02387naa a2200337 a 450000100080000000500110000800800410001910000190006024501240007926000090020350001630021252011810037565000260155665000240158265000190160665000160162565000230164165300270166465300350169165300300172665300310175665300210178770000180180870000190182670000290184570000190187470000140189370000260190770000250193377300910195820291802017-05-29       2015    bl uuuu     u00u1 u    #d1 aASSMANN, J. M.  aCarbon and nitrogen cycling in an integrated soybean-beef cattle production system under different grazing intensities.  c2015  aTítulo em português: Ciclagem de carbono e nitrogênio em sistema integrado de produção de soja e bovinos de corte sob diferentes intensidades de pastejo.  aThe objective of this work was to evaluate the effect of grazing intensity on the decomposition of cover crop pasture, dung, and soybean residues, as well as the C and N release rates from these residues in a long?term integrated soybean?beef cattle system under no?tillage. The experiment was initiated in 2001, with soybean cultivated in summer and black oat + Italian ryegrass in winter. The treatments consisted of four sward heights (10, 20, 30, and 40 cm), plus an ungrazed area, as the control. In 2009?2011, residues from pasture, dung, and soybean stems and leaves were placed in nylon?mesh litter bags and allowed to decompose for up to 258 days. With increasing grazing intensity, residual dry matter of the pasture decreased and that of dung increased. Pasture and dung lignin concentrations and C release rates were lower with moderate grazing intensity. C and N release rates from soybean residues are not affected by grazing intensity. The moderate grazing intensity produces higher quality residues, both for pasture and dung. Total C and N release is influenced by the greater residual dry matter produced when pastures were either lightly grazed or ungrazed.  aBiogeochemical cycles  aSoil organic matter  aAvena Strigosa  aGlycine Max  aLolium Multiflorum  aCiclagem de nutrientes  aIntegração lavoura-pecuária  aIntegrated crop-livestock  aMatéria orgânica do solo  aNutrient cycling1 aANGHINONI, I.1 aMARTINS, A. P.1 aCOSTA, S. E. V. G. de A.1 aKUNRATH, T. R.1 aBAYER, C.1 aCARVALHO, P. C. de F.1 aFRANZLUEBBERS, A. J.  tPesquisa Agropecuária Brasileira, Brasília, DFgv. 50, n. 10, p. 967-978, out. 2015.