Three types of soil were mixed with water containing DPA (2000 mg·liter-1) and benomyl (300 mg·liter-1) at 1% to 5% (w/w). `Rome' apples (Malus domestica Borkh.) were dipped in the mixtures over 8 days. The efficiency of DPA as a scald inhibitor was not consistently affected by soil type, soil concentration, or age of mixture. Chemical names used: methyl[1-[(butylamino)carbonyl]-1 H-benzimidazol-2-yl]carbamate (benomyl); diphenldyamine (DPA).
Morris Ingle, J.C. Morris and M.C. D'Souza
Igenicious N. Hlerema, Bahlebi K. Eiasu and Susan H. Koch
Pineapple (Ananas comusus) production generates hard currency and, as a labor-intensive industry, it creates jobs. The profitability of pineapple farming in South Africa faces several challenges, including low yield potential and cadmium (Cd) contamination of soils, which damaged the reputation of the industry. To increase the income of pineapple farmers, research was conducted to evaluate the utilization of pineapple crop residue for oyster mushroom (Pleurotus ostreatus) production and to establish the Cd levels in the mushrooms produced on Cd-contaminated pineapple crop residue. Treatments were maize residue (M), pineapple residue (P), and a mixture of maize and pineapple residues [at 1:1 ratio (on a dry weight basis), M + P]. Biological efficiencies of 90%, 77.6%, and 29% were recorded for the M + P, P, and M treatments, respectively. The P and M + P substrates significantly increased mushroom yield. Mushroom protein contents were 23.3%, 18.86%, and 18.81% (on a dry weight basis) in the M + P, P, and M treatments, respectively. Mushrooms in the P substrate had the highest Cd level (3.3 mg/kg). In the M + P substrate, Cd reduced to a safe level (0.15 mg/kg). This indicates that mushrooms have biosorption capacity, and could be used to solve the problem of Cd pollution and increase the income of pineapple production.
Valtcho D. Zheljazkov and Tess Astatkie
Some agricultural soils in North America are lead (Pb)-enriched as a result of the application of lead arsenate (PbHAsO4) insecticide. A controlled-environment experiment was conducted with Pb-enriched Canning soil series in Nova Scotia, Canada, to evaluate the remediation potential of 10 plant species in combination with the fungicide benomyl applied as a soil drench to suppress mycorrhizae. Overall, the highest biomass was provided by yellow poppy followed by Indian mustard and thorn apple. The application of benomyl increased Pb concentration in thorn apple tissue but not in the other crops. The phytoremediation potential (Pb removal with the harvested biomass) was higher with clary sage, alyssum, garden sage, and Indian mustard with benomyl treatments and lower in the Swiss chard, thorn apple without benomyl, and in the geranium with benomyl treatments. The results suggest that some plants can be used for phytoremediation of mildly Pb-contaminated soils.
Longyi Yuan, Yang Gao and Deying Li
Petroleum-based spills on turfgrass often occur during lawn care maintenance. Damage caused by diesel and hydraulic fluid is particularly difficult to correct. The objective of this study was to compare the effectiveness of combining mulching with remediation for reseeding spilled areas in lawns. Diesel and hydraulic fluid were applied to plots at a rate of 15 L·m−2. Immediately after the spill treatments, two liquid humic amendments and an activated flowable charcoal were applied at a volume rate of 8 L·m−2, respectively, with tap water/dishwashing detergent used as a control. Nitrate nitrogen was added to each remediation treatment to facilitate remediation. The spilled areas were reseeded with perennial ryegrass (Lolium perenne) and then mulched with biochar, peat pellets, and paper pellets, respectively. At 6 weeks after seeding, humic amendment 1 and activated charcoal showed better turf quality than humic amendment 2. Peat pellet mulching presented better turf quality than other mulching methods. Reseeding perennial ryegrass and mulching with peat pellets after remediation with either humic amendment 1 or activated charcoal resulted in acceptable turf quality 6 weeks after diesel and hydraulic fluid spills. Therefore, this reestablishment method is recommended as a practical way to deal with diesel or hydraulic fluid spills in cool-season turfgrasses.
Ruiqin Bai and Deying Li
Petroleum-based spills on turfgrass often occur during lawn care maintenance. The damages caused by hydrocarbons to turfgrass can be long lasting and difficult to correct because of the stable and toxic nature of hydrocarbons. The objective of this study was to compare the effectiveness of using detergent, nitrate nutrient, humic substance, and activated charcoal to enhance bioremediation and turf recover after gasoline, diesel, and hydraulic fluid spills. The turfgrass quality and reestablishment of perennial ryegrass (Lolium perenne) reseeded at 0, 1, and 2 weeks after spills were evaluated. The results showed that using a liquid humic substance to remediate soil and reseed immediately after a gasoline spill was a practical method to reestablish acceptable turfgrass quality in 5 weeks. The most significant injury to perennial ryegrass caused by gasoline was bleaching of green tissues. Gasoline caused negligible residual herbicidal effects under the remediation regime in this study. However, diesel or hydraulic fluid showed phytotoxicity and residual effects in the contaminated soil for more than 2 months. Seeds applied immediately after diesel and hydraulic fluid spills lost viability as a result of the herbicidal effect of these hydrocarbons. As a result, reseeding was only successful 4 months after diesel and hydraulic fluid spills. Therefore, the time span for reestablishing perennial ryegrass turf may be too long for practical purposes in the lawn care industry.
Amy Fulcher, Diana R. Cochran and Andrew K. Koeser
, many in the manufacturing sector are questioning the sustainability of plastic container production ( Thompson et al., 2009 ). The volume of plastics, coupled with the potential for agrochemical and soil contamination, as well as photodegradation, limit
M. Courtney, M. Mcharo, D. La Bonte and W. Gruneberg
based on estimates with low aluminum concentration. Aluminum is considered an artifact of soil contamination and residual soil Fe is included in the Fe concentration measurement (Gabriela Burgos, personal communication, 2004). Mean aluminum estimates by
Jenny C. Moore and Annette L. Wszelaki
across the years (2015–2018) to avoid cross-treatment mulch and soil contamination as BDMs are tilled into the soil at the end of every cropping season. Eight treatments ( Table 1 ) were randomized within each main plot in 2015. The 2015 and 2016
Valtcho D. Zheljazkov, Vasile Cerven, Charles L. Cantrell, Wayne M. Ebelhar and Thomas Horgan
), latitude and growing conditions ( Topalov, 1962 ), soil contamination ( Zheljazkov et al., 2006 ; Zheljazkov and Nielsen, 1996 ), soil amendments ( Zheljazkov, 2005 ; Zheljazkov and Warman, 2004 ), and agronomic practices such as harvest stage ( Clark and
Timothy M. Spann and Michelle D. Danyluk
that sugar cane that was hand cut and left in the row for mechanical loading had 3.2% more trash, primarily as a result of soil contamination, compared with combine-harvested cane. The fact that our data showed an order of magnitude more sand in 3210