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Exploratory studies on production, utilization and proximate composition of some minor root and tuber crops in Nigeria Полный текст
2013
Olojede, A.O. | Akinpelu, A.O. | Dalyop, T.Y. | Lenka, D. | Nwosu, K.I. | Iluebbey, P. | Dixon, A.G.O.
Several exploration trips were made between 2004 and 2006 to collect germplasm of minor root and tuber crops grown in Nigeria. Information collected included local names, locations, production/agronomic practices, utilization and marketing, among others. Samples of materials collected were analyzed for their proximate compositions. A total of 158 collections were made, comprising 76 turmeric, 31 Hausa potato, 29 Livingstone potato and 22 Polynesian arrowroot accessions. Turmeric is cultivated and utilized in 19 states, Hausa potato – 6 states, Livingstone potato – 2 states, while Polynesian arrowroot was collected from 10 states but utilized as food only in five states. The highest number of turmeric collections was obtained in Ekiti state (15.8%). While the highest collections of Hausa potato (32.3%) and Livingstone potato (82.8%) were obtained respectively from Kaduna and Plateau states, 18.2% of Polynesian arrowroot collections were each obtained in Benue and Oyo states. Most of the crops are produced in smallholdings of less than 0.1 ha. Cultivation was mostly by old women except Polynesian arrowroot that was collected in the wild. The carbohydrate content (NFE) of the crops ranges between 60.23-80.40 g/100 g, crude protein (7.58- 14.00 g/100 g), total ash (3.01-6.97 g/100 g), calcium (0.27-0.45 g/100 g) and phosphorus (0.27-0.59 g/100 g) all on dry weight basis. These crops play key roles in the food supply system, income generation, improved health and preservation of cultural heritage of the rural household. More research efforts in the areas of crop improvement, production practices, postharvest handling and value chain development were suggested as a way to harness their economic potentials.
Показать больше [+] Меньше [-]Energy efficiency of potato production practices for bioethanol feedstock in northern Japan Полный текст
2013
Koga, Nobuhisa | Kajiyama, Tsutomu | Senda, Keiichi | Iketani, Satoru | Tamiya, Seiji | Tsuda, Shogo
In 2007–2009, field experiments were conducted to identify agronomic practices affording the lowest energy inputs (i.e. total energy inputs from fuels and other agricultural material inputs required to produce 1L of ethanol) under potato-based bioethanol feedstock production in northern Japan. On a hectare basis, for a standard 4.4m−2 planting density, conventional practices [two inter-row cultivations (weeding and preparation for ridging) and final ridging] yielded an estimate of 4.85kLha−1, representing an energy input of 5.86MJL−1. The energy input savings arising from the lesser fuel consumption associated with fewer tractor operations under no- and low-ridge cropping practices were outweighed by a reduction in ethanol yields, resulting in slightly greater energy inputs (6.09±0.65 and 5.89±0.30MJL−1, respectively). Similarly, poorer ethanol yields outweighed the reduction in energy inputs arising from lessened seed potato production-associated energy inputs under lowered planting densities of 3.8 and 3.3m−2, resulting in ethanol yield-based energy inputs of 5.98±0.33 and 6.01±0.41MJL−1, respectively. Omitting fungicide applications significantly lowered biocide-related energy inputs, but yielded 20 and 63% lower ethanol yields for Phytophthora-resistant and -susceptible genotypes, respectively, substantially worsening energy efficiencies (6.24±0.42 and 12.2±6.3MJL−1). In northern Japan, use of high starch-yielding genotypes served as the only way to increase ethanol yields and improve energy efficiency for potatoes used in bioethanol feedstock production. A 29% greater ethanol yield (6.26±0.46kLha−1) and 21% better energy efficiency (4.63±0.23MJL−1) were achieved by replacing the standard potato cultivar with a high starch-yielding variety. The yield-based energy inputs with a high starch-yielding potato variety were significantly lower than those with conventional sugar beet in northern Japan (5.82MJL−1).
Показать больше [+] Меньше [-]Management practices and agro-ecological effects on crop water productivity in Meja watershed, Ethiopia
2013
Debela, A.A. | Erkossa, Teklu | Zuberi, M.I.
Mixed crop–livestock farming system is a major livelihood strategy in most sub-Sahara African countries. Low water use efficiency and water scarcity characterize the dominant rainfed agricultural production system in the densely populated highlands of Ethiopia. Improving water productivity in the rainfed system is among the ways of overcoming the water scarcity challenge. This study was conducted in Meja watershed, located in Jeldu district, West Shewa in the Ethiopian part of the Blue Nile Basin to estimate economic crop water productivity based on agro-ecology and crop management practices. The watershed was classified into three landscape positions (local agro-ecologies) and major crops representing at least 70% of each landscape position were identified through discussion with farmers and development agents. Five farmers field were randomly selected for each major crop and crop management practices implemented by the farmers were monitored and yield (grain or tuber and straw) was measured at harvest. The local market value of the crops and the production cost was estimated based on the local market value for labour and other inputs. CROPWAT model was used to estimate effective precipitation based on weather data generated using NewLocClim and crop characteristics. The result indicated that the landscape positions, crop variety and management practices significantly influenced the net economic water productivity. The net economic crop water productivity for barley, wheat, tef, sorghum and maize grains and fresh potato tubers were 3.31, 2.45, 3.09, 3.01 and 5.20 and ETB 13.56 m-3, respectively. Similarly, physical water productivity of the crops ranged from 0.47 for teff to 9.98 kg m-3 for fresh potato tubers. Hence, farmers can enhance economic benefit from the land and water resources they are endowed with rainfed by using improved agronomic practices that could raise grain/tuber and biomass yield. Enhancing improved input use, improving access to market for outputs and integrating livestock with crops may further augment the benefit at system scale.
Показать больше [+] Меньше [-]Sustainability assessment of GM crops in a Swiss agricultural context Полный текст
2013
Speiser, Bernhard | Stolze, Matthias | Oehen, Bernadette | Gessler, Cesare | Weibel, Franco P. | Bravin, Esther | Kilchenmann, Adeline | Widmer, Albert | Charles, Raffael | Lang, Andreas | Stamm, Christian | Triloff, Peter | Tamm, Lucius
The aim of this study was to provide an ex ante assessment of the sustainability of genetically modified (GM) crops under the agricultural conditions prevailing in Switzerland. The study addressed the gaps in our knowledge relating to (1) the agronomic risks/benefits in production systems under Swiss conditions (at field and rotation/orchard level), (2) the economic and socio-economic impacts associated with altered farming systems, and (3) the agro-ecological risks/benefits of GM crops (at field and rotation/orchard level). The study was based on an inventory of GM crops and traits which may be available in the next decade, and on realistic scenarios of novel agricultural practices associated with the use of GM crops in conventional, integrated, and organic farming systems in Switzerland. The technology impact assessment was conducted using an adapted version of the matrix for “comparative assessment of risks and benefits for novel agricultural systems” developed for the UK. Parameter settings were based on information from literature sources and expert workshops. In a tiered approach, sustainability criteria were defined, an inventory of potentially available, suitable GM crops was drawn up, and scenarios of baseline and novel farming systems with GM crops were developed and subsequently submitted to economic, socio-economic, and agro-ecological assessments. The project had several system boundaries, which influenced the outcomes. It was limited to the main agricultural crops used for food and feed production and focused on traits that are relevant at the field level and are likely to be commercially available within a decade from the start of the project. The study assumed that there would be no statutory restrictions on growing GM crops in all farming systems and that they would be eligible for direct payments in the same way as non-GM crops. Costs for co-existence measures were explicitly excluded and it was assumed that GM foods could be marketed in the same way as non-GM foods at equal farm gate prices. The following model GM crops were selected for this study: (1) GM maize varieties with herbicide tolerance (HT), and with resistance to the European corn borer (Ostrinia nubilalis) and the corn rootworm (Diabrotica virgifera); (2) HT wheat; (3) GM potato varieties with resistance to late blight (Phytophthora infestans), to the nematode Globodera spp., and to the Colorado beetle (Leptinotarsa decemlineata); (4) HT sugar beet with resistance to “rhizomania” (beet necrotic yellow vein virus; BNYVV); (5) apples with traditionally bred or GM resistance to scab (Venturia inaequalis), and GM apples with stacked resistance to scab and fire blight (Erwinia amylovora). Scenarios for arable rotations and apple orchards were developed on the basis of the model crops selected. The impact assessments were conducted for the entire model rotations/orchards in order to explore cumulative effects as well as effects that depend on the farming systems (organic, integrated, and conventional). In arable cropping systems, herbicide tolerance had the most significant impact on agronomic practices in integrated and conventional farming systems. HT crops enable altered soil and weed management strategies. While no-till soil management benefited soil conservation, the highly efficient weed control reduced biodiversity. These effects accumulated over time due to the high proportion of HT crops in the integrated and conventional model rotations. In organic production systems, the effects were less pronounced, mainly due to non-use of herbicides. Traits affecting resistance to pests and diseases had a minor impact on the overall performance of the systems, mainly due to the availability of alternative crop protection tools or traditionally bred varieties. The use of GM crops had only a minor effect on the overall profitability of the arable crop rotations. In apple production systems, scab and fire blight resistance had a positive impact on natural resources as well as on local ecology due to the reduced need for spray passages and pesticide use. In integrated apple production, disease resistance increased profitability slightly, whereas in the organic scenario, both scab and fire blight resistance increased the profitability of the systems substantially. In conclusion, the ecological and socio-economic impacts identified in this study were highly context sensitive and were associated mainly with altered production systems rather than with the GM crops per se.
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