Changes in soil properties and fertility status caused by slash-and-burn fires in Nagaland Jamir Temsusangla I., Sharma Y.K.*, Sharma S.K. Department of Agricultural Chemistry and Soil Science, School of Agricultural Sciences and Rural Development, Nagaland University, Medziphema, 797106, Nagaland, India *Corresponding author (Email: yk2310sharma@rediffmail.com)
Online Published on 10 January, 2023. Abstract Slash and burn method of land clearing, an integral part of the traditional farming system, is widely practised by farmers in North Eastern states of India. Thirty sites in fifteen villages of Mokokchung district of Nagaland were selected for soil sampling to study the impact of first year slash and burn by farmers on physicochemical properties and macro- and micronutrient status. Pre-burnt sampling was done in January 2018 and soil samples were collected from primary forest fields chosen for slash-and-burn cultivation by the farmers. Post-burnt sampling was done from the same sites in May 2018, when farmers started sowing. The results revealed that the pH, electrical conductivity (EC), bulk density (BD), available phosphorus (P), available potassium (K), exchangeable calcium (Ca) and magnesium (Mg) increased significantly after biomass burning. In post burnt soils, the pH increased from 4.86 to 5.61, EC 0.15 to 0.18 dS m−1, bulk density 1.09 to 1.13 Mg m−3, available P 15.1 to 21.0 kg ha−1, available K 144 to 178 kg ha−1, exchangeable Ca 0.97 to 1.15 cmol(p+)kg−1 and exchangeable Mg 0.35 to 0.45 cmol(p+)kg−1. Porosity, soil organic carbon, available N, available S, DTPA extractable zinc (Zn), manganese (Mn), iron (Fe) and copper (Cu) decreased significantly in post burnt soils. Porosity decreased from 53.01 to 50.95%, soil organic carbon 23.56 to 19.01 g kg−1, available N 366 to 311 kg ha−1, available S 26.9 to 21.2 kg ha−1, DTPA extractable Zn, Mn, Fe and available Cu from 1.00 to 0.78, 29.36 to 25.13, 58.4 to 50.3 and 0.64 to 0.58 mg kg−1, respectively. Soil texture and particle density did not affect remarkably due to biomass burning. In some cases soil colour became lighter after biomass burning. Top Keywords Mokokchung district, Nagaland, Slash-and-burn, Soil properties, Macronutrients, Micronutrient cations. Top |