- Authors:
- Gobbi, F. C.
- Vanin, J. P.
- Conti, C.
- Dallmeyer, A. U.
- Fey, E.
- Pivetta, L. A.
- Source: Central theme, technology for all: sharing the knowledge for development
- Year: 2008
- Summary: The soil preparation, characterized by intense lossening soil and low straw remaining in the soil surface, it is usually used for the cultivation of cassava and has worried producers, technicians, agronomists and researchers because of the environmental problems associated with this kind of preparation. Thus, this study aimed to evaluate the physical properties of soil proportionate by different tillage systems as well as the performance of a planter of cassava. The experiment was conducted in the municipality of Maripa - PR, in Latosol eutroferrico red. It was used the randomized blocks design with split plot disposition, where the main plots went consist of five tillage systems (tillage system with offset disk harrow, disk plow and chisel plow, conservation tillage with chisel plow in April and no-tillage) and two subplots (fallow and consortium of forage turnip+oats). It was evaluated the cone index, the soil moisture, porosity of air and water, total porosity, soil bulk density, the depth of the seed cuttings of cassava and, the population of plants. The soil tillage with disc plow and chisel plow provided better physical conditions in comparison to the no tillage system. The depth of deposition of the seed cuttings of cassava was lower in no-tillage system and in the coverage with forage turnip+oats. The plants population was not influenced by soil tillage systems and coverages.
- Authors:
- Levien, R.
- Gamero, C. A.
- Furlani, C. E. A.
- Silva, R. P. da
- Cortez, J. W.
- Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
- Volume: 32
- Issue: 1
- Year: 2008
- Summary: To evaluate the effect of soil tillage and management of winter cover crops (black oat+radish intercrop) on the soil temperature, an experiment was conducted in a Nitossol (Alfisol) in Botucatu, state of Sao Paulo, Brazil, in the 2000 autumn/winter season. A design in randomized blocks was used in a 3*3 factorial scheme (three tillage and three cover crop managements). Soil tillage consisted of: conventional tillage, conservation tillage with chiselling, and no-tillage. The cover crops managements included plant killing with post-emergence herbicide, rolling, or shredding. The soil temperature (thermocouples) was evaluated at a depth of 5 cm, every hour, 7, 14, 30, 45, and 60 days after plant emergence; the soil water content at a depth of 10 cm, at the same dates and, the soil surface coverage (dry mass and cover index) were measured immediately after treatment application. Lower soil temperatures were observed in the no-tillage system than under conventional tillage until the 14th day after plant emergence (DAE). From the 30th DAE, the temperature was no longer influenced by the treatments due to the soil cover and sufficient water availability in the soil. The cover managements with plant rolling, shredding, or herbicide had no influence on the soil temperature. The soil temperature did not affect the development of the cover crops.
- Authors:
- Source: Vegetable Crops Research Bulletin
- Volume: 68
- Year: 2008
- Summary: Field experiments were conducted in Poland, on a grey-brown podzolic soil, to assess the yields of scorzonera ( Scorzonera hispanica cv. Einjahrige Riesen) roots in different soil and plant cultivation systems, i.e. ridge and flat cultivation, reduced soil tillage prior to sowing (shallow tillage) and the application of cover crops ( Sinapis alba, Vicia sativa, Phacelia tanacetifolia and Avena sativa) in conservation tillage and no-tillage systems. Reduced spring tillage did not have a negative effect on the yields of scorzonera roots. Cultivation of plants on ridges had a positive effect on the total and marketable yields of roots compared to flat soil cultivation. Mulching with cover crops had a significant influence on the increase in the marketable yield of roots. No-tillage cultivation did not have a negative effect on the total and marketable yields of roots. Reduction in spring tillage prior to sowing, soil mulching and no-tillage cultivation had no negative effects on the inulin content of scorzonera roots. Among the investigated cover crops, Sinapis alba was the most beneficial plant for increasing the inulin content of roots. Cultivation of plants on ridges and flat soil and reduction in spring pre-sowing tillage did not have a significant effect on the protein content of roots. Irrespective of the soil cultivation methods, a significantly higher protein content was found in the roots harvested from the plots mulched with Vicia sativa. The various plant cultivation conditions exerted a considerable influence on nutrient uptake. Roots of the plants cultivated on ridges contained higher amounts of P, K and Ca. Soil mulching created better conditions for nutrient absorption. A significant effect of Sinapis alba in increasing the P and K content of roots was also observed.
- Authors:
- Balkcom, K. S.
- Arriaga, F. J.
- Bergtold, J. S.
- Stoll, M. E.
- Price, A. J.
- Kornecki, T. S.
- Rap, R. L.
- Source: Communications in Biometry and Crop Science
- Volume: 3
- Issue: 1
- Year: 2008
- Summary: Research has shown that some cover crops are allelopathic and can inhibit weed germination and growth. Additionally, negative allelopathic effects have been documented in cash crops planted into cover crop residue. However, little literature exists comparing relative the allelopathic potential of cover crops producers utilize in conservation-agriculture systems. This study assessed the effects of twelve cover crop extracts on radish ( Raphanus sativus L.) and cotton ( Gossypium hirsutum L.) radicle elongation, in three trials, using an extract-agar bioassay. In Trial 1 the cover crops were black oat ( Avena strigosa Schreb) cv. SoilSaver, crimson clover ( Trifolium incarnatum L.) cv. AU Robin, white lupin ( Lupinus albus L.) cvs. AU Homer and AU Alpha, rye ( Secale cereale L.) cv. Elbon, wheat ( Triticum aestivum L.) cv. Vigoro Grazer, and triticale (* Triticosecale Wittmack) cv. Trical 2700. In Trial 2 the cover crops were forage rape ( Brassica napus L. var. napus) cv. Licapo, sunn hemp ( Crotalaria juncea L.), Austrian winter field pea ( Pisum sativum spp. arvense L. Poir), black medic ( Medicago lupilina L.), hairy vetch ( Vicia villosa Roth), black oat cv. SoilSaver, and crimson clover cv. AU Robin. Cotton was evaluated using the same bioassay and all of the cover crops mentioned above in a single trial (Trial 3). All cover crop extracts inhibited radicle elongation compared to water. Allelopathic potential was highly variable among cultivars within a cover crop species, and within a cultivar. Allelopathic differences among cover crops give an additional weed control tool in conservation systems. However, winter cover selection may impact on cash crop performance if producers plant their crop into green residue.
- Authors:
- Wei, C. F.
- Tang, X. H.
- Wang, Z. F.
- Luo, Y. J.
- Gao, M.
- Source: Pedosphere
- Volume: 18
- Issue: 5
- Year: 2008
- Summary: The effect of different tillage systems on the size distribution of aggregates and organic carbon distribution and storage in different size aggregates in a Hydragric Anthrosol were studied in a long-term experiment in Chongqing, China. The experiment included three tillage treatments: conventional tillage with rotation of rice and winter fallow (CT-r) system, no-till and ridge culture with rotation of rice and rape (RT-rr) system, and conventional tillage with rotation of rice and rape (CT-rr) system. The results showed that the aggregates 0.02-0.25 mm in diameter accounted for the largest portion in each soil layer under all treatments. Compared with the CT-r system, in the 0-10 cm layer, the amount of aggregates >0.02 mm was larger under the RT-rr system, but smaller under the CT-rr system. In the 0-20 cm layer, the organic carbon content of all fractions of aggregates was the highest under the RT-rr system and lowest under the CT-rr system. The total organic carbon content showed a positive linear relationship with the amount of aggregates with diameter ranging from 0.25 to 2 mm. The storage of organic carbon in all fractions of aggregates under the RT-rr system was higher than that under the CT-r system in the 0-20 cm layer, but in the 0-60 cm soil layer, there was no distinct difference. Under the CT-rr system, the storage of organic carbon in all fractions of aggregates was lower than that under the CT-r system; most of the newly lost organic carbon was from the aggregates 0.002-0.02 and 0.02-0.25 mm in diameter.
- Authors:
- Diaz Franco, A.
- Salinas Garcia, J. R.
- Garza Cano, I.
- Mayek Perez, N.
- Source: Revista Fitotecnia Mexicana
- Volume: 31
- Issue: 3
- Year: 2008
- Summary: Conservation tillage promotes agricultural soil sustainability and the inoculation of arbuscular mycorrhiza fungi (AMF) enhances crop growth and yields. In this study, single and combined effects of tillage systems and inoculation of AMF on charcoal rot ( Macrophomina phaseolina) incidence and severity, and grain yield in maize ( Zea mays L.) were determined. The study was conducted in semi-arid dryland conditions. Three factors with different levels were tested in maize hybrid 'Pioneer 3025W': four tillage systems (moldboard or conventional tillage, subsoil-bedding, shred-bedding and no-tillage); two fertilization levels (inoculated seeds with AMF Glomus intraradices, and fertilization rate of 60N-40P-00K); and three years of evaluation (2003 to 2005). Chlorophyll leaf index (CI), incidence (IM) and severity (SM) of M. phaseolina, arbuscular mycorrhizal colonization (AMC), and grain yield (GY) were determined. No tillage showed the lowest charcoal rot (IM and SM), but also the lowest GY. Tillage systems did not affect AMC of maize. Inoculation was similar to chemical fertilization in CI, IM, SM and GY, although with increase of AMC on mycorrhization treatment. The highest values CI, lesser IM and SM, and highest GY were found in 2004 due to the highest rain fall (460 mm) compared to 2003 (230 mm) and 2005 (125 mm). Results indicate that conservation tillage is a strategy to reduce charcoal in maize crop, although associated with grain yield losses, respect to conventional tillage.
- Authors:
- Asbjornsen, H.
- Schulte, L. A.
- Tyndall, J.
- Secchi, S.
- Source: Journal of Soil and Water Conservation
- Volume: 63
- Issue: 3
- Year: 2008
- Summary: from conclusion: "A conservation policy based on targeting would bring about benefits for both society and agricultural producers. With the increasing pressures being exerted on agriculture to intensify production at present, we argue that a targeted approach is timely and necessary to maintain-if not increase-the level of agroecosystem services currently provided. The targeted conservation program we outline does just this. It focuses on those portions of watersheds and/or landscapes that provide the greatest ecological benefits and more than adequately compensates farmers for taking land out of production. We further argue that a targeted approach is feasible in light of historical federal expenditures for the farm sector, and farmer compensation would more adequately reflect the quantity or quality of the conservation benefit being produced. The better targeting of resources, rather than increases in their absolute levels, is key in the provision of agroecosystem services under the current high crop price environment."
- Authors:
- Hyberg, S.
- Iovanna, R.
- Feather, C.
- Barbarika, A.
- Year: 2008
- Authors:
- Volume: MS Thesis.
- Year: 2008
- Authors:
- Furtan, W. H.
- Davey, K. A.
- Source: Canadian Journal of Agricultural Economics/Revue Canadienne D'Agroeconomie
- Volume: 56
- Issue: 3
- Year: 2008
- Summary: The adoption of conservation tillage technology since the 1970s has been one of the most remarkable changes in the production of crops on the Canadian Prairies. The decision whether to adopt conservation tillage technology or not requires the producer to go through a thorough decision-making process. In Canada, there has been little economic research on the question of what farm, regional, and environmental characteristics affect the adoption decision. Using 1991, 1996, and 2001 Census of Agriculture data together with other data sources we estimate a probit model explaining the adoption decision. We find that important variables include farm size, proximity to a research station, type of soil, and weather conditions.
