past few years. Yard waste compost includes grass clippings, leaves from trees and shrubs, woody branches, and other materials that are the result of yard trimmings ( Ozores-Hampton et al., 1999 ). Facilities designed to process YWC have become more
Courtney D. DeKalb, Brian A. Kahn, Bruce L. Dunn, Mark E. Payton and Allen V. Barker
Dennis B. McConnell and Wayne H. Smith
Three foliage plants, Dracaena fragrans, Peperomia obtusifolia and Schefflera arboricola were grown in 24 different mixes. Potting mixes were formulated using yard waste compost from two sources, a commercial mix (Metro 300) and a prepared mix (peat: pine bark sand). All potting mixes produced acceptable plants with no phytotoxicity associated with any mix. Only minor differences were discerned in the growth rate of P. obtusifolia and S. arboricola.
The growth rate of D. fragrans showed the greatest response to potting mix formulations. Plants in a standard potting mix (P/PB/S) used in the industry for D. fragrans grew slower than plants in many of the mixes containing various fractions of yard waste compost. Chemical and physical properties of the potting mixes used showed physical properties had the greatest variability. Overall, the best growth for all 3 plants was in a potting mix composed of 87.5% Metro 300/12. 5% YWC#1 and worst growth was in YWC#2 (100% composted (live oak leaves).
Brian A. Kahn, Niels O. Maness, Donna R. Chrz and Lynda K. Carrier
carotenoids, and total glucosinolates in pak choi tissues. The work reported here was part of a larger study designed to compare two unblended organic materials—spent mushroom substrate (SMS) and yard waste compost (YWC), both hereafter referred to as composts
Sandra A. Balch, Dick L. Auld and Richard E. Durham
The objective of this study was to assess the feasibility of utilizing composted municipal yard waste as a component of potting media, which is predominantly composed of peatmoss, a nonrenewable and increasingly expensive medium. Green Comet broccoli (Brassica oleracea L. Italica group) was grown in five ratios (1:0, 1:2, 1:3, and 0:1) of composted yard waste: commercial soilless potting medium. Plant heights were recorded weekly. At the end of 6 weeks, measurements were taken on plant height, fresh weight, dry weight, and root: shoot ratios. Media leachate was tested for pH and soluble salt levels. Germination tests were run using the same potting mix ratios. Percent germination and seedling survivability were recorded. Results show that yard waste compost can be used as a component of potting media, although seed germination and seedling growth are inhibited at high compost levels.
Qingren Wang, Yuncong Li and Waldemar Klassen
A pot experiment with summer cover crops and soil amendments was conducted in two consecutive years to elucidate the effects of these cover crops and soil amendments on `Clemson Spineless 80' okra (Abelmoschus esculentus) yields and biomass production, and the uptake and distribution of soil nutrients and trace elements. The cover crops were sunn hemp (Crotalaria juncea), cowpea (Vigna unguiculata), velvetbean (Mucuna deeringiana), and sorghum sudangrass (Sorghum bicolor × S. bicolor var. sudanense) with fallow as the control. The organic soil amendments were biosolids (sediment from wastewater plants), N-Viro Soil (a mixture of biosolids and coal ash, coal ash (a combustion by-product from power plants), co-compost (a mixture of 3 biosolids: 7 yard waste), and yard waste compost (mainly from leaves and branches of trees and shrubs, and grass clippings) with a soil-incorporated cover crop as the control. As a subsequent vegetable crop, okra was grown after the cover crops, alone or together with the organic soil amendments, had been incorporated. All of the cover crops, except sorghum sudangrass in 2002-03, significantly improved okra fruit yields and the total biomass production (i.e., fruit yields were enhanced by 53% to 62% in 2002-03 and by 28% to 70% in 2003-04). Soil amendments enhanced okra fruit yields from 38.3 to 81.0 g/pot vs. 27.4 g/pot in the control in 2002-03, and from 59.9 to 124.3 g/pot vs. 52.3 g/pot in the control in 2003-04. Both cover crops and soil amendments can substantially improve nutrient uptake and distribution. Among cover crop treatments, sunn hemp showed promising improvement in concentrations of calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), boron (B), and molybdenum (Mo) in fruit; magnesium (Mg), Zn, Cu, and Mo in shoots; and Mo in roots of okra. Among soil amendments, biosolids had a significant influence on most nutrients by increasing the concentrations of Zn, Cu, Fe, and Mo in the fruit; Mg, Zn, Cu, and Mo in the shoot; and Mg, Zn, and Mo in the root. Concentrations of the trace metal cadmium (Cd) were not increased significantly in either okra fruit, shoot, or root by application of these cover crops or soil amendments, but the lead (Pb) concentration was increased in the fruit by application of a high rate (205 g/pot) of biosolids. These results suggest that cover crops and appropriate amounts of soil amendments can be used to improve soil fertility and okra yield without adverse environmental effects or risk of contamination of the fruit. Further field studies will be required to confirm these findings.
John J. Sloan, Raul I. Cabrera, Peter A.Y. Ampim, Steve A. George and Wayne A. Mackay
sphagnum PM (SunGro Horticulture, Bellevue, WA) and aged PB (Calloway's Nurseries, Fort Worth, TX). The alternative blends used non-traditional materials, including municipal yard waste compost (compost), lime-stabilized wastewater BS (City of Fort Worth
Zhengli Zhai, David L. Ehret, Tom Forge, Tom Helmer, Wei Lin, Martine Dorais and Athanasios P. Papadopoulos
pot) on 26 Feb. in the experimental greenhouse compartment. Two composts were compared in this experiment: yard waste (YW) compost and swine (Sw) compost. Yard waste compost was produced by the City of Vancouver Green Waste Recycling Program. It is a
Qingren Wang, Waldemar Klassen, Edward A. Evans, Yungcong Li and Merlyn Codallo
O 5 –12K 2 O at 670 kg·ha −1 was banded 25 cm from each side of the bed center and rototilled into the soil and the beds were reformed. Yard waste compost (All Grow Compost, produced by the Palm Beach Solid Waste Authority and delivered by Synagro
Rebecca J. Long, Rebecca N. Brown and José A. Amador
toward aerobic composting, the amount of yard waste compost available for land application is likely to increase ( Arsova et al., 2008 ). For farmers to effectively and sustainably incorporate organic wastes as sources of plant nutrients they need to know
Michelle Miller, Robert Linderman and Leslie Fuchigami
The beneficial use of vesicular–arbuscular mycorrhizae (VAM) in mineral soils is well-documented, but little is known about the effect of soilless mixes on mycorrhizal colonization of roots. Previous research indicates that mycorrhizal colonization is affected by pH, soluble salts, phosphorus levels, cation exchange capacity, percent organic matter, and some peats. No other research has been published, to our knowledge, on the role of commonly used horticultural composts and mycorrhizal establishment. This study examined four different composts for their effect on VAM establishment using onion roots as an indicator. The composts used in the study were vermicompost, spent mushroom compost, yard waste compost, and processed manure fiber. Plant growth parameters, phosphorus (P) levels and rate of desorption, and microbial populations were analyzed in relation to the percent of VAM colonization of the roots. Significant differences were found in percent VAM colonization between composts. The primary factors influencing VAM colonization were the initial levels of P in the blends and the rate and amount of P released. The experiment raised questions about the balance between mineralized P and organic P in composts and their effect on VAM fungal spore germination.