In order to explore salt tolerant plant growth promoting rhizobacteria (PGPR), 121 isolates were recovered from Tsunami affected area of Andaman and Nicobar Islands, India, out of which 23 were grown at 10% NaCl. Out of total isolates grown at 10% NaCl concentration, 14 solubilized phosphate, 13 showed siderophore production, five showed Indole acetic acid (IAA) production and 16 produced one or more extra cellular enzymes. Isolates SJ10 and CR5 showed the highest enzyme production and PGP properties and five isolates showed antagonistic activity against Sclerotium rolfsii. Screening of potential isolates for nitrogen fixing gene (nifH) showed only three isolates (MM3, MM6 and MRC11) possessed nifH gene. Salt tolerant Bacillus PGPR could be used as a bio-inoculant to enhance the crop growth under Tsunami affected soils.

The Government of India is promoting natural farming (NF) which is evolved from our ancient heritage and traditional cultivation practices. Though NF has many advantages, it is facing several challenges like low yield in initial years, expecting high outputs from low cost of cultivation, lack of local cultivars and livestock, less availability of tree based diverse inputs, dependency on purchase or exchange inputs from other farm hold and dispute in farming type and crop composition. On these backdrops, sustainable and/or resilient agroforestry (AF) systems can be synergized by using principles and practices of AF with NF. This AF assisted NF hybrid model is helpful in diversification and restoration of agroecosystem. AF includes at least one livestock components along with perennial trees and agricultural crops. Trees and livestock based NF is the foremost nature based solution (NBS) for climate change mitigation, food security and land degradation neutrality. In NF, to prepare various plant protection formulations neem, pongamia and various perennial species byproducts are essential which can be substituted by tree components in AF. It also provides continues supply of inputs for jeevamrut and beejamrut preparations along with continuous biomass mulching through nitrogen fixing trees. In addition, AF assisted NF practices reduce methane emission from ruminating livestock by reducing heat stress and increasing the feed quality. Some studies on NF have indicated that yield levels were drastically reduced in several cropping systems. Instead of integrating tree and animal components, these studies focused solely on the multi-location evaluation of various cropping systems. Therefore, it would be premature to recommend its wide-spread adaption or adoption prior to scientific validation of this NF. This review provides detail information and implications of AF assistance in NF and recommends preferentially, climate resilient, economical, native and naturalized trees and livestock incorporation, along with amalgamation of traditional and improved AF practices.

The crop productivity in calcareous soils is low due to their low organic matter content, high pH levels and improper nutrient management without considering the indigenous nutrient supplying capacity and crop yield potential; therefore, this study was conducted for a quantitative assessment of the nutrient supplying capacity of a calcareous soil on the productivity of hybrid and conventional rice and maize crops using an omission plot technique. The treatments included the ample application of Nitrogen (N), Phosphorus (P), Potassium (K), Sulphur (S) and Zinc (Zn), and an unfertilized check and omissions of N, P, K, S and Zn in rice and maize for six cropping seasons. The impact of the nutrient omission towards crop productivity was highest for nitrogen followed by phosphorous, potassium, zinc and sulphur. The total grain yield (3 yr average) in the hybrid rice–maize system was highest (16.32 t ha⁻¹) for the optimum fertilized plot and lowest (6.34 t ha⁻¹) for the unfertilized check. The sustainable yield index indicated that hybrid and conventional rice-maize cropping systems were more sustainable in the amply fertilized plot than in the nutrient-limited and unfertilized treatment plots. The average percent contributions of nitrogen, phosphorous, and potassium from the soil towards total nutrient removal were 36, 80 and 137 kg ha⁻¹, in the hybrid system and 24, 54 and 104 kg ha⁻¹ in the conventional system, respectively. The return on investment (ROI) of the N, P, K, S and Zn for the hybrid rice was 21.2, 7.1, 6.7, 4.1, and 0.3 USD, respectively, while for the maize it was 28.8, 7.6, 4.9, 6.5, and 0.7 USD, respectively. The results suggest that there is a direct link between the soil nutrient supplying capacity and the nutrient requirements by different types of crops in calcareous soil; therefore, the omission plot technique used for the assessment of the indigenous nutrient supplying capacity could be used in the larger domain for improved nutrient management, through synchronization with a targeted crop yield for improved productivity, soil fertility, nutrient use efficiency and farm income.