scholarly journals Physical Properties of Biocontainers for Greenhouse Crops Production

2010 ◽  
Vol 20 (3) ◽  
pp. 549-555 ◽  
Author(s):  
Michael R. Evans ◽  
Matt Taylor ◽  
Jeff Kuehny

The vertical dry strength of rice hull containers was the highest of all containers tested. Plastic containers and paper containers had similar vertical dry strengths. Containers composed of 80% cedar fiber and 20% peat (Fertil), composted dairy manure (Cowpot), and peat had lower dry vertical dry strengths than the aforementioned containers but had higher vertical dry strengths than those composed of bioplastic (OP47), coconut fiber, and rice straw. Rice hull containers and paper containers had the highest lateral dry strengths. Rice straw, Cowpot, and plastic containers had similar dry lateral strengths, which were significantly higher than those of OP47, Fertil, coconut fiber, and peat containers. Highest dry punch strengths occurred with traditional plastic and Cowpot containers, while the lowest dry punch strengths occurred with OP47, Fertil, coconut fiber, peat, and rice straw containers. Plastic, rice hull, and paper containers had the highest wet vertical and lateral strengths. Plastic containers had the highest wet punch strength, while Fertil, Cowpot, and peat containers had the lowest wet punch strengths. When saturated substrate was placed into containers and the substrate surface and drainage holes were sealed with wax, plastic, OP47, and rice hull containers had the lowest rates of water loss per unit of container surface area, while peat, Fertil, and rice straw containers had the highest rates of water loss per unit of container surface area. The amounts of water required to produce a geranium (Pelargonium ×hortorum) crop were significantly higher and the average irrigation intervals were shorter for peat, Fertil, coconut fiber, Cowpot, and rice straw containers than for traditional plastic containers. The amounts of water required to produce a geranium crop and the average irrigation intervals were similar among plastic, rice hull, and OP47 containers. Algal and fungal coverage on the outside container walls averaged 47% and 26% for peat and Fertil containers, respectively, and was higher than for all other containers tested, which had 4% or less algal and fungal coverage. After 8 weeks in the field, Cowpot containers had decomposed 62% and 48% in the Pennsylvania and Louisiana locations, respectively. Peat, rice straw, and Fertil containers decomposed 32%, 28%, and 24%, respectively, in Pennsylvania, and 10%, 9%, and 2%, respectively, in Louisiana. Coconut fiber containers had the lowest level of decomposition at 4% and 1.5% in Pennsylvania and Louisiana, respectively.

HortScience ◽  
2013 ◽  
Vol 48 (6) ◽  
pp. 732-737 ◽  
Author(s):  
Stephanie A. Beeks ◽  
Michael R. Evans

The physical properties of new 15.2-cm plastic and comparably sized bioplastic, solid ricehull, slotted ricehull, paper, peat, dairy manure, wood fiber, rice straw, and coconut fiber containers were determined. Additionally, the physical properties of these containers were determined after being used to grow ‘Rainier Purple’ cyclamen (Cyclamen persicum L.) in ebb-and-flood benches for 15 weeks in a greenhouse environment. The punch strength of new coconut fiber containers was the highest of the containers. The used plastic containers had strengths of 228.0, 230.5, and 215.2 N for the bottom, middle, and top zones, respectively. The used peat, dairy manure, and wood fiber containers had strengths of less than 15 N for each zone. Tensile strength of all new containers was 10 kg. The plastic, bioplastic, solid ricehull, slotted ricehull, paper, and coconut fiber containers had used strengths that were similar to plastic containers. Total water used for wood fiber containers was higher than plastic containers. Irrigation intervals for plastic containers were similar to bioplastic, solid ricehull, slotted ricehull, paper, and coconut fiber containers. The irrigation interval for plastic containers was 1.32 days and the wood fiber container had the shortest irrigation interval at 0.61 day. Container absorption for coconut fiber containers was 255 mL and was higher than plastic containers. Wood fiber container absorption was 141 mL and lower than plastic containers. Plastic, bioplastic, solid ricehull, and slotted ricehull containers had no visible algal or fungal growth. The wood fiber containers had 79% of the container walls covered with algae or fungi and the bottom and middle zones had 100% algae or fungi coverage. The bottom zone of rice straw, dairy manure, and peat containers also had 100% algae or fungi coverage. The bioplastic, solid ricehull, and slotted ricehull containers in this study proved to be good substitutes for plastic containers. These containers retained high levels of punch and tensile strength, had no algal and fungal growth, and required a similar amount of solution as the plastic containers to grow a cyclamen crop. The peat, dairy manure, wood fiber, and rice straw containers proved not to be appropriate substitutes for plastic containers because of the low used strengths, high percentage of algal and fungal coverage, and shorter irrigation intervals as compared with plastic containers.


2015 ◽  
Vol 25 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Michael R. Evans ◽  
Andrew K. Koeser ◽  
Guihong Bi ◽  
Susmitha Nambuthiri ◽  
Robert Geneve ◽  
...  

Nine commercially available biocontainers and a plastic control were evaluated at Fayetteville, AR, and Crystal Springs, MS, to determine the irrigation interval and total water required to grow a crop of ‘Cooler Grape’ vinca (Catharanthus roseus) with or without the use of plastic shuttle trays. Additionally, the rate at which water passed through the container wall of each container was assessed with or without the use of a shuttle tray. Slotted rice hull, coconut fiber, peat, wood fiber, dairy manure, and straw containers were constructed with water-permeable materials or had openings in the container sidewall. Such properties increased the rate of water loss compared with more impermeable bioplastic, solid rice hull, and plastic containers. This higher rate of water loss resulted in most of the biocontainers having a shorter irrigation interval and a higher water requirement than traditional plastic containers. Placing permeable biocontainers in plastic shuttle trays reduced water loss through the container walls. However, irrigation demand for these containers was still generally higher than that of the plastic control containers.


2013 ◽  
Vol 23 (2) ◽  
pp. 173-176 ◽  
Author(s):  
Stephanie A. Beeks ◽  
Michael R. Evans

The objective for this research was to evaluate the growth of a long-term crop in biodegradable containers compared with traditional plastic containers using a subirrigation system. Plastic, bioplastic, solid ricehull, slotted ricehull, paper, peat, dairy manure, wood fiber, rice straw, and coconut fiber containers were used to evaluate plant growth of ‘Rainier Purple’ cyclamen (Cyclamen persicum) in ebb-and-flood subirrigation benches. The days to flower ranged from 70 to 79 and there were no significant differences between the plastic containers and the biocontainers. The dry shoot weights ranged from 23.9 to 37.4 g. Plants grown in plastic containers had dry shoot weights of 27.6 g. The dry shoot weight of plants grown in containers composed of wood fiber was 23.9 g and was lower than plants grown in plastic containers. The plants grown in the bioplastic, solid ricehull, slotted ricehull, paper, peat, dairy manure, rice straw, and coconut fiber containers had significantly higher dry shoot weights than plants grown in plastic containers. Dry root weights ranged from 3.0 to 4.0 g. The plants grown in the plastic containers had dry root weights of 3.0 g. Plants grown in paper and wood fiber containers had higher dry root weights than those grown in plastic containers. The only container that negatively affected plant growth was the wood fiber container. Plants preformed the best in solid ricehull, slotted ricehull, and coconut fiber containers based on dry shoot and dry root weights, but all containers were successfully used to produce marketable cyclamen plants.


HortScience ◽  
1993 ◽  
Vol 28 (12) ◽  
pp. 1182-1184 ◽  
Author(s):  
N.K. Lownds ◽  
M. Banaras ◽  
P.W. Bosland

Physical characteristics [initial water content, surface area, surface area: volume (SA: V) ratio, cuticle weight, epicuticular wax content, and surface morphology] were examined to determine relationships between physical properties and water-loss `rate in pepper fruits. `Keystone', `NuMex R Naky', and `Santa Fe Grande' peppers, differing in physical characteristics, were stored at 8, 14, or 20C. Water-loss rate increased linearly with storage time at each temperature and was different for each cultivar. Water-loss rate was positively correlated with initial water content at 14 and 20C, SA: V ratio at all temperatures, and cuticle thickness at 14 and 20C. Water-loss rate was negatively correlated with surface area and epicuticular wax content at all temperatures. Stomata were absent on the fruit surface, and epicuticular wax was amorphous for each cultivar.


HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 643-649 ◽  
Author(s):  
Johann S. Buck ◽  
Michael R. Evans

Fresh parboiled rice hulls ground in a hammer mill and screened through a 1.18-mm screen and collected on a 0.18-mm screen (RH3) and particles with a specific diameter of 0.5 to 1.0 mm had total pore space (TPS), air-filled pore space (AFP), and water-holding capacity (WHC) similar to that of Canadian sphagnum peat (peat). However, RH3 had more available water, a higher bulk density (BD), and a higher particle density (PD) than peat. When blended with 20% to 40% perlite or 1 cm aged pine bark, RH3-based substrates had lower TPS, similar AFP, and lower WHC than equivalent peat-based substrates. The RH3-containing substrates had higher BD and average PD than equivalent peat-based substrates. When blended with parboiled rice hulls (PBH), RH3-based substrates had lower TPS than equivalent peat-based substrates. When blended with 20% to 40% PBH, RH3-based substrates had lower AFP than equivalent peat-based substrates. RH3-based substrates containing up to 20% PBH had lower WHC than equivalent peat-based substrates. RH3-based substrates containing 40% PBH had a higher WHC than equivalent peat-based substrates. When blended with PBH, all RH3-based substrates had higher BD and average PD than equivalent peat-based substrates. The addition of 40% RH3 to a peat-based substrate containing 20% perlite decreased substrate TPS, whereas the addition of 10% to 40% decreased AFP. The addition of 10% to 30% RH3 increased WHC. The addition of 30% RH3 to a peat-based substrate containing 20% 1 cm aged pine bark decreased substrate TPS and the addition of 20% to 40% RH3 decreased AFP. The addition of 10% RH3 increased WHC, but the addition of 20% or more RH3 did not affect WHC. The addition of 30% RH3 increased the BD, but the addition of RH3 had no effect on average PD. The addition of 20% or more and 30% or more RH3 to a peat-based substrate containing 20% PBH decreased substrate TPS and AFP, respectively. The addition 20% RH3 decreased WHC. The addition of 10% to 40% RH3 increased BD. Overall, RH3 was the ground rice hull product that had physical properties most similar to peat. Peat-based substrates in which up to 40% of the peat was replaced with RH3 had physical properties that, although different from peat controls, were within commonly recommended ranges for substrates used to grow greenhouse crops.


HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 1008-1011 ◽  
Author(s):  
Michael R. Evans ◽  
Douglas Karcher

When the substrate surface and drainage holes of feather fiber, peat, and plastic containers were sealed with wax, hyperbolic growth curves were good fits to cumulative water loss on a per container and per cm2 basis, with R2 values ranging from 0.88 to 0.96. The effect of container type was significant as the differences in asymptotic maximum water loss (max) values for all container pairs were significant at P < 0.05 for both water loss per container and water loss per cm2. The predicted total water loss for peat containers was ≈2.5 times greater than feather containers, and the predicted water loss per cm2 for the peat container was ≈3 times greater than feather containers. Vinca [Catharanthus roseus (L.) G. Don.] `Cooler Blush' and impatiens (Impatiens walleriana Hook f.) `Dazzler Rose Star' plants grown in feather and peat containers required more water and more frequent irrigations than those grown in plastic containers. However, plants grown in feather containers required less water and fewer irrigations than plants grown in peat containers. The surface area of containers covered by algal or fungal growth was significantly higher on peat containers than on feather containers. No fungal or algal growth was observed on plastic containers. Additionally, primarily algae were observed on peat containers whereas most discoloration observed on feather containers was due to fungal growth. Dry feather containers had a higher longitudinal strength than dry plastic containers but a lower longitudinal strength than dry peat containers. Wet feather containers had higher longitudinal strength than wet peat containers but a similar longitudinal strength as wet plastic containers. Dry feather and plastic containers had similar lateral strengths and both had significantly higher lateral strength than dry peat containers. Wet feather containers had significantly lower lateral strength than wet plastic containers but had higher lateral strength than wet peat containers. Dry and wet plastic containers had higher punch strength than wet or dry peat and feather containers. Dry peat containers had significantly higher punch strength than dry feather containers. However, wet feather containers had significantly higher punch strength than wet peat containers. Decomposition of peat and feather containers was significantly affected by container type and the species grown in the container. When planted with tomato (Lycopersicum esculentum L.) `Better Boy', decomposition was not significantly different between the peat and feather containers. However, when vinca and marigold (Tagetes patula L.) `Janie Bright Yellow' were grown in the containers, decomposition was significantly higher for feather containers than for peat containers. Therefore, containers made from processed feather fiber provided a new type of biodegradable container with significantly improved characteristics as compared to peat containers.


2007 ◽  
Vol 7 (3) ◽  
pp. 5941-6036 ◽  
Author(s):  
F. Domine ◽  
M. Albert ◽  
T. Huthwelker ◽  
H.-W. Jacobi ◽  
A. A. Kokhanovsky ◽  
...  

Abstract. Snow on the ground is a complex multiphase photochemical reactor that dramatically modifies the chemical composition of the overlying atmosphere. A quantitative description of the emissions of reactive gases by snow requires the knowledge of snow physical properties. This overview details our current understanding of how those physical properties relevant to snow photochemistry vary during snow metamorphism. Properties discussed are density, specific surface area, optical properties, thermal conductivity, permeability and gas diffusivity. Inasmuch as possible, equations to parameterize these properties as a function of climatic variables are proposed, based on field measurements, laboratory experiments and theory. The potential of remote sensing methods to obtain information on some snow physical variables such as grain size, liquid water content and snow depth are discussed. The possibilities for and difficulties of building a snow photochemistry model by adapting current snow physics models are explored. Elaborate snow physics models already exist, and including variables of particular interest to snow photochemistry such as light fluxes and specific surface area appears possible. On the other hand, understanding the nature and location of reactive molecules in snow seems to be the greatest difficulty modelers will have to face for lack of experimental data, and progress on this aspect will require the detailed study of natural snow samples.


1980 ◽  
Vol 3 ◽  
pp. 158-174 ◽  
Author(s):  
Bruce M. Bell

The edrioasteroids (seat stars) are a small but diverse group of Paleozoic (Lower Cambrian through Pennsylvanian) echinoderms known to include five morphologically distinct types of thecal construction. Domal and clavate thecae predominate, although some are globoid and others axially elongate. Adult thecal diameters range from 6 – 7 mm to approximately 9 cm, but 15 – 30 mm is the norm. Edrioasteroids are not common fossils, although when proper conditions for preservation existed, entire populations were often fossilized so that hundreds or even thousands of specimens can be recovered through excavation. Apparently, preservation depended upon catastrophic kills, most of which seem to have resulted from storm-deposited mud deeply burying the entire substrate surface area.


2018 ◽  
Vol 192 ◽  
pp. 03035
Author(s):  
Thachanan Samanmulya ◽  
Pawinee Deetae ◽  
Patthranit Wongpromrat

This study focused on adsorption of atrazine in adsorbent synthesized from Rice Straw. Rice Straw biochar were used in the study as they exhibited significantly high adsorption capacity for pesticide. Briefly, rice straw was pyrolysis at 600°C under nitrogen then biochar was modified using H3PO4. Biochar were characterized for their physico-chemical characteristics. The elemental analysis of biochar was performed using CHNS Analysis. The surface area and pore volume of adsorbents were estimated using the Brunauer, Emmett, and Teller (BET Analysis). In parts of Batch adsorption experiments was performed in range of room temperature and were divided to 2 parts. Part 1: Study of the kinetics adsorption was investigated using two models, namely, the pseudo-first-order and the pseudo-second-order models. Part 2: study of Adsorption isotherms. The results of CHNS analysis shows the elemental analysis that 51.795% of C, 0.763% of H, 1.634% of N and 0.654 % of S and the result of BET Analysis shows the surface area is 372.4 m2/g and pore volume of adsorbents is 0.315 cm3. From plotting between qt(mg/g) and time (t) shows the dynamics of the adsorption of atrazine onto the biochar at 15 ppm of initial atrazine concentrations. In general, atrazine was adsorbed quickly around 1-30 min. This could be due to fast mass transfer of solute from the solution to surface of adsorbent s as a result of concentration gradient of the solute. The study of the kinetics adsorption showed that the pseudo-second-order model best described the adsorption which agrees with chemisorption as the rate controlling mechanism.


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