Bioretention systems have gained considerable popularity as a more natural approach to stormwater management in urban environments. The choice of bioretention media is frequently cited as one of the ...critical design parameters with the ultimate impact on the performance of the system. The goal of this review is to highlight data that challenge the importance of media as being the dominant design parameter and argue that the long-term performance is shaped by the interactions between media and the living components of a bioretention system, especially vegetation. Some of the key interactions are related to the impact of plant roots on media pore structure, which has implications on infiltration, storage capacity, and treatment. Another relevant interaction pertains to evapotranspiration and the associated impacts on the water balance and the water quality performance of bioretention systems. The impacts of vegetation on the media are highlighted and actual, as well as potential, impacts of plant-media interactions on bioretention performance are presented.
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•Plant-media interactions impact physico-chemical properties of bioretention systems.•Bioretention design does not address the combined effects of media and vegetation.•Plant impacts may enhance or compromise bioretention performance.•Root-induced changes to media properties need further investigation.•The impact of evapotranspiration on water quality needs further investigation.
The medium from which seedlings are transplanted influences seedling growth and survival on the field. The objective of the experiment was to compare how growing media affect the growth and survival ...of cocoa seedlings under field conditions. The seedlings were raised in both soil and soilless media and were transplanted on the field in June, when they were six months old. The experimental design was a randomized complete block design with three different growing media: 1. top soil, 2. sawdust + poultry manure + rice husk biochar (70%:25%:5%), and 3. sawdust + poultry manure + municipal solid waste compost (50%:35%:15%). The cocoa seedlings were transplanted at a spacing of 3 m × 3 m at 12 plants per plot and each plot size measured 45 m × 45 m. Data were collected on plant height, leaf number, stem girth, leaf chlorophyll content, percentage of plants that shed their leaves, and percentage of survival. Results indicated that seedling survival at the onset and end of the dry season was significantly (P < 0.05) higher for seedlings transplanted from soilless media compared to those from the top soil treatment. Irrigation will be necessary to maintain high seedling survival when seedlings are transplanted from the top soil for a well-established plantation.
Using the right growing media is pivotal for cultivating high-quality seedlings. While topsoil remains a prevalent choice in nurseries, there is a growing need to explore its effectiveness in cashew ...seedling production and find potential alternatives that might reduce our dependence on it. A three-month experiment was undertaken at the Cocoa Research Institute of Nigeria’s nursery. The setup followed a Completely Randomized Design (CRD) incorporating ten treatment variations, each replicated thrice. These treatments involved two cashew nut types, Jumbo and Medium, and five distinct growing media: 100% Topsoil, 100% Sawdust, 75% Topsoil + 25% Sawdust, 50% Topsoil + 50% Sawdust, and 25% Topsoil + 75% Sawdust. For the procedure, each of these media was filled into perforated polythene bags measuring 30cm x 15cm, with one seed planted per bag. Data collected were on % emergence, morphological, shoot and root data. Data were subjected to ANOVA using SAS (version 2010) statistical package and means were separated using DMRT at (P≤0.05). Findings revealed no notable variance in percentage mean emergence at four weeks post-planting or in leaf count at the twelve-week mark. Control treatments (100% topsoil) for jumbo and medium had the shortest plant height, lowest number of leaves, seedling vigour, fresh root weight and taproot length. 100% topsoil as a growing medium for raising cashew seedlings should be discouraged as the experimented growing media offered statistically the same or improved emergence, morphology, and root growth development.
This research paper presents a case study analysis of the behavior of three Sedum varieties and their growth in three different types of substrates without additional watering or fertilizing. The ...study aims to identify a suitable substrate for propagation and to provide insight into the plant’s growth patterns. By analyzing the growth of the Sedum species and varieties—SS’PW’, SS’CB’, and SS’P’—without intervening in their growth process, we were able to identify factors that play a more crucial role in promoting root growth, plant growth, aesthetic value, and use. Over a 20-month period, various technical tools were employed to conduct observations and measurements for both plants and weather conditions. The type of substrate significantly affected plant growth, with the green roof substrate exhibiting the highest overall average monthly root growth rate (0.92 ± 0.05 d, 1.01 ± 0.05 b, 0.96 ± 0.05 c) while in the case of stem growth, among all three varieties, the best results were obtained in the commercial mix (0.87 ± 0.04 a, 0.40 ± 0.02 c, 0.35 ± 0.02 d). Based on the morphological analyses, all values were significantly lower than the control. Best results for leaf weight and surface area were noticed in the green roof substrate with an average growth of 46%, 53%, 55%, and for stem weight, length, and thickness in the commercial mix with 64%, 61%, and 55% compared to the control, respectively. Leaves had varying morphological characteristics, but the chromatic characteristics were preserved. The plants had an overall poor growth which may not be desirable in landscape designs. The findings of this study are applicable in the planning and execution of eco-friendly infrastructure initiatives, leading to the development of more robust and environmentally friendly urban settings.
•Biochar can be used for peat replacement in substrates.•Biochar reduces the over-explotation of peatlands.•Biochar and paper sludge are phytonutrient for lettuce.•Biochar addition doubles crop ...yield.
Peatlands are crucial sinks for carbon in the terrestrial ecosystem, but they are jeopardized by their use as fuel or as growing media. Much research has been performed aiming to find high quality and low cost substrates from different organic wastes, such as coir, compost, sewage or paper sludges, and thus decrease peat consumption. The main objective of this work is to study the effect on peat and coir-based growing media of deinking sludge (R) and biochar obtained by pyrolysis of deinking sludge at 300°C (B300). For this reason, mixtures of peat or coir with deinking sludge and corresponding biochar were prepared mixing them at 50/50 v/v ratios. The results showed that it is possible to improve the chemical and hydrophysical properties of peat and coir with addition of biochar and deinking sludge. Indeed, biochar increased air space, water holding capacity and total porosity of peat-based growing media whereas for coir, the best hydrophysical properties were obtained after deinking sludge addition. Finally, the use of biochar plus peat as growing media can increase lettuce yield by more than 100% with respect to peat growing media, which can be related with the improvement of hydrophysical growing media properties. This yield increment along with the reduction of the over-exploitation of peat can justify the use of biochar as growing media in spite of the cost associated to the pyrolysis process.
•A washing pre-treatment was applied to livestock derived substrates.•The washing pre-treatment did not affected negatively substrate physical properties.•The growing media with washed composts ...showed positive effects on seedlings.
The search for alternative materials for peat substitution in soilless systems has led to an increasing use of compost as ingredient of growing media. These materials may have similar characteristics to peat for their potential use as substitutes of this non-renewable material. However, the high salinity is one of the most usual limiting factors in compost for its use in growing media. This work evaluates the effect of the use of a washing pre-treatment to improve the quality of livestock waste-derived composts as peat substitutes in substrates for pepper (Capsicum annuum L.) seedling production. For this, different growing media were prepared using as ingredients five composts from livestock manures and anaerobic digestates (M1, M2, M3, D1 and D2), with or without a washing pre-treatment. Each respective material was mixed with peat in the proportions 25 %, 50 % and 75 % (volume:volume), using as control treatment pure (100 %) peat. The main physico-chemical, chemical and physical characteristics of the composts before and after washing and those of the growing media were studied, as well as germination and biomass production of the seedlings. The use of a washing pre-treatment was effective in the reduction of compost salinity, without implying a negative effect on the physical properties and nutrient content of the growing media, which were adequate for being used in seedling production, as reflected in the beneficial effects on the germination and growth of pepper seedlings.
•Plastic waste from agriculture and horticulture was co-pyrolyzed with waste biomass.•Low ratios of LDPE plastic were found to have a positive effect on biochar yield.•High ratios of LDPE plastic ...were found to have negative effect on biochar yield.•Pyrolysis has the potential to valorize mixed biomass with low levels of LDPE plastic.
Complete separation of mixed plastic and biomass waste is a technically difficult, laborious, expensive and time-consuming process. Hence, co-pyrolysis of these agricultural waste streams with low levels of plastic contamination presents a novel approach for the management of these plastic containing wastes, producing stable forms of carbon with potential use in environmental, agricultural and industrial applications. In this study, spent growing medium along with plastic growing bags, and bean crop residues along with mulching sheets were selected to assess how the presence of plastics would affect the characteristics of the biochars produced. These feedstocks were combined in mass ratios (of plastic in the biomass-plastic mixture) of 0, 0.25, 2.5, 5 and 10 %. The resulting feedstock underwent slow pyrolysis in a fixed bed pyrolysis reactor at a temperature of 550 °C to ensure complete conversion of the plastic components of the feedstock. From the results obtained from pyrolysis, low ratios of plastic were found to have a positive impact on biochar yield, while high plastic ratios were found to have negative effect. Higher level of plastic in the feedstock have resulted peculiar functional groups in the biochar, including carboxylate anions, amides and aromatic groups. Biochars produced from spent growing medium along with plastic grow bags (GM biochars) showed no phytotoxic effect, irrespective of the concentration of plastic contamination in the feedstock. Biochars produced from bean crop residues along with mulching sheets (BM biochars) on the other hand showed high level of phytotoxicity (zero germination), irrespective of level of plastic contamination. After washing all BM biochar, very low phytotoxicity levels with no statistically significant effect of plastic contamination were observed, with the exception of 10BM that showed somewhat a reduced germination rate (93 %). The results of this study will be beneficial for determining the tolerable level of plastic contamination in managing mixed agricultural waste biomass and to produce biochars suitable for environmental, agricultural and/or industrial applications.
Hydroponics is a viable alternative for urban contexts with limited resources and space since it offers efficient and low-maintenance planting methods. This study specifically examines the ...development of synthetic soil by utilizing hydrochar obtained from wild weeds (Amaranthus sp.). X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FE-SEM) were used to study the hydrochar after it was made using the hydrothermal carbonization method. The analysis showed that the hydrochar had an undefined crystal structure and an uneven, varied porosity. The expansion capacity test clearly showed a significant growth potential of 32%. Nevertheless, the water retention tests revealed a progressive decline in the capacity to retain water as time passed. The kinetics model was used to simulate the release of NPK from the counterfeit soil. The P and K components adhered to a first-order model, but the N elements adhered to the Kosmeyer-Peppas model. The use of artificial soil as a substrate for kale plants had excellent outcomes, with the highest growth rate of 0.75 cm reported on day 7. Subsequently, the growth stabilized and gradually decreased to 0.3 cm by day 21. Hydrochar generated from wild weeds (Amaranthus sp.) is a practical choice for hydroponic farming systems, as it provides fertilizer storage and slow-release advantages.
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•Artificial soil from wild weed hydrochar has been successfully prepared.•N element release from artificial soil follows the Kosmeyer-Peppas kinetic model.•P and K elements released from artificial soil follow the first-order kinetic model.•Ground kale exhibited the highest growth peak on day 7 in artificial soil.•The resulting artificial soil can be used as a hydroponic media for horticulture plants.
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