Hurricane Andrew created over 17 yrs. of wood debris in a few hrs. in Dade County on 8-24-92. The rush to burn debris contributed to respiratory health problems. Through meetings with FEMA, Army Corps of Engineers, Dade County and environmental groups, SCS and SDSWCD pushed the idea of recycling this waste. Mulching and eventual composting of wood debris and using farmland as reuse sites were promoted. A joint pilot project established a team of mobile chippers coordinated by representatives of each agency. FEMA funded the project and chippers began working in groves after trees were trimmed and branches were stacked in tree rows. Over 600 ha. ware chipped and mulched during the 10 wk. contract period. More than 800 ha. are to be done under a new contract. Mulched material from other sites were delivered free to landowners who covered exposed roots of trees and replaced soil blown away by high winds. Over 200,000 m3 of mulch were delivered 5 mos. after the hurricane and 1.2 million m3 more were requested. For final pickup of debris, central grinding sites ware established and mulch was hauled to growers for mulch or compost.
Abstract
A study was conducted on Anthurium andreanum Lind, cv Ozaki Red testing sugarcane bagasse, wood shavings, black cinder, black cinder base with bagasse mulch, and tree fern chips, media and fertilizer levels of 448, 196, and 370 kg N-P-K/ha per yr at 1, 2, and 3 × rates. Media ranking from best to poorest for flower production, flower stem length, and flower size were: sugarcane bagasse, wood shavings, black cinder base with bagasse mulch, tree fern chips and black cinder. The low fertilizer rate gave as good or better results in flower production as the high rates. The 2 × rate produced slightly longer flower stems and larger flowers than 1 × or 3 × rate. Flower production decreased with age of plant, but both stem length and flower size increased.
`Giles' pecan [Carya illinoinensis (Wangenh.) K. Koch] seedlings were either not mulched or mulched with wood chips arranged in a 1- or 2-m-wide square that was 30 cm deep. Mulch treatments were in factorial combination with two N rates applied as either a single application at budbreak or as a split application at budbreak and 3 weeks later. Tree height was positively related to mulch width each year of the 3-year study, and trunk diameter was positively related to mulch width during the second and third years of the experiment. Leaf P and K concentration during 2 years and leaf N during 1 year of the study were positively related to mulch width. Trees receiving the higher N rate were taller during 2 of 3 years, but leaf N concentration was not affected by N rate. No differences in the parameters measured were observed whether N was applied as a single or as a split application.
In several northeastern USDA Low-Input Sustainable Agriculture (LISA) projects, we compared natural (hay-straw, wood-chips, recycled newspaper pulp) and synthetic (polypropylene films and polyester fabrics) mulch materials with mowed sodgrass, tillage, and residual herbicides, as orchard groundcover management systems (GMS). Treatments were applied in 2m-wide strips under newly planted apple (Malus domestica cvs. Liberty, Empire, Freedom. and others) trees on MARK rootstock, planted at 3 by 5m spacing, in 1990. Edaphic, economic, tree nutritional and fruit yield impacts of these GMS were evaluated for four years in five Hudson Valley orchards. All the mulches cost more to establish and maintain ($450 to 4500/ha) than mowed sod ($150/ha), tillage ($120/ha), or residual herbicide ($50/ha) systems. There were few differences in soil water or nutrient availability, leaf nutrient content, tree growth or fruit yield in the mulch systems compared with herbicide or tillage GMS. Meadow voles (Microtus spp.) caused considerable damage to trees in the synthetic and straw mulches, despite the use of trunk guards. Wood-chips were the most enduring, least expensive, and most effective natural mulch. There were insufficient short-term benefits to offset the greater costs of synthetic mulch fabrics or films, in comparison with conventional herbicide snip systems for orchard floor management.
. Similarly, Bartley et al. (2017) reported 90% to 100% control for more than 3 months with three different wood-derived mulches. Weed discs, plastic bags ( Chong, 2003 ), rice ( Oryza sativa ) hulls ( Altland et al., 2016 ), pelletized shredded newspaper
Abstract
The response of ‘Hull Thornless’ blackberry (Rubus spp.) to annual applications of three N rates (0, 41, and 123 kg N/ha) and straw or wood chip mulch plus 41 kg N/ha was studied. Pruning weight per plant increased linearly with increasing N rate in 1986 and 1987 and with straw mulch in 1987. Plants mulched with wood chips had the largest mean cane cross-sectional area, while neither N rate or straw mulch had an affect. Number of lateral branches per cane was not affected by any treatment. Yield increased linearly with N rate. Plants that received straw mulch produced yields that were greater than or equal to the high N rate. Mean fruit weight increased in response to straw mulch and increasing N levels in 1986, but only to the straw mulch in 1987. The number of flowers per cane and per inflorescence increased with increasing N rate, but inflorescence number per cane and fruit set were not affected. As N rates increased, yield per square centimeter of cane basal cross-sectional area increased. Both mulches decreased inflorescence number per square centimeter of cane basal cross-sectional area, but did not influence any other components of yield. Mean cane cross-sectional area, lateral branches per cane, inflorescences per cane, flowers per inflorescence, and mean fruit weight were significantly and positively correlated with yield per plant in 1987. Averaged over years, as the fertilizer N rate increased, primocane foliar N content increased, P declined, and K, Ca, Mg, and Mn were not affected. Mulching had no effect on nutrient element content.
The use of shredded bark, wood chips, and other organic mulches to conserve water and moderate soil temperatures is a common practice in landscape maintenance. Four mulch materials (cottonseed hulls, cypress pulp, pine bark, and pine straw) were examined to determine effects on plant growth and soil conditions in annual flower beds during a 1-year rotation of warm season to cool season annuals. Inhibited plant growth was observed in pine bark treatments at the conclusion of the growing season for both plantings. Effects on soil conditions were insignificant over the year-long study in pine bark treatments. To further investigate potential phytotoxic effects of pine bark and other mulch used in the initial study, a seed bioassay was performed to determine the influence of mulch extracts in solution on germination and primary root elongation.
Organic orchards represent a significant and growing component of Washington state agriculture. Comparison studies have shown that organic apple systems can be equally profitable yet more environmentally sustainable than their conventional counterparts. Despite this success, sustainable methods of weed control, fertility, and soil quality stabilization and improvement have remained a challenge. Intensive cultivation is commonly used to control weeds in organic orchards. This can lead to reduced or degraded soil organic matter, structure, water infiltration, aerated pore space, and other soil productivity parameters. In addition, tillage accelerates nutrient cycling and can result in the loss of valuable nutrients from the system. To address the need for sustainable organic methods of weed management, an integrated study of alternative understory management options was established in a newly planted orchard in 2005. Weed control measures included efficient tillage using a Wonder weeder, organically approved herbicide, wood chip mulch, and living cover mulches. Three rates of nitrogen (low, medium, and high) were applied across the Wonder weeder, wood chip, and living cover mulch plots in order to determine ideal N fertility rate. Analyses of total C and N and N-15 in organic fertilizers, soil pools, living cover biomass, and tree leaves are being used to track N and C cycling and partitioning, N-use efficiency, soil quality, and to determine optimal fertility guidelines. Preliminary results indicate intense competition between living mulch understory and orchard trees, and a trade-off may exist between maximizing soil quality and orchard productivity.
Chive (Allium schoenoprasum) is one of the most popular culinary herbs in the Virgin Islands, and local demand is always high throughout the year. However, local production is not sufficient to meet increasing demands. Chive production is constrained by insect pests, weeds, and high cost of irrigation water. A study was conducted to compare the influence of organic and synthetic mulches on yield and economic returns from chive production. The study also evaluated the effect of mulch on weeds and water use. Chives were planted in plots consisting of three rows 3.6 m long. Plants were spaced 20 cm within rows 41 cm apart. The plots were mulched with grass straw, wood chips, shredded paper, and white plastic. A control plot (no mulch) was also planted for comparison. Plots were arranged in randomized complete-block design with four replications. All plots were drip-irrigated and soil moisture tension maintaned at 30 kPa. Chives grown with grass straw mulch produced taller plants and higher number of tillers (slips) than all other mulch treatments. Total fresh yield of plots with grass straw mulch was superior to all other mulch treatments including the control. On the average, plots with grass straw mulch produced 1203 g/m2 of fresh chives. All mulches resulted in reduced weed population compared to the control (no mulch). Due to high rainfall during the growing season, differences in irrigation water use were not significant. Economic comparison indicated that the net return above mulch costs was 50% higher with grass straw than with other mulch treatments. To improve production and income, herb growers should consider using grass straw and realize other benefits, including weed control and improved soil fertility.
A 2-year field study in Lexington, Ky., evaluated weed control efficacy and influence on yields of several organic mulches in two organically managed bell pepper (Capsicum annuum) production systems. Five weed control treatments [straw, compost, wood chips, undersown white dutch clover (Trifolium repens) “living mulch,” and the organically approved herbicide corn gluten] were applied to two production systems consisting of peppers planted in double rows in either flat, bare ground or on black polyethylene-covered raised beds. In the first year, treatments were applied at transplanting and no treatment was found to provide acceptable season-long weed control. As a result, bell pepper yields in both production systems were very low due to extensive weed competition. First year failures in weed control required a modification of the experimental protocol in the second year such that treatment application was delayed for 6 weeks, during which time three shallow cultivations were used to reduce early weed pressure and extend the control provided by the mulches. This approach increased the average weed control rating provided by the mulches from 45% in 2003 to 86% in 2004, and resulted in greatly improved yields. In both years, polyethylene-covered raised beds produced higher yields than the flat, bare ground system (8310 lb/acre compared to 1012 lb/acre in 2003 and 42,900 lb/acre compared to 29,700 lb/acre in 2004). In the second year, the polyethylene-covered bed system coupled with mulching in-between beds with compost or wood chips provided excellent weed control and yields. When using the wood chip mulch, which was obtained at no cost, net returns were $5587/acre, which is similar to typical returns for conventionally grown peppers in Kentucky. Net returns were substantially decreased when using compost due to the purchase cost. Results from this study indicate that shallow cultivation following transplanting, combined with midseason mulch application, resulted in high yields in an organically managed bell pepper system that were comparable to yields of most varieties grown conventionally in a variety trial conducted on the same farm.