• Authors:
    • Ralisch, R.
    • Nakashima, P.
    • Gasparetto, N. V. L.
    • Domingos, M. M. M.
    • Tavares Filho, J.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 33
  • Issue: 6
  • Year: 2009
  • Summary: Structural changes caused by management systems to soil can result in compaction and may change crop root development. With the aim to evaluate the effects of the farming systems on the soil structure by qualitative (cultural profile) and quantitative (soil density) methodologies, a field study was carried out in Maringa, state of Parana, Brazil (23degrees29′S, 51degrees59′W). A conventional tillage system with crop succession of corn ( Zea mays L.) and soybean ( Glycine max) and a no-till system with crop rotation of wheat ( Triticum spp.), corn ( Zea mays L.), common bean ( Phaseolus vulgaris), black oats ( Avena strigosa), and soybean ( Glycine max) established for more than 20 years were evaluated. An area under natural forest near the experimental field was evaluated as reference. After the description of the cultural (soil) profile, deformed samples were collected from the homogeneous soil volumes: two samples under forest, two samples in the no-till system and three samples in the conventional system. The physical and morphologic analyses of the soil structures of the layers 0-20 and 20-40 cm showed: (a) the two different tillage system promoted distinct depths of anthropic horizons; (b) the soil structure affected root distribution; (c) soil compaction under conventional system occurred in vertical and horizontal directions (d) soil structure was best under the no-till system; (e) the cultural profile methodology is efficient in soil morphology evaluations.
  • Authors:
    • Durán Zuazo, V. H.
    • Rodríguez Pleguezuelo, C. R.
    • Arroyo Panadero, L.
    • Martínez Raya, A.
    • Francia Martínez, J. R.
    • Cárceles Rodríguez, B.
  • Source: Pedosphere
  • Volume: 19
  • Issue: 4
  • Year: 2009
  • Summary: Sloping and mountainous olive production systems are widespread, occupying large parts of the Mediterranean landscape prone to water erosion. Soil erosion, runoff, and soil water content patterns over a three-year period were monitored in erosion plots on a mountainside with rainfed olive (Olea europaea cv. Picual) trees under: 1) non-tillage with barley strips of 4 m width (BS); 2) non-tillage with native vegetation strips of 4 m width (NVS); and 3) non-tillage without plant strips (NT). The erosion plots, located in Lanjaron (Granada, south-eastern Spain), on a 30% slope, were 192 m(2) in area. For assessing soil water dynamics in real-time and near-continuous soil water content measurements, multisensor capacitance probes were installed in the middle of plant strips and beneath the olive tree at five soil depths (10, 20, 30, 50, and 100 cm). The highest erosion and runoff rates were measured under NT, with a mean of 17.3 Mg ha(-1) year(-1) and 140.0 mm year(-1), respectively, over the entire study period. The BS and NVS with respect to the NT reduced erosion by 71% and 59% and runoff by 95% and 94%, respectively. In general, greater available soil water content was found under BS than NVS and NT, especially beneath the olive tree canopies. These results supported the recommendation of non-tillage with barley strips in order to reduce erosion and to preserve soil water for trees in traditional mountainous olive-producing areas, where orchards cover vast tracts of land.
  • Authors:
    • Rashakani, M. A.
    • Robati, J.
    • Germi, Y. S.
  • Source: Proceedings 37th International Symposium 'Actual tasks on agricultural engineering', Opatija, Croatia, 10-13 veljače, 2009
  • Year: 2009
  • Summary: Applying the precision planters such as punch planters is one of the methods for increasing yield performance by retaining the conservation tillage advantages. In this study, a type of dibble punch planter with seed plate metering device was designed and constructed for maize planting, and was tested in the field on three soil conditions (tilled, untilled with no residue, untilled with wheat residue) and at three forward speeds (1.5, 3, 4.5 km h -1). Then, the planter performance was evaluated with quality of feed index, miss index, multiple seed index, depth index and radius of contact cross section area in the field. Field test results showed that the second speed (3 km h -1) has relatively higher feed index. The difference of feed index was not significant between tilled soil and untilled soil (with residue) and also between v1 and v2. Also, the difference between the different levels of soil conditions and forward speeds was significant (p
  • Authors:
    • Beber Vieira, F. C.
    • Zanatta, J. A.
    • Piccolo, M. d. C.
    • Costa, F. d. S.
    • Bayer, C.
    • Gomes, J.
    • Six, J.
  • Source: Soil & Tillage Research
  • Volume: 106
  • Issue: 1
  • Year: 2009
  • Summary: It has been shown that cover crops can enhance soil nitrous oxide (N(2)O) emissions, but the magnitude of increase depends on the quantity and quality of the crop residues. Therefore, this study aimed to evaluate the effect of long-term (19 and 21 years) no-till maize crop rotations including grass [black oat (Avena strigosa Schreb)] and legume cover crops [vetch (Vigna sativa L), cowpea (Vigna unguiculata L. Walp), pigeon pea (Cajanus cajan L. Millsp.) and lablab (Dolichos lablab)] on annual soil N(2)O emissions in a subtropical Acrisol in Southern Brazil. Greater soil N(2)O emissions were observed in the first 45 days after the cover crop residue management in all crop rotations, varying from -20.2 +/- 1.9 to 163.9 +/- 24.3 mu g N m(-2) h(-1). Legume-based crop rotations had the largest cumulative emissions in this period, which were directly related to the quantity of N (r(2) = 0.60, p = 0.13)and inversely related to the lignin:N ratio(r(2) = 0.89,p = 0.01) of the cover crop residues. After this period, the mean fluxes were smaller and were closely related to the total soil N stocks (r(2) = 0.96, p = 0.002). The annual soil N(2)O emission represented 0.39-0.75% of the total N added by the legume cover crops. Management-control led soil variables such as mineral N (NO(3)(-) and NH(4)(+)) and dissolved organic C influenced more the N(2)O fluxes than environmental-related variables as water-filled pore space and air and soil temperature. Consequently, the synchronization between N mineralization and N uptake by plants seems to be the main challenge to reduce N(2)O emissions while maintaining the environmental and agronomic services provided by legume cover crops in agricultural systems. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Swanton, C. J.
    • Tardif, F.
    • Hamill, A. S.
    • Sikkema, P. H.
    • Gulden, R. H.
  • Source: Weed Science
  • Volume: 57
  • Issue: 6
  • Year: 2009
  • Summary: Glyphosate-resistant (GR) crops have been adopted rapidly since their commercial introduction, and with the increase in commercially available crops resistant to glyphosate, continuous use of the same herbicide mode of action is now possible in some crop rotations. A 6-yr study was initiated to investigate the effects of conventional herbicides compared with continuous use of gyphosate in GR or Roundup Ready corn and GR soybean in a corn-soybean and a corn-soybean-winter wheat rotation. Individual experiments were fully phased and established at three locations under conventional tillage (CT) and at two locations under no-tillage (NT). Results indicated that midseason weed ground cover was lower when weeds were controlled with glyphosate; however, in most cases, this did not result in improved corn or soybean yields. Within locations, species richness, which strongly influenced other diversity indicators, was most affected by the herbicide treatments. Including winter wheat in the crop rotation had little effect on corn and soybean weed ground cover, density, and community structure and only affected soybean yield. Moreover, no effects of herbicide system used in previous corn and soybean were observed in winter wheat, with the exception of species diversity in NT, where species diversity tended to be greater when weeds in previous corn and soybean were treated with conventional herbicides. After 6 yr, the effects of continuous use of GR crops in rotation were similar to those reported in previous Studies; however, continued monitoring and longer-term investigations of these systems are necessary to detect the early stages of development of herbicide-resistant biotypes.
  • Authors:
    • Kpomblekou-A, K.
    • Hamido, S. A.
  • Source: Soil & Tillage Research
  • Volume: 105
  • Issue: 2
  • Year: 2009
  • Summary: Increasing numbers of vegetable growers are adopting conservation tillage practices and including cover crops into crop rotations. The practice helps to increase or maintain an adequate level of soil organic matter and improves vegetable yields. The effects of the practices, however, on enzyme activities in southeastern soils of the United States have not been well documented. Thus, the objectives of the study were to investigate the effects of cover crops and two tillage systems on soil enzyme activity profiles following tomato and to establish relationships between enzyme activities and soil organic carbon (C) and nitrogen (N). The cover crops planted late in fall 2005 included black oat (Avena strigosa), crimson clover (Trifolium incarnatum L.), or crimson clover-black oat mixed. A weed control (no cover crop) was also included. Early in spring 2006, the plots were disk plowed and incorporated into soil (conventional tillage) or mowed and left on the soil surface (no-till). Broiler litter as source of N fertilizer was applied at a rate of 4.6 Mg ha(-1), triple super phosphate at 79.0 kg P ha(-1), and potassium chloride at 100 kg K ha(-1) were also applied according to soil testing recommendations. Tomato seedlings were transplanted and grown for 60 days on a Marvyn sandy loam soil (fine-loamy, kaolinitic, thermic Typic Kanhapludults). Ninety-six core soil samples were collected at incremental depths (0-5, 5-10, and 10-15 cm) and passed through a 2-mm sieve and kept moist to study arylamidase (EC 3.4.11.2), L-asparaginase (EC 3.5.1.1), L-glutaminase (EC 3.5.1.2), and urease (EC 3.5.1.5) activities. Tillage systems affected only L-glutaminase activity in soil while cover crops affected activities of all the enzymes studied with the exception of urease. The research clearly demonstrated that in till and no-till systems, L-asparaginase activity is greater (P
  • Authors:
    • Clayton, G. W.
    • Turkington, T. K.
    • Irvine, R. B.
    • O'Donovan, J. T.
    • Harker, K. N.
  • Source: Weed Science
  • Volume: 57
  • Issue: 3
  • Year: 2009
  • Summary: Wild oat causes more crop yield losses and accounts for more herbicide expenditures than any other weed species on the Canadian Prairies. A Study was conducted from 2001 to 2005 at four Canadian Prairie locations to determine the influence of repeated cultural and herbicidal management practices on wild oat Population density, biomass, and seed production, and on barley biomass and seed yield. Short or tall cultivars of barley were combined with normal or double barley seeding rates in continuous barley or a barley-canola-barley-field-pea rotation under three herbicide rate regimes. The same herbicide rate regime was applied to the same plots in all crops each year. In barley, cultivar type and seeding rate were also repeated on the same plots year after year. Optimal Cultural practices (tall cultivars, double seeding rates, and crop rotation) reduced wild oat emergence, biomass, and seed production, and increased barley biomass and seed yield, especially at low herbicide rates. Wild oat seed production at the quarter herbicide rate was reduced by 91, 95, and 97% in 2001, 2003, and 2005, respectively, when call barley cultivars at double seeding rates were rotated with canola and field pea (high management) compared to short barley cultivars at normal seeding rates Continuously planted to barley (low management). Combinations of favorable cultural practices interacted synergistically to reduce wild oat emergence, biomass and seed production, and to increase barley yield. For example, at the quarter herbicide rate, wild oat biomass was reduced 2- to 3-, 6- to 7-, or 19-fold when optimal single, double, or triple treatments were combined, respectively. Barley yield reductions in the low-management scenario were somewhat compensated for by full herbicide rates. However, high management at low herbicide rates often produced more barley than low management in higher herbicide rate regimes.
  • Authors:
    • Gao, H. W.
    • Liu, L. J.
    • Li, H. W.
    • Wang, Q. J.
    • He, J.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: In the annual double cropping areas of North China Plain, low crop yield and water availability are the main limiting factors to crop production. Conservation tillage has been proposed to improve water conservation and sustain soil productivity. The objectives of the study were to compare conservation tillage (CT) with conventional tillage (CV) under the current double cropping system of corn-winter wheat in the Hebei, North China Plain. The field study consisted of eight conservation tillage treatments and two conventional tillage treatments, with different surface ground cover (0%, 50% and 100%). The tillage treatments consisted of no-till, subsoiling, rototilling and plowing. The CT treatments maintained soil temperatures that were approximately 0.4degreesC greater during cold condition and about 0.5degreesC lower during warm condition at 5 and 10 cm soil depths than the CV treatments, respectively. The greatest differences were achieved by the double no-till system with 100% residue cover treatment in terms of soil temperature and crop growth. Winter wheat yield and water use efficiency (WUE) were improved by 6.7% and 30.1% with CT compared to the CV treatments, and for corn, 8.9% and 6.8%, respectively. We conclude that conservation tillage for the annual double cropping system is feasible, and the double no-till with 100% residue cover is the most effective way of improving crop yields and WUE on the North China Plain.
  • Authors:
    • de Alba, S.
    • Benito, G.
    • Lacasta, C.
    • Alcázar, M.
    • Alba, S. de
  • Source: Advances in Geoecology or Land degradation and rehabilitation: dryland ecosystems. Papers presented at the Fourth International Conference on Land Degradation, Cartagena, Murcia, Spain, 12-17 September 2004.
  • Volume: 40
  • Year: 2009
  • Summary: In Europe, especially in the Mediterranean area, water erosion seriously affects 50% to 70% of agricultural land. However, there is a lack of field-data on water erosion rates for agricultural areas in semiarid Mediterranean climates. This paper describes an experimental field station (La Higueruela Station) for the continuous monitoring of water erosion that was set up in 1992 in central Spain (Toledo, Castilla-La Mancha). In the study area, the annual precipitation is around 450 mm with a very irregular inter-annual and seasonal distribution, which includes a strong drought in summer. The geology is characterized by non-consolidated Miocene materials, mostly arcosics. The area presents a low relief and gentle slopes, generally
  • Authors:
    • Steinbach, H. S.
    • Alvarez, R.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: The Argentine Pampas is one of the most important cropping regions of the World. Limited tillage systems, and specially no-till, had widespread in recent years, occupying actually around 70% of the surface devoted to annual crops. We review results produced in field experiments installed along the Pampas to determine the effect of the adoption of these tillage systems on some soil properties and crops yield. It was performed a meta-analysis of data from experiments where plow tillage (mouldboard plow), reduced tillage (chisel plow, disk plow or harrow disk) and no-till were compared. Treatments effects were contrasted by paired t-tests between groups of paired data. Soil bulk density and cone penetration resistance of the 0-20 cm layer were higher under limited tillage systems than under plow tillage. Increases of bulk density under no-till in comparison to plow tillage were generally small, averaging 4%, but cone penetration increased by 50% in many soils. The increase of bulk density was greater in soils of initial low bulk density. Neither bulk density increases nor cone penetration changes reached critical threshold for roots development. Aggregate stability and water infiltration rate were higher in soils subjected to limited tillage systems than under plow tillage. The improvement of aggregate stability was higher in poorer structured soils, with an average increase of 70% under no-till in relation to plow tillage. Under no-till infiltration rate doubled in average that of plow tillage. Soil water content during the critical periods of sowing and flowering was generally greater under limited tillage but, conversely, nitrate nitrogen levels were greater in plow tillage. Higher soil water content under no-till in relation to plow tillage may satisfied the evapotranspiration demand of 1-3 days of crops during the critical flowering period, being nitrate nitrogen in average 21 kg ha -1 lower under no-till. Soybean ( Glycine max (L.)-Merr.) yield was not affected by tillage system, meanwhile wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields were lower under reduced tillage and no-till than under plow tillage without nitrogen fertilization. Wheat and corn no-till yields were 10-14% lower that yields under plow tillage as a mean. When fertilizers were applied, wheat and corn yield differences between tillage treatments generally disappeared. The adoption of limited tillage systems in the Pampas leads to soil improvement but also generates the necessity of increase nitrogen fertilizers utilization to sustain yields of graminaceus crops.