• Authors:
    • Brenneman, T.
    • Sorensen, R.
    • Lamb, M.
  • Source: Peanut Science
  • Volume: 37
  • Issue: 1
  • Year: 2010
  • Summary: Strip tillage with various crop covers in peanut ( Arachis hypogaea, L.) production has not shown a clear yield advantage over conventional tillage, but has been found to reduce yield losses from some diseases. This study was conducted to determine pod yield and disease incidence between two tillage practices, five winter cover crops, three peanut cultivars, and three fungicide programs. Conventional and strip tillage treatments were implemented on a Greenville sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults) near Shellman, GA. Five winter cereal grain cover crops (strip tillage) and a no-cover crop treatment were sprayed at recommended (1R), half recommended (0.5R) or untreated (0R) fungicide programs. Within peanut cultivars, leaf spot ( Cercospora arachidicola Hori) intensity decreased as the number of fungicide applications increased; however, stem rot ( Sclerotium rolfsii) incidence was the same for the 1R and 0.5R fungicide programs but increased 0R program. Conventional tilled peanuts developed more leaf spot compared with strip tillage. There was no difference in leaf spot ratings among winter crop covers. There was no difference in stem rot incidence with tillage or winter cover crop. There was no yield difference with peanut cultivar. Pod yield was the same for the 1R and 0.5R fungicide program (3867 kg/ha) but decreased at the 0R fungicide program (2740 kg/ha). Pod yield was greater with conventional tillage and strip tillage with black oats ( Avena sativa L.) (3706 kg/ha) compared with strip tillage of other winter crop cover treatments (3358 kg/ha). Conventional tillage had more leaf spot, equal incidence of stem rot, and higher yield compared with strip tillage. The 0.5R fungicide program had the same yield compared with the 1R fungicide program implying a possible 50% savings on fungicide applications on well rotated fields with lower disease risk.
  • Authors:
    • Claupein, W.
    • Mohring, J.
    • Bühler, A.
    • Gruber, S.
  • Source: European Journal of Agronomy
  • Volume: 33
  • Issue: 2
  • Year: 2010
  • Summary: Conventional tillage systems with high soil disturbance are being steadily replaced by tillage systems with low or no soil disturbance. An approach using three methodological steps (greenhouse, deliberate seed burial and field) revealed the long-term vertical distribution and losses of a soil seed bank as effects of different tillage operations. Seeds (oilseed rape; Brassica napus L.) and seed substitutes (plastic pellets) acted as models for a seed bank. (a) A pot experiment in the greenhouse showed that emergence rates were highest in soil depths of 1-5 cm. Germination and emergence was clearly reduced in depths of 0 and 7 cm, and emergence was completely inhibited at 12 cm. About 40-50% of seeds fell dormant in 0 and 12 cm depth, while almost no seeds fell dormant in 1-7 cm depth. (b) The high-dormancy variety Smart persisted to a high extent (60% of the initial seed number), but only 8% of seeds of the low-dormancy variety Express persisted over 4.5 years, after deliberate seed burial. Seed persistence was similar in all soil depths of 0-10 cm, 10-20 cm, and 20-30 cm. (c) The field experiment lasted from 2004 to 2009 and had different tillage treatments of inversion and non-inversion tillage: stubble tillage immediately after harvest combined with primary tillage by mouldboard plough (SP), chisel plough (SC), or rototiller (SRTT); primary tillage without stubble tillage by mouldboard plough (P), chisel plough (C); or no tillage (NT). The seed bank from an artificial seed rain of 20,000 seeds m -2 was significantly higher in all treatments with immediate stubble tillage, and clearly declined over time. However, seed bank depletion was slow once a seed bank had been established. The distribution of oilseed rape seeds and plastic pellets (7000 pellets m -2 broadcast) tended to equalise over the soil layers of 0-10, 10-20 and 20-30 cm over the course of five years. Since seed bank depletion was not attributable to a specific soil depth, shallow and low disturbance tillage did not generally result in a high seed persistence. More important than the depth was the timing of tillage. Though no-till systems provided conditions for seeds to fall dormant at the soil surface to a small extent, the effect lasted only for a limited time. Seed substitutes can be well used in methodological approaches to picture movement of seeds in the soil in order to optimize tillage strategies in agricultural practice.
  • Authors:
    • Duroueix, F.
    • Sauzet, G.
    • Lieven, J.
  • Source: 21ème Conférence du COLUMA. Journées Internationales sur la Lutte contre les Mauvaises Herbes, Dijon, France, 8-9 décembre, 2010
  • Year: 2010
  • Summary: CETIOM evaluated cultural methods during the intercropping period in the Berry region. Shallow tillage before winter oilseed rape (WOSR) or before winter barley were not effective to stimulate weed germination. Before winter wheat drilling, it gave whole satisfaction. Other results indicated a back-effect of the cultivation before WOSR establishment on the autumnal infestation of Crane's-bills. Deep cultivation (10-15 cms), realized a few weeks preceding the WOSR drilling, amplified the autumnal weed emergence, probably by bringing old seeds from depth to the surface and by breaking their dormancy. In comparison, a very shallow cultivation sharply reduced the subsequent weed infestation in the WOSR. Finally, if the interest of no-till drilling to limit the weed emergence was confirmed, that of the delayed drilling was not attested.
  • Authors:
    • Franti, T. G.
    • Drijber, R. A.
    • Wortmann, C. S.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 4
  • Year: 2010
  • Summary: Continuous no-till (NT) can be beneficial relative to tillage with fewer field operations, reduced erosion, and surface soil improvement. Field research was conducted at two locations for 5 yr in eastern Nebraska to test the hypotheses that one-time tillage of NT can result in increased grain yield, reduced stratification of soil properties persisting for at least 5 yr, a net gain in soil organic carbon (SOC), and a restoration of the soil microbial community to NT composition. Stratification of soil test P, SOC, and bulk density was similar for all tillage treatments at 5 yr after tillage. Water stable soil aggregates (WSA) were not affected by tillage treatments except that there was more soil as macroaggregates at one location in the 5- to 10-cm depth with moldboard plow tillage (MP) compared with NT. Tillage treatments had no effect on SOC mass in the 0- to 30-cm depth. Soil microbial biomass was greater at the 0- to 5-cm compared with the 5- to 10-cm depth. Biomass of bacteria, actinomycetes, and arbuscular mycorrhizal fungi was greater with NT compared with one-time MP at one location but not affected by the one-time tillage at the other location. Microbial community structure differed among tillage treatments at the 0- to 5-cm depth at one location but not at the other location. Grain yield generally was not affected by tillage treatment. One-time tillage of NT can be done without measureable effects on yield or soil properties.
  • Authors:
    • Antle, J.
    • Ogle, S.
    • Paustian, K.
    • Basso, B.
    • Grace, P. R.
  • Source: Australian Journal of Soil Research
  • Volume: 48
  • Issue: 8
  • Year: 2010
  • Authors:
    • Liu,C. W.
    • James,D. C.
    • Carter,M. R.
    • Cade-Menun,B. J.
  • Source: Journal of Environmental Quality
  • Volume: 39
  • Issue: 5
  • Year: 2010
  • Summary: In many regions, conservation tillage has replaced conventional tilling practices to reduce soil erosion, improve water conservation, and increase soil organic matter. However, tillage can have marked effects on soil properties, specifically nutrient redistribution or stratification in the soil profile. The objective of this research was to examine soil phosphorus (P) forms and concentrations in a long-term study comparing conservation tillage (direct drilling, "No Till") and conventional tillage (moldboard plowing to 20 cm depth, "Till") established on a fine sandy loam (Orthic Humo-Ferric Podzol) in Prince Edward Island, Canada. No significant differences in total carbon (C), total nitrogen (N), total P, or total organic P concentrations were detected between the tillage systems at any depth in the 0- to 60-cm depth range analyzed. However, analysis with phosphorus-31 nuclear magnetic resonance spectroscopy showed differences in P forms in the plow layer. In particular, the concentration of orthophosphate was significantly higher under No Till than Till at 5 to 10 cm, but the reverse was true at 10 to 20 cm. Mehlich 3-extractable P was also significantly higher in No Till at 5 to 10 cm and significantly higher in Till at 20 to 30 cm. This P stratification appears to be caused by a lack of mixing of applied fertilizer in No Till because the same trends were observed for pH and Mehlich 3-extractable Ca (significantly higher in the Till treatment at 20 to 30 cm), reflecting mixing of applied lime. The P saturation ratio was significantly higher under No Till at 0 to 5 cm and exceeded the recommended limits, suggesting that P stratification under No Till had increased the potential for P loss in runoff from these sites.
  • Authors:
    • Caesar-TonThat, T.
    • Wright, S. F.
    • Sainju, U. M.
    • Kolberg, R.
    • West, M.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a Changing World, Brisbane, Australia, 1-6 August 2010. Congress Symposium 2: Soil ecosystem services
  • Year: 2010
  • Summary: Lentil ( Lens culinaris Medikus CV. Indianhead) used to replace fallow in spring-wheat ( Triticum aestivum) rotation in the semi-arid Eastern Montana USA, may improve soil quality. We evaluate the 14 years influence of continuous wheat under no-tillage (WNT), fallow-wheat under conventional tillage (FCT) and no-tillage (FNT), lentil-wheat under tillage (LCT) and no-tillage (LNT) on soil formation and stability, and on the amount of immunoreactive easily-extractable glomalin (IREEG) and soil aggregating basidiomycete fungi in the 4.75-2.00, 2.00-1.00, 1.00-0.50, 0.50-0.25, and 0.25-0.00 mm aggregate-size classes, at 0-5 cm soil depth. The 4.75-2.00 mm aggregate proportion was higher in LNT than FNT and higher in LT than FT treatments and mean weight diameter (MWD) was higher when lentil was used to replace fallow under NT. No-till systems had higher glomalin and basidiomycete amount than CT in all aggregate-size classes and glomalin was higher in LNT than FNT in aggregate-size classes less than 0.50 mm. We conclude that residue input in NT systems triggers fungal populations which are involved in soil binding in aggregates, and that replacing fallow by lentil in spring wheat rotation in dryland seems to favor aggregate formation/stability under NT probably by increasing N fertility during the course of 14 years.
  • Authors:
    • Dejoux, J. F.
    • Aubinet, M.
    • Bernhofer, C.
    • Bodson, B.
    • Buchmann, N.
    • Carrara, A.
    • Cellier, P.
    • Di Tommasi, P.
    • Elbers, J. A.
    • Eugster, W.
    • Gruenwald, T.
    • Jacobs, C. M. J.
    • Jans, W. W. P.
    • Jones, M.
    • Kutsch, W.
    • Lanigan, G.
    • Magliulo, E.
    • Marloie, O.
    • Moors, E. J.
    • Moureaux, C.
    • Olioso, A.
    • Osborne, B.
    • Sanz, M. J.
    • Saunders, M.
    • Smith, P.
    • Soegaard, H.
    • Wattenbach, M.
    • Ceschia, E.
    • Beziat, P.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 139
  • Issue: 3
  • Year: 2010
  • Summary: The greenhouse gas budgets of 15 European crop sites covering a large climatic gradient and corresponding to 41 site-years were estimated. The sites included a wide range of management practices (organic and/or mineral fertilisation, tillage or ploughing, with or without straw removal, with or without irrigation, etc.) and were cultivated with 15 representative crop species common to Europe. At all sites, carbon inputs (organic fertilisation and seeds), carbon exports (harvest or fire) and net ecosystem production (NEP), measured with the eddy covariance technique, were calculated. The variability of the different terms and their relative contributions to the net ecosystem carbon budget (NECB) were analysed for all site-years, and the effect of management on NECB was assessed. To account for greenhouse gas (GHG) fluxes that were not directly measured on site, we estimated the emissions caused by field operations (EFO) for each site using emission factors from the literature. The EFO were added to the NECB to calculate the total GHG budget (GHGB) for a range of cropping systems and management regimes. N2O emissions were calculated following the IPCC (2007) guidelines, and CH4 emissions were estimated from the literature for the rice crop site only. At the other sites, CH4 emissions/oxidation were assumed to be negligible compared to other contributions to the net GHGB. Finally, we evaluated crop efficiencies (CE) in relation to global warming potential as the ratio of C exported from the field (yield) to the total GHGB. On average, NEP was negative (-284 +/- 228 gC m(-2) year(-1)), and most cropping systems behaved as atmospheric sinks, with sink strength generally increasing with the number of days of active vegetation. The NECB was, on average, 138 +/- 239 gC m(-2) year(-1), corresponding to an annual loss of about 2.6 +/- 4.5% of the soil organic C content, but with high uncertainty. Management strongly influenced the NECB, with organic fertilisation tending to lower the ecosystem carbon budget. On average, emissions caused by fertilisers (manufacturing, packaging, transport, storage and associated N2O emissions) represented close to 76% of EFO. The operation of machinery (use and maintenance) and the use of pesticides represented 9.7 and 1.6% of EFO, respectively. On average, the NEP (through uptake of CO2) represented 88% of the negative radiative forcing, and exported C represented 88% of the positive radiative forcing of a mean total GHGB of 203 +/- 253 gC-eq m(-2) year(-1). Finally, CE differed considerably among crops and according to management practices within a single crop. Because the CE was highly variable, it is not suitable at this stage for use as an emission factor for management recommendations, and more studies are needed to assess the effects of management on crop efficiency.
  • Authors:
    • Mary, B.
    • Laurent, F.
    • Aubrion, G.
    • Fontaine, A.
    • Kerveillant, P.
    • Beaudoin, N.
    • Constantin, J.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 135
  • Issue: 4
  • Year: 2010
  • Summary: Improved agricultural practices are encouraged to reduce nitrate leaching and greenhouse gas emissions. However, the effects of these practices are often studied at annual or rotation scale without considering their long-term impacts. We have evaluated the effects of catch crops (CC), no-till (NT) and reduced nitrogen fertilization (N-) on nitrogen fate in soil-plant system during 13-17 years in three experiments in Northern France. CC were present in all sites whereas tillage treatment and N fertilization rate were tested separately at one site. Crop biomass, N uptake and N leaching were monitored during the whole period. The N balance, i.e. the difference between N inputs and crop exportations, was only affected by fertilization rate whereas leached N varied with all techniques. CC was the most efficient technique to decrease N leaching (from 36 to 62%) and remained efficient on the long term. NT and N- had a positive but smaller impact. N storage in soil organic matter was markedly increased by CC (by 10-24 kg ha -1 yr -1), decreased by N- (-7.3 kg ha -1 yr -1) and not significantly affected by NT. The differences in gaseous N losses (denitrification+volatilization) between treatments were assessed by nitrogen mass balance. CC establishment had no significant effect on N gaseous emissions while NT increased them by 3.60.9 kg N ha -1 yr -1 and N- reduced them by 13.64.6 kg N ha -1 yr -1. Catch crops appear as a win/win technique with respect to nitrate leaching and C and N sequestration in soil.
  • Authors:
    • Piccolo, M. de C.
    • Feigl, B. J.
    • Cerri, C. C.
    • Cerri, C. E. P.
    • Frazao, L. A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 135
  • Issue: 3
  • Year: 2010
  • Summary: The Brazilian Cerrado soils were incorporated into the agricultural production process in the 1970s. The introduction of pastures and/or annual crops utilizing different management systems produced changes in the dynamics of soil organic matter. This study evaluated the microbial attributes of a Typic Quartzipsamment (Arenosols in FAO classification) in native vegetation, pastures, and soybean cultivation under conventional (CT) and no-till (NT) systems. The soil samples (0-5, 5-10 and 10-20 cm layers) were collected in July 2005 and February 2006 from different systems: native Cerrado (CE), CT for 4 years with soybean (CT4 S), CT for 4 years with soybean in rotation with millet (CT4 S/M), an area that has been under pasture for 22 years (PA22), and an area that remained under pasture for 13 years, followed by NT with soybean in rotation with millet for 5 years (NT5). Soil inorganic N (nitrate and ammonium), microbial C and N and basal respiration were determined. The soil metabolic quotient (qCO 2) and the C mic:C org ratios were calculated. The predominant form of inorganic N in the native Cerrado (CE) and in the pasture area (PA22) was ammonium, while the conventional system (CT4 S/M) and no-till system (NT5) areas presented higher nitrogen availability for crops in the form of nitrate. The microbial C and N concentrations increased in the wet season, and the highest values were found in the Cerrado (CE) and in pasture (PA22) areas, where the permanent soil cover and the lack of soil disturbance by agricultural practices allowed more favorable conditions for microbial development. The CT4 S area presented the highest qCO 2 index and the lowest C mic:C total ratio, indicating that the conversion of total carbon into microbial carbon is less efficient in this system. Since sandy soils are more susceptible to degradation, the use of more conservationist management systems promotes more favorable conditions to microbial development and maintenance.