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- Author or Editor: Monica Ozores-Hampton x
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A rapid increase in municipal solid waste (MSW) production (2 kg/person per day), combined with a decreasing number of operating landfills, has increased waste disposal costs. Composting MSW can be an alternative method of waste disposal to traditional landfilling or incineration. Weed control methods using waste materials such as bark, straw, and sawdust were used in commercial crop production for many years before the advent of chemical weed control. Weed growth suppression by mulching can often be almost as effective as conventional herbicides. A 10 to 15 cm-deep mulch layer is needed to completely discourage weed growth in these systems, and best results are obtained with composted materials. In recent years, composts made from a large variety of waste materials have become available on a commercial scale. Preliminary investigations into the use of MSW compost as a weed control agent have shown that compost, especially in an immature state, applied to row crop middles reduced weed growth due to its high concentration of acetic, propionic, and butyric acids. Subsequently, compost can be incorporated into the soil for the following growing season to potentially improve soil physical and chemical properties. Integrated pest management programs that incorporate biological control should be adopted wherever possible because some weed species with persistent seeds can escape chemical control.
The success of long-term vegetable production and maintenance of environmental quality is dependent on soil quality. Indicators of soil quality include cation exchange capacity (CEC), organic matter (OM), carbon (C), pH, and the number and community structure of soil organisms. The use of appropriate compost has been shown to improve soil quality and enhance the response to fertilizer, therefore improving growth and yield of vegetable crops. The objective of this study was to evaluate changes in the chemical and biological properties of soil in response to compost use in conventional vegetables production systems. A survey was conducted on 5 farms (three in Immokalee, and one each in Delray Beach, and Clewiston) growing tomato, pepper, and specialty vegetables. Most of the farms were applying composted yard trimming waste alone or in combination with biosolids or horse manure at application rates of between 7 to 112 Mg·ha-1 once a year. Soil samples were taken from composted and non-composted areas in each farm during Feb. and Mar. 2002. Soil pH, OM, C, K, Ca, Mg, Cu, Fe, MN and Zn were higher in the composted areas compared with the non-composted areas for each farm. CEC values in composted areas were double those in non-composted areas. Most importantly, application of compost enhanced the overall soil microbial activity as determined by total microorganism number, SRD (species richness diversity), and TSRD (total species richness diversity) of six functional groups including heterotrophic aerobic bacteria, anaerobic bacteria, fungi, actinomycetes, pseudomonads, and nitrogen-fixing bacteria, in all the participating farms. The greatest soil quality improvement was seen in soils receiving the highest rates of compost for the longest time.
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.
In 1997, 24.7 million t of solid waste were produced in Florida (about 4.3 kg per person per day). If all biodegradable material was composted, 12.4 million t of compost would be produced annually. If this compost was used as a soil amendment in fruit and vegetable production, knowledge of its N mineralization rate would be important to determine the application rate. We measured the field N mineralization of four commercial Florida composts mixed with sandy soil (dry weight rate): Jacksonville (yard trimming compost, 127 t•ha-1), Sumter (municipal solid waste compost, 67 t•ha-1), and Nocatee and Palm Beach (yard trimming and biosolids composts, 63 and 56 t•ha-1). The control treatment was unamended soil. Open-top, 20-cm long PVC columns were filled with soil/compost mixtures and fitted at the bottom with a trap containing cation and anion exchange resin to capture leaching NO3 and NH4-N. The columns were buried in the soil at ground level and incubated in situ for 45 and 90 days in the spring. The resin was extracted with 1 N KCl and the mass of NO3-N and NH4-N adsorbed was determined. A similar procedure measured the NO3-N and NH4-N left in the soil/compost mixture. After 90 days in the field, net N immobilization was observed with Nocatee (-4.3%), Sumter (-3.0%), and Jacksonville (-1.3%) composts, while N mineralized (6.4%) from Palm Beach compost. Where N immobilization occurred, composts had initial C: N greater than 20: 1 and N concentration <1.6%. Mineralization occurred where compost had C: N ratio lower than 20: 1 and N concentration greater than 1.6%.
Intensive peat mining in Chile and worldwide produces a significant increase in production costs and less market availability. Alternative systems to promote peat mining sustainability are an immediate necessity. A viable alternative for replacing peat in tomato transplant production is to use worm castings or vermicompost. Vermicomposting is a biological process that relies on the action of earthworms (Eisenia sp.) to stabilize waste organic materials. The objective of this study was to evaluate the use of Ecobol-S® worm castings as a replacement for peat in tomato transplant production. Three experiments were designed using a randomized complete-block design containing two factors (planting date and worm casting rate). Tomatoes were seeded in a growth chamber using five growth media made up of the different ratios of worm castings, peat, and rice hulls [0:70:30 (control) 18:52:30; 35:35:30; 52:18:30; and 70:0:30], respectively. It was determined that Ecobol-S® worm castings have an adequate C:N and particle size for tomato transplant production. However, limitations were observed due to its high EC and low C content. During early fall, with high temperature in the growth chamber, it is not recommended to use worm castings in transplant production due to nutrient leaching caused by frequent irrigation. In mid-fall, it is recommended to use a rate of 35% worm castings, while in early winter it is recommended to use a rate of 52% to obtain strong and healthy transplants. Therefore, worm castings can be used as a viable alternative in the tomato transplant industry in Chile and possibly worldwide.
The nursery industry in Florida relies entirely on peat as a major component in potting soil. Escalating peat costs are a major concern, so alternative media are attractive in Florida. The objectives of the project were to study the feasibility of using food waste compost (FWC) to replace peat in different annual ornamental crops. The experiments were conducted in Spring 2004 at the University of Florida/SWFREC Immokalee, Fla. The crops basil (Ocimum basilicum L.), marigold (Calendulaofficinalis L.), and periwinkle (Vincarosea L.) were grown in mixes of FWC. The treatments were: 1) 100% FWC; 2) 60% FWC, 25% vermiculite, 15% perlite; 3) 30% FWC, 30% peat, 25% vermiculite, 15% perlite; and 4) 0% FWC, 60% peat, 25% vermiculite, 15% perlite, by volume. Basil `U.H' was direct seeded; marigold and periwinkle were transplanted (5 cm tall) in pots (2 inches). All treatments received 4 g per pot of Osmocote (19-6-12) for 4 months. Percentage of basil germination and biomass were higher in mixes with 60% and 30% FWC as compared with 100% FWC and the control. Lower basil biomass in the control media was due to high weed biomass grown in the peat control media. There were no differences in biomass and number of flowers per plant among marigold treatments. But, periwinkle dry biomass and number of flowers per plant were higher in the control and 30% FWC than in 60% and 100% FWC, indicating a negative effect of FWC in periwinkle. It can be concluded that FWC may become a viable alternative to replace peat in basil and marigold when included in potting mixes between 30% and 60% by volume, but a negative effect was reported in periwinkle production.
At two locations MSW was incorporated into the soil at 0, 90, 134 t/ha. Bell pepper and eggplant were transplanted into the field. Total marketable and large size fruit yield of eggplant were significantly higher in the MSW compost treatments than in the control. There were no significant differences in the mean size of marketable and large size eggplant fruit. Total marketable bell pepper yield tended to be higher in the MSW compost treatments than the control, but differences were not significant. MSW compost treatments resulted in significantly higher large pepper yield than the control, but mean fruit size was not affected by MSW.. In general plants with MSW compost yielded higher than the control.
The Chilean organic wine industry has comparative advantages with Europe and the United States because of its ideal environmental conditions, resulting in low presence of pests and diseases and lower production cost. Additionally, the wine production process is one of the strictest in the world, so the transformation from conventional to organic wine production can be achieved economically. A survey was conducted of 32 Chilean organic vineyards during 2004. The survey included 18 questions about total surface area, certification, varieties, final market, etc. The survey covered 95% of the land under organic wine production, with a total of 1892 ha, of which 1088 ha have organic certification and 804 ha are in transition to organic production. The major vineyards and valleys with organic wine production are Maipo (33.7%), Colchagua (17.2%), El Maule (14.0%), Curicó (9.9%), and Cachapoal (8.8%). The most important organic red varieties currently under production are `Cabernet Sauvignon' (40.9%), `Merlot' (15.1%), `Syrah' (9.1%), `Carmenere' (7.3%), `Malbec' (3.3%), and `Pinot Noir' (2.5%). The white varieties are `Sauvignon Blanc' (6.4%), `Chardonnay' (5.1%), and `Semillón' (1.0%). The potential for the organic wine industry in Chile is tremendous since organic vineyards represent only 2% of the total vineyard industry.
Many vegetable growers rely on methyl bromide or other soil fumigants to manage soil pathogens, nematodes, and weeds. Nonchemical alternatives such as solarization and organic amendments are as yet largely unproven, but do offer promise of more sustainable solutions. The objective of this study was to evaluate the effects of long-term organic amendments and soil solarization on soil chemical and physical properties and on growth and yield of pepper (Capsicum annuum L.) and watermelon (Citrullus lanatus [Thunb.] Manst.). Main plots consisted of a yearly organic amendment or a nonamendment control. Four subplots of soil sanitation treatments consisted of solarization, methyl bromide, Telone, and nonfumigated. Each subplot was divided into two sub-subplots, one with weed control and one without weed control. Plant biomass was higher in plots with organic amendments than in nonamended plots. There were no differences in marketable pepper and watermelon yields between organic amended and nonamended plots during the 1998-99 and 1999-2000 seasons, respectively. However, higher pepper yields were produced from organic amended plots in the 1999-2000 season. Soil pH and Mehlich 1-extractable P, K, Ca, Mg, Zn, Mn, Fe, and Cu were higher in organic amended plots than in nonamended control plots. Soil organic matter concentration was 3-fold higher in amended soil than in nonamended soil. Effects of soil sanitation and weed management varied with crop and season. The methyl bromide and Telone treatments produced higher yields than soil solarization. In general, weed control did not affect plant biomass and yield for any of the crops and seasons. The results suggest that annual organic amendment applications to sandy soils can increase plant growth and produce higher or comparable yields with less inorganic nutrient input than standard fertilization programs.