Research trends on biochar-based smart fertilizers as an option for the sustainable agricultural land management: Bibliometric analysis and review

Abstract

Several studies have investigated nutrient-enriched and nutrient poor biochar to improve soil properties, increase nutrient use efficiency and crop productivity. Review articles have presented formulations and production methods of biochar-based fertilizers. They reported nutrient-enriched biochar improves -45ves crop productivity, soil health and preserves the environment. But so far, none of the studies has conceptualized the nutrient-enriched biochar as a biochar-based smart fertilizer or presented the conceptual and intellectual structures and the collaborative networks of authors and countries working on biochar-based smart fertilizers. For the first time, this study has mapped the scientific knowledge generated on the topic and established a solid ground for its innovative progress and research pursuits. A total of 2,779 scientific publications on biochar-based fertilizers were exported from scopus database in August 2022 and were analyzed using bibliometrix software package and the biblioshiny web interface in R version 4.1.3. The results indicated that the papers in our collection cover the period from 2007 to 2022 with a raising number from 2017 to 2021. Almost all documents (99.38%) were co-authored with an average of 6 authors (5.76) per article. The analysis of keywords and the evolution of topics revealed that biochar-based smart fertilizers in relation to organic nutrient sources, soil microbiology and soil sanitation were the most studied topics in the scientific debates. China had more collaboration in the network working on biochar-based fertilizers, while the West African countries belonging to the network have not developed any collaboration so far. This suggests the formulation of research projects that may involve African countries to work with other countries including China, USA, Germany, Australia and Poland. This study is more comprehensive in terms of a global view of the conceptual and intellectual contours and network of actors on biochar-based smart fertilizers. Future research on the topic should be conducted more in the fields under farmers’ conditions and may focus on (i) enrichment of biochar with nutrients from organic sources before its application to the soil, (ii) soil remediation and microbiology in relation to biochar-based fertilizer applications, and (iii) economic profitability of biochar fertilizers for small-scale farmers.

Sustainable Technological Applications of Green Carbon Materials

“…Biochar is one of the biomass-based carbon materials that has been highly investigated. Biochar is a product of the valorization of feedstocks, like municipal organic waste and agri-industrial residues, through slow pyrolysis [28][29][30][31][32][33][34][35][36][37]. Thermal processes, like pyrolysis and carbonization, convert biomass into a carbon-rich microporous material with a well-developed porous structure, a highly specific surface area, and a high degree of aromatization (Figure 6) [28][29][30][31].…”

“…These features can be tuned using different raw materials and the technical characteristics of pyrolysis. Biochar is added to soil to modify its physical and chemical composition, microbial activity, soil fertility, and pollution load [28][29][30][31][32][33][34][35][36][37]. Carbon nanomaterials have another important role in agricultural practices, namely as nanocarriers for pesticides and fertilizers, allowing the controlled release of active molecules [20].…”

“…These features can be tuned using different raw materials and the technical characteristics of pyrolysis. Biochar is added to soil to modify its physical and chemical composition, microbial activity, soil fertility, and pollution load [28][29][30][31][32][33][34][35][36][37]. Biochar contains inorganic elements that are macronutrients, particularly N, P, and K, and micronutrients to plants; when added to soils, they will improve their fertility, resulting in high crop yields [28,29].…”

“…Slow-release fertilizers (SRFs) are a solution to nutrient loss from the soil through leaching, volatilization, denitrification, and surface runoff. Biochar SRFs (BSRFs), derived from agricultural waste, are being proposed as a more sustainable alternative [32][33][34]. BSRFs are obtained by the co-pyrolysis of biomass with a chemical substance containing the nutrient, such as phosphate rock or urea [32].…”

Low-Cost Class a Evapotranspiration Pan for Reference Evapotranspiration Estimation in Protected and Field Environments: A Practical Approach

“…Additionally, other agricultural technologies are being developed and implemented to improve crop productivity (yield per area) and the sustainability of the agricultural activity, and indeed, they will affect the soil and plant responses and the agronomic recommendations for gypsum management. Such improved technologies include (i) smart fertilizers (e.g., slow and controlled release fertilizers, bioformulated fertilizers, nanofertilizers, beneficial nutrients) developed to enhance nutrient use efficiency and crop yield with low impacts on the natural environment (Raimondi et al, 2021;Karthik and Maheswari, 2021;Tayade et al, 2022;Verma et al, 2022;Abiola et al, 2023;Areche et al, 2023;Chakraborty et al, 2023); genetic engineering and genome editing techniques of crop plants to improve their resistance to stresses and use-efficiency of agricultural amendments (Jan and Shrivastava, 2017;Mackelprang and Lemaux, 2020;Clouse and Wagner, 2021;Lebedev et al, 2021;Raza et al, 2022); large-scale application of artificial lights (light supplementation) to field crops (Lemes et al, 2021), and digitalization-integration-robotization plus AI (artificial intelligence), DL (deep learning) and blockchain of agriculture (Krithika, 2022;Srivastava, et al, 2022;Adamides and Edan, 2023;Ali et al, 2023;Mahibha and Balasubramanian, 2023;Cheng et al, 2023;Mesías-Ruiz et al, 2023;Okolie et al, 2023;Wakchaure et al, 2023;Zeng et al, 2023) are emerging and represent some of the most recent advances for modern sustainable and productive agriculture.…”