Effect of Long-term Nutrient Management on Microbial Abundance, Resistance and Resilience in an Alfisol under Abiotic Stresses
| dc.contributor.advisor | Sarvendra Kumar | |
| dc.contributor.author | VISHWANATH | |
| dc.date.accessioned | 2019-11-14T09:51:23Z | |
| dc.date.available | 2019-11-14T09:51:23Z | |
| dc.date.issued | 2019 | |
| dc.description | T-10145 | en_US |
| dc.description.abstract | Information on soil resilience and resistant is of paramount importance for managing various abiotic stresses as anticipated under changing scenario of climate change. Longterm manuring and fertilization experiment could be considered as appropriate to study resistance and resilience in soil. In the the present investigation, abundance of microbial groups, their resistance and resilience of soil microbial function against abiotic stresses and relationships of resistance and resilience with abundance of microbial groups were studied. To accomplish these objectives, soil samples (0-15 cm depth) were collected from seven selected treatments (control, N, NP, NPK, NPK+hand weeding, NPK+FYM & NPK+Lime) under soybean (Glycine max) crop of in the kharif season of 2018 from the ongoing Long-term Fertiliser Experiment (LTFE) continuing at experimental farm of Birsa Agricultural University, Ranchi since the year of 1972. The samples were analysed for soil enzymes activities (dehydrogenase, fluorescein diacetate & β-glucosidase), organic carbon, microbial biomass carbon, substrate induced respiration and different microbial groups immediately after sampling (0 day). Soil samples were exposed to two different stress i.e. (i) heat (48 °C temperature for 24 h) (ii) moisture (air dry soil moisture content 1.2%) and incubated for 60 days at 28 ºC with optimal moisture content (2/3rd water holding capacity). Above mentioned soil parameters were analysed at 1, 15, 30 and 60 day(s) after stress. The results indicated that, long-term manuring and fertilization significantly affected enzymes activities, organic carbon, microbial biomass carbon, substrate induced respiration, metabolic quotient, and microbial groups (bacteria, fungi, Actinomycetes, and ammonia oxidising bacteria). Among the selected seven treatments, balanced fertilization with NPK (i.e., 100% NPK based on initial soil test values) + FYM (farmyard manure) showed the highest values of the above-mentioned soil parameters, while the control treatment consistently recorded the lowest values. By and large, balanced application of NPK along with hand weeding recorded significantly higher values of soil parameters over balanced application of NPK with weedicide. Abiotic stresses significantly decreased the enzymes activities, microbial biomass carbon, 83 substrate induced soil respiration (SIR) and different microbial groups. The magnitude of reduction varied between 30 - 84% for heat stress with corresponding value 25-88 in case of moisture stress. The extent of reduction of different soil properties due to stress was highest in N alone (100% N) and NP (100% NP) treatments. Interestingly, continuous hand weeding with balanced fertilization helped in build-up of higher resistance and resilience of soil biological parameters as compared to weedicide with balanced fertilizer application. Among the biochemical parameters, highest resistance index was observed with SIR, whereas, resilience of SIR ranged from 0.13 to 0.96 and –0.25 to 0.94 under heat and moisture stress, respectively. Dehydrogenase activity proved to be a good indicator of soil abiotic stress as had been least resilient against heat and moisture stress as compared to other soil enzymes. Among the soil microorganisms, resistance and resilience of ammonia oxidising bacteria was lowest, while fungi and actinomycetes were at par and higher than those of population density of bacteria. Moisture stress (drought) is more detrimental for soil biological functions than heat stress. Resistance index of dehydrogenase activity was more consistently associated with initial level of bacterial (r2=0.45) and AOB (r2=0.45) than Actinomycetes and fungi population under stress. However, under similar abiotic stress, resilience index of dehydrogenase activity at 15th day was correlated well with actinomycetes (r2=0.80) and bacterial (r2=0.77) population in soil. It can be concluded that, application of farmyard manure with balanced NPK was the most effective in improving the biochemical and microbial population as well as resistance and resilience of capacity of biological functions in soil against the heat and moisture stress. Key words: soil function, abiotic stress, soil microbes, manuring and fertilization | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810135323 | |
| dc.keywords | soil function, abiotic stress, soil microbes, manuring and fertilization | en_US |
| dc.language.iso | en_US | en_US |
| dc.publisher | DIVISION OF SOIL SCIENCE AND AGRICULTURAL CHEMISTRY ICAR-INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI | en_US |
| dc.sub | Soil Science and Agriculture Chemistry | en_US |
| dc.subject | null | en_US |
| dc.theme | Effect of Long-term Nutrient Management on Microbial Abundance, Resistance and Resilience in an Alfisol under Abiotic Stresses | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Effect of Long-term Nutrient Management on Microbial Abundance, Resistance and Resilience in an Alfisol under Abiotic Stresses | en_US |
| dc.type | Thesis | en_US |