Soil Organic Carbon and Tree Density in Homegardens of Rangpur District, Bangladesh

Tropical agroforestry systems are considered to have a huge potential to sequester and store carbon (C) both in the aboveground biomass and the belowground biomass, as well as in soil. Compared to many other types of agroforestry systems homegardens are popular in the tropics and the sub tropics because they tend to sequester more C in soil than monoculture plantations and they can also serve as an important ecological tool in terms of species composition and storage of soil organic carbon (SOC). Tree species density is reported to be a important factor that influences SOC content in many of tropical agroforestry systems. This research was carried out to determine the SOC and tree density characteristics in homegardens in four selected villages in Rangpur district, Bangladesh. For determination of SOC, 128 number of soil samples were collected and combined to make a composite sample for each sampling depths (0­­­–10 cm and 15–25 cm) in each of the two different sampling sites of homegardens. Average estimated SOC was 49.24 Mg ha-1, where the size of the homegarden in related to tree density (1630 trees ha-1) resulted in the highest amount of SOC (63.62 Mg ha-1). This study demonstrates that homegardens with high tree density sequester more SOC.