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Sewage sludge (SS) is a source of nutrients, and it improves the physical, chemical, and biological properties of soil, thereby increasing crop productivity. Accordingly, this study was aimed to evaluate the growth and development of the silver vase bromeliad (Aechmea fasciata) cultivated in a substrate with different doses of SS. To accomplish this, silver vase bromeliad plants were cultivated for 120 days in pots containing pine bark as a substrate with varying doses of solid SS (0, 18, 36, 54, or 72 g SS L−1). The experiment was carried out in a completely randomized block design, comprising five treatments and four replications, with four plants per pot, totaling 80 plants. Substrate fertilization with SS improved the nutritional status as well as the physiological and morphological parameters of the silver vase bromeliad. Fertilization with 72 g SS L−1 added to pine bark resulted in the best outcomes for plant height and the number of leaves. [ABSTRACT FROM AUTHOR]

We analyzed the effect of substrate mixtures containing vermicompost (VC), tezontle (TZ), and pine bark (PB) in the following percentage proportions (v/v): T1: 00VC-20TZ-80PB; T2: 10VC-20TZ-70PB; T3: 20VC-20TZ-60PB; T4: 30VC-20TZ-50PB, plus two reference controls identified as T5: peatmoss (100%; PM) and T6: tree branch (TB) on growth and nitrogen concentration of Tillandsia flavobracteata and T. limbata. Tillandsia flavobracteata displayed the greatest height in T6 and T4, while the greatest height for T. limbata was obtained in T3. In T. flavobracteata the greatest number of leaves was obtained in T1, whereas in T. limbata no significant differences were found. Nitrogen was higher in T. limbata, especially when grown in T1 and T6. We were able to demonstrate that both Tillandsia species can grow and produce healthy plants under our experimental conditions, while the tested substrates differentially affected growth and nitrogen concentration in each species. [ABSTRACT FROM AUTHOR]

Composts have the potential for remediating heavy metal-contaminated soils. This sorption study investigated the potential of composted pine bark (PB) and its co-composts with goat manure (PBG) and sewage sludge (PBS) to immobilize lead [Pb (II)], copper [Cu (II)], zinc [Zn (II)] and nickel [Ni (II)]. The Langmuir maximum sorption capacity (qmax) of the composts followed the order PBG ≫ PBS > PB for the tested metal ions. The qmax values of PBG compost followed the order Cu (II) > Pb (II) > Zn (II) > Ni (II) whereas for PB and PBS composts they followed the order Pb (II) > Cu (II) > Zn (II) > Ni (II). Increasing solution pH improved the Cu and Zn retention capacities of the acidic PB and PBS composts but had no effect on the nearly neutral PBG compost. Thus, the PBG compost had better metal immobilization capacity than the PB and PBS composts, which may require liming to improve their effectiveness. [ABSTRACT FROM PUBLISHER]

Rocket (Eruca sativa Mill.) is a green leafy vegetable that is increasingly used as an ingredient in salad. The floating system is a way to grow this crop, at high density from sowing to harvest and easy to use in relation substrate culture, and it is well known water culture can be limited by hypoxia. Few studies have examined the use of peroxides or peracetic acid in nutrient solutions as a source of oxygenation. The aim of the study was to evaluate the rocket grown in substrates as compared to the floating system, with a stabilized mixture of peracetic acid in the nutrient solution. The experiment was carried out in and Talca (Chile) from October to November 2008. The treatments were substrate culture perlite and composted pine bark (1:1); floating system with trays filled with the same substrate and 0, 40 and 80 mg·L-1 of stabilized peracetic acid mix (PA). The fresh and dry weight of rocket leaves at harvest we evaluated. We recorded total nutrient solution uptake; the average dissolved oxygen; pH and electrical conductivity (EC). A randomized complete block design with four replicates was conducted using Tukey's multiple range test (P < 0.05). The results suggest from 40 to 80 mg·L-1 PA applied to the nutrient solution, increases the fresh and dry weight in the rocket crop grown by floating system and may compensate this limiting factor in the growth, if it was compared with higher oxygen available substrate culture. [ABSTRACT FROM AUTHOR]

A shadehouse pot trial was conducted to study the efficiency of single and dual inoculations with selected Trichoderma and Bacillus isolates on performance of dry bean plants (Phaseolus vulgaris L.) grown in composted pine bark (CPB) potting medium. All the plant treatments inoculated with Trichoderma spp. and/or Bacillus spp. had higher photosynthetic efficiency (Fv/Fm values). Of the treatments, only B. subtilis B69 showed a significant increase (P = 0.02) in Fv/Fm values over the growth period. The Trichoderma and Bacillus treated plants showed increase in dry shoot biomass. The greatest degree of nodulation was observed in Trichoderma and/or Bacillus treated plants. Increase in nitrogen concentrations were observed in leaves of plants inoculated with Trichoderma and Bacillus isolates. Only T. atroviride SY3A significantly increased phosphorus concentrations in leaves. These results depict and highlight the role these organisms can play in plant root-plant growth promoting rhizobacteria or plant growth promoting fungi (PGPR/PGPF) interaction in a nutrient-poor growth medium. [ABSTRACT FROM AUTHOR]

The feasibility of using pine bark and composted sewage sludge to produce alternative substrates was studied. The substrates tested were 1 and 2) pine bark fertilized with 1 and 4 g L-1 of a slow-release NPK fertilizer (15 : 11 : 13) and 3) a substrate in which 15% (v/v) of the pine bark was replaced by composted sewage sludge. Treatments abbreviated as PB, PB + N, and PB + CSS in text. Pinus pinea and Cupressus arizonica plants were grown in these substrates for 2 years and plant and substrate characteristics were tested periodically along the experiment. Additionally, nitrate and heavy metal concentrations were determined in leachates collected from each substrate. The suitability of the prepared substrates was appropriate for the production of Pinus pinea and Cupressus arizonica in real production conditions. The root/shoot dry weight ratio of both plant species in PB + N was significantly lower than in the other substrates. The highest nitrogen content in shoot corresponded to plants grown in the PB + N substrate, even though PB + CSS had higher nitrogen content than PB and PB + N substrates. Concentration of nitrate and heavy metals in leachates was lower than the level allowed in the European Union regulation. [ABSTRACT FROM AUTHOR]

Incorporated crumb rubber (CR) increased Zn tissue levels up to nine times the normal range in tree species. There was a linear increase in Zn tissue accumulation with increasing percentages of crumb rubber for river birch (Betula nigra L.), lacebark elm (Ulmus parvifolia Jacq.), and pecan [Carya illinoinensis (Wangenh.) C. Koch]. Pecan leaves containing high levels of Zn exhibited no visual symptoms, unlike the remaining tree species exhibiting leaf chlorosis. Results suggest that crumb rubber incorporated at rates greater than 25% may cause abnormally high concentrations of Zn to accumulate in plant tissue. [ABSTRACT FROM AUTHOR]