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

• Published in: Agronomy (Basel) Vol. 12; no. 3; p. 641
• Main Authors: Amorim, Helen C. S., Ashworth, Amanda J., Zinn, Yuri L., Sauer, Thomas J.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2022
• Subjects: Agricultural wastes; Agroforestry; Biomass; Calcium; Carbon; Carya illinoinensis; Chemical properties; Decomposition; Environmental conditions; Fertility; Fertilization; fertilization management; Fertilizers; Leaf litter; Nutrient availability; nutrient cycling; Nutrient retention; Nutrients; Organic carbon; Organic matter; Organic soils; Plant species; Poultry; poultry litter; Quercus rubra; Soil chemistry; Soil depth; Soil fertility; soil organic matter; Soil pH; Soils; Species; Sustainable development; Trees; United States > US
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy12030641

Tree species and fertilization sources may affect the soil organic carbon (SOC) and fertility in agroforestry (AF) systems in temperate regions, but this remains unexplored. This study assesses the longitudinal trends in the SOC and major nutrients in a 17-year AF site established on an Ultisol in Fayetteville, AR. We evaluated how management and fertilization (mineral vs. organic) affect the soil’s physical and chemical properties using the tree species: red oak (Quercus rubra L.) and pecan Carya illinoinensis (Wangenh.) K. Koch. Long-term applications of poultry litter increased the soil pH, whereas the Mg and S concentrations decreased compared to the baseline levels (1999). Poultry litter increased the soil P concentration in 53% compared to the baseline levels and reduced the soil C:N ratio. After 17 years, increased Ca, SOC, and N concentrations were observed in the soils under the pecan stands that received poultry litter. Positive correlations occurred between the SOC and N (r = 0.96) as well as the Ca (r = 0.71) and P (r = 0.61) at a soil depth of 0–15 cm. Our findings demonstrated that the changes in SOC and fertility in the AF soils vary according to tree species and fertilization, mostly due to distinctive leaf litter and nutrient inputs. Organic matter accumulation increased the SOC retention and nutrient availability in the temperate AF systems.