• Authors:
    • Fiorin, J.
    • Nicoloso, R.
    • Tornquist, C.
    • Amado, T.
    • Campos, B.
  • Source: Revista Brasileira de Ciencia do Solo
  • Volume: 35
  • Issue: 3
  • Year: 2011
  • Summary: Soil C-CO 2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM). The main soil C-CO 2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO 2 emissions and their relationship with carbon (C) mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Koppen classification), mean annual precipitation of 1,774 mm and mean annual temperature of 19.2degreesC. Treatments consisted of two tillage systems: (a) conventional tillage (CT) and (b) no tillage (NT) in combination with three cropping systems: (a) R0 - monoculture system (soybean/wheat), (b) R1 - winter crop rotation (soybean/wheat/soybean/black oat), and (c) R2 - intensive crop rotation (soybean/black oat/soybean/black oat+common vetch/maize/oilseed radish/wheat). The soil C-CO 2 efflux was measured every 14 days for two years (48 measurements), by trapping the CO 2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO 2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method, with sampling 14, 28, 56, 84, 112, and 140 days after the beginning of the evaluation period for C measurements. Four C conservation indexes were used to assess the relation between C-CO 2 efflux and soil C stock and its compartments. The crop residue C mineralization fit an exponential model in time. For black oat, wheat and maize residues, C mineralization was higher in CT than NT, while for soybean it was similar. Soil moisture was higher in NT than CT, mainly in the second year of evaluation. There was no difference in tillage systems for annual average C-CO 2 emissions, but in some individual evaluations, differences between tillage systems were noticed for C-CO 2 evolution. Soil C-CO 2 effluxes followed a bi-modal pattern, with peaks in October/November and February/March. The highest emission was recorded in the summer and the lowest in the winter. The C-CO 2 effluxes were weakly correlated to air temperature and not correlated to soil moisture. Based on the soil C conservation indexes investigated, NT associated to intensive crop rotation was more C conserving than CT with monoculture.
  • Authors:
    • Hontoria, C.
    • Lammerding, D.
    • Tenorio, J.
    • Walter, I.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 2
  • Year: 2011
  • Summary: It is widely accepted that conservation tillage management affords benefits to soil properties and reduces production costs; therefore these practices could be attractive to farmers from semiarid regions. The objective of this study was to assess the long-term effects of different tillage practices under semiarid conditions on macroaggregate stability (water stable aggregates, WSA), soil organic carbon (SOC), and particulate organic carbon (C-POM) content of an Alfisol from Spain. The experimental design involved a split plot and four randomized blocks in which tillage was the main factor and crop rotation (fallow-wheat-pea-barley) the secondary factor. Three tillage systems were compared: no tillage (NT), minimum tillage (MT), and conventional tillage (CT). Soil samples were collected on November 2006 and October 2007. In November 2006 no significant differences in WSA were found among the tillage treatments. In October 2007, however, the mean WSA in the upper soil layer for the NT was significantly higher, 24%, that in the CT. No significant differences were seen for the subsurface layer. Under NT, the SOC and C-POM values for the surface soil layer were significantly higher than those for the other treatments on both sampling dates. At the subsurface depth, no significant differences were seen in either of these variables. The SOC and C-POM values were more homogeneous throughout the soil profile in the plowed soil than in the NT for which the corresponding values were more stratified. The results show that NT will help improve soil structure and soil fertility, which is particularly relevant to semiarid conditions like the area studied.
  • Authors:
    • Ventrella, D.
    • Giorgio, D.
    • Bovera, F.
    • Lestingi, A.
    • Tateo, A.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 9
  • Issue: 1
  • Year: 2011
  • Summary: A field trial was conducted to evaluate the effects of tillage system and fertilizer N applied to the preceding gramineous rotational crop on horse bean ( Vicia faba L. minor) yield and N uptake, chemical composition and nutritive value. The study took place during the periods 2002-2003 and 2004-2005 within the framework of a long-term experiment started in 1990 and involving a 2-year rotation including triticale and horse bean. The experimental layout was a split-plot design with three replicates and four tillage systems in the main plots. Tillage treatments included conventional tillage (CT), two-layer tillage (TT), surface tillage (ST) and minimum tillage (MT). In the subplots, the three N fertilization rates, applied to the preceding triticale crop, were 0 kg ha -1 (N 0), 50 kg ha -1 (N 50) and 100 kg ha -1 (N 100). Over the whole experimental period, tillage system did not significantly influence horse bean seed yield, N uptake, crude protein content and 48-h in vitro true dry matter digestibility. In spite of many significant interactions among experimental variables, there were comparable results under the different tillage systems, in both the less favourable and more productive years. N fertilization, applied to the preceding gramineous crop, did not exert noteworthy effects on horse bean seed quantiqualitative parameters studied. Continuous reduced tillage management, such as two-layer, surface and minimum tillage, would represent a viable alternative to conventional tillage for horse bean production, under rainfed Mediterranean conditions. In addition to their nutritional significance, these results are of economic and environmental importance, given the interest in adopting reduced tillage systems to limit the risk of soil erosion and degradation. The rate of fertilizer N should be optimized as a function of the production and quality of the preceding cereal crop.
  • Authors:
    • Silva Junior, A.
    • Alves, M.
    • Muraishi, C.
    • Souza, Z.
  • Source: ACTA SCIENTIARUM-AGRONOMY
  • Volume: 33
  • Issue: 3
  • Year: 2011
  • Summary: This study was conducted at the Experimental Station belonging to UNESP Engineering University, Ilha Solteira Campus, based in Selviria, Mato Grosso do Sul State, Brazil, with the aim of evaluating chemical alterations in an Oxisol after being managed for two years with organic and/or chemical fertilization and different tillage systems during the agricultural years of 2004/2005 and 2005/2006. The treatments were: conventional-tillage; chisel tillage and no-tillage; the fertilization treatments were: control (no fertilization); chemical fertilization (300 kg ha -1 from the 20-00-20); organic fertilization (cattle manure - 20 Mg ha -1); organic+1/2 the recommended chemical fertilization for the used crop; 20 and 30 Mg ha -1 of sewage sludge. Soybean was used in the first year and sorghum in the next year, evaluating the soil chemical attributes in four layers. The soil chemical attributes were changed in the first year; the organic fertilization, sewage sludge and organic+chemical fertilization were efficient to change the chemical attributes; the sewage sludge was more efficient in soil P recuperation and, the no-tillage system contributed to soil K increase.
  • Authors:
    • Amarante, I.
    • Machado, J.
    • Fontaneli, R.
    • Santos, H.
  • Source: Pesquisa Agropecuaria Gaucha
  • Volume: 17
  • Issue: 1
  • Year: 2011
  • Summary: The effects of soil management systems and crop rotation on sorghum yield characteristics agronomic were evaluated during the period 2003/04 to 2010/11 at EmbrapaTrigo, Passo Fundo, RS, Brazil. Four soil management systems: (1) no tillage, (2) minimum tillage, conventional tillage using a disk plow and a disk harrow, and (4) conventional using a moldboard and a disk harrow; and three crop rotation system I (wheat/soybean), system II (wheat/soybean and common vetch/sorghum), and system III (wheat/soybean, white oats/soybean and common vetch/sorghum) were compared. An experimental design of blocks at random, with split-plots and three replications, was used. The main plot was formed by the soil management systems, while the split-plot constituted of the crop rotation systems. Minimum tillage and no-tillage presented higher yield of sorghum, while conventional tillage using a moldboard plow remained in intermediate position and tillage using disk plow the lowest yield of sorghum. The yield of sorghum grown after common vetch in system II was higher than yield obtained for sorghum after common vetch in system I. No significant differences were observed in sorghum characteristics agronomic as a result of soil management and crop rotation systems.
  • Authors:
    • Kocyigit, R.
    • Rice, C. W.
  • Source: BULGARIAN JOURNAL OF AGRICULTURAL SCIENCE
  • Volume: 17
  • Issue: 4
  • Year: 2011
  • Summary: The soil surface CO 2 flux is the second largest flux in the terrestrial carbon budget after photosynthesis. Plant root and microbial respiration produce CO 2 in soils, which are important components of the global C cycle. This study determined the amount of CO 2 released during spring wheat ( Triticum aestivum L.) growth under no-till (NT) and conventional tillage (CT) systems. This experiment was conducted at Kansas State University North Agronomy Farm, Manhattan, KS, on a Kennebec silt loam. This study site was previously under dry land continuous corn production with NT and CT for more than 10 years. Spring wheat ( Triticum aestivum L.) was planted with two tillage systems (NT and CT) as four replicates in March. Surface CO 2 flux was measured weekly during plant growth. Soil water content at the surface (5 cm) tended to be greater in NT and decreased from planting to harvest. Soil microbial activity at the surface was usually higher in NT and decreased from planting to harvest, while activity was constant in the deeper depths. The higher microbial activity at the surface of NT occurred after 60 days of planting where soil water content was the most limiting factor on microbial activity. Soil CO 2 flux varied in response to changes in soil water content and the variation and magnitude of the increase was greater at higher soil water contents. Conventional tillage released 20% more CO 2 to the atmosphere compare to NT after 10 years in the North American Great Plains Regions.
  • Authors:
    • Lenssen, A. W.
    • Sainju, U. M.
    • Jabro, J. D.
    • Evans, R. G.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 42
  • Issue: 18
  • Year: 2011
  • Summary: We evaluated the effect of no tillage (NT) and conventional tillage (CT) on soil penetration resistance (PR), bulk density (BD), gravimetric moisture content (MC), and saturated hydraulic conductivity (Ks) during the fallow phase of a spring wheat-fallow rotation. The study was conducted on two soils mapped as Williams loam at the Froid and Sidney sites. Soil measurements were made on 19 May, 23 June, and 4 August 2005 at the Froid site and on 6 June and 8 July 2005 at the Sidney site. Tillage had no effect on either soil properties except on the PR at Sidney. However, soil PR, MC, and BD varied significantly with depth regardless of tillage and location. Further, soil PR and MC varied with the date of sampling at both locations, and PR generally increased with decreased MC at all soil depths. Soil Ks was slightly influenced by tillage at both locations.
  • Authors:
    • Esker, P. D.
    • Jirak-Peterson, J. C.
  • Source: Plant Disease
  • Volume: 95
  • Issue: 5
  • Year: 2011
  • Summary: Corn anthracnose (Colletotrichum graminicola) is an important disease of field coni (Zea mays). Two phases, leaf blight and stalk rot, can reduce yield through either premature leaf senescence or reduced grain harvest due to stalk lodging. Corn residue is an important source of primary inoculum and is increased through cultural practices such as no-tillage and continuous corn cropping, which are common practices in Wisconsin. Field studies conducted at the Arlington Agricultural Research Station (ARS) and the West Madison ARS showed that the incidence and severity of anthracnose leaf blight were higher in continuous-corn crop rotations than in soybean corn rotations (91% higher incidence, 24 to 78% higher severity). Anthracnose stalk rot was marginally affected by tillage in 2008 (P = 0.09), with higher incidence in chisel-plowed treatments. There was a positive association between spring residue cover and anthracnose leaf blight but no association was found between residue and stalk rot. No association was found between anthracnose leaf blight and stalk rot. There was a negative association between anthracnose leaf blight and yield but not between anthracnose stalk rot and yield. Managing residue levels through crop rotation would help to reduce anthracnose leaf blight but further work is needed to elucidate factors that lead to stalk lodging prior to harvest.
  • Authors:
    • Halloran, J. M.
    • Olanya, O. M.
    • Griffin, T. S.
    • Honeycutt, C. W.
    • Larkin, R. P.
    • He, Z.
  • Source: Phytopathology
  • Volume: 101
  • Issue: 1
  • Year: 2011
  • Summary: Four different potato cropping systems, designed to address specific management goals of soil conservation, soil improvement, disease suppression, and a status quo standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics. The status quo system (SQ) consisted of barley under-seeded with red clover followed by potato (2-year). The soil-conserving system (SC) featured an additional year of forage grass and reduced tillage (3-year, barley/timothy-timothy-potato). The soil-improving system (SI) added yearly compost amendments to the SC rotation, and the disease-suppressive system (DS) featured diverse crops with known disease-suppressive capability (3-year, mustard/rapeseed-sudangrass/rye-potato). Each system was also compared with a continuous potato control (PP) and evaluated under both irrigated and nonirrigated conditions. Data collected over three potato seasons following full rotation cycles demonstrated that all rotations reduced stem canker (10 to 50%) relative to PP. The SQ, SC, and DS systems reduced black scurf (18 to 58%) relative to PP; ST reduced scurf under nonirri2ated but not irrigated conditions; and scurf was lower in DS than all other systems. The SQ. SC, and DS systems also reduced common scab (15 to 45%), and scab was lower in DS than all other systems. Irrigation increased black scurf and common scab but also resulted in higher yields for most rotations. SI produced the highest yields under nonirrigated conditions, and DS produced high yields and low disease under both irrigation regimes. Each cropping system resulted in distinctive changes in soil microbial community characteristics as represented by microbial populations, substrate utilization, and fatty acid methyl-ester (FAME) profiles. SI tended to increase soil moisture, microbial populations, and activity, as well result in higher proportions of monounsaturated FAMEs and the FAME biomarker for mycorrhizae (16:1 omega 6c) relative to most other rotations. DS resulted in moderate microbial populations and activity but higher substrate richness and diversity in substrate utilization profiles. DS also resulted in relatively higher proportions of FAME biomarkers for fungi (18:2 omega 6c), actinomycetes, and gram-positive bacteria than most other systems, whereas PP resulted in the lowest microbial populations and activity; substrate richness and diversity; proportions of monounsaturated and polyunsaturated FAME classes; and fungal, mycorrhizae, and actinomycete FAME biomarkers of all cropping systems. Overall, soil water, soil quality, and soilborne diseases were all important factors affecting productivity, and cropping systems addressing these constraints improved production. Cropping system approaches will need to balance these factors to achieve sustainable production and disease management.
  • Authors:
    • Brandenburg, R. L.
    • Shew, B. B.
    • Wilkerson, G. G.
    • Jordan, D. L.
    • Lassiter, B. R.
  • Source: Weed Technology
  • Volume: 25
  • Issue: 4
  • Year: 2011
  • Summary: Experiments were conducted in North Carolina during 2005, 2006, and 2007 to determine peanut and weed response when peanut was planted in strip tillage after desiccation of cereal rye, Italian ryegrass, oats, triticale, wheat, and native vegetation by glyphosate and paraquat before planting with three in-season herbicide programs. Control of common ragweed and yellow nutsedge did not differ among cover crop treatments when compared within a specific herbicide program. Applying dimethenamid or S-metolachlor plus diclosulam PRE followed by imazapic POST was more effective than a chloroacetamide herbicide PRE followed by acifluorfen, bentazon, and paraquat POST. Incidence of spotted wilt in peanut (caused by a Tospovirus) did not differ when comparing cover crop treatments, regardless of herbicide program. Peanut yield increased in all 3 yr when herbicides were applied POST, compared with clethodim only. Peanut yield was not affected by cover crop treatment. Response to cover crop treatments was comparable, suggesting that growers can select cereal rye, Italian ryegrass, oats, or triticale as an alternative to wheat as a cover crop in peanut systems without experiencing differences associated with in-season weed management.