S. H. Raihan, M. K. Hasan, M. A. Wadud, N. A. Roshni and J. Ferdous
Bangladesh’s soil organic matter is quite low. To replenish biodegradable materials, it is important to investigate the best organic amendment for enhanced crop production. A field study was carried out at the Agroforestry Field Laboratory of Bangladesh Agricultural University in Mymensingh from December 2019 to March 2020 to assess the influence of different tree leaf biomass applications on vegetative characters, yield contributing characters and yield of carrot. In this research, six experimental treatments were imposed, T0= represents the Control (recommended fertilizer dose), T1= Mander (Erythrina orientalis) tree leaf biomass, T2= Ipil-Ipil (Leucaena leucocephala) tree leaf biomass, T3= Minjiri (Cassia siamea) tree leaf biomass, T4= Jhau (Casuarina equisetifolia), T5= Sissoo (Dalbergia sissoo) tree leaf biomass, the experiment was conducted in a Randomized Complete Block Design (RCBD) with three replications. The results revealed that the tree fresh leaf biomasses significantly influenced the growth, yield and yield contributing parameters of carrots viz. plant height (cm), the number of leaves per plant, leaf length (cm), leaf breadth (cm), length of root (cm), diameter of root (cm), fresh weight of root (gm), dry weight of root (%) and yield of carrot (t/ha) at different days after seed sowing. The highest (28.72 t ha-1) root yield of carrot was obtained in the recommended fertilizer dose followed by the treatments of T2, T1, T3, T4 (23.98, 21.98, 21.26, 20.22 t ha-1) respectively, while the lowest (18.29 t ha-1) root yield was produced in the T5 treatment. When it came to root yield, the ipil-ipil tree outperformed the other tree leaf biomasses because it was closest to the appropriate fertilizer dose. The sissoo tree leaf biomass produced the lowest output in this situation. However, the green leaf biomass of ipil-ipil tree might be substituted for or applied in conjunction with inorganic fertilizer. In the agroforestry system, tree leaves can be used as a source of organic matter. This would greatly reduce the amount of chemical fertilizer needed to grow carrots in Bangladesh..
Keywords: Agroforestry; tree leaf biomass; organic matter; yield.