Effect of species diversity levels and microbial consortium on biomass production, net economic gain, and fertility of marginal land

Abstract

AbstractIncreasing the income of crop growers per unit area and restoring the fertility of marginal soils are major challenges of agricultural sustainability in the Indian agrarian economy. This study investigates the benefits of plant communities consisting of Indian licorice (Abrus precatorius L.), stevia (Stevia rebaudiana B.), chilli (Capsicum annum L.), and a microbial consortium of four plant growth‐promoting bacteria and fungi (Bacillus pseudomycoides, Bacillus firmus, Aspergillus luchuensis, and Aspergillus tamarii) on production of plant biomass, income of growers, and its ability to improve soil fertility over a 2 year period. The three crop species were planted in all possible groupings at one, two, and three species diversity levels with three replication and two treatments, that is, with plant growth‐promoting microbes (PGPM) and without PGPM. The maximum increases in biomass (6.8 mega gram ha−1) and aboveground carbon sequestration (3.2 mega gram ha−1) were found for the three species diversity level of LSC (Indian licorice–stevia–chilli) plus PGPM. The highest belowground carbon sequestration (35 mega gram ha−1) and maximum soil fertility benefits [for example, pH (1.16‐times), electrical conductivity (7.53‐times), bulk density (1.84‐times), soil total organic carbon (3.99‐times), available nitrogen (5.95‐times), dehydrogenase (6.16‐times), microbial biomass carbon (4.06‐times), and colony‐forming units (4.44‐times)] were recorded at the two species diversity level of LC (Indian licorice‐chilli) with and without PGPM, compared with the soil properties before cultivation of these plants/additives. The highest net income (9.9 Lac ha−1 yr−2) was estimated for the two species diversity level (LS) plus addition of PGPM.