Department of Biotechnology, The Neotia University (TNU), Sarisha, West Bengal, 743368, India.
Department of Microbiology, Kingston College of Science, Barasat, Kolkata, 700126, India.
Environ Monit Assess. 2020 Mar 20;192(4):245. doi: 10.1007/s10661-020-8200-y.
Several strategies were undertaken to increase the fertility of landfill soil as rapid urbanization remarkably decreases the agricultural land, posing challenges to the fast-growing human population. Towards this direction, soil microcosms were prepared wherein the addition of nutrient or biofertilizer or the combination of both increased the soil nitrogen and phosphate content considerably. The maximum amount of nitrogen fixation and phosphate solubilization occurred in microcosm treated with biofertilizer and nutrient. To investigate the underlying cause, we observed that separate application of nutrient or biofertilizer or combined application of both increased the abundance of nitrogen-fixing and phosphate-solubilizing bacteria in the microcosms. However, the highest abundance of nitrogen-fixing and phosphate-solubilizing bacteria was spotted in a microcosm challenged with nutrient and biofertilizer together. It was detected that with increasing population of nitrogen-fixing and phosphate-solubilizing bacteria, the soil nitrogen and phosphate level also got enhanced, respectively, thus establishing a strong positive correlation between them. The microcosm treated with biofertilizer and nutrient manifested the highest degree of heterotrophic microbial growth and microbial activity than the microcosms either treated with nutrient or biofertilizer. The microcosm treated with nutrient and biofertilizer was found to exhibit the highest functional diversity compared to others. A surface plot was constructed to demonstrate the association among microbial activity, functional diversity, and the availability of soil nitrogen and phosphate content of soil. The result indicates that the combined application of nutrient and biofertilizer increases the microbial activity leading to the formation of a heterogeneous ecosystem that enhances the nitrogen and phosphate content of landfill soil considerably.
为了应对快速城市化导致可用于农业的土地显著减少、给快速增长的人口带来挑战的问题，人们采取了多种策略来提高垃圾填埋场土壤的肥力。为此，人们制备了土壤微宇宙，在其中添加养分或生物肥料，或者两者结合，可显著增加土壤中的氮和磷含量。在添加生物肥料和养分的微宇宙中，固氮和溶磷的量达到最大。为了探究其中的原因，我们发现，单独添加养分或生物肥料，或者两者同时添加，都能增加微宇宙中固氮和溶磷细菌的丰度。然而，在同时添加养分和生物肥料的微宇宙中，固氮和溶磷细菌的丰度最高。我们还发现，随着固氮和溶磷细菌数量的增加，土壤中的氮和磷含量也分别得到了提高，因此二者之间存在很强的正相关性。与单独添加养分或生物肥料的微宇宙相比，同时添加养分和生物肥料的微宇宙中的异养微生物生长和微生物活性更高。与其他微宇宙相比，同时添加养分和生物肥料的微宇宙的功能多样性最高。我们构建了一个曲面图来展示微生物活性、功能多样性以及土壤氮和磷含量之间的关系。结果表明，养分和生物肥料的联合施用可以提高微生物活性，形成一个异质的生态系统，从而显著提高垃圾填埋场土壤的氮和磷含量。
