No abstract

Precision agriculture is crucial for ensuring food security in a growing global population. Nutrients, their presence, concentration, and effectiveness, are key components in data-driven agriculture. Assessing macro and micro-nutrients, as well as factors such as water and pH, helps determine soil fertility, which is vital for supporting healthy plant growth and high crop yields. Insufficient soil nutrient assessment during continuous cropping can threaten long-term agricultural viability. Soil nutrients need to be measured and replenished after each harvest for optimal yield. However, existing soil testing procedures are expensive and time-consuming. The proposed research aims to assess soil nutrient levels, specifically nitrogen and phosphorus concentrations, to provide critical information and guidance on restoring optimal soil fertility. In this research, a novel chip-level colorimeter is fabricated to detect the N and P elements of soil onto a handheld colorimeter or spectrophotometer. Chemical reaction with soil solution generates color in the presence of nutrients, which are then quantitatively measured using sensors. The test samples are collected from various farmlands, and the results are validated with laboratory analysis of samples using spectrophotometers used in laboratories. ANOVA test has been performed in which F value > 1 in our study indicates statistically significant differences between the group means. The alternate hypothesis, which proposes the presence of significant differences between the groups, is supported by the data. The device created in this paper has crucial potential in terms of environmental and biological applications.

Hydrothermal liquefaction (HTL) is an evolving technology that can convert waste with high moisture and low energy content to electricity, heat, hydrogen and other synthetic fuels more efficiently. The lee Review article side is that the HTL process produces enormous amounts of wastewaters (HTWW), having high organic and nutrient load. The discharge of the HTWW would contaminate the environment and result in the loss of valuable bioenergy sources. The valorization of HTWW has drawn considerable interest. Therefore, this review highlights the valorization of wastewater during the HTL of biomass. The review paper begins with the discussion of the role of microalgae in valorizing the HTWW. The survey illustrates that the selection of appropriate technology is dependent on biomass characteristics of the microalgae. Finally, potential research opportunities are recommended to improve the viability of the HTL wastewater valorization for bioenergy production. Overall, this review concludes that combining various processes, such as microalgae-anaerobic digestion, and bio-electrochemical system -microalgae-anaerobic digestion would be beneficial in maximizing HTWW valorization.