scholarly journals Effect of Fertilizer Rate on Plant Growth and Leachate Nutrient Content during Production of Sedum-vegetated Green Roof Modules

HortScience ◽  
2014 ◽  
Vol 49 (6) ◽  
pp. 819-826 ◽  
Author(s):  
Mary Jane Clark ◽  
Youbin Zheng
Keyword(s):  
Plant Growth ◽  
Green Roof ◽  
Control Plant ◽  
Nutrient Content ◽  
Green Roofs ◽  
Plant Production ◽  
Growth Differences ◽  
Roof Module ◽  
Cutting Production ◽  
Module System

With the increasing popularity of green roofs, efficient green roof plant production is required to adequately supply the industry. Applying fertilizer at an appropriate rate can provide sufficient plant nutrition for efficient plant growth without excess nutrient leaching into the environment. This study compared rates of controlled-release fertilizer (CRF) applied to green roof modules at the plant production stage to determine an optimum CRF rate for encouraging plant growth and vegetative coverage while minimizing the amount and concentration of leached nutrients. After sedum cuttings were rooted in green roof modules on 29 Aug. 2011, CRF was applied at 5, 10, 15, 20, 25, 30, and 35 g·m−2 nitrogen (N) and modules were compared with an unfertilized control. Plant growth, vegetative coverage, and overall appearance requirements were met after fertilization at 20 g·m−2 N. Modules fertilized at less than 20 g·m−2 N did not reach the target proportion coverage during the study. When fertilized at 20 g·m−2 N, green roof modules reached the target proportion coverage after 240 days of growth. Differences in leachate volumes were observed among treatments 35 days after fertilization and fertilization at 20 g·m−2 N minimized leaching of most nutrients. Therefore, with the green roof module system used in this study, an application of 20 g·m−2 N for green roof module or sedum cutting production is an optimum CRF rate for plant growth and vegetative coverage while minimizing negative environmental impacts.

scholarly journals Plant Nutrition Requirements for an Installed Sedum-Vegetated Green Roof Module System: Effects of Fertilizer Rate and Type on Plant Growth and Leachate Nutrient Content

HortScience ◽  
2013 ◽  
Vol 48 (9) ◽  
pp. 1173-1180 ◽  
Author(s):  
Mary Jane Clark ◽  
Youbin Zheng
Keyword(s):  
Plant Growth ◽  
Organic Fertilizer ◽  
Green Roof ◽  
Nutrient Content ◽  
Chicken Manure ◽  
Plant Performance ◽  
Fertilizer Rate ◽  
Shoot Height ◽  
Roof Module ◽  
Module System

The objectives of this study were to compare fertilizer rates and types to identify an optimum rate to maintain green roof vegetative coverage and encourage plant growth (i.e., plant performance) while minimizing the amount and concentration of nutrients leached from a green roof module system. Sedum-vegetated modules with no added fertilizer (control) were compared with modules fertilized with 5, 7.5, 10, 15, 20, 30, and 60 g·m−2 nitrogen (N) of 16N–2.6P–10K POLYON® Homogenous NPK plus Minors, 5–6 month controlled-release fertilizer (CRF), 5 g·m−2 N of a 2.9N–2.2P–2.3K fly-larvae processed chicken manure fertilizer (5-Sus), or 5 g·m−2 N of 4N–4P–4K Gaia Green All Purpose organic fertilizer (5-OR). The total amount and concentration of aluminum (Al), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), NH4+, nickel (Ni), NO3–, phosphorus (P), lead (Pb), sulfur (S), and zinc (Zn) in leachate as well as plant overall appearance, winter injury, vegetative coverage, shoot height, bloom duration, and leaf color of green roof modules were evaluated between July 2011 and Aug. 2012. A CRF fertilizer rate of 15 g·m−2 N maximized vegetative coverage and overall plant appearance while maintaining leachate quality within Ontario and Canadian guidelines for most of the measured elements. The amount of Zn in the CRF appeared to be higher than plant demand and the high amount and concentration of P in leachate was likely the result of release from the growing substrate. The 5-Sus fertilizer resulted in increased coverage the first spring and increased greenness soon after application compared with the same rate of CRF. Overall, 15 g·m−2 N of CRF was the best treatment based on vegetative coverage and plant growth in sedum-vegetated green roof modules.

scholarly journals Growth of Native Aromatic Xerophytes in an Extensive Mediterranean Green Roof as Affected by Substrate Type and Depth and Irrigation Frequency

HortScience ◽  
2013 ◽  
Vol 48 (10) ◽  
pp. 1327-1333 ◽  
Author(s):  
Maria Papafotiou ◽  
Niki Pergialioti ◽  
Lamprini Tassoula ◽  
Ioannis Massas ◽  
Georgios Kargas
Keyword(s):  
Plant Growth ◽  
Plant Species ◽  
Green Roof ◽  
Green Roofs ◽  
Native Plant ◽  
Substrate Type ◽  
Irrigation Frequency ◽  
Artemisia Absinthium ◽  
Grape Marc ◽  
Local Character

Green roofs could be a way to increase vegetation in the center of old Mediterranean cities. The need for conservation of local character and biodiversity requires the use of native plant species, whereas the deficiency of water, particularly in semiarid regions, requires the use of species with reduced irrigation needs. Moreover, the aged buildings lead to the use of lightweight green roof constructions. Therefore, research was undertaken to investigate the possibility of using three Mediterranean aromatic xerophytes, Artemisia absinthium L., Helichrysum italicum Roth., and H. orientale L., at an extensive green roof in Athens, Greece. Simultaneously, the possibility of using locally produced grape marc compost was investigated. Substrate type and depth and irrigation frequency effects on growth of these species were studied. Rooted cuttings were planted mid-May in plastic containers with a green roof infrastructure fitted (moisture retention and protection of the insulation mat, drainage layer, and filter sheet) and placed on a fully exposed third floor flat roof at the Agricultural University of Athens. Two types of substrates were used, grape marc compost:soil:perlite (2:3:5, v/v) and peat:soil:perlite (2:3:5, v/v, as a control), as well as two substrate depths, 7.5 (shallow) and 15 cm (deep), and two irrigation frequencies, sparse (5 or 7 days in shallow and deep substrate, respectively) and normal (3 or 5 days in shallow and deep substrate, respectively). Increased contents of macroelements, total phosphorus (P) and potassium (K) in particular, were recorded in the compost-amended substrate, whereas both substrates had similar physical properties. Plant growth was recorded from May to October. The deep compost-amended substrate, independent of irrigation frequency, resulted in taller plants with bigger diameter and aboveground dry weight in all species. However, a remarkable result was that shallow compost-amended substrate with sparse irrigation resulted in similar or even bigger plant growth of all plant species compared with deep peat-amended substrate with normal irrigation. Thus, all three species were found suitable for use in Mediterranean extensive or semi-intensive green roofs, whereas the use of grape marc compost in the substrate allowed for less water consumption and the reduction of substrate depth without restriction of plant growth at the establishment phase and the first period of drought.

scholarly journals Green Roof Plant Suitability Analysis for Northern Climates

2013 ◽  
Vol 23 (5) ◽  
pp. 563-574 ◽  
Author(s):  
Katherine L. Vinson ◽  
Youbin Zheng
Keyword(s):  
Plant Species ◽  
Green Roof ◽  
Green Roofs ◽  
Plant Production ◽  
Suitability Analysis ◽  
Production Growth ◽  
Diverse Plant Species ◽  
Extensive Green Roofs ◽  
Different Levels ◽  
Diverse Plant

To select plant species and species combinations for northern climates, mats with different plant species and species combinations were constructed on a green roof plant production farm and later transported and installed on an urban rooftop. There were three treatments: two different planting combinations, which together consisted of 10 diverse plant species [both stonecrop (Sedum) species and nonstonecrop species], and a control, which consisted of 26 stonecrop species used for standard mat production. Growth measurements and observations were made at both sites and special attention was paid to the performance of species during the harvest, transportation, and installation stages, as well as during recovery postinstallation. All species but false rock cress (Aubrieta cultorum) were found to be suitable for extensive green roof applications in northern climates, although there were variations of suitability among the species. Good, mediocre, and poor interactions formed between numerous species, displaying different levels of compatibility. Finally, all species were considered appropriate for a mat production system; species that failed to germinate, species planted postinstallation, the frequently displaced rolling hens and chicks (Jovibarba sobolifera), and false rock cress were exceptions. Overall, many species in this study displayed successful, well-rounded growth. Based on results, species and species combinations were recommended for extensive green roofs in northern climates.

Evaluation of Green Roofs for Runoff Retention, Runoff Quality, and Leachability

2009 ◽  
Vol 44 (1) ◽  
pp. 33-47 ◽  
Author(s):  
Tim Van Seters ◽  
Lisa Rocha ◽  
Derek Smith ◽  
Glenn MacMillan
Keyword(s):  
Plant Growth ◽  
Total Phosphorus ◽  
Green Roof ◽  
Green Roofs ◽  
Winter Period ◽  
Roof Runoff ◽  
Continuous Precipitation ◽  
Growing Media ◽  
The Media ◽  
Receiving Water

Abstract This three-year study evaluates the quantity and quality of runoff from an extensive green roof on a multistory building in Toronto. Laboratory physical, chemical, and leachate analyses of eleven commercially available green roof growing media were also undertaken to help identify the potential influence that the growing media may have on runoff chemistry. Continuous precipitation and runoff data collected over 18 months outside of the winter period indicated that the green roof discharged 63% less runoff than a neighbouring conventional modified bitumen roof. Runoff volumes from the green roof averaged 42% less than the conventional roof in April and November, and between 70 and 93% less during the summer months. Water samples were collected from both roofs during 21 rain events in 2003 and 2004 and analyzed for general chemistry (e.g., pH, total suspended solids), metals, nutrients, bacteria (n = 16), and polycyclic aromatic hydrocarbons (n = 18). Loads of most chemical variables in green roof runoff were lower than from the conventional roof. Exceptions included constituents such as calcium, magnesium, and total phosphorus, which were either naturally present in the media or were added to promote plant growth. Total phosphorus concentrations in green roof runoff were significantly higher than the conventional roof (α = 0.001), and regularly exceeded the Ontario receiving water objective (0.03 mg/L). Phosphorus concentrations fell significantly after the first year of monitoring (α = 0.001), suggesting that the nutrient is being leached from the media. Chemical analyses of green roof growing media showed that levels of most constituents were similar to or lower than typical background concentrations for agricultural soils in Ontario. However, leachate concentrations from several media exceeded receiving water standards for phosphorus, aluminum, copper, iron, and vanadium. This study highlights the importance of engineering green roof media to minimize leaching of nutrients and other contaminants while maintaining their ability to support plant growth.

scholarly journals Irrigation Volume, Application, and Controlled-release Fertilizers: I. Effect on Plant Growth and Mineral Nutrient Content in Containerized Plant Production

1998 ◽  
Vol 16 (3) ◽  
pp. 176-181
Author(s):  
Kelly M. Groves ◽  
Stuart L. Warren ◽  
Ted E. Bilderback
Keyword(s):  
Controlled Release ◽  
Plant Growth ◽  
Dry Weight ◽  
Nutrient Content ◽  
Plant Production ◽  
Mineral Nutrient ◽  
Wide Range ◽  
Top Dry Weight ◽  
Irrigation Volume ◽  
Controlled Release Fertilizers

Abstract An experiment with four volumes of irrigation and five controlled-release fertilizers (CRFs) was conducted to evaluate effects on plant growth and mineral nutrient content. Rooted cuttings of Cotoneaster dammeri ‘Skogholm’ and seedlings of Rudbeckia fulgida ‘Goldsturm’ were grown in 3.8 liter (4 qt) containers in a pine bark:sand substrate (8:1, by vol) incorporated with 3.5 g (0.12 oz) N per container with one of the following five CRFs: Meister 21N–3.5P–11.1K (21–7–14), Osmocote 24N–2.0P–5.6K (24–4–7), Scotts 23N–2.0P–6.4K (23–4–8), Sustane 5N–0.9P–3.3K (5–2–4) or Woodace 21N–3.0P–9.5K (21–6–12). Irrigation volumes of 200 ml (0.3 in), 400 ml (0.6 in), 800 ml (1.1 in), or 1200 ml (1.7 in) were applied once daily (single) or in two equal applications with a two hr interval between irrigation allotments (cyclic). All measured variables were unaffected by irrigation application (cyclic or single). Top dry weight of cotoneaster increased quadratically with increasing irrigation volume for all CRFs. Maximum top dry weight was obtained with 612 ml (0.8 in), 921 ml (1.3 in), 928 ml (1.3 in), 300 ml (0.6 in), or 909 ml (1.3 in) for plants fertilized with Meister, Osmocote, Scotts, Sustane, and Woodace, respectively. Osmocote, Scotts, and Woodace produced 90% of maximum top weight over a wide range of irrigation volumes [≈ 550 ml (0.8 in) to 1200 ml (1.5 in)]. Stomatal conductance of cotoneaster fertilized with Osmocote 24–4–7 increased linearly with increasing volume of irrigation, whereas net photosynthetic rate increased quadratically and was highest at 800 ml (1.1 in). All CRFs, excluding Sustane, had similar dry weights when irrigated with 200 ml (0.3 in). At 800 ml (1.1 in) and 1200 ml (1.7 in), cotoneaster fertilized with Osmocote 24–4–7 and Scotts 23–4–8 produced greater top dry weight compared to Meister, Sustane, and Woodace. Top dry weight of rudbeckia increased quadratically with increasing irrigation volume regardless of CRFs. Maximum dry weight was produced with 1160 ml, 931 ml, 959 ml, 1091 ml, or 1009 ml for plants grown with Meister, Osmocote, Scotts, Sustane, or Woodace, respectively. Ninety percent of the maximum top dry weight of both species within each CRF could be obtained with a 40% reduction in irrigation volume. Nitrogen content of cotoneaster and rudbeckia were unaffected by irrigation volume, whereas P and K content, depending upon CRF and plant, was reduced at low irrigation volumes.

scholarly journals Assessment of Physical Properties and Stonecrop Growth in Green Roof Substrates Amended with Compost and Hydrogel

2010 ◽  
Vol 20 (2) ◽  
pp. 438-444 ◽  
Author(s):  
Michael W. Olszewski ◽  
Marion H. Holmes ◽  
Courtney A. Young
Keyword(s):  
Plant Growth ◽  
Physical Properties ◽  
Green Roof ◽  
Total Porosity ◽  
Dry Weight ◽  
Green Roofs ◽  
Coverage Area ◽  
Practical Applications ◽  
Shoot Dry Weight ◽  
Growing Conditions

There is a lack of quantifiable data concerning physical analyses specific to shallow-depth green roof substrates and their effects on initial plant growth. Physical properties were determined for green roof substrates containing (by volume) 50%, 60%, or 70% heat-expanded coarse slate and 30% heat-expanded fine slate amended with 20%, 10%, or 0% landscape and greenhouse waste compost. Each substrate also was amended with hydrogel at 0, 0.75, 1.50, or 3.75 lb/yard3. There were no differences in total porosity among substrates containing 0%, 10%, or 20% compost, although total porosity increased for all substrates amended with hydrogel at 3.75 lb/yard3. Container capacity increased in substrates containing 3.75 lb/yard3 hydrogel, except for substrates containing 10% compost where hydrogel had no effect. Aeration porosity decreased when 10% or 20% compost was added to substrates. Determination of aeration porosity at an applied suction pressure of 6.3 kPa (AP-6.3 kPa), indicated that AP-6.3 kPa was higher in substrates containing 0% compost than substrates containing 20% compost. Shoot dry weight and coverage area measurements of ‘Weihenstephaner Gold’ stonecrop (Sedum floriferum) and ‘Summer Glory’ stonecrop (Sedum spurium) were determined 9 weeks after plug transplantation into substrates. Both stonecrop species responded similarly to substrate amendments. Initial plant growth was greater in substrate containing 20% compost and 3.75 lb/yard3 hydrogel than nonamended substrate resulting in 198% and 161% higher shoot dry weight and coverage area, respectively. Alkaline heat-expanded slate and acidic compost components affected initial pH of substrates, but there was less variation among final substrate pH values. We conclude that compost and/or hydrogel amendments affected physiochemical properties following incorporation into slate-based green roof substrates, resulting in greater initial plant growth, and that these amendments may have practical applications for improving growing conditions on green roofs.

scholarly journals Growth and Flowering of Salvia nemorosa ‘Ostfrieland' in Response to Reduced Irrigation1

2020 ◽  
Vol 38 (2) ◽  
pp. 63-67
Author(s):  
Amanda Bayer
Keyword(s):  
Soil Moisture ◽  
Plant Growth ◽  
Irrigation System ◽  
Control Plant ◽  
Dry Weight ◽  
Plant Production ◽  
Stem Length ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Shoot Dry Weight

Abstract Reduced irrigation (RI) can conserve water and control plant growth; however, the timing of RI applications can impact plant growth and flowering. The goal of this research was to quantify growth of Salvia nemorosa L. ‘Ostfrieland' (East Friesland) in response to RI. A soil-moisture sensor automated irrigation system was used to apply four irrigation treatments: RI and well-watered (WW) controls (20% and 38% substrate water content) and two combination treatments to apply RI for either the first two weeks (20% followed by 38%, RIWW ) or final four weeks (38% followed by 20%, WWRI ) of the six-week study. Flower number, height, compactness, and relative chlorophyll content (SPAD) were not different across treatments. Average flower stem length was greater for the WW and RIWW treatments than for the RI treatment. Shoot dry weight was less for the RI treatment compared to the WW and RIWW treatments, respectively]. Cumulative irrigation volume was lowest for the RI treatment and highest for the RIWW treatment. Visually, plants in the RIWW treatment had an open, floppy habit that would likely negatively impact sales in a retail setting. Plants in the RI treatment were smaller, but visually appealing. Index words: soil moisture sensor, plant production, herbaceous perennial, container plants. Species used in this study: ‘Ostfrieland' salvia (Salvia nemorosa L.).

scholarly journals The Effect of Irrigation Treatment on the Growth of Lavender Species in an Extensive Green Roof System

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 863
Author(s):  
Angeliki T. Paraskevopoulou ◽  
Panagiotis Tsarouchas ◽  
Paraskevi A. Londra ◽  
Athanasios P. Kamoutsis
Keyword(s):  
Stomatal Conductance ◽  
Plant Growth ◽  
Hydraulic Properties ◽  
Irrigation Management ◽  
Green Roof ◽  
Irrigation Treatment ◽  
Green Roofs ◽  
Extensive Green Roof ◽  
Roof System ◽  
Irrigation Treatments

In green roofs, the use of plant species that withstand dry arid environmental conditions and have reduced water requirements is recommended. The current study presents the effect of irrigation amount on the growth of four different species of lavender; Lavandula angustifolia, Lavandula dentata var. candicans, Lavandula dentata var. dentata, and Lavandula stoechas established on an extensive green roof system and used in urban agriculture. Two irrigation treatments (high and low) determined by the substrate hydraulic properties were applied. Plant growth studied at regular intervals included measurements of plant height, shoot canopy diameter, plant growth index, shoot dry weight and stomatal conductance. The results were consistent and showed that low irrigation reduced plant growth. With the exception of L. stoechas, the appearance of plants watered with the low irrigation treatment was satisfactory, and their use under low water amount irrigation is supported. Interspecies differences among lavender species were present in both irrigation treatments. Overall, L. dentata var. candicans showed the greatest growth, followed in descending order by L. dentata var. dentata and L. angustifolia. In parallel, for stomatal conductance, L. dentata var. candicans showed the lowest value, similar to L. dentata var. dentata, and L. angustifolia the largest. Differences in plant characteristics and size among the latter three species can be considered in the design of extensive green roof systems. The use of substrate hydraulic properties was shown to be important for irrigation management on extensive green roof systems.

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