Trials were conducted on hill (slopes 50%—70%) with A..auriculiformis and Hopea ordorata. Results showed that it required time* 13.5 hours/ha to open pit for planting with an auger that is about 1/3rd of T1 and one-half of T2 . Trials showed no adverse affect on survival (80%) or growth of the mentioned species. Auger pits provide a significant environmental advantage over traditional pits. Amount (O.D.wt.) of soil excavated from T1 &T2 was 11.4 (T1 ) to 6.6 (T2 ) kg/pit, or 43.3 ton/ha** to 19.7 ton/ha** respectively. But in auger pits, amount of soil excavated was only 0.6 kg /pit, or 1.8 tons /ha. Although excavated soil is returned to planting pit, it is still vulnerable to erosion when rains begin. Erosion is very likely during planting period (monsoon) on steep slopes, roadsides and embankments. Trials showed that erosion loss from standard pits were 17.0 t/ha to 8.0 t / ha (40%—50% of excavated soil) but less than 0.2 t/ha from auger pits (only 10% of excavated soil). Auger was provided free of cost to CFs of 10 villagers of the watershed areas. They planted stumps of teak, polybag seedlings of G. arborea, jackfruit, Syzygium spp, lemon, Bambusa spp, A.auriculiformis, H.ordorata, Papaya, Olea europea, Eucalyptus spp. P. emblica, C. equisetifolia, etc, survived satisfactorily. Farmer’s attitude to adapt the technology was enthusiastic due to easy working and minimizing time but they did not consider the minimizing of soil loss. But lesser soil loss by auger method contributing towards restoration of fertile topsoil too. The method needs popularization and large-scale auger preparation facilities.
In trial plot contour rows were established by hedge (species gliricidia, ipil-ipil, Indigofera tasmanii , Desmodium) at 4-6m distance. I. tasmanii showed better performance in SALT-1 and SALT-2. At 3 pruning (1st+2nd +3rd pruning 3.5+ 2.7 + 2.8=9.0 ton/ha foliage at 1.0m height) it produced 9.0 t/ha foliage. Estimated soil erosion loss was 15—20 t/ha and 12—18 t/ha in the 1st and 2nd year respectively at 65 % slope gradient (Paul and Emdad 2001). However, in SALT plot, CHTs Development Board (1996) allowed up to 35% slope gradient for seasonal crops, 35%—70 % for fruit trees and more than 70% for forest species. Soil erosion loss in improved AF practices is apparently less than traditional one. At Bandarban site the magnitude of soil erosion loss was found in the following order: fallow > pineapple > rice > agro forestry (Paul, et al., 1996). Under 55%—65% slope land condition (texture SCL-Cl) average soil loss was found 9.70 ton/ha, 27.86 ton/ha, 23.80 ton/ha and 7.70 ton/ha respectively in the cropping practice rice- fallow- pineapple and AF plots. Yield of some crops under SALT plot was as follows: Local rice (spatial mixed)-1.2t/ha; Rice, BARI-21 (spatial)-2.2t/ha; Maize (inter cropping)-2.6t/ha; Zinger (spatial)-18.0t/ha and local sesame (Inter mixed)-0.50t/ha. High labor involvement in hedgerow development under SALT sometime makes the hill farmers reluctant to adopt this technology. However, this attitude may be overcome through intensive training and motivational activities. But in the present study there was lack of seed source.
Expt-1 showed that at 1st year survival of seedlings were 50% but in the following year that was unable to compete under teak. Their stock density was 3,000 seedlings/ha. The cause of incompatibility of the introduced species may be due to canopy closeness (90%), heavy soil texture and very steep condition of the hill. In Expt-2 that survival was 95% in the 1st year but declined to 85% in the following year. Plantation floor was covered with different type of grass/weeds. There site quality was better than Expt-1. Soil erosion was estimated about 5.0 ton/ha. In one-year-old plantation till date the introduced species are showing compatibility with teak. The experiment needs continuity of the study.
Findings NVS trial plots were set up with 2CFs in 1.50 ha of land. Introduced forest (9), horticultural (7) and vegetables plants NVS lines were set up at 3m—5m distance and maintained a natural weed line of 0.50m—0.60m wide. At 1st year weed biomass was estimated 2 ton/ha (O.D wt.). Moisture content in weeds ranged 80%—90%. Field preparation was done at pre-monsoon and planting was carried out in monsoon. Most of the tree species (2,600 nos.) were planted by auger hole method. At 1st year survival of species were 98% and 85% in the next year. Forest species planted on upper slope, horticultural species in mid but only rice in valley was planted by farmer’s initiatives. Estimated soil loss was 7 ton /ha— 9 ton /ha in the 1st year but failed to collect in the following years. Farmers were happy with yield of banana, pineapple and papaya. It needs further study.