Organomineral fertilizer application enhances Perilla frutescens nutritional quality and rhizosphere microbial community stability in karst mountain soils.

Introduction: Applications of organomineral fertilizer (OMF) are important measures for developing organic agriculture in karst mountain areas. However, the influence of OMF on the structure and function of soil microbial diversity and their relationship with crop yield and quality are still unclear. Methods: Based on soil science, crop science, and high-throughput sequencing methods, we investigated the changes of rhizosphere soil microbial communities of Perilla frutescens under different fertilization measures. Then, the relationship between P. frutescens yield and quality with soil quality was analyzed. Results: The results showed that the addition of OMF increased the amount of total carbon and total potassium in soil. OF, especially OMF, improved P. frutescens yield and quality (e.g., panicle number per plant, main panicle length, and unsaturated fatty acid contents). Both OF and OMF treatments significantly increased the enrichment of beneficial microorganism (e.g., Bacillus, Actinomadura, Candidatus_Solibacter, Iamia, Pseudallescheria, and Cladorrhinum). The symbiotic network analysis demonstrated that OMF strengthened the connection among the soil microbial communities, and the community composition became more stable. Redundancy analysis and structural equation modeling showed that the soil pH, available phosphorus, and available potassium were significantly correlated with soil microbial community diversity and P. frutescens yield and quality. Discussion: Our study confirmed that OMF could replace CF or common OF to improve soil fertility, crop yield and quality in karst mountain soils.

A scoping review on biochar-based fertilizers: enrichment techniques and agro-environmental application.

Biochar is a carbonized biomass that can be used as a soil amendment. However, the exclusive use of biochar may present some limitations, such as the lack of nutrients. Thus, biochar enrichment techniques have made it possible to obtain biochar-based fertilizers (BCFs), with great potential to improve soil fertility. Nevertheless, there is still a lack of information about the description, advantages, and limitations of the methods used for biochar enrichment. This review provides a comprehensive overview of the production methods of enriched biochar and its performance in agriculture as a soil amendment. Studies demonstrate that the application of BCF is more effective in improving soil properties and crop yields than the exclusive application of pure biochar or other fertilizers. The post-pyrolysis method is the most used technique for enriching biochar. Future studies should focus on understanding the mechanisms of the long-term application of BCFs.

Full-Scale Composting of Different Mixtures with Meal from Dead Pigs: Process Monitoring, Compost Quality and Toxicity.

ABSTRACT: Abundant by-products of large swine industries, such as slaughterhouse sludge and carcasses, require adequate treatment to prevent negative effects of their direct disposal in the open environment. This study is aimed to evaluate the efficiency of composting using meal from dead pigs through physicochemical analyses and phytotoxic assays. Five treatments were tested, all including 50% sawdust: T1, with 50% slaughterhouse sludge (control); T2, with 20% slaughterhouse sludge and 30% meal from dead pigs; T3, with 10% slaughterhouse sludge and 40% meal from dead pigs; T4, with 20% organic stabilizing compost and 30% meal from dead pigs and T5, with 30% organic stabilizing compost and 20% meal from dead pigs. The phytotoxicity assays used lettuce, cucumber, celia, soybean, rice and wheat as bioindicators. Inclusion of meal from dead pigs was related to reduction in pH, C/N ratio, humidity and temperatures inside the pile, although thermophilic peaks lasted longer than 50 days and the final composts showed high content of nitrogen and phosphorous. The germination of bioindicators was reduced in all tested treatments, compared to the control. The composts from treatments that included meal from dead pigs presented acceptable nutrient content, which may indicate their use as organic fertilizers. However, after 4 months, all bioindicators in contact with such composts presented impaired germination. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12649-021-01422-0.

Fertilization and cropping systems: performance and oil content of basil varieties / Fertilização e sistemas de cultivo: desempenho e teor de óleo de variedades de manjericão

Sweet basil (Ocimum basilicum L.) is an aromatic and medicinal crop that produces metabolites rich in chemical constituents for various purposes. The composition of the essential oil is variable due to external factors during production, such as fertilization and the environment, and the oil concentration may vary even among the genotypes of a species. For sweet basil mores studies are needed to clarify understanding about the biomass and essential oil yield and nutrient management. The objective of this study was to evaluate the biomass and essential oil yield of basil varieties with organo-mineral fertilizer under different agricultural systems. The experimental design was a randomized complete block (DBC), with three replications, in a 2X4 factorial scheme, with two varieties (Maria Bonita and Genovese) and four fertilizations (50 and 100% organo-mineral, one mineral source and one organic source). Two areas were carried out simultaneously (greenhouse and field) to evaluate plant height, fresh biomass, essential oil content, yield and chemical composition. Results indicate that Genovese showed superior height and biomass yield when mineral or organic fertilizer was used at the greenhouse. Organo-mineral and organic fertilizers provided significantly better results of biomass yield in both varieties at field cultivation. The oil content was higher in the field, reflecting higher oil yields in field treatments in comparison to greenhouse. We concluded that the environment of cultivation and the way fertilizer sources release the nutrients can be determinan factors in the performance of basil plants; without protected cultivation, the content of essential oil is higher and the organo-mineral fertilizer can provide better nutrient supply to the plants mainly during rainy season.

O manjericão (Ocimum basilicum L.) é uma cultura aromática e medicinal que produzmetabolitos ricos em constituintes químicos para vários fins. A composição do óleo essencial é variável com fatores externos durante a produção, como fertilização e meio ambiente, podendo variar até mesmo entre os genótipos de uma espécie. Para melhor compreensão sobre o rendimento de biomassa e óleo essencial e manejo de nutrientes no cultivo de manjericão são necessários mais estudos. Dessa forma, o objetivo deste estudo foi avaliar o rendimento de biomassa e óleo essencial de variedades de manjericão com fertilizante organomineral em diferentes sistemas agrícolas. O delineamento experimental foi o de blocos casualizados (DBC), com três repetições, em esquema fatorial 2X4, com duas variedades (Maria Bonita e Genovese) e quatro fertilizações (50 e 100% organomineral, uma fonte mineral e uma fonte orgânica). Duas áreas foram realizadas simultaneamente (estufa e campo) para avaliar a altura da planta, biomassa fresca, teor de óleo essencial, rendimento e composição química. Os resultados indicam que Genovese apresentou altura e rendimento de biomassa superior quando o fertilizante mineral ou orgânico foi utilizado na estufa. Os fertilizantes organominerais e orgânicos proporcionaram resultados significativamente melhores do rendimento de biomassa em ambas as variedades no cultivo de campo. O teor de óleo foi maior no campo, refletindo maiores rendimentos de óleo em tratamentos de campo em comparação com estufa. Concluímos que o ambiente de cultivo e a forma como as fontes de fertilizantes liberam os nutrientes podem ser fatores determinantes no desempenho das plantas de manjericão; sem cultivo protegido, o teor de óleo essencial é maior e o fertilizante organomineral pode fornecer um melhor suprimento de nutrientes para as plantas principalmente durante a estação chuvosa.

Reuse of Organomineral Substrate Waste from Hydroponic Systems as Fertilizer in Open-Field Production Increases Yields, Flavonoid Glycosides, and Caffeic Acid Derivatives of Red Oak Leaf Lettuce (Lactuca sativa L.) Much More than Synthetic Fertilizer.

Effects of organic waste from a hydroponic system added with minerals (organomineral fertilizer) and synthetic fertilizer on major polyphenols of red oak leaf lettuce using HPLC-DAD-ESI-MS(3) were investigated. Interestingly, contents of the main flavonoid glycosides and caffeic acid derivatives of lettuce treated with organomineral fertilizer were equal to those synthesized without soil additives. This was found although soil nutrient concentrations, including that of nitrogen, were much lower without additives. However, lettuce treated with synthetic fertilizer showed a significant decrease in contents of caffeic acid derivatives and flavonoid glycosides up to 78.3 and 54.2%, respectively. It is assumed that a negative effect of a high yield on polyphenols as described in the growth-differentiation balance hypothesis can be counteracted by (i) a higher concentration of Mg or (ii) optimal physical properties of the soil structure. Finally, the organomineral substrate waste reused as fertilizer and soil improver resulted in the highest yield (+78.7%), a total fertilizer saving of 322 kg ha(-1) and waste reduction in greenhouses.