• Authors:
    • Hammond, R.
  • Source: IOBC/WPRS Bulletin
  • Volume: 64
  • Year: 2011
  • Summary: Slugs are often problems in field crops grown using conservation tillage practices in the eastern United States, as well as certain locations in the Midwest and the southern USA, as well as in Canada. Although most concern has been on corn and soybean, reports of problems from dry beans, cotton, oil-seed rape, sunflowers, winter wheat, and fall planted alfalfa are often received. Although most problems are in fields located in the original forested areas of eastern and southern USA, reports are also being received from the Great Plains' grass lands of slug issues in irrigated no-till fields. Overall, slug problems have increased in geographical area as growers in the USA and Canada have adopted conservation tillage practices. As in other areas of the world, determining new methods of slug control is of utmost importance in order to allow growers to continue using conservation tillage practices. In areas that are new to slugs, a primary concern is educating growers on IPM approaches to slug management.
  • Authors:
    • Hartman, J. C.
    • Orozco, R. A.
    • Nippert, J. B.
    • Springer, C. J.
  • Source: Biomass and Bioenergy
  • Volume: 35
  • Issue: 8
  • Year: 2011
  • Summary: Switchgrass ( Panicum virgatum L.) is a broadly adapted warm-season grass species native to most of the central and eastern United States. Switchgrass has been identified as a potential biofuel species because it is a native species that requires minimal management, and has a large potential to sequester carbon underground. Since the 1990's, switchgrass has been bred to produce cultivars with increased biomass and feedstock quality. This review addresses potential ecological consequences of widespread switchgrass cultivation for biofuel production in the central United States. Specifically, this review address the ecological implications of changing use of marginal and CRP land, impacts on wildlife, potentials for disease and invasions, and changes in soil quality through reductions in erosion, decomposition rates, and carbon sequestrations. A central theme of the review is the utility of maintaining landscape heterogeneity during switchgrass biofuel production. This includes implementing harvest rotations, no till farming, and mixed species composition. If negative ecological consequences of switchgrass cultivation are minimized, biofuel production using this species has economical and environmental benefits.
  • Authors:
    • He, Jin
    • Li, HongWen
    • Wang, QingJie
    • Zhang, XiRui
    • Li, Hui
    • Zhang, DongYuan
  • Source: Nongye Jixie Xuebao (Transactions of the Chinese Society of Agricultural Machinery)
  • Volume: 42
  • Issue: 10
  • Year: 2011
  • Summary: According to the problems of few available no-till seeders and residues-blocking and bed-damaging during the seeding of wheat in maize residues cover fields in permanent raised beds (PRB) in northwest oasis farming areas, the new anti-blocking (residue-chopping and throwing by powered L-type hammering blade and residue-cutting by knife type opener) and bed renovation (bed-reshaping by double-wing plough) ideas were put forward. The powered hammering blade no-till wheat seeder for PRB was designed. The key parameters for L-type hammering blade, opener and double-wing plough were determined. The experiment in maize residue cover fields showed that the seeder was effective in solving residues blocking. Compared with 2BMF-5 no-till wheat seeder, the spring wheat yield was similar and bed renovation effect was better with the decreased soil disturbance.
  • Authors:
    • Heddadj, D.
    • Cloarec, M.
  • Source: Options Mediterraneennes. Serie A, Seminaires Mediterraneens
  • Issue: 96
  • Year: 2011
  • Summary: An experimental device has been set up for ten years at the Kerguehennec Experimental Station (Chambre Regionale d'Agriculture de Bretagne) located in Brittany (western France) on the basis of a corn/wheat/rape/wheat rotation. The study, in the western context of France, compares three tillage practices (moldboard plowing, surface tillage and no-tillage) and two nutrient sources (mineral and poultry manure), each management systems repeated three times. The aim of this study was to evaluate the effect of reduced tillage and manure fertilization on the evolution of soil characteristics: porosity, aggregate stability, organic carbon, hydraulic conductivity and earthworm populations. The results show that treatments without plowing know a decline of global porosity on the layer 0-25 cm, particularly in the case of the no-till. Although the abundance and biomass of earthworms are increased in reduced tillage, the decrease of porosity is not compensated. The consequence is the decline of hydraulic conductivity, in the case of the no-till. Surface tillage seems to constitute the best compromise, because it maintains or improves the infiltrability thanks to the improvement of aggregate stability in the surface layer and the protection of soil surface by the presence of a mulch.
  • Authors:
    • Dhaliwal, I. S.
    • Hegazy, R. A.
  • Source: Agricultural Engineering International: the CIGR Journal
  • Volume: 13
  • Issue: 1
  • Year: 2011
  • Summary: The main operational problem in direct drilling of paddy straw residue is the accumulation and wrapping of loose straw within/on the tines and frame of no-till drills and traction problems with the ground wheel. A residue management equipment (RME) is developed to cut and remove paddy straw away from furrow openers of the no-till drill. The equipment consisted of nine parts; each part consisted of two powered wheels, one wheel for cutting the residue and the other wheel for removing them away from no-till drill furrow openers. This equipment was attached with the no-till drill with inverted "T" type furrow opener and the experiments have been conducted to compare the no-till drill with RME and same no-till drill without RME. No-till drill with RME increased the fuel consumption and time required by 29.6% and 13.14%, respectively. Adding RME to the no-till drill decreased the amount of residue clogged by 33% and increased the percentage of cut hill from 14.9 to 63.7%. The average numbers of effective tiller, spike length and plant heights were more for no-till drill with RME. Furthermore, the grain yield was increased by 12.4% for fields with no-drill with RME.
  • Authors:
    • Balkcom, K. S.
    • Burmester, C. H.
  • Source: Better Crops With Plant Food
  • Volume: 95
  • Issue: 3
  • Year: 2011
  • Summary: Increased no-till or reduced tillage within Alabama wheat fields has raised research questions on how the trend might impact optimal N fertilizer rates and timings. Monitoring tiller growth as a means to predict N requirements was another option assessed across major soil types within the region.
  • Authors:
    • Avci, M.
  • Source: Agronomy for Sustainable Development
  • Volume: 31
  • Issue: 2
  • Year: 2011
  • Summary: Central Anatolian soils have high risk of erosion, degradation and intensive cultivation. Consequently, they are in danger of exhausting their agricultural use unless conservation agricultural practices are adopted. Conservation agriculture is a key tool in sustainable production systems throughout the world and is developed around soil management technology that minimizes soil disturbance, maximizes the soil cover and promotes crop diversity to offer benefits to farmers and to the environment. It has been particularly effective at sustaining crop production in semi-arid rain-fed regions such as the Central Anatolian soils, where potential evaporation exceeds precipitation during most months of the year, dry farming is extensively practiced, water and wind erosion is common, and proper application of water- and soil-conserving tillage technology is critical. The area under plow expanded its limits as the number of tractors in agriculture dramatically increased in the 1960s. This is the starting point for inappropriate use of the agricultural land. The conservation agricultural technologies, therefore, are of utmost importance for the region. Common farmers' practices of a fallow-wheat system in the central plateau of Turkey are incompatible with the conservation agriculture concept. The objective of this review is to re-evaluate the performances of the partial and full conservation tillage practices previously tried in the region. This review reached the following conclusions: (1) agreeing with the conservation principles, fall tillage as a primary operation in the fallow phase was found to be useless compared with leaving the land without tillage; (2) therefore, much research has focused on spring tillage as a primary operation and employed conventional, semi-conservative and conservative methods. Results showed that the conventional system, in addition to being ecologically unfriendly, is unprofitable as compared with other conservation practices regarding the updated cost analysis; (3) similarly, tillage depth in primary spring tillage was determined to be shallower than the depths currently practiced by farmers, in agreement with the conservation principles; (4) fallow tillage operations in summer to create dust mulch for eliminating soil moisture loss did not increase the crop yields and soil moisture as compared with chemical fallow; (5) no-till fallow was similar to the conventional clean fallow system in terms of moisture and yield levels. However, no-tillage resulted in 50% reduction in the cost of tillage besides its ecologically-friendly effects; (6) the existing dryland agricultural systems in the plateau should be transformed into or changed toward sustainable systems, although further research is required on residue and stubble management, and integrated weed control methods to drill the soil with high amounts of residue on the field.
  • Authors:
    • Attard, E.
    • Recous, S.
    • Chabbi, A.
    • Berranger, C. de
    • Guillaumaud, N.
    • Labreuche, J.
    • Philippot, L.
    • Schmid, B.
    • Roux, X. le
  • Source: Global Change Biology
  • Volume: 17
  • Issue: 5
  • Year: 2011
  • Summary: Land-use practices aiming at increasing agro-ecosystem sustainability, e.g. no-till systems and use of temporary grasslands, have been developed in cropping areas, but their environmental benefits could be counterbalanced by increased N2O emissions produced, in particular during denitrification. Modelling denitrification in this context is thus of major importance. However, to what extent can changes in denitrification be predicted by representing the denitrifying community as a black box, i.e. without an adequate representation of the biological characteristics (abundance and composition) of this community, remains unclear. We analysed the effect of changes in land uses on denitrifiers for two different agricultural systems: (i) crop/grassland conversion and (ii) cessation/application of tillage. We surveyed potential denitrification (PD), the abundance and genetic structure of denitrifiers (nitrite reducers), and soil environmental conditions. N 2O emissions were also measured during periods of several days on control plots. Time-integrated N 2O emissions and PD were well correlated among all control plots. Changes in PD were partly due to changes in denitrifier abundance but were not related to changes in the structure of the denitrifier community. Using multiple regression analysis, we showed that changes in PD were more related to changes in soil environmental conditions than in denitrifier abundance. Soil organic carbon explained 81% of the variance observed for PD at the crop/temporary grassland site, whereas soil organic carbon, water-filled pore space and nitrate explained 92% of PD variance at the till/no-till site, without any residual effect of denitrifier abundance. Soil environmental conditions influenced PD by modifying the specific activity of denitrifiers, and to a lesser extent by promoting a build-up of denitrifiers. Our results show that an accurate simulation of carbon, oxygen and nitrate availability to denitrifiers is more important than an accurate simulation of denitrifier abundance and community structure to adequately understand and predict changes in PD in response to land-use changes.
  • Authors:
    • Basch, G.
    • Freixial, R.
    • Carvalho, M. de
    • Barros, J. C.
  • Source: Revista de Ciências Agrárias
  • Volume: 34
  • Issue: 1
  • Year: 2011
  • Summary: The study was carried out over 2 years (2007/2008 and 2008/2009) on a private farm in the Alentejo region (Evora), in the South of Portugal where rainfed wheat is sown after the beginning of the autumn rainfall season. The wheat crop was established using no-till which permits the post-emergence application of herbicides at an early weed development stage. To control J. bufonius and different broad-leaved weeds, a mixture of two herbicides was used when the weeds were at the 3-4 pair of leaves development stage. The herbicides applied were mesosulfuron-methyl+iodosulfuron-methyl-sodium+mefenpyr-diethyl (H1) and clortoluron (H2) at two different doses. Best J. bufonius control was achieved with the higher dose of the herbicide H2 and the highest broad-leaved weeds control was obtained when the higher dose of the herbicide H1 was applied. Although no significant differences in grain yield were observed between the different herbicide treatments, there was a tendency for higher grain yields with an increase of control efficacy of Juncus bufonius L.
  • Authors:
    • Baraibar, B.
    • Ledesma, R.
    • Royo-Esnal, A.
    • Westerman, P. R.
  • Source: Crop Protection
  • Volume: 30
  • Issue: 9
  • Year: 2011
  • Summary: Harvester ants from the species Messor barbarus (L.) are important seed predators in semi-arid cereal fields of NE Spain, and can contribute substantially to weed control. However, occasionally they harvest newly sown crop seeds at sowing in autumn, or ripe cereal grains close to harvest in summer, causing yield losses. A preliminary study was conducted in 34 commercial winter cereal fields to measure yield loss, and to identify factors that influence it. The area affected by ants was measured ten days prior to the anticipated harvest date. Ant colony size, nest density, crop height, weed densities and temperatures at sowing were assessed. At sowing, harvester ants did not cause yield losses (0.2% of potential yield on average). At harvest, yield losses were generally low as well (0.6%) although occasionally higher losses were recorded (max. 9.2%). Yield losses significantly increased with increasing nest density, nest size and with number of years of no-till. The results of this study show that in 2009 yield losses caused by M. barbarus were insignificant and more than offset by the benefits provided by the destruction of weed seeds.