Volume 1 | Issue 1
Scholics Journal of Sustainability Minds and Markets
Site-Specific Nutrient Management and Plant Biostimulants For Enhancing Crop Productivity And Soil Health: A Review
Abstract
Site-specific nutrient management (SSNM) is the science and management of soil nutrients accounting for soil spatial and temporal variability to enhance productivity and environmental sustainability. It enhances productivity and quality in agriculture and agriculture-based activities while reducing resource use. Humic acids, seaweed extract, and plant growth-promoting rhizobacteria are among the biostimulants that improve the crop-microbiome system by promoting nutrient transport efficiency and optimizing the crop root structure. The purpose of this review is to give a full overview of the synergistic assimilation of Site-specific nutrient management (SSNM) and biostimulants as tools to improve crop and soil health. Chemical inputs are a major component of agricultural operations and can drive up short-term productivity, but lead to adverse long-term impacts on soil health and nutrient-use efficiency (NUE) and can cause pollution from agriculture in nonpoint source ways. Precision Nutrient Management (PNM) addresses these challenges by providing nutrients in real time in response to the metabolic needs of the crop through the use of real-time proximal crop sensors, satellite crop sensors, in-situ electrochemical soil diagnostics, and decision support systems (DSS). The effects of precision nutrient management and biostimulants on crop improvement and soil health were evaluated, considering the interaction between the two components, through 42 selected studies with special focus on existing challenges, gaps in research, and future perspectives. Existing evidence shows that the use of 25% synthetic inputs can be successfully replaced by integrating precision nutrient management and biostimulants in rainfed wheat systems to guarantee yield stability under environmental stress, improve nutrient use efficiency (NUE), enhance soil biological health, increase crop quality, reduce environmental losses, and present significant research contradictions such as the negative effect of mineral fertilizer co-application on soil microbial biomass carbon (Cₘᵢc) and the feedback inhibition of microbial activity by high doses of mineral fertilizers. The problems encountered in adoption, gaps in standardization, and prospects such as engineered synthetic microbial consortia (SynComs) and smart nano-sensors are discussed, laying the foundation for the development of self-optimizing and climate-resilient biotechnology. A circular bio-economic solution is proposed in this review: the integrative Microbe-Sensor Closed Loop (MSCL) framework.
Nano Fertilizers as a Potential Substitute for Conventional Fertilizers in Modern Agriculture: Evidence, Opportunities, Challenges and Future Perspectives
Abstract
Modern intensive agriculture relies heavily on synthetic fertilizers, yet nutrient-use efficiency (NUE) is low, typically 30–35% for nitrogen, 18–20% for phosphorus and 35–40% for potassium. The unrecovered fraction is lost through volatilization, leaching, runoff and soil fixation, and contributes to groundwater contamination, eutrophication and greenhouse gas emissions. Nano fertilizers, defined as nutrient formulations with at least one dimension in the 1–100 nm range, have been proposed as a way to improve nutrient delivery. This review synthesizes laboratory and field evidence on uptake mechanisms, agronomic performance, substitution potential, and environmental and economic implications. It distinguishes engineered nanoparticle fertilizers from commercial liquid nano-urea and nano-DAP formulations, and it draws on field studies in rice, wheat, teosinte, forage sorghum and cotton, with supporting reports in maize and pearl millet. The evidence supports partial, not complete, substitution, and only under specific conditions. In rice, 50% of the soil-test N and P dose combined with nano-DAP seedling root dipping and two foliar sprays gave grain yields statistically at par with the full dose (4.08 and 4.02 versus 4.12 and 4.05 Mg ha⁻¹ in two seasons) and the highest benefit–cost ratio (2.26). In contrast, in a two-year rice–wheat trial, 50% of the recommended nitrogen dose (RDN) plus two foliar sprays of liquid nano-urea reduced grain yield by 13% in rice and 17.2% in wheat relative to 100% RDN, together with lower SPAD values, tiller density, dry matter and grain protein (−35% in rice, −24% in wheat). These contrasting outcomes are consistent with differences in delivery mode and in the absolute nutrient mass supplied, but they come from different crops, products and sites, so the comparison is indicative rather than definitive. Long-term field evidence on nanoparticle accumulation, soil microbial effects and aquatic toxicity remains limited. Priorities include multi-location, multi-year trials, clearer uptake mechanisms, crop- and soil-specific dose and timing, long-term ecotoxicity assessment, and harmonized regulation.
Role of nano urea and nano DAP in integrated nutrient management: A review
Abstract
Global agriculture has experienced a dramatic evolution, resulting in a huge surge in the use of synthetic mineral fertilizers, which have caused significant ecological consequences, soil degradation, and reduced nutrient use efficiency (NUE). The integrated use of mineral, organic and biological sources of nutrients in a systematic way is integrated nutrient management (INM), and it aims to balance all the sources of nutrients to achieve soil health and productivity. In recent years, new nano-urea and nano-diammonium phosphate (nano-DAP) fertilizers, which are highly reactive and slow-release substitutes for conventional bulk fertilizers, have been developed in the field of nanotechnology. This review critically collates the experimental evidence of 39 peer-reviewed papers to assess the agronomic, physiological, economic and environmental effects of applying nano-fertilizers in INM practices. Conjoint field trials showed that foliar application of nano-urea (4 mL/L) and nano-DAP (2–2.5 mL/L) at critical vegetative stages did not reduce but significantly improved the vegetative growth, chlorophyll content, dry matter and yield of various field crops such as wheat, pearl millet, potato, sorghum, blackgram and groundnut when compared with the Recommended Dose of Fertilizers (RDF). The ultra-small particle size (typically 20–50 nm, up to ~100 nm) of the nano-formulations allows rapid penetration through the cuticle and stomata, reducing losses via volatilization, leaching and fixation in the soil. Moreover, the integration of nano-fertilizer enhances the biological health of soil by promoting the growth of microbial populations (bacteria, fungi and actinomycetes) and enzyme activity. Synchronized INM treatments lower bulk-fertilizer, labor and transportation costs on an economic basis, resulting in higher benefit-cost ratios (B:C). However, there are a number of critical research gaps, such as a considerable “yield penalty” noted when solid nitrogenous fertilizers are totally replaced by foliar applications of nano-urea in some vegetable cropping systems (e.g., okra) and a high risk of soil nutrient mining when basal solid fertilizer rates are insufficient. The review underscores the importance of multi-season and long-term field trials under varying soil-climatic conditions for developing application criteria for nano-fertilizers under sustainable agriculture conditions.
Medicinally Important Weeds of North-East Assam with Special Reference to Dimoria Block, Kamrup Metropolitan District, Assam
Abstract
Weeds are commonly regarded as undesirable plants because they occur spontaneously in cultivated fields, fallow lands, roadsides, homesteads, wetlands and other disturbed habitats and compete with crops for available resources. Nevertheless, many weed species have ethnomedicinal, nutritional and ecological importance and are incorporated into traditional healthcare systems. Assam, in North-East India, has a rich tradition of plant-based healthcare. Dimoria Block of Kamrup Metropolitan district is an important setting for examining this knowledge because of its diverse vegetation and multi-ethnic population. This literature-based review synthesizes 27 common or weed-like medicinal plants relevant to Dimoria and the wider Kamrup–Assam region, drawing on original ethnobotanical studies conducted in Dimoria, Sonapur and other parts of Assam. The underlying Dimoria study documented 80 medicinal plant species belonging to 45 families and reported traditional uses for 56 human ailments, while an earlier Sonapur survey documented 40 medicinal plant species. The 27 plants reviewed here are associated with traditional applications for gastrointestinal complaints, fever, respiratory and skin conditions, wounds, urinary and liver disorders, pain and reproductive complaints. The review highlights that the distinction between weeds and medicinal plants depends on ecological and cultural context. Reported traditional uses do not establish clinical efficacy. Taxonomic verification and further phytochemical, pharmacological and toxicological investigations are needed to assess potential benefits and risks.
Pulse Crops for Sustainable Agriculture and Their Contributions to Soil Health, Nutrient Management and Resource Use Efficiency: A Review
Abstract
Pulse crops are an important part of sustainable agriculture, as they help to enrich the soil with nutrients, promote natural resource management, and boost its fertility. Pulses are crucial sources of dietary protein and are also valuable for their ecological value in terms of biological nitrogen fixation, addition of organic matter, and enhancing soil biological activity. The review aims to highlight the potential use of pulse crops in sustainable agriculture systems with specific reference to soil health, soil nutrient management, resource-use efficiency and long-term productivity. The 60 research papers were reviewed under the following six main themes: biological nitrogen fixation, soil organic carbon, soil fertility improvement, nutrient availability, residue management, water-use efficiency, nutrient-use efficiency, and weed management. The findings of the reviewed shows that rotation and the use of pulse crops in conservation tillage production systems can enhance soil structure, organic carbon, water infiltration, water-holding capacity, and the availability of essential nutrients. Pulse crops can also fix their own nitrogen, especially when associated with Rhizobium, which can help to lower the need for synthetic nitrogen fertilisers and increase the nitrogen available to the following crop. Crop residues also play an important role in nutrient recycling, building soil organic matter, mitigating erosion and sustaining soil biological activity. Pulses may also help to address the challenges posed by climate change and soil degradation as they optimise use of resources and productivity of cropping systems as a whole. Therefore, pulse crops can be effectively used as a means to sustain soil health, optimise nutrient cycles, improve resource-use efficiency and ensure resilient and sustainable agricultural production in response to changing climatic conditions in diversified and conservation agriculture systems.