The unique properties of NB, such as its nano-size effect and greater adsorption capacity, have the potential to mitigate ammonia (NH₃) emission, but may also pose threats to soil life and their associated processes, which are not well understood. We studied the influence of different NB concentrations on NH₃ emission, soil microbial biomass, nutrient mineralization, and corn nutrient uptake from farmyard manure (FM). Three different NB concentrations i.e., 12.5 (NB1), 25 (NB2), and 50% (NB3), alone and in a fertilizer mixture with FM, were applied to corn. NB1 alone increased microbial biomass in soil more than control, but other high NB concentrations did not influence these parameters. In fertilizer mixtures, NB2 and NB3 decreased NH₃ emission by 25% and 38%, respectively, compared with FM alone. Additionally, NB3 significantly decreased microbial biomass carbon, N, and soil potassium by 34%, 36%, and 14%, respectively, compared with FM. This toxicity to soil parameters resulted in a 21% decrease in corn K uptake from FM. Hence, a high NB concentration causes toxicity to soil microbes, nutrient mineralization, and crop nutrient uptake from the FM. Therefore, this concentration-dependent toxicity of NB to soil microbes and their associated processes should be considered before endorsing NB use in agroecosystems.

Basic soil composition, or more precisely, soil organic matter, soil clay mineralogy and soil texture have been in the core of most infrared spectroscopy research for soils. Of course, nutrient availability, soil structure, soil microbial activity and soil fertility have also been a major subject of interest over the past two decades. The determination of soil nutrients is now becoming a routine work at large scale to gain high yield. The large number of soil nutrients determining techniques are used. The current paper presented that among tested techniques, Near-infrared reflectance spectroscopy (NIRS) is a best technique which has been used widely with minimum time, low in cost, ecofriendly and rapid determination of chemical, physical properties and organic matter present in soil. Obviously, this useful technique can be used to estimate properties such as mineral composition, SOM, water, percentage of carbon, nitrogen and clay content. It could be used directly in soil mapping, for monitoring soil, for making inferences about its quality and function, and making geomorphological interpretations of its distribution. The development of most accurate and trustworthy NIRS approaches are required.