Low Greenhouse Gas Agriculture: Mitigation and Adaptation Potential of Sustainable Farming Systems

Is low greenhouse gas emission (GHG) agriculture possible? Is it, in fact, desirable? In seeking answers to these two basic but extremely relevant questions, this study examines current farming practices, and incorporates scientific databases from longterm field experiments as case studies for low GHG agriculture. Further, the study examines the changes that will be needed for low greenhouse gas agriculture systems to become a reality. It also elucidates the adaptive capacity of agro-ecological farming system approaches, using organic system case studies from the scientific literature. Each year, agriculture emits 10 to 12 percent of the total estimated GHG emissions, some 5.1 to 6.1 Gt CO2 equivalents per year. Smith, et al. (2007) and Bellarby, et al. (2008) have proposed mitigation options for GHG emissions, finding that both farmers and policymakers will face challenges from the GHG-related changes needed in agriculture. Areas for improvement include increased use of no-till cropping, agro-forestry, and integrated crop and animal farming, and decreased use of external inputs in food and agriculture. The techniques offered by organic agriculture are valuable for consideration in these efforts

La roya del sorgo

Four grain sorghum (Sorghum bicolor (L.) Moench.) lines showing distinct reactions to sorghum rust (Puccina purpurea Cooke) were planted under subhumid tropical oceanic conditions in northwestern Puerto Rico in an oxisol of pH 5.5 in May 1985. Disease development was periodically monitored until harvest. Rust levels were established using either no application or two applications each of either oxycarboxin, triadimefon or mancozeb fungicide. Noticeable rust was found at boot stage and increased with maturity. Rust differences were most apparent at physiological maturity. At that stage foliar rust coverage was estimated at 20, 16, 1 and 0% for SC 212, SC 307, TAM 428, and SC 120, respectively. Greatest rust control was found for oxycarboxin, triadimefon, and mancozeb in that order of efficacy. Oxycarboxin treatment resulted in over 80 and 60% less rust; 25 and 40% more grain yield; 0 and 20% greater seed density; and 80 and 71% more foliar sorghum anthracnose in SC 307 and SC 212, respectively, in comparison with those of nontreated plots. Fungicide treatments did not increase yields of either TAM 428 or SC 120, sorghum cultivare showing moderately resistant and very resistant rust reactions, respectively.La roya del sorgo causada por Puccinia purpurea Cooke causó pérdidas considerables en rendimiento de grano en 2 de 4 cultivares evaluadas en Isabela en 1985. Se establacieron diversas grados de severidad de la roya con diferentes fungicidas foliares con eficacia variable. Las líneas experimentales se seleccionaron por diferencia en resistencia. La epidemia de roya empezó en el estadio de hoja bandera y aumentó drásticamente después de la floración. Las diferencias de los tratamientos se notan más claramente en la maduración fisiológica. En esta etapa, la roya cubrió un 20, 16, 1 y 0% del follaje de SC 212, SC 307, TAM 428 y SC 120, respectivamente. Oxicarboxin fue el fungicida más eficaz contra la roya. Le siguieron triadimefon y mancozeb en ese orden. Al comparar los tratados con oxicarboxin con los sin tratar la roya disminuyó de 80 a 60%; el rendimento de grano aumentó 25 y 40% y la densidad de las semillas de 0 a 20% en las variedades de sorgo SC 307 y SC 212, respectivamente. Las variedades TAM 428, que es moderadamente resistente a la roya, y SC 120, que es muy resistente, no mostraron mejoría al tratarlas con los fungicidas

La roya del sorgo: II. Combate y pérdidas

Four sorghum lines of varying rust susceptibility, ranging from very resistant to susceptible, were planted in early September T985 in Isabela, Puerto Rico. Rust reactions were periodically evaluated from boot stage until grain harvest. At physiological maturity, foliar rust coverage was 24, 19, 7, and 0.5% for SC 212, SC 307, TAM 428, and SC 120, respectively. Four rust fungicide (oxycarboxin at 0.5 kg/ha/spray), applications at and after boot stage resulted m final rust coverage of 7, 3, 1, and 0% on SC 212, SC 307, TAM 428, and SC 120, respectively. Over all cultivars, one, two, and four applications gave 32.9, 73.7, and 85.4% rust control compared to the nontreated plots. In moderately and very resistant varieties (TAM 428 and SC 120), rust control was greater (74.5%) than that found in moderately and very susceptible ones (55.2% for SC 307 and SC 212). On SC 307 and SC 212, yield losses from rust were 29 and 50%, respectively. Reductions in 100-seed weights in SC 307 and SC 22 (28 and 41 %, respectively) approximated yield loss levels. Yield of SC 212 was superior to that of SC 307 when rust was controlled with oxycarboxin and inferior to that of SX 307 when rust was untreated. Moderately rust resistant TAM 428 showed no response to rust control despite 7% rust coverage. This same rust level reduced yield of the susceptible varieties. Because of the genotypic differences in rust-yield reactions, a generalized model relating visual rust coverage to plant performance appears inappropriate.En septiembre de 1985, se probaron líneas de sorgo que presentaron diferentes grados de susceptibilidad a la roya en Isabela, Puerto Rico. Durante la etapa de madurez fisiológica los porcentajes de área foliar afectada por la roya fueron 24, 19, 7 y 5 en las variedades SC 212, SC 307, TAM 428, y SC 120, respectivamente. Cuatro aplicaciones foliares de oxicarboxin (0.5 kg./ha.) durante la etapa de la hoja bandera y después de ella reprimieron la roya hasta obtenerse valores finales en porcentaje del área foliar afectada de 7, 3, 1 y 0, respectivamente, en las mismas variedades. Una, dos y cuatro aplicaciones reprimieron la roya en un 32.9, 73.7, y 85.4%, respectivamente, en estas cultivares. La eficacia de la represión química del patógeno fue mayor en variedades con alta o moderada resistencia a la roya (74.5%) si la comparamos con las variedades de moderada resistencia o de alta susceptibilidad (55.2%). La enfermedad redujo los rendimientos en 50 y 29% en las cultivares SC 212 y SC 307, respectivamente. Las respuestas en rendimiento al reprimir la roya fueron mayores en la variedad SC 212 que en la SC 307. El peso de 100 semillas disminuyó 41% y 28% en SC 212 y SC 307, respectivamente

Standing in the Way of Control : Small Farmers, Water Use, and Technology Adoption in Oregon

In recent years, several interrelated forces—prolonged drought, growing populations, height-ened environmental protections, sustained agricultural use, and hydrologic alterations due to climate change—have increased pressure on water users in the Western United States, where the agricultural sector accounts for up to 90% of total water withdrawals. Technology im-provements developed since the 1950s have increased irrigation efficiency on many farms, and more recently networked technologies have promised to transform agriculture again, through advanced analytics, in-field sensors, and other telecommunications technology. While economies of scale and access to capital have spurred growth on larger farms, imple-mentation on smaller farms has lagged. This thesis is based on research initially proposed by Intel Labs and uses ethnographic interviews with farmers and policymakers in Oregon to un-derstand the both the barriers to technology implementation and the underlying factors asso-ciated with on-farm water use and technology adoption in Oregon. An analysis of interview data reveals several significant barriers to technology implementation, many of which are re-lated to the perceptions small farmers hold about themselves, their community, technology, regulation, water use, and the future. This thesis also examines the interconnections between Integrated Water Resources Management (IWRM) and networked technology implementa-tion, and examines the utility of that policy framework to explain the challenges faced by small farmers as stakeholders in relation to water management decisions in Oregon

Edades de corte e incidencia de enfermedades de dos sorgos forrajeros y sus rendimientos en materia seca y proteina bruta

Two forage sorghum hybrids ( ATx 623 X GL and FS25A) were grown from April 1985 to February 1987 at the Agricultural Experiment Station of the University of Puerto Rico at Lajas, Puerto Rico to determine the influence of maturity stage increases of 10 days (from the 45th to the 85th day) and how the presence and severity of foliar diseases affect the dry forage and crude protein yields. Dry matter content was higher for FS25A (16.1%) than for ATx 623 X GL (14.9%) whereas total yield for dry matter (DMY) was higher for ATx 623 X GL (3.84 t/ha) than for FS25A (3.51 t/ha). Both content and yield of dry matter increased with maturity stage in both genotypes. The sorghum hybrids did not differ significantly in crude protein content (CPC), but crude protein yield (CPY) was higher for ATx 623 X GL (421.6 kg/ha) than for FS25A (358.9 kg/ha). CPC declined with increased plant maturity. Foliar diseases appeared to limit DFY and CPY in both sorghum hybrids. Downy mildew, leaf blight, rust, grey leafspot, and zonate leafspot appeared seasonally. Leaf blight and downy mildew were the most prevalent from January to May, grey leafspot from May to September, and zonate leafspot from September to November. Rust was severe during all seasons.Se llevo a cabo un estudio con dos híbridos de sorgo forrajero (ATx 623 X GL y FS25A) de abril de 1985 a febrero de 1987 en la Subestación Experimental Agrícola de Lajas para medir la influencia sobre la producción de etapas de corte cada 10 días (desde el 45to al 85 to día) y como la incidencia de enfermedades afecta el rendimiento de forraje seco y proteína bruta. El contenido medio global de materia seca fue mayor en FS25A (16.1%) que en ATx 623 X GL (14.9). Lo contrario ocurrió con el rendimiento de forraje seco, ya que se obtuvo un rendimiento mayor con ATx 623 X GL (3.84 t./ha.) que con FS25A (3.51 t./ha.). El rendimiento de forraje seco y el contenido de materia seca aumentaron a medida que el forraje maduro. Las diferencias entre ambos híbridos en contenido medio de proteína bruta no fueron significativas. No obstante, la media ponderada para el rendimiento de proteína bruta total fue mayor para ATx 623 X GL (421.6 kg./ha.). El contenido y el rendimiento total de proteína bruta disminuyeron significativamente a medida que la etapa de corte aumentó de 45 a 85 días. Los rendimientos de forraje seco y de proteína bruta total también disminuyeron en ambos híbridos debido a la incidencia de enfermedades. Estas enfermedades fueron anublo lanoso ("downy mildew"), tizón ("leaf blight"), roya ("rust"), y mancha foliar ("zonate leafspot"). La época del año fue un factor determinante para la presencia de estas enfermedades. De enero a mayo la enfermedad más prevaleciente fue el anublo lanoso. Sin embargo, de mayo a julio predominó la mancha cercospórica y de septiembre a noviembre la mancha foliar

Impacts of Organic and Conventional Management on the Nutritional Level of Vegetables

The nutrient concentration of fruits and vegetables in the U.S.A. has declined in the past 50–70 years. Crop management practices utilizing on-farm inputs are thought to increase crop nutritional quality, but few studies have evaluated this under long-term side-by-side trials. An experiment was conducted from 2004 to 2005 at Rodale Institute’s long-term Farming Systems Trial to investigate the nutritional quality of vegetables under organic manure (MNR) and conventional (CNV) farming systems, with or without arbuscular mycorrhizal fungi (AMF) treatment. AMF reduced the vitamin C content in carrots in both systems in 2004, but the reduction was 87% in CNV and 28% in MNR. AMF also reduced antioxidants in carrots in both CNV and MNR. This trend was likely due to the suppression of native AMF colonization by the non-native AMF inoculum used. Between 2004 and 2005, MNR increased the vitamin C in green peppers by 50% while CNV decreased the vitamin C in red peppers by 48%. Tomatoes under MNR had a 40% greater vitamin C content compared to CNV in 2005. The vegetable yield declined between 2004 and 2005, except for tomato, where the yield increased by 51% and 44% under CNV and MNR, respectively. In general, MNR tended to increase the nutrient concentration of vegetables compared with CNV, while the AMF effects were inconclusive

Phomopsis Sojae: Colonization of Hosts, Interactions With Other Pathogens, and Losses on Soybeans

101 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1979.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD