Evaluation of Different Agro-forestry Systems for their Effect on Alkali Soils

A field study was conducted to find out the suitable agro-forestry systems for a highly alkali soil and their effect on improving the soil properties at Central Soil Salinity Research Institute, Regional Research Station, Lucknow. The soil was poor in organic carbon (OC 0.08%) and available nitrogen (94 kg N ha-1) but high in available phosphorus (25 kg P2O5 ha-1) and potassium (237 kg K2O ha-1). The treatments included T1: Kallar grass (Leptochloa fusca) for 4 years followed by Gutton panic (Panicum maximum) grass (without amendments); T2: Vilayati babul (Prosopis juliflora) as sole tree crop; T3: Desi babul (Acacia nilotica) as sole tree crop; T4: Vilayati babul (Prosopis juliflora) + Kallar grass (Leptochloa fusca) for 4 years followed by berseem (Trifolium alexandrinum) for 3 years (without amendments) and T5: Desi babul (Acacia nilotica) + Kallar grass (Leptochloa fusca) for 4 years followed by Rhodes grass (Chloris gayana) for 3 years. After 84 months of planting, all the growth parameters including survival per cent, plant height, diameter at breast height (DBH), diameter at stump height (DSH) and lopped biomass of Prosopis juliflora and Acacia nilotica grown in combination with inter crops of grasses were higher as compared to the sole plantation. Plant height was recorded to be 20 and 14% higher in Prosopis juliflora and Acacia nilotica, respectively grown in combination with grasses than the sole plantation of these species. The pH of the surface soil (0-15 cm) with Prosopis juliflora in combination with kallar grass (Leptochloa fusca) for 4 years followed by berseem (Trifolium alexandrinum) for 3 years silvipastoral system has reduced to the level of 8.87. However, pH was > 9.0 in case of the remaining treatments. Vilayati babul (Prosopis juliflora) + berseem (Trifolium alexandrinum) silvipastoral system gave highest net return (Rs. 15,155 ha-1 yr-1) followed by gutton panic (Panicum maximum) as sole crop (Rs. 7,660 ha-1 yr-1) than the sole plantation of Prosopis juliflora (Rs. 5,610 ha-1 yr-1) and Acacia nilotica (Rs. 3,260 ha-1 yr-1), and appeared to be the most suitable and economically viable alternate land use system for alkali soils.