ASSESSING THE IMPACT OF DIFFERENT POPLAR CLONES ON SOIL PROPERTIES, NUTRIENT CYCLING, AND LITTER DECOMPOSITION IN A SIXYEAR-OLD AGROFORESTRY PLANTATION

Poplar trees are increasingly significant due to rising wood demand and declining land productivity.A study at Dr. Rajendra Prasad Central Agricultural University, Pusa (Samastipur), evaluated the impact of seven six-year-old poplar (Populus deltoides Bartr.)clones (PAU-1, PAU-2, PAU-3, PAU-4, S-1, S-2, and G-48) on soil physicochemical properties, litterfall, nutrient cycling, litter decomposition, and nutrient release.Clones were planted in a randomized block pattern with three replications at a spacing of 42 meters.Soil samples were collected from seven poplar clones and open field sites at depths of 0 to 15 cm and 15 to 30 cm respectively.The G-48 clone showed the most notable pH reduction (0.197 units), followed by PAU-1 (0.180 units), while S-2 showed the least change (0.045 units).Electrical conductivity (EC) was lower under all plantations compared to open areas.Available macronutrients (N, P 2 O 5 , K 2 O) improved for all plantations, with G-48 and PAU-1 showing the most significant enhancement.Clones G-48, PAU-1, and PAU-2 notably decreased bulk density and increased wet aggregate stability, with G-48 showing the highest stability.G-48 also had the highest litterfall (3.79 Mg ha -1 ), followed by PAU-1 (2.98 Mg ha -1 ) and S-2 (1.42 Mg ha -1 ).The nutrient return order was N > K > P for all clones, with G-48 showing the greatest return.Leaf litter decomposition was fastest in G-48, PAU-1, and S-1, with half-lives of 47-58 days.G-48 exhibited unique nutrient release patterns, including initial immobilization of N and P for 150 days, followed by mineralization, while K showed continuous mineralization.The study highlights the diverse effects of Poplar plantations, particularly G-48, on soil properties and ecosystem dynamics, emphasizing their potential for enhancing soil quality and sustainable land management.