Tree-crop interaction as affected by tree spacing and pruning management in Bangladesh.
Samsuzzaman S., Ali M. A., Momin M. A., Karim M. R., Uddin M. M.
Author Affiliation: Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh.
Indian Forester 128 : 1231-1244
Abstract : Three studies were carried out in Bangladesh to generate some basic information on the effect of tree species on crops and thereby investigate alternative management practices for better system productivity. The first study involved a simple monitoring, conducted during January 1989-March 1990 at the Regional Agricultural Research Station in Ishurdi, of the yield of mustard and rice underneath six selected tree species (Acacia nilotica, Albizia lebbeck, Phoenix sylvestris, Acacia catechu, Mangifera indica and Artocarpus heterophyllus). Based on the results of the first study, a follow-up experiment was conducted during April 1990-March 1993 at the Agricultural Research Station in Pabna to investigate the effect of tree spacing (6 m × 1 m, 8 m × 1 m, 10 m × 1 m and 12 m × 1 m) and root pruning on tree-crop interaction. This experiment utilized wheat, rice and one-year-old Acacia nilotica in an alley cropping system. The third experiment involved the determination of the effect of shoot pruning on tree-crop interaction. This experiment was conducted at the Farming System Research site in Ishurdi and involved 10- to 12-year-old Acacia nilotica and Albizia lebbeck trees, and a rice-radish-wheat cropping pattern. The highest yield of mustard (0.788 t/ha) and rice (2.89 t/ha) was obtained under Albizia lebbeck and Acacia nilotica, respectively. The results of the second experiment indicate that the wider the tree spacing the lower the reduction in the yield of adjacent crops. Root and shoot pruning increased the grain yield of wheat by 22%. Shoot pruning also contributed to a significant fuelwood generation every season. Moreover, root and shoot pruning was found to reduce tree-crop competition, thereby enhancing crop yield. The highest increase in the yield of rice (27%) and radish (71%) were obtained due to pruning of Acacia nilotica two and three times a year, respectively. Pruning of Albizia lebbeck three times a year contributed to the highest increase in rice (50%) and radish (55%) yields.