Soil quality assessment of an agroforestry system following long‐term management in the Ozark Highlands

Abstract

The Soil Management Assessment Framework (SMAF) is a quantitative soil quality (SQ) evaluation tool that is widely applied to assess soil response to specific agricultural management practices over time. Considering the reported SQ benefits of agroforestry (AF) systems and the potential usefulness of SMAF, the objective of this study was to evaluate the effects of tree species (pecan [Carya illinoinensis (Wangenh.) K. Koch] and northern red oak [Quercus rubra L.]), soil fertility source (poultry litter [PL] and inorganic N fertilizer [control]), and soil depth (0-15 and 15-30 cm) on SMAF-derived SQ indices after 17 yr of management at an AF site in northwest Arkansas. Averaged across soil depth, soil organic C scores under red oak with PL application had a lower score (0.48) than red oak fertilized with inorganic N (0.60) and pecan receiving long-term PL applications (0.60), which did not differ from pecan with inorganic N fertilizer application (0.51). Averaged across soil depth, the soil quality index (SQI) for pecan receiving PL applications was 1.1 times greater than that under red oak receiving PL and soils under pecan receiving inorganic N fertilizer. Soil quality assessments use in AF are novel, as SMAF has not been used to identify soil health in these systems, although specific tree crop codes need to be developed in SMAF. Results of this study demonstrate that soils planted under various tree species respond dissimilarly to fertilizer sources and that management may improve overall SQ.

Soil Organic Carbon and Nutrients Affected by Tree Species and Poultry Litter in a 17-Year Agroforestry Site

“…These results agreed with previous reports in the literature and demonstrated that SOM accumulation plays a major role in nutrient cycling and availability in AF systems [2,4]. Our findings may represent a guideline for improving the SOM accumulation, SOC retention, and fertility in temperate AF systems and, therefore, an opportunity to offset anthropogenic CO 2 emissions and improve soil quality [43].…”

“…These results demonstrated that poultry litter applications increased the overall soil fertility compared to the control treatment (inorganic fertilizer), with more pronounced effects in 2008. Organic fertilizers, such as animal manures, have been shown to neutralize soil acidity, increase nutrient levels, and improve biological activity and diversity relative to inorganic fertilizers, thus contributing to improved soil health [41][42][43].…”

Framework to develop an open‐source forage data network to improve primary productivity and enhance system resiliency

“…This stronger relationship suggests a greater dependence on receiving adequate precipitation for annual systems. Conversely, perennial systems were able to maintain near-normal (93%-112% of their expected productivity) under low-precipitation conditions, thus suggesting deep rooted perennial systems with greater diversity and likely greater microbial diversity and soil health (Gurmessa et al, 2021;Ylagan et al, 2021) are critical to sustainable food production, especially under current and future stochastic climatic conditions. Similarly, Sanford et al (2021) compared annual row crop systems with perennial systems in a 26-year experiment in the North Central United States and found that more diverse, perennial systems exhibited greater resilience under drought.…”

Using Apparent Electrical Conductivity to Delineate Field Variation in an Agroforestry System in the Ozark Highlands

“…Specific details on the 2016 to 2021 tree fertilizer amounts and application areas per tree species are presented on Table 1. Additional site establishment and management details have been reported [15,[17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”