Conventional agriculture has important challenges to guarantee soil fertility and sustainable food production. Many agricultural soils in the world are degraded and multiple strategies are currently being developed to restore them. The study of beneficial soil microorganisms has attracted increasing interest due to their relevant role in sustainable agricultural development. The balance and maintenance of ecosystem services, such as biomass transformation, nutrient cycling, plant growth, and health, are directly dependent on soil microbial activity. Therefore, it is important to promote its establishment and propagation. An ancient technique that favors soil biodiversity is the production and application of compost. While numerous studies have focused on the benefits of plant cultivation, fewer studies have focused on the benefits for soil microbiota. The objective of this review was to elucidate the role of the microbiota in the composting process and its impact on soil microorganisms in agriculture. The review presents the advances in the knowledge and importance of microorganisms involved in the composting process and how compost promotes the maintenance and multiplication of beneficial microbial consortia and their ecosystem functions in agricultural soils, shifting towards a more sustainable and resilient agriculture.
Knowledge of the agricultural soil microbiota, of the microbial consortia that comprise it, and the promotion of agricultural practices that maintain and encourage them, is a promising way to improve soil quality for sustainable agriculture and to provide food security. Although numerous studies have demonstrated the positive effects of beneficial soil microorganisms on crop yields and quality, the use of microbial consortia in agriculture remains low. Microbial consortia have more properties than an individual microbial inoculum, due to the synergy of the microorganisms that populate them. This review describes the main characteristics, ecosystem functions, crop benefits, and biotechnological applications of microbial consortia composed of arbuscular mycorrhizal fungi (AMF), plant growth-promoting rhizobacteria (PGPR), and Actinobacteria, to promote the restoration of agricultural soils and, consequently, the quality and health of agricultural crops. The aim is to provide knowledge that will contribute to the development of sustainable and sufficiently productive agriculture, which will adapt in a good way to the pace of the growing human population and to climate change.
Knowledge of the agricultural soil microbiota, of the microbial consortia that comprise it, and the promotion of agricultural practices that maintain and encourage them, is a promising way to improve soil quality for sustainable agriculture and to provide food security. Although numerous studies have demonstrated the positive effects of beneficial soil microorganisms on crop yields and quality, the use of microbial consortia in agriculture remains low. Microbial consortia have more properties than an individual microbial inoculum, due to the synergy of the microorganisms that make them up. This review describes the main characteristics, ecosystem functions, crop benefits and biotechnological applications of microbial consortia composed of arbuscular mycorrhizal fungi, plant growth promoting bacteria and actinobacteria, to promote the restoration of agricultural soils and, consequently, the quality and health of agricultural crops. The aim is to provide knowledge that will contribute to the development of sustainable and sufficiently productive agriculture, which will adapt in a good way to the pace of the growing human population and to climate change.
The agronomic management of symbiotic (S) inoculations, by means of bio-fertilizers (BF), is aimed at inducing modifications of the plant rhizosphere and thereafter of the phenotype and yield of the crop. It is here shown that the yield response of maize to a symbiotic treatment may be correlated to six easy-to-calculate indicator variables on the basis of the raw foliar pH, NIR-Spectroscopy of leaves, and the NIRS of hay litter-bags from soils. It has been confirmed, in a set of thirteen pairwise comparisons of Symbiotic (S) soil inoculated by BF vs. Control (non-inoculated soil; C), that the inoculation on average acidified the leaves by -3.7% pH units (P<0.0001). The responses in yield ranged from +25.2% to -9.2% (av.ge +3.5%; P = 0.03), but with average null responses in two centers and a significant response (+11%) in a third center. NIR-Tomoscopy scans (No. 574) were also performed on the leaves, and in addition, hay-litter-bags that had previously been buried in fields were dug up after two months, and 431 NIR- scans were acquired. The effect-size on the yield was expressed as the logarithm of the response ratio, i.e. the mean of the inoculated Symbiotic treatment divided by the mean of the non-inoculated Control for each pairwise comparison. A multiple regression model was developed to predict the symbiotic response to the treatment using six independent variables, including the squared litter-bag fingerprints, and an R2adj. level of 0.78 (P=0.01) was reached, with a standard error of ±4%. Validation in one external maize field, with a positive response to bio-fertilizers, demonstrates the juxtaposition of the estimated and accomplished yield. In a second experiment, with 40 pairwise comparisons, the two tested maize varieties did not respond to five types of bio-fertilizer, and the negative results were predicted at 84% (P 0.0012). The soil biota is a key factor for the application of appropriate microbial inoculants in the field, but the genotype/genotype interactions between the microbial strain (s) and the crop cultivar (s) require prior screening to obtain the desired results.
There are two problematic solid residues from agriculture and agro‐industry, produced in vast amounts in rural areas: those from coffee bean production and processing and those deriving from the extraction process of olive oil. Notwithstanding these residues originating in different geographical areas, they have striking similarities. They both derive from traditional, conventional and organic agriculture; they have a high content in lignins, celluloses and (poly)phenols; they are produced in million tonnes annually; they pose relevant environmental problems for disposal; they contain bioactive compounds; and the approach for their re‐use is often similar, sometimes overlapping. The most promising re‐uses in rural areas are for agriculture, as animal feed and for energy production. There are also minor uses, suitable for the production of added‐value commodities. The re‐use will be dependent on a variety of factors according to the diversity of (a) pedoclimatic areas that include altitude and latitude, soil texture and organic matter content, water regime and availability, (b) level of expertise of the small farmers, (c) social environment that includes training opportunities and availability to create associative forms among producers, (d) access to trade and communication networks and (e) easy access to community‐level processing installations. The perspectives of agronomic management and valorization are compatible with the objectives of a regenerative, sustainable agriculture.
28 September 1999 in SAE International Journal of Advances and Current Practices in Mobility
The first part of the paper gives an overview of the environmental conditions with which a future two stroke powered vehicle must comply and explains the reasons for which a direct gasoline injection into the combustion chamber offers a potential solution. The paper continues with a description of the fuel/air mixture injection used in the F.A.S.T. concept and gives a detailed overview of the layout of the 125 cc engine to which it is applied. The structure of its electronic engine management system, mandatory for the necessary control precision, is presented. Hereafter is made a short introduction to the visualization and numerical computation tools used for the engine design optimization. The paper concludes with a detailed presentation and discussion of the experimental results obtained with the engine operated, either in steady state and transient conditions on an engine test rig, and mounted in a classic small dimension two-wheel vehicle submitted to road tests.