The effects of municipal solid waste (MSW) materials on growth, yield, and mineral element concentrations in tomato (Lycopersicon esculentum Mill.) (1991 and 1992) and squash (Cucurbita maxima Duch. Ex Lam.) (1992 and 1993) were evaluated. Agrisoil compost (composted trash), Eweson compost (co-composted trash and sewage sludge), or Daorganite sludge (chemically and heat-treated sewage sludge) were incorporated into calcareous limestone soil of southern Florida. The control had no MSW material added to the soil. The effect of MSW on crop growth, yield, and mineral element concentrations varied considerably between years for tomato and squash. In 1991, tomato plants grown in soil amended with Eweson or Daorganite had a greater canopy volume than plants in the control treatment. Tomato plants grown in Daorganite had greater total fruit weight (1991) than plants in Agrisoil and more marketable fruit (1992) than control plants. In both years, tomato plants in Agrisoil had higher root Zn concentrations than plants in the other treatments. In 1992, tomato plants in Eweson had lower root Mn concentrations than plants in the other treatments, whereas Mg concentrations in the roots were higher in the Daorganite treatment than in Eweson. Tomato plants in Agrisoil had higher Pb concentrations in the roots than plants in all other treatments. In 1991, leaves of tomato plants in Agrisoil had lower Ca concentrations than leaves of plants in the control treatment. In 1992, leaf Zn concentrations were greater for tomato and squash in Agrisoil than in the control or Daorganite. In 1992, canopy volume and yield of squash were greater for plants in Daorganite than for plants in the control and other MSW treatments. Although canopy volume and total squash fruit weight did not differ among treatments in 1993, plant height was greater for squash plants in the MSW treatments than for those in the control. In 1993, leaf Mg concentrations were greater for squash grown in Daorganite than for plants in the control or Agrisoil. In 1993, fruit Cd concentration was higher for plants with Eweson than for plants in the control or Agrisoil. However, the fruit Cd concentration in squash grown in Eweson compost (1.0 mg/kg dry weight) was far below a hazardous level for human consumption. Our results indicate that amending calcareous soils with MSW materials can increase growth and yield of tomato and squash with negligible increases in heavy metal concentrations in fruit.
M. Ozores-Hampton, H.H. Bryan, B. Schaffer, and E.A. Hanlon
Monica Ozores-Hampton and Herbert H Bryan
Municipal solid waste compost was applied with a side delivery applicator on top of the bed as a mulch in May 1993, 6 months after transplanting at Homestead, Fla. Papaya (`Know You No 1') was grown with and without compost mulch. Compost was distributed on the surface of the bed ≈90 cm wide and 5 cm thick. There were no mulch effects on trunk diameter nor plant height. Plant height was affected by papaya sex 4 and 6 months after transplanting. Hermaphroditic plants were taller than female plants. There were no mulch effects on marketable yield per plant, marketable size, or number of cull fruit. Sex, however, influenced papaya size and total cull number. Hermaphroditic plants produced larger marketable fruit and more cull fruits than female plants. Lower plant mortality rates were found after 1.5 years in the mulched plants compared to unmulched plants. Soil and tissue analysis showed no differences in N, P, K, Mg, S, Mn, Fe, Cu, and B, except for Zn. Zinc contents in soil and tissue were higher in the mulched areas than unmulched areas.
Monica Ozores-Hampton, Thomas A. Bewick, Peter Stoffella, Daniel J. Cantliffe, and Thomas A. Obreza
The influence of compost (derived from MSW and biosolids) maturity on seed germination of several weed species was evaluated. A bioassay was developed by extracting 20 g of compost of different maturities with various volumes of water, then measuring germination percentage of ivyleaf morningglory (Ipomoea hederacea) seeds placed on extract-saturated filter paper in a petri dish. A 20 g (dry weight) compost: 50 mL of water generated an extract that produced the widest percentage seed germination variation in response to composts of different maturity. Ivyleaf morningglory, barnyardgrass (Echinochloa crus-galli L.), purslane (Potulaca oleracea L.), and corn (Zea mays L) were selected as plant indicators to determine the compost maturity stage with maximum germination inhibition. Compost 8-week-old decreased percent germination, root growth, and germination index (combines germination rate and root growth), and increased mean days to germination (MDG) of each plant indicator. Immature 8 week-old compost extract effect on MDG and germination percent of 15 weed species was evaluated. Extract from 8-week-old compost inhibited germination in most weed species, except yellow nutsedge (Cyperus esculentus). Compost extracts derided from immature (3-day, 4-, and 8-week-old) compost resulted in delayed and reduced germination percent of important economic weed species.
Nancy E. Roe, Peter J. Stoffella, and Donald Graetz
Compost (biosolids and yard trimmings at 134 t·ha-1) was applied to a sandy field soil with fertilizer at 0%, 50%, or 100% of the grower's standard rate (71N-39P-44K kg·ha-1 broadcast and 283N-278K kg·ha-1 banded in bed centers). Raised beds were constructed and covered with polyethylene mulch, and `Elisa' bell peppers (Capsicum annuum L.) were transplanted into the plots. Foliage samples taken at early harvest indicated that leaf N concentrations increased and Cu concentrations decreased with increasing fertilizer rates. Leaf concentrations of P, K, Ca, and Mg increased and Cu decreased in plots amended with compost. Marketable pepper yields from plants grown in plots amended with compost were 30.3, 35.7, and 31.1 t·ha-1 in plots with 0%, 50%, and 100% fertilizer rate, respectively. Without compost, yields were 19.8, 31.1, and 32.0 t·ha-1 with 0%, 50%, and 100% fertilizer rate. `Valient' cucumbers (Cucumis sativus L.) were seeded through the same polyethylene mulch into the previous pepper plots. Marketable cucumber yields were not affected by residual fertilizer, but were higher (26.8 t·ha-1) in plots amended with compost than without compost (22.7 t·ha-1). In a second experiment, a biosolids-yard trimming-mixed waste paper (MWP) compost and a biosolids-yard trimming-refuse-derived fuel (RDF) compost were applied at 0 or 134 t·ha-1 with fertilizer at 0%, 50%, or 100% fertilizer rates, respectively. With no fertilizer, total yields from pepper plants were higher in plots amended with composts than without composts. In 50% fertilizer plots, yields were similar between compost treatments. At 100% fertilizer rate, yields with MWP compost were significantly higher than yields with RDF compost or with no compost. In plots without fertilizer or with 50% fertilizer rates, mean fruit size (g/fruit) was largest with MWP compost, intermediate with RDF compost, and smallest without compost. With 100% fertilizer, mean fruit size was larger with either compost than without compost. Composts combined with low rates of fertilizer generally produced higher pepper yields than other treatments. Residual compost increased yields of a subsequent cucumber crop. Yields from pepper plants without fertilizer were higher when soil was amended with composts with added MWP or RDF, but, with fertilizer, yields were similar or only slightly increased.
M. Ozores-Hampton, B. Schaffer, and H. H. Bryan
The effects of amending soil with municipal soil waste (MSW) on growth, yield and heavy metal content of tomato were tested with different irrigation rates. The following MSW materials were incorporated into oolitic limestone soil: 1) Agrisoil compost (composted trash), 2) Daorganite compost (sewage sludge), 3) Eweson (composted trash and sewage sludge), and 4) no MSW (control). Two rates (high and low) were applied to the soil for each compost. There were no significant effects of irrigation rate on any of the variables tested for tomato in 1991 or 1992. Therefore, the lowest irrigation rate appeared to be adequate for optimum tomato production. Plants grown in Daorganite at the lowest rate of 8 t/ha had greater growth and yield than plants grown in the other MSW materials or the control. Agrisoil and Eweson composts did not increase growth or yield, which may have been due to suboptimal application rates of these materials. There were no differences in the concentration of heavy metals in fruit or leaves among MSW materials or rates. MSW rate generally had no effect on root heavy metal concentration, except for Eweson where the high rate resulted in a higher root zinc concentration than the low rate. There were signifant differences in root concentrations of lead, zinc, and copper among MSW materials. Leaf concentrations of all heavy metals tested were within normal ranges for tomato.
Monica Ozores-Hampton, Thomas A. Obreza, and George Hochmuth
Large volumes of compost produced from waste materials like yard trimmings, household trash (municipal solid waste), or biosolids (wastewater sludge) will likely become available for use by the Florida vegetable industry in the future. Using compost to produce vegetables has the potential to increase water and fertilizer conservation and reduce leaching from inorganic fertilizers in Florida's sandy soils. Compost quality for vegetable production systems should be based on soluble salts, phytotoxic compounds, C:N ratio, plant nutrients, trace metals, weed seeds, odor, moisture, pH, water-holding capacity, bulk density, cation exchange capacity, and particle size. In Florida, immature compost contained phytotoxic compounds that were harmful to crop germination and growth. Amending soil with mature composted waste materials has been reported to increase the growth and yields of vegetable crops grown in Florida. However, a beneficial response does not always occur, and the magnitude of the response is often not predictable.
Jianjun Chen, Dennis B. McConnell, Cynthia A. Robinson, Russell D. Caldwell, and Yingfeng Huang
Three composts, derived from municipal solid waste with biosolids, yard trimmings, and yard trimmings with biosolids, were mixed by volume with sphagnum peat and pine bark to formulate 12 substrates. After characterizing physical and chemical properties, the substrates, along with a control, were used for rooting single eye cuttings of pothos (Epipremnum aureum) and terminal cuttings of maranta (Maranta leuconeura) and schefflera (Schefflera arboricola) in enclosed polyethylene tents. All cuttings initiated roots with no significant difference in root numbers per cutting 14 days after sticking, but root lengths 21 days and root-ball coverage ratings 45 days after sticking were significantly affected by substrates. Five of 12 compost-formulated substrates resulted in root lengths of cuttings equal to or longer than the control. In addition to desirable physical properties such as bulk density, total porosity, and air space, common chemical characteristics of the five substrates included low concentration of mineral elements, initial electrical conductivity ≤3.0 dS·m-1 based on the pour through extraction method, and pH between 3.8 to 5.0. The five substrates were formulated by combining composted municipal solid waste with biosolids or yard trimmings with biosolids volumetrically at 20% or less or composted yard trimmings at 50% or less with equal volumes of sphagnum peat and pine bark.
Mike Litvany and Monica Ozores-Hampton
Commercial citrus (Citrus sp.) groves in Florida use an average of 150 lb/acre (168 kg·ha-1) of elemental nitrogen (N) per year. There are about 853,000 acres (345,000 ha) of commercial citrus requiring about 63,975 tons (62,652 t) of N. At an average analysis of 12% N, about 533,125 tons (483,811 t) of blended nitrogenous fertilizers are applied to citrus annually. To meet this annual N demand from compost, it would be necessary to produce 3,198,750 tons (2,901,906 t) of 2% N compost. The market for high-quality compost products in Florida is far greater than the current or projected production capacity of the state. As long as the cost benefits of compost are clear to citrus growers, demand will always exceed supply. Not all composts are equal in their nutrient availability. The best composts for use as fertilizers are derived from sewage sludge or biosolids, municipal solid waste and sludge, food waste, and/or animal manure combined with a bulking agent such as sawdust or wood chips. Composts made from wood waste as their only feedstock contain large amounts of lignin and cellulose to break down within a reasonable period to directly offset chemical fertilizers. Ultimately, they will mineralize in the soil and provide all of the benefits described earlier, but their rates of availability are in years rather than months, like the other composts.
Nancy E. Roe, Peter J. Stoffella, and Herbert H. Bryan
Increasing disposal problems with polyethylene (PL) mulch and greater availability of compost prompted an investigation into the effects of using compost as a mulch on horizontal raised bed surfaces with living mulches (LMs) on vertical surfaces. Wood chips (WC), sewage sludge-yard trimming (SY) compost, and municipal solid waste (MW) compost were applied at 224 t·ha-1 on bed surfaces. Sod strips of `Jade' (JD) or `Floratam' (FT) St. Augustinegrass (Stenotaphrum secundatum Kuntze) or perennial peanut (Arachis glabrata Benth.) (PP) or seeds of a small, seed-propagated forage peanut (Arachis sp.) (SP) were established on the vertical sides of the raised beds before transplanting bell pepper (Capsicum annuum L.) into the beds. Phytophthora capsici reduced pepper plant stand in PL-mulched plots compared with organic mulch (OM) and LM. Despite the stand reduction, total pepper yields were highest in PL plots and, in the OM plots, decreased in the order SY > MW > WC. Early fruit yields and yield per plant were highest from plants in PL plots followed by SY. Among LMs, plants in SP plots produced highest early yields and FT produced the lowest. Plants in PL plots produced the largest fruit. When the same plots were seeded with winter (butternut) squash (Cucurbita pepo L.), plant stands were higher in MW than WC and SY. Squash yields were similar between PL and OM plots.
James E. Altland and Charles Krause
objective of this research was to determine the effect of sphagnum moss, municipal solid waste compost (MSC), and elemental S on pH of substrates composed primarily of switchgrass and subsequent plant growth. Our approach was to initially use a short