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Alburquerque M.A.,Federal University of Parana | Dieckow J.,Federal University of Parana | Sordi A.,Federal University of Parana | Piva J.T.,Federal University of Santa Catarina | And 4 more authors.
Soil Use and Management

To identify crop rotation systems capable of sequestering C and N to 1 metre depth in a subtropical Ferralsol of Southern Brazil managed under long-term zero-tillage (21 yrs), we evaluated six crop sequences: wheat (Triticum aestivum)-soybean (Glycine max) [W-S], the baseline; oat (Avena strigosa, as cover crop)-maize (Zea mays)-wheat-soybean [O-M-W-S]; vetch (Vicia villosa, as legume cover crop)-maize-wheat-soybean [V-M-W-S]; vetch-maize-oat-soybean-wheat-soybean [V-M-O-S-W-S]; ryegrass (Lolium multiflorum, for hay)-maize-ryegrass-soybean [R-M-R-S]; and alfalfa (Medicago sativa, for hay)-maize [A-M]. Compared to W-S and to 1 metre, the hay-based system of A-M showed the largest C and N sequestration rates (0.50 and 0.06 Mg/ha/yr, respectively). Alfalfa, being a perennial legume under cut-regrowth cycles, possibly added more C and N through roots. The other hay system, R-M-R-S, also sequestered C efficiently (0.27 Mg/ha/yr), but not N (0.01 Mg/ha/yr). The legume-based system of V-M-W-S sequestered significant amounts of both C (0.29 Mg/ha/yr) and N (0.04 Mg/ha/yr). The grass-based system of O-M-W-S showed the lowest sequestration of C (0.09 Mg/ha/yr). In all systems, a positive relationship (R2 = 0.71) occurred between estimated addition of root C and soil C stock to 1 metre. Whenever C and N sequestration occurred, more than half of that occurred below 20 cm depth. Results suggest that adoption of legume-based systems, perennially as A-M or annually as V-M-W-S, is efficient for C and N sequestration in subtropical zero-tillage soils and that roots possibly contribute more to that sequestration than aboveground biomass. © 2015 British Society of Soil Science. Source

Piva J.T.,Federal University of Parana | Piva J.T.,Federal University of Santa Catarina | Dieckow J.,Federal University of Parana | Bayer C.,Federal University of Rio Grande do Sul | And 7 more authors.
Agriculture, Ecosystems and Environment

We assessed the impact of integrated crop-livestock (CL), with silage maize (Zea mays L.) in summer and grazed annual-ryegrass (Lolium multiflorum Lam.) in winter, and continuous crop (CC), with annual-ryegrass used only as cover-crop, on net greenhouse gas emission from soil (NetGHG-S) in a subtropical Ferralsol of a 3.5-year-old experiment in Brazil. Emissions from animal excreta in CL were estimated. Soil N2O fluxes after N application to maize were higher in CL (max. 181μgN2O-Nm-2h-1) than in CC (max. 132μgN2O-Nm-2h-1). The cumulative annual N2O emission from soil in CL surpassed that in CC by more than three-times (4.26 vs. 1.26kgN2O-Nha-1, p<0.01), possibly because of supplementary N application to grazed ryegrass in CL (N was not applied in cover-crop ryegrass of CC) and a certain degree of soil compaction visually observed in the first few centimetres after grazing. The estimated annual N2O emission from excreta in CL was 2.35kgN2O-Nha-1. Cumulative annual CH4 emission was not affected significantly (1.65 in CL vs. 1.08kg CH4-Cha-1 in CC, p=0.27). Soil organic carbon (OC) stocks were not affected by soil use systems, neither in 0-20-cm (67.88 in CL vs. 67.20Mgha-1 in CC, p=0.62) or 0-100-cm (234.74 in CL vs. 234.61Mgha-1 in CC, p=0.97). The NetGHG-S was 0.652MgCO2-Ceqha-1year-1 higher in CL than in CC. Crop-livestock emitted more N2O than CC and no soil OC sequestration occurred to offset that emission. Management of fertiliser- and excreta-N must be focused as a strategy to mitigate N2O fluxes in CL. © 2013 Elsevier B.V. Source

Araujo M.A.,Federal University of Parana | de Souza J.L.M.,Federal University of Parana | Tsukahara R.Y.,Fundacao ABC para Assistencia e Divulgacao Tecnica Agropecuaria
Acta Scientiarum - Agronomy

The objective of this study was to evaluate the performance of simplified and agrometeorological models in the soybean crop productivity estimate, looking for crop season prediction and planning, in the Ponta Grossa region, Paraná State, Brazil. The soil of the studied region is classified as Typic Hapludox and the climate as Cfb. The soybean crop productivity (11 seasons) and climate data were provided by the ABC Foundation and SIMEPAR, respectively. The reference evapotranspiration was estimated by the Penman-Monteith method and the daily water balances were determined using a program especially developed for this purpose. After innumerable analyses, the best results were obtained when the following were considered: (a) the temporal distribution of real productivity of soybean crop seasons in two groups, which were called 'Year 1' and 'Year 2', according to the experimental crop rotation (b) the fit of model coefficient and factors to multiple regression analyses. The Stewart et al. (1976) and Jensen (1968) models provided the best productivity estimates (R2 > 0.73). Source

Santos N.Z.D.,Federal University of Parana | Dieckow J.,Federal University of Parana | Bayer C.,Federal University of Rio Grande do Sul | Molin R.,Fundacao ABC para Assistencia e Divulgacao Tecnica Agropecuaria | And 3 more authors.
Soil and Tillage Research

To improve C sequestration in no-till soils requires further development of crop rotations with high phytomass-C additions. The objectives of this study were (i) to assess long-term (17 years) contributions of cover crop- or forage-based no-till rotations and their related shoot and root additions to the accumulation of C in bulk and in physical fractions of a subtropical Ferralsol (20-cm depth); and (ii) infer if these rotations promote C sequestration and reach an eventual C saturation level in the soil. A wheat (Triticum aestivum L., winter crop)-soybean (Glycine max (L.) Merr, summer crop) succession was the baseline system. The soil under alfalfa (Medicago sativa L., hay forage) intercropped every three years with maize (Zea mays L., summer crop) had the highest C accumulation (0.44MgCha-1year-1). The bi-annual rotation of ryegrass (Lolium multiflorum Lam., hay winter forage)-maize-ryegrass-soybean had a soil C sequestration of 0.32MgCha-1year-1. Among the two bi-annual cover crop-based rotations, the vetch (Vicia villosa Roth, winter cover crop)-maize-wheat-soybean rotation added 7.58MgCha-1year-1 as shoot plus root and sequestered 0.28MgCha-1year-1. The counterpart grass-based rotation of oat (Avena strigosa Schreb., winter cover crop)-maize-wheat-soybean sequestered only 0.16MgCha-1year-1, although adding 13% more C (8.56Mgha-1year-1). The vetch legume-based rotation, with a relative conversion factor (RCF) of 0.147, was more efficient in converting biomass C into sequestered soil C than oat grass-based rotation (RCF=0.057). Soil C stocks showed a close relationship (R2=0.72-0.98, P<0.10) with root C addition, a poor relationship with total C addition and no relationship with shoot C addition. This suggests a more effective role of root than shoot additions in C accumulation in this no-till soil. Most of the C accumulation took place in the mineral-associated organic matter (71-95%, in the 0-5cm layer) compared to the particulate organic matter. The asymptotic relationship between root C addition and C stocks in bulk soil and in mineral-associated fraction supports the idea of C saturation. In conclusion, forages or legume cover crops contribute to C sequestration in no-till tropical Ferrasols, and most of this contribution is from roots and stored in the mineral-associated fraction. This combination of soil and rotations can reach an eventual soil C saturation. © 2010 Elsevier B.V. Source

Pauletti V.,Federal University of Parana | de Pierri L.,Federal University of Parana | Ranzan T.,Federal University of Parana | Barth G.,Fundacao ABC para Assistencia e Divulgacao Tecnica Agropecuaria | Motta A.C.V.,Federal University of Parana
Revista Brasileira de Ciencia do Solo

The effects of lime and gypsum are widely discussed in the literature, but their magnitude in relation to effects in the soil profile is dependent on the time since application of these inputs. Thus, the aim of this study is to evaluate the effect of long-term application of gypsum and lime on chemical properties of a soil in crop rotation in a no-till system. The experiment was carried out in Jaguariaíva, Paraná state, Brazil, in a sandy loam Latossolo Vermelho-Amarelo distrófico típico (Oxisol), from 2002 to 2008. A randomized block experimental design was used in a factorial arrangement with ten treatments, consisting of five doses of gypsum (0, 1.5, 3.0, 6.0 and 12.0 Mg ha-1) and two doses of lime (0 and 3.42 Mg ha-1) with three replications. The following crops were evaluated over a period of 72 months: black oat (2004, 2006 and 2007), maize (2005/2006), wheat (2003) and soybean (2003/2004, 2004/2005, 2006/2007 and 2007/2008). Soil sampling and soil analysis was carried out in 2005 and 2008 up to a depth of 100 cm, and leaf tissue analysis of the soybean crop in 2007/2008. Liming amended pH, increased the concentration of Ca and Mg and decreased Al in the surface layers of the soil. Gypsum brought about an increase in pH and in the concentrations of Ca and S at greater depth, leached Mg and did not leach K. Liming increased the yield of maize, soybean (one of the four crop seasons evaluated) and black oat. Gypsum favored yield in corn and wheat, and in soybean only when there was water deficit. However, when there was no water stress, high doses of gypsum decreased soybean yield through inducing Mg deficiency. Source

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