scholarly journals Physical and Chemical Properties of Green Roof Media and Their Effect on Plant Establishment

2011 ◽  
Vol 29 (2) ◽  
pp. 81-86 ◽  
Author(s):  
Michael W. Olszewski ◽  
Courtney A. Young

Abstract There are few research reports on components of green roof media. Better elucidation will allow landscape installers to select the ideal medium for individual or regional situations. The present study examined the effects of heat-expanded clay media components on: (1) physical and chemical properties and (2) growth of Sedum floriferum (stonecrop) and Dianthus gratianopolitanus (dianthus) plugs on a green roof. The addition of fine grade components caused an increase in bulk density and a decrease in total porosity, aeration porosity, and aeration porosity at applied suction pressure of 6.3 kPa. Container capacity reached a maximum following the addition of 40–60% (by vol) fine grade particles. Stonecrop and dianthus plugs were planted in early summer (June 29, 2010) into 6.4 cm (2.5 in) depth media containing 10–60% fine or medium grade heat-expanded clay located in a green roof garden. By early autumn (October 3, 2010), dianthus cover and plant weight were greatest in media containing 50–60% fine grade heat-expanded clay or 60% medium grade heat-expanded clay while stonecrop growth was inadequate regardless of media type.

2017 ◽  
Vol 35 (2) ◽  
pp. 174-179 ◽  
Author(s):  
Maristela Watthier ◽  
Magnólia AS Silva ◽  
José E Schwengber ◽  
Maria H Fermino ◽  
Tiago V Custódio

ABSTRACT Different properties of substrates based on tung compost (TC), carbonized rice husk (CRH) and earthworm humus (H) were analyzed, besides the effect of the formulations on the production of lettuce seedlings, cv. Veneranda. The experiment was carried out in Pelotas, Rio Grande do Sul State, Brazil, from December 2012 to February 2013, in a greenhouse, using completely randomized design with seven treatments and three replications. The used substrates were formulated on a volume basis: T1= commercial substrate S10® (control); T2= 90% carbonized rice husk (CRH) + 10% humus (H); T3= 75% CRH + 15% tung compost (TC) + 10% H; T4= 55% CRH + 35% TC + 10% H; T5= 35% CRH + 55% TC + 10% H; T6= 15% CRH + 75% TC + 10% H; T7= 90% TC + 10% H. Seedlings were produced in polystyrene trays with 200 cells, being evaluated 35 days after sowing. The substrate with larger proportion of CRH (T2 with 90% CRH) showed suitable dry density (DD) and total porosity (TP), high pH and aeration space (AS), low easily available water (EAW), electric conductivity (EC), and nutrient content, constituting an inert substrate, not being indicated as substrate due to the lower development of the seedlings. Using 15% TC, an increase was noticed in DD, AEW, EC and nutrients and, a decrease in TP, AS and pH due to, mainly, the size of tung compost particles, which accommodated themselves and altered physical and chemical properties of the substrates. Substrates with 90% and 75% TC (T7 and T6) provided the greatest shoot length, fresh and dry shoot mass and leaf area for lettuce seedlings due to higher nutrient content, also considering physical and chemical properties of these substrates. Pure CRH is not indicated to be used as substrate, but mixed with tung compost (T6), it provides high quality seedlings. Tung compost was effective in producing lettuce seedlings, since the composting is able to eliminate phytotoxic substances from this material which can hinder the seedling growth.


2019 ◽  
pp. 68-73

The decline in soil organic matter, nutrient depletion, and loss of soil fertility due to soil degradation contribute to low agricultural productivity. Organic amend- ments (OAs) have the potentials to reverse soil degradation processes by improv- ing the soil's physical and chemical properties and consequently improve crop growth and yield performance. At Cranfield University, United Kingdom, a greenhouse study investigated the effects of Mushroom Compost, Anaerobic Di- gestate Waste, and Poultry Manure amendments applied at 10 t ha-1 and 30 t ha-1 equivalent rates on the physical and chemical properties of degraded soil. The treatments were laid out in the greenhouse in a completely randomized design replicated four times. The results showed that all the OA treatments significantly increased the soil water holding capacity, total porosity, and significantly reduced bulk density when compared with the un-amended control treatment. Further, the OA treatments showed significant increases in the soil Total-P, Olsen-P, Total-N, total oxides of N, ammonium-N, Available-K, and Available-Mg, relative to the control treatment. The results demonstrate the effectiveness of these OAs in im- proving soils’ physical and chemical properties, and so enhancing soil health and overall ecosystem functioning. The study demonstrated that these OAs improve the physicochemical properties of degraded so


2014 ◽  
Vol 1613 ◽  
pp. 89-94 ◽  
Author(s):  
Martha L. Domínguez ◽  
Oscar G. Villegas ◽  
Héctor Sotelo ◽  
Carlos M. Acosta ◽  
Mario Pérez ◽  
...  

ABSTRACTThis study aimed to evaluate the effect of 12 substrates in the seedling growth of chili apple (Capsicum pubescens R. & P.) hybrid Grajales ST. The substrates were prepared with different proportions of five materials: perlite, coconut fiber, loam, Sunshine3 ® and wood dust. The seeds were sown in trays of 50 cavities. For the substrates were determined physical and chemical properties. Significant differences in growth parameters of seedlings are the effect of the substrate. Based on the remarkable accumulation of dry matter of each of the organs of the seedling, and their relative distribution, one can surmise a seedling quality with 47.70 % dry matter in leaves, 35.34 % in stem and 16.95 % in root. The substrate with better features for the production of chile apple seedlings was prepared with 25 % loam and 75 % perlite (v/v), which showed retention of 85.5 % moisture, electrical conductivity of 0.03 dS·m-1 and total porosity of 62.5 %.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


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