Abstract
Barren laterite lands are available plenty in Kasargode District of Kerala, India and being used mainly for extracting laterite bricks for building construction. These lands are found barren due to lack of vegetation and rocky nature. Afforestation in these lands is very essential to avoid extraction of laterite bricks so as to prevent degradation of lands. To develop vegetation in these laterite lands the soil properties of laterite was examined as a first step of afforestation process. It was found that the soils have lack of plant growth promoting microbes (PGPM) and poor in major nutrients (N, P, K). Therefore, the PGPM specifically arbuscular mycorrhizal fungi (Glomus fasciculatum and Glomus geosporum) and bacteria (Azospirillum brasilense and Bacillus megaterium) were used for afforestation in laterite lands along with Swietenia macrophylla G. King a commercially important tree of Kerala, India. The laterite soils were collected and used as potting media for growing seedlings of S. macrophylla in nursery and the cultured PGPM were inoculated in to the seedlings of S. macrophylla and maintained for 3 months. The PGPM inoculated seedlings showed improved growth, biomass and nutrient uptake. Thereafter the seedlings were transplanted at laterite lands at Karmanthodi, Bovikanam, Kasargode, Kerala, India and monitored their growth for 12 months. The seedlings inoculated with PGPM showed up to 98% survival rate with improved growth. From this study it was understood that PGPM have the potential to increase the efficiency of plant growth system in S. macrophylla seedlings through supply of essential levels of N, P and K that helped for successful afforestation in hardy laterite lands.
Highlights
Laterite is a residual ferruginous rock commonly found in tropical regions and has close genetic association with bauxite
arbuscular mycorrhizal (AM) fungal spores were isolated from the collected rhizosphere soils samples of Acacia auriculiforms found grown naturally adjacent to the barren laterite lands at Kasargode, Kerala, India by the method of Gerdemann and Nicolson (1963)
Results of this study shows afforestation success with S. macrophylla be improved in barren laterite lands with use of Plant growth promoting microbes (PGPM) (Figures 3, 4, 5 and 6)
Summary
Laterite is a residual ferruginous rock commonly found in tropical regions and has close genetic association with bauxite. Lateritic soils are rich in iron and aluminum usually formed in hot tropical areas and showed rusty-red colour due to iron oxides They develop by intensive and long lasting weathering of the underlying parent rock. Laterite soil are widely used for arable cultivation, grazing and constructional purposes in the Northern part of Kerala (India). The mechanisms of PGPM are mobilization of nutrients (Lifshitz et al 1987) stimulation of root growth by production of phytohormones (Bothe et al 1992; Kloepper et al 1980) and antagonism against soil borne plant pathogens (Kloepper et al 1988). S. macrophylla is commonly found in northern parts of Kerala, India this tree was selected for afforestation in barren laterite lands as it has natural adaptation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
