Date of Graduation
8-2023
Document Type
Thesis
Degree Name
Master of Science in Crop, Soil & Environmental Sciences (MS)
Degree Level
Graduate
Department
Crop, Soil & Environmental Sciences
Advisor/Mentor
Savin, Mary C.
Committee Member
Ashworth, Amanda J.
Second Committee Member
Roberts, Trenton L.
Third Committee Member
Daniels, Michael B.
Keywords
Cover crops; Organic amendments; Poultry litter; Soil enzyme activity; Soil quality
Abstract
Improving soil health is a growing area of interest within large- and small-scale agricultural systems in Arkansas as producers face increasing input costs, increased awareness of variability and intensity in extreme weather events, decreasing resource availability, and suboptimal productivity related to environmental degradation. Practices aimed at improving soil health such as cover cropping and the use of organic amendments are increasingly recommended and adopted; however, research on optimal management in the Mid-South is lacking. Two studies were conducted to evaluate the effectiveness of soil health management under both small- and large-scale farming operations in Arkansas. The objective of the small-scale study was to evaluate the effect of cover crop (CC) termination and poultry litter (PL) application methods and subsequent crop, which included winter barley (Hordeum vulgare L.) and soft red winter wheat (Triticum aestivum L.), on enzyme activity, nutrient availability, soil carbon, and aggregate stability within the first year. Soil response to CC termination method and PL application method was minimal after only one year. Small grains had a more immediate effect on soil properties related to nutrient cycling, including acid phosphatase and arylsulfatase activities and nutrient availability. Results of a subsequent greenhouse study confirmed the importance of crop species influence on nutrient cycling. These studies indicate that while differences in soil health management may require more evaluation, crop species contribute within a short-time scale to soil rhizosphere dynamics. The objective of the large-scale study was to evaluate the effect of PL application rate combined with flood or furrow irrigation methods on nutrient cycling enzyme activity, nutrient availability, soil carbon, and soil respiration under recently land-leveled rice (Oryza sativa L.) production fields within one year. The results of this study did not consistently demonstrate a benefit in applying higher PL rates within the limited period of the study, regardless of irrigation method. The β-D glucosidase activity was the only soil enzyme to show greater concentrations under increased PL rates and flooded irrigation; however, all measurements of soil carbon were greater under the lowest PL rate combined with furrow irrigation. Soil respiration and nutrient availability were unaffected by PL rate and irrigation method in the first year. These results indicate that more than one year of PL application, under both flooded and furrow irrigated management, may be required to overcome the spatial variability and disturbance caused by land leveling. Overall, the results of both studies demonstrate that changes in soil health from management may not occur on a short-term basis, given the strong legacy effects of past management. However, these legacy effects are not inherently negative and support the role of soil conservation management in building resilient and healthy soils.
Citation
Holder, T. (2023). Short-term Response in Soil Health to Management Practices within Large- and Small-Scale Cropping Systems in Arkansas. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/4860
