Abstract
The experiment was carried out in Char Kalibari of Old Brahmaputra River under Sadar Upazila, Mymensingh, during the period from March, 2011 to September, 2014, to develop agroforestry practices for char land based farming system. In this study, eleven different vegetables viz., chilli (Capsicum annuum), sweetgourd (Cucurbita moschata), sweet potato (Ipomoea batatus), radish (Raphanus sativus), carrot (Daucus carota), coriander (Coriandrum sativum), bittergourd (Momordica charantia), Kangkong (Ipomoea reptans), Indian spinach (Basella alba), Amaranth (Amaranthus spp.) and Okra (Abelmoschus esculenta) were grown in association with nine different timber and fruit tree species viz., mahogany (Swietenia macrophylla), eucalyptus (Eucalyptus camaldulensis), lombo (Khya sp.), karanja (Pongamia pinnata) and akashmoni (Acacia auriculiformis), mango (Mangifera indica), guava (Psidium guajava), jujube (Zizyphus spp.) and lemon (Citrus spp.) under six different experiments in winter and summer seasons. Six different experiments of this study were: (i) Winter vegetable cultivation in association with Akashmoni tree, (ii) Sweet gourd cultivation with different fruit and timber tree species, (iii) Bitter gourd cultivation with different fruit and timber tree species, (iv) Radish cultivation as leafy vegetable with different fruit tree species, (v) Summer vegetable cultivation with different timber tree species, and (vi) Summer vegetable cultivation with different fruit tree species. In each study year (Year-1, year-2 and year-3), these six experiments were conducted as repetition of previous year. Seedlings of all tree species were transplanted during March, 2011, after establishment of the transplanted tree seedlings different vegetables cultivation were started from winter, 2011 and continued up to summer, 2014. It was found that growth and yield of all tested summer vegetables were better in open field condition in all vegetables cultivation year. During year-1, growth and yield of all tested vegetables either in winter or summer season was not significantly affected by different timber and fruit trees, during year-2, it was significant and during year-3, it was more significant. Average yield reduction of different vegetables during year-1, year-2 and year-3 was 4.76, 18.30 and 36.76%, respectively. It was found that average yield reduction with different timber and fruit tree species also gradually increased with the increasing time period (2011-14) but rate of variation was not similar. During second and third year, vegetable yield reduction was maximum with lemon tree (23.3 and 56.66%) followed by jujube (22.67 and 49.3%), eucalyptus (22.58 and 41.66%) and akashmoni (20.52 and 33.65%) tree. Vegetable yield reduction with mahogony, lombo, karanja, mango and guava tree was remarkable and rate of reduction was almost identical both in year-2 (\(\cong \) 16%) and year-3 (\(\cong \)27%). From benefit cost analysis it was found that gross return from fruit and timer trees gradually increased over time period. Finally, it was found that gross income of this study was also gradually increased over time period i.e. year-1, year-2 and year-3. Though vegetable yield decreased remarkably but considering other returns from fruit and trees as well as ecological consideration, this study will be a viable farming system for char land of Bangladesh.