The Effect of Fertilizer Rate and Pruning Material on Growth and Yield of Carrot (Daucus carota) under Alley Cropping System

The study was conducted at the Agroforestry Farm of Sylhet Agricultural University from October 2020 to March 2021 to evaluate the growth and yield performance of carrot and determine soil fertility status during the hedge establishment period of alley cropping. Hedges for alley cropping were established using ipil-ipil (Leucaena leucocephala) and vegetable hummingbirds (Sesbania grandiflora) tree species. The experiment was laid out in a randomized complete block design (RCBD). During the hedge establishment period, the carrot was cultivated in the alley of the hedgerow using four different treatments with three replications. The treatments were T0 (No application of fertilizer and pruning materials), T1 (application of recommended fertilizer dose), T2 (application of half dose of the recommended fertilizer + pruning materials), and T3 (application of pruning materials). The results exhibited that growth parameters, viz. plant height (cm), leaf number per plant, root length (cm), and root diameter (cm) of carrot were almost similar in all treated plots, except control (T0). The carrot yield was statistically similar in all fertilizer and pruning materials treated plots, but it was drastically reduced in the control plots and decreased by about 40-45% compared to fertilizer and pruning materials applied plots. During hedgerow establishment, soil pH among different plots has not changed significantly compared to the initial field, but organic matter (OM), nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) in different alleys found to be increased significantly in treatment T2 and treatment T1 after carrot cultivation. Improvement in soil fertility was also found in the alleys between the hedgerows of ipil-ipil and vegetable hummingbirds when only pruning material was applied to the soil. Therefore, an alley cropping system with Leucaena leucocephala and Sesbania grandiflora may enhance the yield performance of carrot and organically improve soil fertility during the hedge establishment period.