02210naa a2200277 a 450000100080000000500110000800800410001910000170006024501710007726000090024852013520025765000230160965000170163265000080164965000160165765300200167365300170169365300230171070000150173370000200174870000190176870000170178770000220180470000190182677300870184519053542012-01-31       2011    bl uuuu     u00u1 u    #d1 aBRUNETTO, G.  aNutrient release during the decomposition of mowed perennial ryegrass and white clover and its contribution to nitrogen nutrition of grapevine.h[electronic resource]  c2011  aSustainable management of mineral nutrition in vineyards, as well as in other fruit plantations, should aim at exploiting the use of internal sources of nutrients, in order to reduce the need for external nutrient inputs. In this paper we explore the potential of the grassed alleys to provide nutrients to the vines. We followed for one vegetative season the decomposition of ryegrass and clover, frequently present as floor vegetation in vineyards, using litter bags filled with 15N-enriched grass material. In addition, we quantified the amount of nitrogen (N) transferred from the decomposing litter to field-grown grapevines. Ryegrass and clover had a relatively rapid decomposition rate, with a loss of C approaching 80% in only 16 weeks. The release of nutrients was particularly fast for potassium (95% in 16 weeks) followed by nitrogen (80%), calcium (70-80%), phosphorus (65-85%), magnesium (70-75%), and sulfur (60-70%). In spite of the rapid release of N from decomposing material, the N uptake by grapevines was on average less than 4% of the initial amount of N present in the litter of ryegrass and clover. Even if N release during the decomposition of mowed perennial ryegrass and white clover little contributed to the N nutrition of grapevine in the same growing season, most N from mowed grassed was still recovered in the soil.  aNutrição vegetal  aTrevo Branco  aUva  aViticultura  aErva-castelhana  aNitrogêncio  aNutrição mineral1 aVNTURA, M.1 aSCANDELLARI, F.1 aCERETTA, C. A.1 aKAMINSKI, J.1 aMELO, G. W. B. de1 aTAGLIAVINI, M.  tNutrient Cycling in Agroecosystems, Dordrechtgv. 90, n. 3, p. 299?308, jul. 2011.