Research & reports

Laura Avila, Johannes Scholberg, Nancy E. Roe, C. M. Cherr · HortScience · United States (Florida)

Sunn hemp (Crotalaria juncea) was tested as a summer cover crop in a Community Supported Agriculture vegetable operation in Southeast Florida, United States, from 2003 to 2005. The farm system compared sunn hemp (SH) with a conventional summer fallow, followed by winter/spring tomato and pepper and then sweet corn. Tomato and pepper received 0, 67, 133 or 200 kg N/ha in 2003, and 0, 100 or 200 kg N/ha in 2004/05; sweet corn received 133 or 200 kg N/ha in 2003 and 100 kg N/ha in 2004/05. Average SH biomass was 3.7 Mg/ha. In 2003, tomato yields following SH without supplemental nitrogen were similar to the fallow treatment fertilized with 200 kg N/ha. By the third year, tomato and pepper yields in SH plots were 25% and 26% higher, respectively, than conventional plots, while conventional pepper fertilized with 200 kg N/ha showed only 8% higher yield than plots given 100 kg N/ha plus cover crop. Sweet corn yields were low overall but increased when the preceding tomato/pepper crop received higher nitrogen rates: in 2003, sweet corn fertilized with 200 kg N/ha following an SH-fall vegetable rotation produced 17% higher marketable yield than the fallow treatment, and in 2004–2005, sweet corn within the SH–unfertilized tomato system produced 29% higher yields than a comparable conventional system. The results indicate that in this rotation, both fall vegetable crops and sweet corn benefit from residual nitrogen, with SH mineralization affecting not only the immediately following crop but also yields later in the year.

Myreide Marinez Da Silva, J. L. P. Araujo, Aryon de Almeida Barbosa, Ariana Ferreira da Silva, Leyla Menezes de Santana, C. R. R. S. França · · Brazil

This study assessed the economic viability of an agroecological system for growing vegetables in the Nova Descoberta community, in the interior of Petrolina, Pernambuco state, Brazil. Coriander (Coriandrum sativum) was the economically dominant crop, accounting for nearly 85% of the garden's total monetary income, followed by lettuce (Lactuca sativa) at over 13%, while all remaining crops together reached only 2.3% of total sales value, though the study notes their cultivation was expected to expand with the continuing agroecological conversion process to diversify species grown.

Ron Sawyer, Anne Delmaire, Andrés A. Buenfil · · Mexico

A study shares initial experiences from TepozEco, a pilot program for holistic ecological sanitation planning in Tepoztlan, Mexico, which includes promoting ecological toilets, water demand and greywater management, rainwater harvesting, organic waste recycling, urban agriculture, and environmental education. The project's initial phase is described as encouraging, attributed mainly to an iterative, flexible, and responsive design process—adaptive planning—and a close network of partners and collaborators; while the local context is in some respects unique, particularly regarding institutional resources, local environmental awareness, and local government commitment, the municipality's socioeconomic conditions reflect those of much of Latin America, suggesting TepozEco could serve as an ecological sanitation model for a significant part of Mexico, Central America, and South America.

Vicente de Paula, Mário T. Kato, Lourdinha Florêncio · Revista Brasileira de Engenharia Agrícola e Ambiental · Brazil

A study evaluated the physicochemical and bacteriological quality of water used to irrigate vegetables in an urban agriculture area along the BR-101 southern ring road in Recife, Brazil. Water samples were collected from six existing wells in the agricultural area during the dry season, October to December 2003, and analyzed for physicochemical parameters (electrical conductivity, Ca2+, Mg2+, Na+, K+, Cl-, HCO3-, nitrate-N, ammonium-N, pH, and sodium adsorption ratio) and fecal coliform. The physicochemical quality of the irrigation water showed no risk of soil salinization or alkalinization, nor of specific toxicity to plants.

Constance L. Falk, Pauline Pao, Christopher S. Cramer · HortScience · United States (New Mexico)

In January 2002, the OASIS organic vegetable garden was initiated on the New Mexico State University campus as a Community Supported Agriculture (CSA) venture. The project aims to provide students with experiential education in organic production and business management, investigate the feasibility of small-scale organic drip irrigation in the Chihuahuan desert, and demonstrate the CSA model. In its first two years, the 2/3-acre project grew about 230 varieties and generated $32,000 in revenue, with 32 members in the first year and 69 in 2003.

James R. Allen, Allen, James R. · AgEcon Search (University of Minnesota, USA) · United States

This study compared the feasibility of using composted yard waste and cow manure versus commercial fertilizer (10-10-10) as soil amendments for cool and warm season vegetable crops in urban gardens. Composted materials were applied at 44,800 kg/ha and fertilizer at 336 kg/ha. Most varieties produced yields equal to or greater in compost-amended plots than in fertilizer-treated plots, with significant varietal differences observed. For example, onion yields were 24% higher and tomato yields were 44% higher in compost-amended plots in specific experiments.

V. de M. Benites, F. B. Bezerra, R. O. Mouta, I. R. Assis, R. C. P. Santos, Mário Marcos Moreira da Conceição, Arthur Guerra de Andrade · · Brazil (Rio de Janeiro)

The composting process of grass clippings resulting from the maintenance of Rio de Janeiro International Airport's lawns was evaluated. This process was conducted in a protected environment, using grass clippings as the sole organic matter source, with treatments involving urea, natural phosphate, and pyroligneous acid. After 82 days, the compost was deemed mature, and results indicated the possibility of producing good quality organic fertilizers from grass clippings.

National Park Service, City of Fresno · U.S. National Park Service · United States

The Fresno Sanitary Landfill (FSL) opened in 1937 and closed in 1987, and is described as the oldest 'true' sanitary landfill in the United States and the oldest compartmentalized municipal landfill in the western U.S. Under engineer Jean L. Vincenz, it was the first landfill to use the trench method and compaction, and became a model for modern sanitary landfills nationwide.

A. L. Echemendía, Surey Valdés, Sugey Magdalena Castillo Jiménez, Gloria González, Juan Miguel Zarandona Femández · Redalyc (Universidad Autónoma del Estado de México) · Mexico

A survey of pests and diseases in crops associated with hydroponic systems, organopónicos, and urban gardens in Mexico identified three viral symptomatologies in lettuce (Lactuca sativa), celery (Apium graveolens), and Castilla melon (Cucumis melo), linked to aphid vectors. Using indicator plants, optical and electron microscopy, and ELISA (DAS and indirect variants), the causal agents were identified: Lettuce Mosaic Virus (LMV) in lettuce and a race of Cucumber Mosaic Virus (CMV) in celery, both first reports for the country, and Papaya Ringspot Virus race W (PRSV) in melon, never previously found in that crop. An aphid species colonizing lettuce was also identified for the first time as an LMV vector.

Richard K. Olson, L. Bauer · Lincoln (University of Nebraska) · United States

This is a two-part compilation on small-scale Midwest farming (Part I) and reintegrating agriculture and community in the Midwest (Part II), gathering contributed chapters covering topics such as small and family-sized farms, market gardening, diversified crop/livestock systems, Amish farming agroecosystems, direct marketing, community-supported agriculture, farmers' markets, farmland preservation, and local food-system strengthening in Nebraska, Iowa and the broader Midwest region of the United States.

C. C. Weir, James R. Allen · Journal of Environmental Science and Health Part A Environmental Science and Engineering and Toxicology · United States (New York City)

In the District of Columbia, tomato (Lycopersicum esculentum) and mustard (Brassica juncea) grown on a low-pH, compacted silt-loam soil were compared under plots treated with composted sewage sludge and composted yard waste versus plots receiving commercial N-P-K fertilizer. Yields were generally significantly higher in the compost-treated plots than in the commercial fertilizer plots. Chemical and physical soil analyses showed the composted organic amendments not only improved the compacted soil's poor physical properties but also significantly increased soil pH, organic matter content, and available phosphate and magnesium. Chemical analysis of the edible plant portions for heavy trace metals such as lead and cadmium found levels not high enough to raise health concerns, remaining within ranges established as acceptable by other researchers.

K. Bondari, E. D. Threadgill, J. Bender · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · United States

This study conducted two experiments on tilapia culture. Experiment I aimed to determine the potential of Tilapia aurea in an integrated irrigation system for algae removal and resource recovery. Experiment II investigated the potential use of blue tilapia in urban farming, utilizing a passive solar greenhouse, an indoor pond for overwintering, and an outdoor pond for summer growth.

Earle Barnhart · Birkhäuser Basel eBooks · United States

This paper argues that producing food within a forest ecosystem through careful cultivation of tree crops on hilly, marginal land is a successful and sustainable strategy for conserving soil and nutrients, and holds potential for the northeastern United States, where natural vegetation is predominantly steep, hilly forest unsuited to normal food production. Drawing on forest farming development at the New Alchemy Institute on Cape Cod, Massachusetts, it discusses concepts of ecology, energy use and erosion control in agricultural ecosystems.

Rodale Institute · Rodale Institute · United States

A long-running comparative farming trial launched by Rodale Institute in 1981, comparing conventional (synthetic nitrogen fertilizer and herbicides), organic legume, and organic manure systems across 72 plots for over 40 years. In drought years, organic corn yields are reported to be 31% higher than conventional, and water infiltration rates are significantly faster under organic management.

M. A. Latheef, R.D. Irwin · The Canadian Entomologist · United States

A paper on field experiments conducted in southside Virginia, United States, sought to quantify the effect of companion plants (repellent herbs) on major lepidopteran pests of cabbage. It cites an estimated 33 million home and community gardens grown in the United States during 1976 and 1977 as context, noting that claims about companionate planting's protective effects made by organic growers had little field evidence to substantiate them. The abstract does not report the experiment's specific results.

Rodale Institute · Rodale Institute · United States

The Rodale Institute's history page. J.I. Rodale and his wife Anna bought a 63-acre farm in Emmaus, Pennsylvania in 1940 to begin experimenting with organic agriculture, and founded the Soil and Health Foundation (later renamed Rodale Institute) in 1947. In 1948 the book 'Pay Dirt' argued that chemical agriculture was linked to declining public health.