Substrate pH Research Articles

Grape Vine Waste and Giant Reed Biomass Composts as Peat and Mineral Fertilizer Substitutes for Producing Organic Tomato Transplants

There is a need to develop and determine the efficacy of composts as growing and fertilization media in the production of organic tomato (Solanum lycopersicum) transplants. The use of composts was researched for organic tomato transplant production. Pre-germinated tomato seeds were planted in substrates of different concentrations (20%, 40%, 60% and 100%) of either grape vine-pruning residue or giant reed-biomass composts amended with or without perlite. The substrate pH and salinity as well as nutrient uptake by transplants increased with increasing compost percentage. Compost water wash removed mainly potassium. Emergence, growth, fresh and dry weight, as well as nutrient concentration, were compared with those of seedlings established in a commercial peat-based substrate. When substrates with a grape-vine-compost content of up to 40% were used, transplant fresh weight was similar to that obtained in the control substrate. Locally produced compost-based substrates provided a peat-free alternative for raising tomato transplants. Vegetable growers and especially organic growers will benefit from production and use of compost-based substrates for raising transplants.

Growth and nutrient uptake responses of ‘Seolhyang’ strawberry to various ratios of ammonium to nitrate nitrogen in nutrient solution culture using inert media

� concentration in the petiole sap, EC and pH of the root substrate were quadratic, with a coefficients of R 2 = 0.99***, 0.98***, and 0.73*.

English

    Apart from the status of nutrients within the substrate, the level of inoculum and virulence, major factors relevant for the infection occurrence are temperature and pH necessary for wood colonization process. The impact of these factors on the growth and production of mycelial mass of Lentinus edodes was investigated under laboratory conditions. The aim of the investigation was to determine optimal conditions for the development of the fungus L. edodes for the purpose of their comparison with the conditions where other rival microorganisms develop. The results showed that the optimal temperature for the development of L. edodes was 23°C, whereas the highest weight of the mycelial dry mass was formed at the substrate pH values between 3.00 and 3.63, which means that this fungus can easily perform spontaneous infection.   Key words: Colonization, growth conditions, shiitake, Lentinus edodes.  

Low-Value Trees as Alternative Substrates in Greenhouse Production of Three Annual Species

Abstract Peat and perlite have served as industry standards in greenhouse substrates for over 50 years. The continued availability of peat, paralleled with its inert characteristics, as well as its ability to stay generally pathogen-free have all contributed to its success in the horticulture industry. Expanded perlite has long been used as an amendment in container mediums to provide air space to container substrates without adding to bulk density or affecting substrate pH and EC. However, due to increased restrictions on the harvesting of peat, as well as fluctuations in fuel prices necessary for shipping, the future availability of peat is a largely unknown factor in greenhouse production. Additionally, growers consider perlite to be a general nuisance due to the lung and eye irritation problems. Because of these problems, researchers have focused on identifying and evaluating possible alternatives to standard substrates. These studies evaluated three possible substrate alternatives for use in greenhouse production, including fresh sweetgum (SG), hickory (H), and eastern redcedar (RC), in addition to WholeTree (WT) substrate. Three greenhouse annual crops (petunia, impatiens, and vinca) were planted in varying ratios of these species mixed with peat. Plants grown with SG and H as amendments did not perform as well as a traditional peat:perlite mix with respect to flower number, growth indices, and plant dry weight. However, plants grown in RC tended to be equivalent to those grown in a traditional mix. Data showed that greenhouse producers could amend their standard greenhouse substrate with up to 50% eastern redcedar with little to no differences in plant growth.

ADDITION OF PULP MILL ASH RAISES PH, MODIFIES PHYSICAL PROPERTIES, AND ALTERS YOUNG TOMATO PLANT GROWTH AND MINERAL NUTRITION IN A PEAT-BASED SUBSTRATE

Pulp and paper mills often burn wood waste to fuel their boilers. The ash from a Mississippi pulp mill boiler was evaluated for potential use as an amendment to peat moss-based greenhouse substrates for production of young tomato plants. Between 0 and 50% ash was added to a custom-blended peat moss-based substrate, and these were compared to a commercially available substrate without ash. Addition of ash increased substrate pH, conductivity (EC), bulk density and water holding capacity, while reducing airspace and average particle size. In general, tomato plants grown in 0–40% ash had similar growth indexes as plants grown in commercial substrate. Increasing amounts of ash decreased tomato shoot nitrogen (N), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentration, and increased concentrations of phosphorus (P), calcium (Ca), sulfur (S), and boron (B). These results indicate that pulp mill ash has the potential to be used as a substrate component for greenhouse container production of tomato.

Diaspore bank of bryophytes in tropical rain forests: the importance of breeding system, phylum and microhabitat

Diaspore banks are crucial for the maintenance and resilience of plant communities, but diaspore banks of bryophytes remain poorly known, especially from tropical ecosystems. This is the first study to focus on the role of diaspore banks of bryophytes in tropical rain forests. Our aim was to test whether microhabitat (substrate type) and species traits (breeding system, phylum) are important in explaining the diaspore bank composition. Using samples cultivated in the laboratory, we assessed the number of species and shoots emerging from bark, decaying wood and soil from two sites of the Atlantic rain forest (montane and sea level) in Brazil by comparing the contribution of species by phylum (mosses, liverworts) and breeding system (monoicous, dioicous). More species emerged from bark (68) and decaying wood (55) than from soil (22). Similar numbers of species were found at both sites. Mosses were more numerous in terms of number of species and shoots, and monoicous species dominated over dioicous species. Substrate pH had only weak effects on shoot emergence. Species commonly producing sporophytes and gemmae had a high contribution to the diaspore banks. These superficial diaspore banks represented the extant vegetation rather well, but held more monoicous species (probably short-lived species) compared to dioicous ones. We propose that diaspore bank dynamics are driven by species traits and microhabitat characteristics, and that short-term diaspore banks of bryophytes in tropical rain forests contribute to fast (re)establishment of species after disturbances and during succession, particularly dioicous mosses investing in asexual reproduction and monoicous mosses investing in sexual reproduction.

The Acidification of Sphagnum Moss Substrate during Phalaenopsis Cultivation

Sphagnum moss has been used as the major substrate for cultivating Phalaenopsis spp. in China, Japan, and Taiwan. With a lengthened duration of cultivation, the pH of the moss gradually declines. It is not understood what causes this decline in substrate pH. Using the vegetatively propagated Phal. Sogo Yukidian ‘V3’, this study investigated if substrate, fertilization, light, and plant roots could be the cause of pH decline in the substrate. The results showed that, although increasing fertilizer concentration resulted in a low initial pH (pH measured by the pour-through technique at first fertilization), fertilization itself was not the primary cause of the long-term pH decline. Regardless of whether the sphagnum moss was fertilized, the pH of the substrate without plants increased as time progressed, whereas the pH of the substrate in which living Phalaenopsis plants were growing declined with time. Although the magnitude and course of pH decline were different in various substrates, the pH of sphagnum moss, artificial textile fiber, and pine bark substrates in which living plants were growing declined with time. Whether the substrate was exposed to light (clear pots) or not (opaque pots) had no effect on substrate pH, indicating that algae were not a factor in pH decline. Therefore, the roots of Phalaenopsis may be the major contributor to substrate pH decline during production.

Evaluation of Olive Mill Waste Compost as a Soil Amendment for Cynodon dactylon Turf Establishment, Growth, and Anchorage

A field study evaluated composted olive mill waste (OMC) as a soil amendment in Cynodon dactylon (bermudagrass; C4) turf establishment and maintenance. The study comprised two substudies, each of which had discrete goals: 1) an evaluation of OMC effects on overall bermudagrass growth over the course of 2.5 years when established by seed and subsequently from sprouting of existing rhizomes (2002 to 2004); and 2) a re-evaluation of OMC effects on bermudagrass establishment by seed (2003). Twenty-four plots (1.44 × 1.44 m) were filled with sandy-loam soil and supplemented with one of three OMC proportions (low= 12.5%, medium = 25%, and high = 50% by volume, indicated as substrates S:OMCL, S:OMCM, and S:OMCH, respectively), and non-amended soil served as a control (S). The study evaluated: 1) the substrate's chemical and physical characteristics, including bulk density, water retention curves, pH, and electrical conductivity (EC) measurements; 2) the establishment rate of C. dactylon, either by seed or by sprouting of existing rhizomes after dormancy as determined by measurements that included vertical detachment force (VDF), root growth, and substrate moisture; and 3) the growth rate of C. dactylon as determined through measurements of visual quality, clipping dry weight, root growth, and VDF. The results show that OMC decreased substrate pH in proportion to the OMC supplementation rate and increased EC only at the end of the study and only in the plots with the highest supplementation rate (S:OMCH). Water retention was improved by OMC incorporation except from S:OMCL, which increased water retention only at low tensions. Compared with soil alone, bulk density decreased by 13.5%, 19.7%, and 32.8% as the OMC rate increased, respectively, from 12.5% to 50%. The OMC rate of 50% v/v resulted in a minor reduction in plant visual quality during the cold periods but in a slight improvement during the warm periods. The clipping dry weights were increased by OMC amendments in 2003, which was considered a disadvantage because of the insignificant visual quality differences between substrates during the 2 study years. In 2004, the clipping yields were unaffected by OMC rate. Root dry weight response to OMC varied. For the highest OMC rate, root dry weight was lower during the cold and wet periods, greater during the first stages of bermudagrass establishment by seed, and similar compared with soil without OMC during turf establishment from the sprouting of existing rhizomes after dormancy. The highest OMC rate reduced resistance to vertical detachment force at four sampling dates (of six) during the 2002–2003 study, because the reduced root dry weight and/or increased moisture of the substrate facilitated bermudagrass detachment. In contrast, OMC-supplemented substrates resulted in increased VDF at the first sampling date of establishment both by seed (2003) and by rhizome sprouting after dormancy (2004). It was concluded that, when speedy establishment is imperative (such as in sod farms) or when irrigation is limited, an OMC rate of 50% by volume should be selected. In contrast, for sustainable bermudagrass growth, a rate of 12.5% by volume is preferred, because it increases the visual quality of the grass and root growth.

Technology Optimization on Preparation of Peanut Polypeptide Using Alcalase

In order to exploit and utilize the peanut protein resource and produce high additional value protein products, the preparation technology of peanut polypeptide from peanut protein isolate was investigated using Alcalase. The effects of influencing factors, enzyme dosage, substrate mass fraction, hydrolysis temperature, hydrolysis time and pH value, on hydrolysis was studied during the process of Alcalase hydrolyzing peanut protein isolate by single factor experiment and response surface methodology central composite design. The regression model for the relationship between the influencing factors and the soluble nitrogen mass concentration was established. The optimum parameters for Alcalase enzymatic reaction were obtained as follows: pH value 8.0, enzyme dosage 4762U/g substrate, substrate mass fraction 5%, hydrolysis temperature 50°C, hydrolysis time 180min, and then the soluble nitrogen mass concentration reached to 16.28mg/mL.

Occurrence and correction of lime-induced chlorosis in petunia plants

The effect of various concentrations and ratios of iron (Fe) and manganese (Mn) chelates on growth, micronutrient uptake and chlorophyll content was investigated in a glasshouse experiment using potted petunia plants. The plants were cultivated in a peat substrate amended with dolomitic limestone at rate of 3.0 g/L (control substrate) or 12.0 g/L. The higher rate was established both to restrict the uptake of Fe, Mn and other nutrients and also to test the effectiveness of various Fe and Mn treatments. The plants in all the treatments were fertigated at weekly intervals with a nutrient solution containing macronutrients and micronutrients. Various chelate forms of Fe and Mn were used with the exception of two treatments where these two elements were omitted. The effects of different substrate pH levels (derived from different limestone contents) had a large effect on plant growth, chlorophyll content and content of Fe and Mn accumulated in the plant leaves. The plants in the high-limestone substrate devoid of Fe and Mn had reduced growth and lower chlorophyll content. They also had lower leaf Fe and Mn content than the control plants in the R3 substrate. Regular fertigation with a nutrient solution containing Mn and Fe improved plant growth rate and also increased chlorophyll content. However, its efficiency depended on the chelate form and concentration used. The effect of chelate application on the Fe and Mn leaf content was unclear as it only marginally increased leaf Fe absorption in some treatments. No effect of the various Fe/Mn ratios was observed.

Phytoextraction of Cadmium by Four Mediterranean Shrub Species

The possibility of remediating contaminated soils though the use of high biomass-generating, native plant species capable of removing heavy metals is receiving increased attention. The cadmium (Cd) accumulation capacities of the native Mediterranean, perennial shrubs Atriplex halimus, Phyllirea angustifolia, Rhamnus alaternus and Rosmarinus officinalis were tested by growing transplanted specimens in a pine bark compost substrate (pH 5.6) contaminated with 100 mg Cd kg−1. After 70 days, only R. alaternus showed reduced growth. The increase in biomass seen in all the test species enhanced the phytoextraction of Cd. However, the species behaved as metal excluders, except for the halophyte A. halimus, which behaved as an indicator plant. In this species the leaf Cd concentration reached 35 mg Cd kg−1, with the shoot responsible for some 86% of total Cd accumulation. Atriplex halimus showed the highest bioconcentration factor (BCF) (0.36) and leaf Cd transport index (1.68); consequently, this species showed the highest Cd phytoextraction capacity.

IMPACT OF COMPOSTED DAIRY MANURE ON PH MANAGEMENT AND PHYSICAL PROPERTIES OF SOILLESS SUBSTRATE

Dairy cow manure compost (DMC) was evaluated as a soilless substrate substitute for dolomitic limestone and peat moss in two experiments. The objectives were 1) to quantify the impact of DMC on substrate pH establishment and stabilization throughout crop time and 2) to test the effect of DMC on physical properties of substrate. Peat moss plus DMC (at 5 to 30% by volume) was held constant at 75% volume and perlite at 25% without limestone. Two additional control treatments of 75% sphagnum peat moss and 25% perlite were formulated with and without agricultural dolomitic limestone. Pot chrysanthemum ‘Kory’ plants were transplanted into 16.5-cm diameter (1.4 L) plastic pots and fertilized at each irrigation with 17N-2.2P-14.1K neutral fertilizer. Additions of 0 to 30% DMC resulted in initial substrate pH levels of 3.1 to 6.5. Although pH declined during plant production, the decline was similar in the agricultural limestone and the 20 to 30% DMC treatments that had similar initial pH levels. Thus, pH buffering capacity of DMC was similar to the limestone. The initial EC levels for all substrates were within the acceptable range for seedlings and bedding plants. Magnitude of shrinkage did not relate to addition of DMC and was of little commercial significance. Irrespective of time in the cropping cycle, DMC resulted in increased dry bulk density (Db), decreased total porosity (TP) and container capacity (CC), and little effect on air space (AS). AS levels were in a good range of 15% and above for the 7.6 cm tall test cylinders. End of crop tissue analysis indicated that DMC resulted in higher leaf concentrations of potassium, sulfur, copper, iron, and manganese, lower, but adequate, calcium and magnesium, and similar nitrogen, phosphorus, boron, and zinc concentrations. Maximum plant growth (dry weight) occurred with 15% DMC in Experiment 1 and with 10% DMC in Experiment 2. All limestone and a portion of peat moss were effectively replaced with DMC.

Relationship between plant life forms and ecological indices in a lacustrine ecosystem

Abstract This study is the first to analyze the relationship between ecological indices (substrate moisture, nutrient content, substrate dispersion/aeration, substrate pH and humus content) and life forms of the vascular flora in and around Lake Provala; these relationships may serve as reliable indicators of the ecological conditions prevailing in this ecosystem. Since the development of certain life forms, in addition to climatic conditions, depends on plant requirements for several major environmental factors expressed as ecological indices, we established the relationship between the ecological index and life form of vascular plants collected over an eight year period in this system using correspondence analysis. We found a significant correlation between the development of certain life forms and levels of substrate moisture, nutrient content and substrate dispersion/aeration. These relationships help explain the predominance of hemicryptophytes and hydro-helophytes in the riparian zone of the lake, as these forms are perfectly adapted to water-saturated or aquatic environments rich in nutrients and relatively well aerated. There was no significant relationship between life forms and substrate pH or the content of organo-mineral compounds (humus) in the soil.

Effects of high concentrations of calcium salts in the substrate and its pH on the growth of selected rhododendron cultivars

For proper growth and development, rhododendrons need acidic soils, whereas calcium carbonate (CaCO<sub>3</sub>) in the substrate markedly limits their growth. In this study, we analysed the reactions of rhododendrons to high concentrations of calcium salts and pH in the substrate. We used 4-month-old seedlings of <em>Rhododendron</em> 'Cunningham's White' and 1.5-year-old seedlings and rooted cuttings of <em>R.</em> 'Cunningham's White' and <em>R.</em> 'Catawbiense Grandiflorum'. Their reactions depended mostly on calcium salt type added to the substrate (sulphate or carbonate). An increase in concentrations of phenolic compounds was detected mostly in roots of the plants grown in a substrate with a high calcium carbonate content. Addition of calcium salts to the substrate caused a significant rise in total nonstructural carbohydrates in leaves and roots of the studied plants. As compared to the control, an increase in substrate pH in the variant with calcium carbonate limited the activity of acid phosphatase, while lowering of substrate pH in the variant with calcium sulphate, significantly increased its activity. Along with the rise in substrate pH, a remarkable increase was observed in the activity of nonspecific dehydrogenase (DHA) in the substrate with CaCO<sub>3</sub>, as compared to the control. Unfavourable soil conditions (high calcium content and alkaline pH) caused a decrease in assimilation of minerals by the studied plants (mostly phosphorus and manganese). Our results show that the major factor limiting rhododendron growth is an increase in substrate pH, rather than an increase in the concentration of calcium ions.

Interactions of AChE with A? Aggregates in Alzheimer?s Brain: Therapeutic Relevance of IDN 5706

Acetylcholinesterase (AChE; EC 3.1.1.7) plays a crucial role in the rapid hydrolysis of the neurotransmitter acetylcholine, in the central and peripheral nervous system and might also participate in non-cholinergic mechanism related to neurodegenerative diseases. Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by a progressive deterioration of cognitive abilities, amyloid-β (Aβ) peptide accumulation and synaptic alterations. We have previously shown that AChE is able to accelerate the Aβ peptide assembly into Alzheimer-type aggregates increasing its neurotoxicity. Furthermore, AChE activity is altered in brain and blood of Alzheimer’s patients. The enzyme associated to amyloid plaques changes its enzymatic and pharmacological properties, as well as, increases its resistant to low pH, inhibitors and excess of substrate. Here, we reviewed the effects of IDN 5706, a hyperforin derivative that has potential preventive effects on the development of AD. Our results show that treatment with IDN 5706 for 10 weeks increases brain AChE activity in 7-month-old double transgenic mice (APPSWE–PS1) and decreases the content of AChE associated with different types of amyloid plaques in this Alzheimer’s model. We concluded that early treatment with IDN 5706 decreases AChE–Aβ interaction and this effect might be of therapeutic interest in the treatment of AD.

Modification of Switchgrass Substrate pH Using Compost, Peatmoss, and Elemental Sulfur

Switchgrass (Panicum virgatum) biomass is being evaluated as a potential alternative to pine bark as the primary potting component in containerized nursery crops. Substrates composed entirely of switchgrass have higher pH than what is considered desirable in container substrates. The objective of this research was to evaluate the influence of elemental S, sphagnum moss, and municipal solid waste compost (MSC) as amendments for reducing substrate pH and buffering it against large changes over time. Three experiments were conducted; the first two experiments were conducted using annual vinca (Catharanthus roseus ‘Pacifica Blush’) to quickly assess how pH was affected by the three amendments, and the final experiment was conducted with blueberry (Vaccinium corymbosum ‘Duke’) to assess the long-term effects of substrate amendments. Summarizing across the three experiments, elemental S was effective in reducing substrate pH; however, rates 1 lb/yard3 or greater reduced pH below the recommended level of 5.5 and lower S rates did not maintain lowered pH over time. Sphagnum moss and MSC together at 20% and 10% (v/v), respectively, were effective at reducing substrate pH and buffering against change. Sphagnum moss and MSC provided the additional benefit of improving physical properties of the switchgrass substrates.

Modification of Switchgrass Substrate pH Using Compost, Peatmoss, and Elemental Sulfur

Switchgrass (Panicum virgatum) biomass is being evaluated as a potential alternative to pine bark as the primary potting component in containerized nursery crops. Substrates composed entirely of switchgrass have higher pH than what is considered desirable in container substrates. The objective of this research was to evaluate the influence of elemental S, sphagnum moss, and municipal solid waste compost (MSC) as amendments for reducing substrate pH and buffering it against large changes over time. Three experiments were conducted; the first two experiments were conducted using annual vinca (Catharanthus roseus ‘Pacifica Blush’) to quickly assess how pH was affected by the three amendments, and the final experiment was conducted with blueberry (Vaccinium corymbosum ‘Duke’) to assess the long-term effects of substrate amendments. Summarizing across the three experiments, elemental S was effective in reducing substrate pH; however, rates 1 lb/yard3 or greater reduced pH below the recommended level of 5.5 and lower S rates did not maintain lowered pH over time. Sphagnum moss and MSC together at 20% and 10% (v/v), respectively, were effective at reducing substrate pH and buffering against change. Sphagnum moss and MSC provided the additional benefit of improving physical properties of the switchgrass substrates.

Simultaneous production of natural statins and coenzyme Q10 by Monascus pilosus fermentation using different solid substrates

Simultaneous production of mevinolins (natural statins) and ubiquinones (coenzyme Qs; CoQ9 and CoQ10) were identified and determined in solid substrates fermented (SSF) with Monascus pilosus K-1140. The highest co-production of mevinolins (2.31±0.11 mg/g) and ubiquinones (0.24±0.02 mg/g) was obtained in a mixed grains substrate (rice:sorghum:barley:buckwheat:soybean; 1:1:1:1:1; w/w/w/w/w). The optimal conditions for mixed grains in the SSF were initial moisture content of 50% and initial substrate pH of 6. The total production of CoQs was increased by 32% with the addition of red paprika. Mevinolinic acid (hypocholesterolemic agent) was the main component contributing 81.3 to 91.5% of total mevinolins in the fermented substrates. The results indicate that mixed grain fermented with M. pilosus may be used as a new nutraceuticals with anti-atherosclerotic function without statin-induced CoQ10 deficiency.

Response of Six Begonia Species to Fertilizer Concentration and Substrate pH

Begonia albopicta, B. cucullata var. cucullata, B. echinosepala var. elongatifolia, B. holtonis, B. foliosa var. miniata and B. 'Fuchsifoliosa' are conserved at the Ornamental Plant Germplasm Center (OPGC), in Columbus Ohio as a source of germplasm for breeders and researchers. No cultural information for these species is available. Our objective was to evaluate the response of the above mentioned species to different fertilizer concentrations and substrate pH levels. Rooted cuttings were transplanted into plastic containers using a soilless mix. One of five concentrations ranging from 20 to 600 mg·L -1 N of 17-5-17 water soluble fertilizer were applied in irrigation water for 12 weeks. We found significant responses to the fertilizer concentrations and differences among species on weekly measured substrate EC, shoot length, leaf area, dry weight, average number of inflorescences, and SPAD readings. Growth parameters and visual observations were used to determine optimal fertilizer concentration. High quality B. albopicta, B. cucullata var. cucullata, B. echinosepala var. elongatifolia, and B. holtonis plants were obtained with 200 to 300 mg·L -1 N. On the other hand, low fertilizer concentration was found to be better for B. foliosa var. miniata and B. 'Fuchsifoliosa' in order to avoid high salt stress causing plant death. Seven different pH ranges of the peat-based substrates were obtained by adding different rate of dolomitic hydrated lime ranging from 1.0 to 2.6 kg·m 3 . pH was monitored weekly and maintained accordingly by adding flowable lime or a diluted sulfuric acid solution. The inflorescence number and SPAD readings were significantly different among six species, but there was no significant effect of substrate pH. Significant interaction between species and substrate pH was found in shoot length, leaf area, and dry weight. Substrate pH between 5.6 and 6.0 was found to be adequate for B. albopicta, B. echinosepala var. elongatifolia and B. holtonis. B. foliosa var. miniata plant mortality was observed when grown at a substrate pH below 5.2. The information presented in this work will be useful to OPGC personnel in the maintenance of these species at their facilities, as well as to begonia breeders and collectors.

Use of Processed Biofuel Crops for Nursery Substrates

Abstract Loblolly pine (Pinus taeda) bark availability has decreased, causing shortages in inventory and increased prices for pine bark substrates. One potential alternative to pine bark is the use of biofuel or biomass crops that can be grown locally, harvested, and processed into a suitable substrate. The objective of this research was to assess the suitability of several biofuel crops as alternatives to pine bark in nursery substrates using annual vinca (Catharanthus roseus) as a model crop. Across two experiments, switchgrass (Panicum virgatum), willow (Salix spp.), corn (Zea mays) stover, and giant miscanthus (Miscanthus ×giganteus) were processed through a hammermill equipped with a 0.95 cm (0.375 in) screen. Pine bark was used as a control. Substrate materials were used either alone, amended with 20% (v/v) sphagnum peat moss, or amended with 20% (v/v) sphagnum peat moss and 10% (v/v) municipal solid waste compost. Biofuel-based substrates tended to have greater air space and less container capacity than pine bark substrate. Amending with peat moss, or peat moss and municipal solid waste compost reduced air space and increased container capacity of all substrates. Substrate pH of biofuel-based substrates was higher than pine bark substrates, and was neutral to slightly alkaline. Amending with peat moss reduced pH of biofuel substrates to levels considered more ideal for annual vinca growth. Foliar calcium, magnesium, and iron levels were low across all treatments, although visual foliar deficiency symptoms were not apparent. Shoot growth was greatest in switchgrass and pine bark substrates. Plant growth differed among biofuel and pine bark substrates; however, all plants were considered marketable at the conclusion of the experiment. Modification of chemical and physical properties for each substrate type will be necessary.