Uma Karki

Microclimatic differences between mature loblolly-pine silvopasture and open-pasture

Information is needed on microclimatic differences present in different landscapes, such as open-pasture versus silvopasture, in the Southeast USA. This research tested a hypothesis that microclimatic conditions in mature-pine silvopasture would be milder compared to open-pasture. The research objective was to quantify microclimatic differences between mature-pine silvopasture and open pasture. The research was conducted in a loblolly-pine (Pinus taeda L.)-bahiagrass (Paspalum notatum Flugge) silvopasture and an open bahiagrass pasture, 5-ha each, in Chipley, Florida. Microclimatic parameters (air temperature, soil temperature at 5- and 10-cm depths, wind speed, gust speed, wind direction, humidity, dew point, rainfall, soil-moisture content, total solar radiation, and photosynthetically active radiation) were collected from November 2005 to January 2008 using HOBO© weather stations located in each pasture type. Data were analyzed to determine overall, as well as seasonal, monthly, and diurnal differences between pasture types. Evapotranspiration was calculated from air temperature, wind speed, relative humidity, and total solar radiation. The overall average values for all microclimatic parameters were lower in silvopasture compared to open-pasture. Seasonal, monthly, and diurnal differences between pasture types were also detected for several parameters. These results indicate that milder microclimatic conditions occur in silvopasture versus open-pasture on the Coastal Plain of the Southeast USA.

Agroforestry research and extension education at 1890 universities and its impact in the Southeast

Agroforestry is a sustainable land-use system that involves an intentional integration and management of trees, crops, and/or livestock in a single management unit. Well managed agroforestry systems offer more economical, environmental, and social benefits compared to monocultures of its components. Continuous research, education, and extension efforts are necessary to promote agroforestry practices. Agroforestry research, education, and extension activities ongoing at the 1890 universities located in the South and the Federation of Southern Cooperatives/Land Assistance Fund, Epes, Alabama are presented in this article. Additionally, some of the funding support received by these institutions to conduct agroforestry activities, and the involvement of professionals, farmers, landowners, and students in these activities are discussed.

Diurnal behavior and distribution patterns of Kiko wethers in southern-pine silvopastures during the cool-season grazing period

Goats are commonly used to utilize the understory vegetation in pine silvopasture systems. Understanding goats’ behavior and their distribution patterns is necessary to manage this system well. The objective of this study was to evaluate the diurnal behavior and distribution patterns of goats in Southern-pine silvopastures during the cool-season grazing period. This study was conducted in 2015 and 2016 in Tuskegee, Alabama, USA. Eight different cool-season forages were planted in separate subplots within each plot in mixed-pine silvopasture systems with three replications (3 plots, 0.4-ha each) in the fall of 2014 and 2015. Trees in the silvopasture consisted of longleaf (Pinus palustris Mill.) and loblolly pine (Pinus taeda L.). Twenty-eight Kiko wethers were rotationally stocked in the silvopasture plots in April 2015, and January to April 2016. When study began, trees were 10 years old (DBH: 12 ± 0.2 cm; height: 7 ± 0.1 m), and animals were 5–7 months old. The diurnal behavior (grazing, browsing, loafing, lying, and debarking) and distribution patterns of goats were monitored from dawn to dusk for two consecutive days (2015) or one day (2016) in each plot at each grazing rotation. Grazing was the most dominant diurnal behavior (36–54%) of Kiko wethers followed by lying (29–34%) and loafing (15–22%). The distribution evenness index was more even in 2016 vs. 2015, spring vs. winter, and mid-day vs. morning. Goats also showed some debarking behavior (< 2%), mostly on longleaf pine. The study showed that goats’ behavior and distribution patterns were influenced by year (age), season, and part of the day.

Plant-community characteristics of bahiagrass pasture during conversion to longleaf-pine silvopasture

Silvopasture is considered a sustainable agroforestry practice as a result of benefits the system offers for biodiversity, economic returns, and environmental quality. However, little is known about temporal and spatial dynamics of forage species composition of pastures being converted to silvopasture. Research objectives were to determine (1) the response of forage species composition to a young longleaf pine (Pinus palustris Mill.)-bahiagrass (Paspalum notatum Flugge) silvopasture versus open bahiagrass pasture, and (2) the impact that alley position relative to trees has on forage species composition in a young longleaf pine-bahiagrass silvopasture. The research was conducted in a randomized complete block design with three replications from 2003 to 2007 at Americus, Georgia, USA in a longleaf-pine silvopasture established in 2000 in an existing bahiagrass pasture and an adjoining bahiagrass open-pasture. Silvopasture forage-species composition was measured within alleys. Plant community diversity was greater in the silvopasture versus open-pasture early in the growing season, but open-pasture had greater diversity during the later growing season. Alley position in silvopasture also had a significant effect on understory forage species composition. This study indicated that conversion of bahiagrass pasture to longleaf-pine silvopasture in the Southern Coastal Plain can influence plant-community characteristics by the time trees are six to seven years old.