Abstract
This study was conducted to determine the optimum plant population and cutting management of Atriplex sp. for biological amelioration of salt-affected soils. Two experiments were carried out for five years during 1992-96 at RRS, Daleep Nagar, Kanpur, India. The soil was low in organic C and N, medium in P, and high in K with low infiltration rates. A hard pan of CaCO3 was observed at the 60-90 cm depth. Soil pH varied from 10.2-10.5, with exchangeable sodium percentage >70. The treatments consisted of three plant populations of 5000 plants ha-1 (2 m x 1 m), 3333 plants ha-1 (2 m x 1.5 m), and 2500 plants ha-1 (2 m x 2 m) with three cutting schedules, viz., 60 cm, 80 cm, and 100 cm height yr-1. Litter biomass (3.5 t ha-1) of Mangifera indica was applied to all the treatments. Six-month-old seedlings of A. nummularia and A. amnicola were transplanted on 22 July 1992. Three irrigations were applied during summer in the first year to support the establishment of seedlings. Plant population, i.e., 5000 plants ha-1 of Atriplex sp. produced significantly higher biomass in comparison to the other two plant populations. Similarly, cutting of Atriplex sp. at 80-cm height was found to be superior in terms of productivity. The interaction of 80-cm plant height and 5000 plant ha-1 produced significantly higher green as well as dry biomass yield. Growth characteristics, viz., height, number of branches, number of nodes, basal and foliage cover, and leaf area index, significantly contributed towards biomass. When the produced biomass was fed to different livestock, it was acceptable to goats, sheep, cows, donkeys, buffaloes, and blue bulls. However, milch cattle refused to accept the biomass. Atriplex sp. could successfully be grown on salt-affected soils at 2 m x 2 m spacing and cutting at 80-cm height to rehabilitate salt-affected soils.
