Response to N-fertilizer of Italian ryegrass grown alone and in mixture with berseem clover under continental irrigated mediterranean conditions

[EN] In a field experiment over three growing seasons, the potential benefits of planting berseem clover (Trifolium alexandrinum L) with Westerwold Italian ryegrass (Lolium multiflorum Lam.) were examined under irrigated continental Mediterranean conditions.Similar N rates (0, 30, 60, 90 and 120 kg N ha−1 cut−1) were applied to both pure Italian ryegrass stands and mixtures, each given three successive cuts. One previously unfertilized cut was performed in late winter. Species in the mixture were established at 50:50 seed ratio but the mean proportion of berseem clover was 14%. Mean winter survival of berseem was 87% but 88% of the plants had leaves damaged by the frost. Forage production varied with both N rate and cutting sequence in both the pure stand and the mixture but differences between the two types of swards were significant only at low levels of fertilizer N. Total DM production over the four cuts in plots with N applications of 0,90, 180, 270 and 360 kg N ha−1 a−1 were 7.14, 9.51, 11.66, 13.91 and 14.36 t DM ha−1 a−1 in pure stand, respectively. Corresponding values for the mixture were 8.80, 10.94, 12.90, 14.05 and 13.64 t DM ha−1 a−1. The mean response of Italian ryegrass in the range of 0–360 kg N ha−1 a−1 was 20 kg DM per kg N applied. The corresponding value for the mixture was 13 kg DM per kg N applied. At the berseem clover proportions reached in this work, N equivalence showed values of about 80 kg N ha−1 a−1. As rates of N increased from 0 to 120 kg N ha−1 cut−1, nitrogen concentration increased by 78%. In the applied range of N fertilizers, N03-N was not affected.

Bibliographic Details

Main Authors:	García de Arévalo, Rafael de, Arauzo, Mercedes, Hernáiz, Pedro J.
Format:	artículo biblioteca
Published:	Springer Nature 1994-06
Subjects:	Berseem clover, Fertilizer N, Italian ryegrass, N efficiency, N fractions, N recovery,
Online Access:	http://hdl.handle.net/10261/269333
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