Compost-based Substrates Research Articles

Sustainable Valorization of Organic Materials as Substrates for Soilless Crops in Protected Environments in the Venezuelan Andes

Agricultural production activities generate a large amount of waste, most of which is of organic origin from plant remains. These residues could easily be transformed into a resource, specifically, into a substrate for use in soilless cultivation; however, in most cases, they are not used. Therefore, a characterization of local agricultural residues was carried out to determine their use as a substrate for crop cultivation without soil in a protected environment. The selected substrates were Sphagnum peat, coir fiber, and compost, which were managed alone or in mixtures of 50/50, 75/25, or 25/75% v/v ratios. We also included a mixture of virgin mountain soil and earthworm humus (known as INIA mixture) because it is used by local growers. The results showed that the substrates based on coir fiber, peat, and mixtures of both presented suitable characteristics for horticultural crops. On the contrary, compost-based substrates had high pH values and low organic matter contents that could be improved before use. The relationship found between the evaluated parameters of each substrate allowed us to establish that variables, such as the content of organic matter and water at different tensions and particle sizes, can be utilized to make a quick selection of the substrates produced locally, which would lead to the use of waste in a way that is more consistent with sustainable agricultural production and minimal environmental impact, by being used in the production of crops in containers without soil. In addition, these results can be used as an alternative reference in localities where these residues are easily available.

Utilization of Vermicompost Sludge Instead of Peat in Olive Tree Nurseries in the Frame of Circular Economy and Sustainable Development

The survival of newly planted seedlings and their successful development after transplantation, including faster plant growth, improved plant quality, larger production, and the absence of dependence on arable land, is one of the primary goals of horticultural nurseries. Although peat is the most frequently used amendment in commercial potting substrates, exploiting it degrades essential ecosystems like peatlands and uses slowly renewable resources. This study evaluated the growth and nutrition of olive-rooted cuttings when peat was partially or completely replaced with vermicompost, searching for more sustainable methods and recovering urban wastewater treatment sludge sequentially. The progress of the plants’ growth was compared to that of corresponding plants in which commercial peat had been used as substrate. Leachates from every procedure were also examined, and the results revealed that trace element and heavy metal contents were much lower than those deemed hazardous for aquifers and soil. The outcomes indicated that peat might be effectively replaced with vermicompost sludge, promoting plant growth without further fertilizer. Comparatively to olive cuttings grown in peat-based substrates, those grown in compost-based substrates experienced improved nutrition and development. Further, it was found that irrigation doses were significantly reduced in treatments with a significant amount of vermicompost as the water drained more slowly. A technical-economic analysis was being conducted in the meantime, illustrating the financial benefits for a nursery when peat is replaced with vermicomposted sludge.

Effect of Poultry Manure-Derived Compost on the Growth of eucalypts spp. Hybrid Clones

Interspecific hybrids of E. grandis × E. camaldulensis were generated to widen the plantation area. The aim of this study was to assess root capability and development for six different clones of eucalyptus grown in substrates made with three different composts derived from poultry manure. A factorial design was used to assess the effect of different composts on six growth variables. The analysis detected a greater effect from the genotype than the substrate. E. grandis × E. camaldulensis hybrid vegetative propagation was successful in alternative substrates formulated from composted poultry manure. GC8 was the genotype that showed the greatest differences for four the different variables among the substrates, being both the most sensitive and the one with the highest values for all parameters measured. The hybrids’ vegetative propagation was determined in alternative substrates formulated from poultry manure compost. The physicochemical characteristics of substrates composed of pine bark and sawdust provided adequate conditions for the growth of eucalyptus. GC8 was the genotype most sensitive to the use of different substrates, showing significant differences in the ratio of roots/callus, radicular dry weight, and cutting dry weight. These clones might be a good option for evaluating compost-based substrates for forestry applications.

Feasibility of Using Orange Wattle (Acacia cyanophylla Lindl.) Compost as an Organic Growing Medium for the Production of Cork Oak (Quercus suber L.) Seedlings

In developing countries, or in those countries that do not produce peat, forest soil has traditionally been used as a substrate for cultivation of seedlings in forest nurseries. However, forest soil as a substrate has not been found to produce seedlings of high quality. Additionally, the harvesting of forest soil within forested stands has negative environmental connotations. The objective of this study was to evaluate the use of Acacia cyanophylla–based compost as an alternative growing media to forest soil for the production of cork oak (Quercus suber L.) seedlings in forest nurseries. The experiment was a Randomized Complete Block (RCB) design consisting of four blocks. Each block consisted of fifteen randomly distributed containers for each of the two treatment substrates (forest soil– and Acacia cyanophylla–based compost). Therefore, in total, 120 acorns were examined. Variables related to seed germination, plant growth, and survival were measured. Germination was high, exceeding 90% in both substrates. However, the compost-based substrate had significantly shorter germination times and an increase in the uniformity of the timing of germination. Seedling growth was significantly affected by the type of substrate, while seedling survival was not. As substrates, compost statistically significantly increased the height (39.2 vs. 33.3 cm), diameter (4.5 vs. 3.5 mm), and total biomass (14.7 vs. 10.4 g) of seedlings relative to forest soil. Based on our findings, the use of compost was found to be an attractive alternative to the use of forest soil in forest nurseries, due not only to the environmental benefits, but also due to improvement in seedling quality.

NATURAL ACIDIFIER APPLICATION WITH EFFECTS ON SOIL MICROBIAL ACTIVITY IN SWISS CHARD, TUSCANY BLACK CABBAGE AND TETRAGONIA TETRAGONIOIDES CULTIVATION

Research goal: This research aimed to evaluate the effects of a natural product with acidifying activity on seed germination and growth of Swiss chard (Beta vulgaris subsp. vulgaris), Tuscany black cabbage (Brassica oleracea var. acephala) and Tetragonia tetragonioides plants and whether there were any interactions or interferences with soil microbial activity and fertility parameters. Materials and Methods: The experiments, which started in January 2022, were conducted in the greenhouses of CREA-OF in Pescia (Pt), Tuscany, Italy (43°54′N 10°41′E). The experimental groups were: 1) group control in peat, irrigated with water and substrate previously fertilized; 2) group control in compost, irrigated with water and substrate previously fertilized; 3) group with organic acidifiers (organic acidifying product by Fertalis SRL) in peat irrigated with water and substrate previously fertilized; 4) group with organic acidifiers in compost irrigated with water and substrate previously fertilized. Results and Discussion: The trial significantly improved the agronomic parameters analyzed on Swiss chard, Tuscany black cabbage and Tetragonia tetragonioides plants treated with an organic acidifier. In particular, there was an increase in plant height, vegetative and roots weight, seeds germination and average germination time. In addition, the experiment showed that in plants treated with the organic acidifier, there was a lowering of the pH and a significant increase in substrate microfauna. Conclusions: According to the results obtained in this above-ground experiment, applying a natural acidifier in peat- or compost-based substrate can be beneficial for increasing plant productivity and quality and positively influence the microbiology of the soil. In the experiment, a reduction in the pH of the substrate was found in the theses treated with the acidifier. At the same time, a significant increase in the agronomic quality of the plants (in terms of productivity and growth) was observed. Furthermore, in these theses, it was evident how the microbial presence increased, which positively affected the substrate structure and fertilizer uptake. KEY-WORDS: sustainable agriculture, beneficial microorganisms, plant interactions, succulent plants, substrate microbiology, organic acidifier, alkaline soil

Improving the Quality of Rubber Plants in Bagged Nurseries by the Use of Compost-Based Culture Substrates

The decrease of fertility soils, the rarity of quality potting soil used to fill nursery bags, the high cost of chemical fertilisers and the problems associated with their use are leading planters and rubber nurserymen in developing and/or expanding areas to look for alternative and sustainable fertilization. In this perspective, a trial was carried out at Research Station of CNRA-Bimbresso and in a farmer’s environment in order to evaluate the agronomic quality of compost made from chicken droppings and dry Panicum maximum straw to improve the growth of rubber plants in bagged nurseries. Mixtures based on potting soil and/or compost in different proportions were prepared. The follow-up of the trial focused on determination of the physico-chemical characteristics of the soils, measurement of the parameters of vegetative growth and the grafting success rate evaluation of rubber plants in nursery. The results obtained show that compost-based crop substrates increase soil organic matter, nitrogen, exchangeable bases, etc., in proportion to the doses applied. For the pH, the application of compost resulted in a reduction in soil acidity of about 1.3 unit compared to the initial values at the two study sites. The vegetative behaviour of the rubber plants also shows that qualitative (height and collar diameter) and quantitative (grafting success rate) improvements were recorded in the plants raised in compost-based substrates. The production of rubber plants in bagged nurseries was optimal with compost doses of 27 t⋅ha−1 (at Bimbresso, in the southeast) and 27 t⋅ha−1 combined with fractionated application of urea (at Kimoukro, in the centre), which under the conditions of the present study may be the recommended doses on rubber plants in bagged nurseries at Cote d’Ivoire.

L’effet de différents types de substrats à base de compost et fumier sur la croissance des plants du cèdre de l’Atlas (Cedrus atlantica (Endl.) Manetti ex Carrière) et du chêne vert (Quercus ilex subsp. ballota (Desf.) Samp.)

Reforestation is one of the main axes led by Water and Forests Moroccan Department. The objective of our study is to improve the growing medium, which has a direct effect on the quality of forest plants. The compost-based substrate in organic matter can be an alternative to potting soil. Two series of composts were studied, the first series with goat manure at 5%, and the second without manure. Each series consists of four types of composted forest residual materials : cedar cone residue ; leaves and twigs of Acacia mollissima ; leaves and twigs of holm oak and needles and twigs of Aleppo pine. They were tested on two forest species the cedar Cedrus atlantica and the oak Quercus ilex subsp. ballota. The physico-chemical analyzes of the various substrates clearly show differences in organic matter and mineral salts compared to the potting soil. The best substitutes for forest soil are compost substrates made from Acacia mollissima ; oak and Alep pine.

Water-holding capacity and plant growth in compost-based substrates modified with polyacrylamide, guar gum or bentonite

Humectant agents are used to improve seed germination and survival in hard environments through their effect on water-holding capacity. In this work, we have evaluated the combined effect of substrate composition and humectant agents on the water-holding capacity and growth of Lolium multiflorum in different mixtures based on municipal solid waste composts. A commercial polyacrylamide, bentonite or guar gum have been added to mixtures of two municipal solid waste composts with either manure vermicompost or pine bark compost. Water-holding capacity of the substrates and plant production after five weeks in the greenhouse were evaluated. Only bentonite increased water retention of the substrates, likely because the compost-based substrates already presented high water retention. None of the humectant agents had significant effects on the growth of Lolium multiflorum. The use of bentonite can be recommended for increasing water-holding capacity of organic substrates in this case, but given the overall small effects of the humectant agents, an adequate choice of the organic materials could suffice for the formulation of adequate plant substrates in this case.

Response of Weeping Lantana (Lantana montevidensis) to Compost-Based Growing Media and Electrical Conductivity Level in Soilless Culture: First Evidence.

The most common substrate for potted ornamental plants is prepared with Sphagnum peat; however, the cost and declining availability of high-quality peat, due to environmental constraints, make it necessary to investigate for alternative organic materials. The present study aimed to determine the effects of partial compost replacement with peat and the optimum electrical conductivity (EC) level of the nutrient solution in potted weeping lantana [L. montevidensis (Spreng.) Briq.] under a recirculating soilless system. Three compost-based substrates were prepared by mixing peat (Pe) with sewage sludge-based compost (Co.) at a rate of 0% (Pe90Co0Pu10, control), 30% (Pe60Co30Pu10), or 60% (Pe30Co60Pu10), respectively. The soilless recirculated closed system was equipped with two different EC levels (high and low) of nutrient solution. Growing media main characteristics and plant bio-morphometric parameters were evaluated. Our first evidence clearly demonstrates that the replacement of peat with compost at doses of 30% and 60% gave the poorest results for plant diameter, shoots, leaves, flowers, and fresh and dry mass, probably indicating that the physical characteristics of the compost based substrates may be the major factor governing plant growth rate. Compost media pH and EC values, too, showed negative effects on plant growth. Considering the effect of EC level, all morphological traits were significantly improved by high EC compared to low EC in weeping lantana. Thus, based on first evidence, further research is needed on organic materials for the establishment of ecological substrates with optimal physicochemical characteristics for the growth of weeping lantana.

Effects of municipal solid waste- and sewage sludge-compost-based growing media on the yield and heavy metal content of four lettuce cultivars.

Compost has been recently suggested as an alternative to peat for the preparation of growing substrates in soilless cultivation systems. However, some physico-chemical properties of compost may reduce plant performance and endanger the quality of productions, in particular for possible heavy metal accumulation in edible parts. This study aims at evaluating the suitability of a municipal solid waste compost (MSWC) and a sewage sludge compost (SSC) as components of growing media for the soilless cultivation of lettuce (Lactuca sativa L.). Heavy metal content of SSC complied with legislation limits but, in MSWC, it exceeded (Cu, Pb) or was very close (Cd, Zn) to safe limits. A greenhouse experiment was carried out by cultivating four lettuce cultivars ("Maximus," "Murai," "Patagonia," and "Aleppo") in pots containing a mixture of MSWC and perlite (MSWC + P), SSC and perlite (SSC + P), or peat and perlite (peat + P), the latter used as control. Plant biometric parameters measured after 72days of growth revealed that the yield of plants cultivated on SSC + P was similar to control plants, independently of the cultivar. Conversely, MSWC + P suppressed in general the biomass production, especially for Murai and Patagonia cultivars. Compared to peat + P, both compost-based substrates reduced the leaf accumulation of heavy metals, with a major effect in Maximus plants. The levels of Cd and Pb in the edible part were always below the safe limits imposed by European regulation. Therefore, risks of heavy metal intake in food chain associated with the replacement of peat with compost in the growing media are negligible, even when a compost with a significant amount of heavy metals is used. Besides compost quality monitoring, also an appropriate varietal choice is crucial to obtain good yields and safe products.

Valorization of sieved crushed bricks as a component of compost-based substrates

Valorization of sieved crushed bricks as a component of compost-based substrates

Compost-based substrate for Gazania rigens (L.) cultivation

Compost-based substrate for <i>Gazania rigens</i> (L.) cultivation

Compost based ecological growing media according EU eco-label requirements

Green compost is seen as one of the best solutions for peat replacement in growing media and for increasing their sustainability. However, the poor quality of many composts has restricted their use as substrate components. The EU Ecolabel may be awarded to products and services that have a reduced environmental impact throughout their life cycle. It is voluntary and ensures certain aspects of the origin and quality. The primary aim of this work was to obtain a gorse compost-based substrate fulfilling the requirements for award of the eco-label.Forest biomass consisting mainly of gorse was composted in dynamic piles with or without irrigation (I) at the beginning and with or without addition of 5% v/v poultry manure (PM). There were thus four different composting treatments that were designated PM0I, PM5I, PM5 and PM0. Temperature, moisture, pH and the C/N ratio of the composting biomass were monitored over a period of nearly 10 months. The resulting composts were characterized in physical, chemical and biological terms, and evaluated for compliance with the requirements of the European Union eco-label for growing media. All composts were found to be mature, stable and pathogen-free. All of them were suitable for use as growing media, exhibiting a high aeration and drainage capacity, little water retention and adequate level of available nutrients. In general they also met the requirements of the EU eco-label, although not all were weed seed-free, which was possibly the sole unfulfilled EU eco-label requirement.

LCA case study on lawn establishment and maintenance with various peat and compost contents in substrates.

The environmental impacts of the establishment and maintenance of lawn, including the production and use of various substrates, were analyzed by life cycle assessment (LCA). The project focused on comparing substrates with different peat and compost contents using pilot substrates and developed a calculation tool to optimize landscaping from an ecological perspective. The impact categories were climate change, aquatic eutrophication, acidification, and use of primary energy. Life cycle assessment methodology and ISO standards 14040 and 14044 were used. Two thousand tons of substrates per hectare of lawn area were assumed to be needed; this large amount explains the importance of the substrate properties for all of the impact categories. Degradation of peat was the most significant factor of the influence of climate; thus, the most effective means of reducing the impact of landscaping on climate is to replace peat with compost. Nitrous oxide and methane emissions were related to the use of compost, but most of these emissions will occur regardless of how the sludge or biowaste is treated. Ammonia emissions from composting were the most important factor for acidification. The significance of fuel consumption by machinery in lawn establishment and mowing was low. The high contents of N and P in compost-based substrates may lead to high nutrient emissions into water systems, which can have significant local impact. The tool helps optimize substrate contents to minimize the environmental effects. Integr Environ Assess Manag 2016;12:459-464. © 2016 SETAC.

Primer registro de Agaricus bisporus (Basidiomycota, Agaricaceae) silvestre en Tlaxcala y Veracruz, México

The fungus commonly known as white button mushroom, Agaricus bisporus, is the most commercially cultivated species among edible ones worldwide. In spite of its importance, its presence in wild stage had not been confirmed even when it has been included in lists of species from different states of Mexico. The aim of this study was to determine if this species grows wild in Mexico. Collections were made in the states of Tlaxcala and Veracruz, where 7 strains were isolated from wild specimens. Basidiomes of these strains were grown in commercial compost-based substrate. Wild specimens, deposited at XAL Herbarium, and those obtained in culture were studied macro and micro morphologically. IE 623 strain was used to obtain the DNA ITS ribosomal sequence. The revised specimens match morphologically with A. bisporus and have an average of 63.4% of bisporic basidia. The DNA sequence confirmed the taxonomic identity and through similarity and phylogenetic analysis, it was concluded that the strain derived from a wild specimen and not from a commercially cultivated strain. Native strains of A. bisporus from Mexico could provide important germplasm to improve its commercial cultivation.

Physico-Chemical Evaluation of Organic Wastes Compost-Based Substrates for Eucalyptus Seedlings Growth

ABSTRACTEucalyptus growth was evaluated in five compost-based substrates formulated with different proportions of sewage sludge, coffee husk, peat, chicken manure, cattle manure, pine bark, sawdust, and coconut fiber, compared to two commercial substrates (CS). Organic wastes compost-based substrates (OWS) and CS were characterized regarding the available contents of macro and micronutrients, sodium (Na+), pH, electrical conductivity (EC), and bulk density (BD). Substrate attributes and eucalyptus biomass production were submitted to principal component analysis (PCA) to detect patterns of clustering. The different proportions of organic wastes influenced the physico-chemical characteristics of OWS and, consequently, the eucalyptus biomass production. The highest biomass was observed in one of the CS that is rich in available boron (B) and calcium (Ca), less concentrated in most of the nutrients and with low EC and Na+ contents. The PCA allowed the verification that B availability was the attribute that explained most of the variation in eucalyptus biomass production.

A Comparative Evaluation of the Physical and Chemical Characteristics of Composted Tea Tree (Melaleuca alternifoliaL.) with Pine Bark Growing Media in Tobacco (Nicotiana tabucumL.) Seedling Production

The search for suitable organic growing media substitutes for pine bark based media combinations has been prompted by concerns over high costs and lack of availability to smallholder farmers coupled with increasing demand for soilless media in Zimbabwe. A trial was conducted for 12 weeks to investigate the suitability of tea tree compost-based substrates for tobacco seedling production as a substitute of the traditional pine bark growing media. The use of composted tea tree growing media in float trays significantly (p&lt;0.05) increases the bulk density of the media by 23–59% when compared with pine bark media. The cation exchange capacity of the native pine bark growing media was 14 to 95% lower than that for the composted tea tree media. The use of the composted tea as media for tobacco seedling nursery reduced seed germination by 10–37%, seedling stem height by 4–34%, and seedling stem girth by 6–175%. While the nutrient holding and supplying potential of the growing media in seedling production is important for normal seedling growth, its effect on seedling growth vigor is less important than that exerted by the presence of suitable physical conditions in the media.

Posidonia oceanica (L.) based compost as substrate for potted basil production.

Peat is the main component of growing media but is also a non-renewable resource; therefore European policy strongly encourages the use of peat alternatives such as compost. Posidonia is a Mediterranean seagrass that produces very conspicuous onshore deposits that can be composted. In this study, a commercial green compost and a Posidonia residue-based compost were tested in order to assess their potential use as substitutes or complements to peat. All macro and micro-element concentrations of the substrates were positively and significantly related to the percentage of composts in the growing media. Plant grown on peat showed higher content of P, Ca, K, Na, Cu, Mn, Zn and Fe, and a slightly higher biomass production in comparison to compost-based growing media. In contrast, plants grown on compost-based substrates showed lower uptake of Cd and Cr than peat. The results indicate that both composts can be used as a complement to the peat for substrate preparation, especially at a rate of 30%. The Posidonia-based compost showed better productive results in comparison to the green one. Basil grown on the two compost-based media showed reduced absorption level of potentially toxic metals in comparison to peat.

Fourier transform infrared spectroscopy and partial least square regression for the prediction of substrate maturity indexes

Traditional methods to evaluate the stability and maturity of organic wastes and composting matrices are laborious, time-consuming and generate laboratory chemical wastes. This study focused on the development of partial least square (PLS) regression models for the prediction of the stability and maturity of compost-based substrates based on Fourier transform infrared (FTIR) spectroscopy. The following parameters, selected as conventional maturity indexes, were modeled and used as dataset: dissolved organic carbon (DOC), C/N and NH4+/NO3− ratios, cation exchange capacity (CEC), degree of polymerization (DP), percentage of humic acid (PHA), humification index (HI) and humification ratio (HR). Models were obtained by using data from a wide range of compost based growing media of diverse origin and composition, including 4 commercially available substrates and 11 substrates prepared in our facilities with varying proportions of different organic wastes. The PLS models presented correlation coefficient of calibration (R2cal) close to 0.90 and correlation coefficient (R2) of cross validation (R2cv) presented acceptable values (>0.6), ranging from 0.67 (HR) to 0.92 (C/N). The good performance of the method was also confirmed by the low correlation obtained from the Y-randomization test. R2 for test samples (R2pred) ranged from 0.66 (C/N) to 0.97 (HI) confirming the good correlation between measured and PLS predicted maturity indexes. FTIR spectroscopy combined with PLS regression represents, after modeling process, a fast and alternative method to assess substrate maturity and stability with reduction of time, lower generation of laboratory chemical wastes residues and lower cost per sample than conventional chemical methods. All models adjusted for maturity indexes are predictive, robust and did not present chance correlation.

Diagnosis of the fertility of compost-based growing media: Method comparison and monitoring in pot plant cultivation

Using compost instead of peat as an ingredient in substrate mixtures is a way of increasing the sustainability of pot plant nurseries. However, this use should also include monitoring to assess crop fertility, given that compost generally has a high fertilizer content. Of the different monitoring methods, the most effective, objective and preventive one involves monitoring the nutrient status of the substrate. The main objective of this study was to provide evidence-based information on fast methods used in the field to characterize substrate fertility compared to a water extract method in order to apply these methods in cultures with unusual alternative substrates.We observed a high level of agreement between the concentration of nutrients measured using the IP method and the concentration using the fertility assessment methods most commonly used in horticulture (leachate and water extract methods). By using different compost-based substrates and comparing them to a control substrate, we have shown that the IP method is useful for monitoring substrate fertility in pot plants. Results show that the IP method indicates the nutrient composition of the functional part of the different substrates (root zone) and their development. The induced percolate method is a useful, nondestructive field method for quickly checking the nutrient content of the functional part of substrates.