Effects of conservation practices on soil quality compared with a corn-soybean rotation on a claypan soil

Authors: ALAGELE, S - University Of Missouri; ANDERSON, S - University Of Missouri; UDAWATTA, R - University Of Missouri; Veum, Kristen; RANKOTH, L - University Of Missouri

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2019
Publication Date: 11/1/2019
Citation: Alagele, S.M., Anderson, S.H., Udawatta, R.P., Veum, K.S., Rankoth, L.M. 2019. Effects of conservation practices on soil quality compared with a corn-soybean rotation on a claypan soil. Journal of Environmental Quality. 48(6):1694-1702. https://doi.org/10.2134/jeq2019.03.0121.
DOI: https://doi.org/10.2134/jeq2019.03.0121

Interpretive Summary: Restoration of degraded lands by adoption of recommended conservation management practices can rehabilitate watersheds and lead to improved soil and water quality. The objective of this study was to evaluate soil quality under different types of perennial buffer systems including grass buffers, biofuel crops, grass waterways, and tree-grass buffers. All buffer types were compared to a typical corn-soybean rotation. This study found that measures of soil biological and physical quality were improved under all perennial buffer systems relative to the row cropped system. In particular, soil carbon, a keystone soil quality indicator, was 16-49% greater under the perennial systems relative to the row cropped system. The grassed waterway demonstrated the highest soil quality of all perennial systems, and overall, soil quality measurements varied with depth and across the landscape. This study provides producers and land managers with information on the potential soil quality benefits of a wide range of perennial systems for improved agricultural management.

Technical Abstract: Restoration of degraded lands by adoption of recommended conservation management practices can rehabilitate watersheds and lead to improved soil and water quality. The objective of this study on claypan soils was to assess the effects of grass buffers (GB), biofuel crops (BC), grass waterways (GWW), agroforestry buffers (AB), and distance from tree within the AB treatment on soil quality compared with row crop (RC) management [corn (Zea mays L.)/soybean (Glycine max L.) rotation]. Soil samples were taken from 10 cm depth increments from 0 - 30 cm depth for GB, BC, GWW, and RC treatments with three replicates. For the AB treatment, samples were collected at 50 cm (AB50) and 150 cm (AB150) from the tree base. Soil samples were taken from summit, middle, and footslope landscape positions within the paired watershed study near Novelty, MO, USA. Soil quality parameters of ß-glucosidase, ß-glucosaminidase, dehydrogenase, fluorescein diacetate (FDA) hydrolase, soil organic carbon (SOC), total nitrogen (TN), active carbon (AC), and water stable aggregates (WSA) were measured. Results showed that soil enzyme activity (ß-glucosidase, ß-glucosaminidase, dehydrogenase, FDA), AC, WSA, and TN values were significantly greater (p<0.01) for the GB, BC, GWW, and AB treatments relative to the RC treatment. GB, BC, GWW, AB50, AB150 had 16%, 23%, 49%, 29%, and 21% higher SOC, respectively, than for the RC. The GWW had the highest soil quality values among all treatments. Within the AB treatment, the AB50 had higher values than AB150 for all measured soil quality parameters. The soil surface depth (0 – 10 cm) revealed significantly higher soil enzyme activity, WSA, AC, SOC, and TN relative to the second (10 – 20 cm) and third (20 – 30 cm) sampling depths. The footslope landscape position had the highest soil quality parameters compared to summit and middle landscape positions. Results showed that permanent vegetation management (trees and grasses) enhanced soil quality by improving soil microbial activity, organic matter accumulation, and aggregate stability. Therefore, these perennial vegetative practices have great agricultural and ecological importance.