A glasshouse study was conducted to evaluate the suitability of composted broiler chicken (Gallus gallus) litter as a potting substrate using lettuce (Lactuca sativa L.). Broiler litters containing wood shavings or peanut bulls as bedding materials were composted with either shredded pine bark or peanut hulls. Composted materials were then combined with a commercially available potting substrate. Greatest fresh weight yield was obtained when peanut bull compost was mixed with commercial potting substrate at a ratio of 3:1. Fresh weight was less with pine bark compost than with peanut hull compost. However, there were no differences in lettuce dry weight among composts except for pine bark composted with wood-shaving broiler litter. The pH of this material was below the lettuce tolerance level for mixes at or above 50% compost. There was no evidence of lettuce physiological disorders resulting from excessive nutrient concentration. Most elements analyzed (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, and Al) were within or slightly above sufficiency ranges for Boston-type leaf lettuce. It appears that composting broiler litter for use as a potting substrate or component would be one suitable alternative to land application in the southern United States. We recommend, however, that the pH of substrates be adjusted to suit desired crop requirements.
R.P. Flynn, C.W. Wood, and E.A. Guertal
Mari Marutani, John Brown, Mark Acosta, Joseph Sablan, Sheeka Afaisen, and James McConnell
A grant to construct a “Model Farm” on Guam and the Virgin Islands was approved in 2000 by the USDA/CSREES/Initiative for Future Agriculture and Food Systems Program. The main goal was to establish an integrated model farm that had potential benefits for small agricultural enterprises operated by Asian-Pacific and Caribbean Islanders. University of Guam Triton Farm was established on 3.75 acres (1.5 ha) of the Agricultural Experiment Station. Initially we conducted a soil survey, and established windbreaks/hedgerows. We also built the foundation for aquaculture/aquaponic system, field irrigation systems, and animal production facilities. Then, we planted long-term fruit and ornamental plants while growing short-term vegetable crops for quick returns. Currently we raise tilapia (Oreochromis niloticus), goats (Capra hercus) and layer-chickens (Gallus gallus). We grow banana (Musa spp.), calamansi (X Citrofortunello mitis, hot peppers (Capsicum spp.), cucumbers (Cucumis sativus), lettuce (Lactuca sativa), eggplants (Solanum melongena), and Ti-leaf (Cordyline terminalis). We also try to develop value-added products using local produce. Occasionally we investigate other potential commodities and operational schemes for the farm. These must be suitable for Guam's agro-climate and social and economic structure. We focus on conservation of natural materials, composting, and sustainable agriculture. Education and outreach activity is also an important component of the farm to disseminate technologies and to educate young children about farming.
Vasey N. Mwaja, John B. Masiunas, and Catherine E. Eastman
The effect of cover-crop management on growth and yield of `Bravo' cabbage (Brassica oleracea var. Capitata L.), `Market Pride' tomato (Lycopersicon esculentum Mill.), and `Mustang' snap bean (Phaseolus vulgaris L.) was determined. Each fall, `Wheeler' winter rye (Secale cereale L.) and `Oregon Crown' hairy vetch (Vicia villosa Roth) were interseeded. The following spring, the cover crops were killed by either applying glyphosate and mowing (CC-G) or mowing and disking (CC-D). Trifluralin was preplant incorporated into bare ground as a conventional tillage (CT) treatment. In 1992 and 1993, a chicken (Gallus gallus L.) based fertilizer was applied to half the subplots. The greatest snap bean and cabbage yields were in CT. The system with the greatest tomato yields varied. In 1991, the greatest tomato yields were in the CT treatment, while in 1992 yields were greatest in the CT and CC-D treatments, and in 1993 the greatest yields were in CT and CC-G. Cabbage yields were greater in the fertilized than the unfertilized treatments. In 1992, infestations of diamondback moth, imported cabbageworm, and cabbage looper were greater in CT than in the CC-G treatment. Three years of the CC-G treatment increased soil organic matter from 3.07% to 3.48% and increased soil pH from 6.30 to 6.51, while neither changed in the CT. Chemical names used: N-(phosphonomethyl) glycine (glyphosate); 2,6-dinitro-N,N-dipro`pyl-4-(trifluoromethyl) benzenamine (trifluralin).