improved SOM quality was related to improved WSA.

Tillage Effect on Soil Organic Matter, Mycorrhizal Hyphae and Aggregates in a Mediterranean Agroecosystem

“…Water stable soil aggregates presented higher values under NT (59%) than CT treatment (32%) ( Figure 2A); these results are in accordance with previous studies (Castro Filho et al, 2002;Martínez et al, 2008;Pikul et al, 2009). There are various evidences in relation to the fact that the CT management produces a decrease in the soil aggregation due to mechanical effects or by destruction of the network of AMF fungal mycelium (Alvaro-Fuentes et al, 2008;Six et al, 1999;Wright and Upadhyaya, 1998).…”

Review: Redesigning Canadian prairie cropping systems for profitability, sustainability, and resilience

“…Positive effects of no-till on soil health parameters have been widely documented and include major reductions in soil erosion and fuel consumption, reduced CO 2 emissions, and enhanced water quality, biological activity, soil fertility and production stability (Pretty 2008;Derpsch et al 2010;Lafond et al 2011 and references therein). Studies in the NGP have also reported better soil aggregation, enhanced soil organic C, and increased potentially mineralizable N in no-till soils (McConkey et al 2003;Liebig et al 2004;Pikul et al 2009;Malhi et al 2009;Lafond et al 2011). Microbial biomass, especially of mycorrhizal fungi, is often, but not always, greater in no-till soils (Liebig et al 2004;Helgason et al 2010;Monreal et al 2011); soil organism community structure may also be different in no-till than tilled soils (Helgason et al 2010).…”

Crop and Soil Responses to Using Corn Stover as a Bioenergy Feedstock: Observations from the Northern US Corn Belt

“…Soil for dry aggregate size distribution was collected in the summer of 2011 within about 5 cm of the soil surface after removing visible surface residue. Dry aggregate size distribution using the method described by Chepil [39] and Pikul et al [40] was determined using a rotary sieve operating at 6-rpm to separate air-dried soil into six aggregate size groupings: 0-0.5, 0.5-1.0, 1-2, 2-3, 3-5, 5-9, and 9-20 mm. Total soil mass in aggregates <20 mm and mass of each aggregate size was determined.…”