Published online by Cambridge University Press: 03 October 2008
The response of Italian ryegrass (IRG) to nitrogen fertilization, irrigation frequency and harvest interval indicated that management of nitrogen and water is the determinant of productivity under semi-arid northern Mexican conditions. Where water is non-limiting the effects of harvest interval can be eliminated. A soil moisture balance model indicated the inadvisability of seeding IRG in sandy soils if water is a scarce resource because of the high frequency of irrigation that would be required. The seeding (September) and late production (April) periods were identified as critical in regard to irrigation need and limiting in terms of the area that it would be possible to seed.