Coastal afforestation effects on soil properties at Hatiya in Bangladesh

Abstract

An exploratory study was conducted in the coastal plantation (12- and 17-year-old Sonneratia apetala) of Char Alim and Char Piya and their adjacent barren lands at Char Rehania and Char Nurul Islam in Hatiya under Noakhali district in Bangladesh to determine afforestation effects on soil properties. At soil depths of 0–10, 10–30 and 30–40 cm across three different land strips viz. inland, middle and sea side in 12- and 17-year-old keora (Sonneratia apetala) plantations, soil moisture, particle density, organic matter and C, total N, pH, available P, K, Na, Ca and Mg were significantly (p≤0.05, p≤0.01, p≤0.001) higher, and soil salinity significantly (p≤0.001) lower than that in their adjacent barren lands. Soil moisture, particle density, organic matter and C, total N, pH, soil salinity, available P, K, Na, Ca and Mg of surface soil in Char Alim plantation at inland were 31.09%, 2.24 g·cm⁻³, 2.41%, 4.14%, 0.58%, 7.07, 0.09 dS·cm⁻¹, 28.06 mg·L⁻¹, 0.50, mg·L⁻¹ 11.5 mg·L⁻¹, 3.30 mg·L⁻¹ and 2.7 mmol·kg⁻¹, respectively. Their corresponding values for the same depth and land position at adjacent Char Rehania barren land were 16.69%, 1.25g·cm⁻³, 0.43%, 0.74%, 0.25%, 6.57, 0.13 dS·cm⁻¹, 13.07mg·L⁻¹, 0.30 mg·L⁻¹, 1.4 mg·L⁻¹, 0.30 mmol·kg⁻¹ and 0.50 mg·L⁻¹, respectively. Soil moisture, particle density, organic matter and C, total N, pH, available P, K and Ca decreased, and soil salinity, available Na and Mg increased from inland towards sea side in the plantations. Although soil texture did not differ in most soil depths between plantation and adjacent barren land, proportion of sand particle was significantly (p≤.01) lower and silt particle significantly (p≤0.001) in the plantations higher than that in their adjacent barren lands. In the study, evaluation of all the parameters was also done for the other pair of lands.