Effects of perennial aromatic grass species richness and microbial consortium on soil properties of marginal lands and on biomass production

Abstract

This study investigates the effects of perennial grass species richness levels and consortium of three bacteria on properties of a slightly alkaline soil and on biomass production of grasses. Four species of perennial aromatic grasses namely: vetiver (Vetiveria zizanioides), lemongrass (Cymbopogon citratus), palmarosa (Cymbopogon martinii), and citronella (Cymbopogon winterianus) were planted in all possible combinations at one, two, three, and four species richness levels in a randomized block design with three replications and two treatments, these were PGPR+ (with plant growth promoting rhizobacteria) and without (PGPR−). Species and richness level specific changes in soil physicochemical properties: electrical conductivity (EC); bulk density (BD); total soil organic carbon (TOC); available nitrogen (Nav), microbial colony forming unit (CFU); microbial biomass carbon (MBC), and enzymatic alkaline phosphatase (ALKP) and dehydrogenase activity (DHA) were observed. The highest reduction in soil pH and EC and increase in soil TOC, CFU, Nav, MBC, and enzymes activities were found at two species richness levels of vetiver and lemongrass in both PGPR+ and PGPR− plots followed by monoculture of vetiver. The highest annual total dry biomass 22.8 and 27.5 Mg ha−1 was produced by monoculture of vetiver in PGPR− and PGPR+ plots, respectively, with similar values at two species richness levels of vetiver and lemongrass in PGPR− and PGPR+ plots. The highest plant carbon was found in vetiver monoculture and two species richness levels of vetiver and lemongrass. The soil carbon sequestration potential was highest at two species mixtures of vetiver–lemongrass and lemongrass–palmarosa as well.

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

“…In our study, significant changes in soil physicochemical and biological properties were recorded after 2 years, which may possibly be a consequence of consistent root formation by all the three plants in the various combinations used. Similar impacts were recorded with (designed diversity) aromatic grasses in a similar agroecosystem by Maddhesiya et al (2021). Our highest increase was recorded for the two species diversity level (LC), probably because legumes perform well in intercropping system by fixing atmospheric nitrogen and by facilitating water retention and moisture availability (Angus et al, 2015; Gan et al, 2016) and improving soil organic matter and texture (Stagnari et al, 2017), phosphorous fixation and mobilization (through secretion of organic acids like citrate, malate, etc.)…”

“…Many biological and chemical practices are in use to improve the quality of marginal/degraded land (Gill et al, 2009). Several salt or alkali tolerant varieties of major crops like rice, wheat, mustard, acacia spp., sorghum, and a number of useful perennial grass species have been developed, which can be grown on the marginal soils (Awasthi et al, 2017; Huang, 2018; Maddhesiya et al, 2021; Singh et al, 2018; Wang et al, 2018; Ye et al, 2020).…”

Bacillus sp. and arbuscular mycorrhizal fungi consortia enhance wheat nutrient and yield in the second-year field trial: Superior performance in comparison with chemical fertilizers

“…PGPB regulate the flavonoid genes expression in the rhizospheric soil that increases their SOC and SOM levels (Shahzad et al, 2015). Furthermore, PGPB and AMF inoculation are involved in the reclamation or restoration of marginal soil through positive modulation of soil properties by decreasing soil pH, EC and increasing ß-d-glucosidase (BD), and SOC (Maddhesiya et al, 2021). Enhanced morphological and physiological traits of wheat plant support their effectiveness in improving soil health (Yergeau et al, 2020).…”

PGPR Mediated Alterations in Root Traits: Way Toward Sustainable Crop Production

“…Selection of suitable microbial inoculant is important to improve agriculture land capability to sequester and store carbon (Ahmed et al, 2019). Microbial consortia of (Pseudomonas protegens, Bacillus paramycoides and Bacillus paramycoides) when applied in tall perennial aromatic grass species including vetiver (Vetiveria zizanioides), lemongrass (Cymbopogon citratus), palmarosa (Cymbopogon martinii), and citronella (Cymbopogon winterianus) improved the carbon sequestration (Maddhesiya et al, 2020). High C: N ratio of soil treated with PGPR highlight the significant role of inoculants in enhancing carbon sequestration.…”