northwestern Europe) normally result in well-filled kernels with a low protein concentration (Gooding and Mediterranean areas are suitable for the production of high quality Davies, 1997). Temperature and rainfall conditions of bread-making wheat (Triticum aestivum L.) because of the high temperatures during grain filling. Wheat quality is also influenced by Mediterranean regions, such as those in southern Euvariety and can be enhanced through the use of N fertilizer. However, rope, are characterized by dry, hot summers alternating N fertilization can increase residual soil NO Ϫ 3 after harvest. The purwith humid and temperate winters (Nahal, 1991; Acevpose of this study was to evaluate the effect of supplemental topedo et al., 1999) leading to shorter grain-filling period, dressed N fertilizer on quality and production of high quality breadlower grain yields, and higher protein concentrations in making wheat and on residual soil NO Ϫ 3 under irrigated Mediterranean grain (Borghi, 1997; Ló pez-Bellido et al., 1998). This conditions. Field experiments were conducted at two sites during two climate offers the opportunity for production of high growing seasons on Calcixeroclic Xerochrept soils of the Ebro Valley quality bread wheat, which is lacking in the European (Spain). Five N treatments (100, 200, and 300 kg N ha Ϫ1 applied at Union (Borghi et al., 1997; Corbellini et al., 1998). the end of tillering and 150 or 250 kg N ha Ϫ1 at the end of tillering Nitrogen fertilization management offers the opporplus 50 kg ha Ϫ1 foliar-applied N at the end of the boot stage) were imposed on two cultivars. Topdressed N increased yields, when in-tunity for increasing wheat protein content and quality. creasing from 100 kg N ha Ϫ1 to higher rates only, in soils with low Reports show that N applications combined with a betresidual NO Ϫ 3 . However, N fertilization increased grain protein conter distribution of N during the wheat cycle significantly tents for all locations and years and bread quality parameters but improves bread-making quality (Wuest and Cassman, with a greater effect in soils with low soil NO Ϫ 3 . Residual soil NO Ϫ 3 1992; Gate, 1995; Borghi et al., 1997; Gooding and Daafter harvest increased little with increasing N rates. Grain protein, vies, 1997). These reports also show that delayed appliyield, and quality varied depending mainly on the year and amount cation of N within the growing season favors protein of precipitation during grain filling. A topdress N rate of 200 kg N buildup in the grain over yield and enhances the breadha Ϫ1 would be the most appropriate way to produce high quality making quality of the flour. Bread-making quality inbread-making wheat and minimize the risk of NO Ϫ 3 leaching.

kg Ϫ1 , using short-season dormant or semidormant cultivars with reported annual DM yields of alfalfa that Potassium fertilization rates for alfalfa (Medicago sativa L.) have ranged generally between 10 and 15 Mg ha Ϫ1 in three been increasing with intensive cropping systems or decreasing with policies that generally lead to reduced fertilizer inputs. In this case, to four harvests per season (Markus and Battle, 1965; nutrient buildup or maintenance of high soil test levels may not be Lutz, 1973; Smith, 1975; Rominger et al., 1976; Fixen desirable and drawdown of K reserves may be beneficial in the short and Ludwick, 1983; Barbarick, 1985; Alva et al., 1986; term. The objective of this research was to evaluate the effects of Sheaffer et al., 1986; Burmester et al., 1991; Razmjoo potassium fertilization of alfalfa in areas of high soil exchangeable K and Henderlong, 1997). The reported results of these levels and long growing seasons. A field experiment was established trials show that the effects to the applications of K varied under irrigation from 1993 to 1997 in the Mediterranean environment with production practices, growing conditions, and soil of the Ebro Valley (Spain) on a silty clay loam soil. The treatments K contents, ranging from no DM yield response with were five annual rates of K (0, 41.5, 83, 166, and 332 kg K ha Ϫ1 ) and the application of 300 kg K ha Ϫ1 with a soil test level two rates of K (166 and 332 kg K ha Ϫ1 ) applied prior to seeding on of 75 mg K kg Ϫ1 (Lutz, 1973) to a maximum response two alfalfa cultivars. The average annual dry matter (DM) yield was 21.5 Mg ha Ϫ1 and showed a small linear response to K fertilization with the application 448 kg K ha Ϫ1 for a soil with extract-(Pr Ͼ F ϭ 0.0589). Total K removal in the herbage increased linearly able K of 55 mg K kg Ϫ1 (Rominger et al., 1976). These with each rate of K and reached 1728 kg K ha Ϫ1 with the application studies show that in general, K application increased of 332 kg K ha Ϫ1 yr Ϫ1 , compared with 1546 kg K ha Ϫ1 without K plant and soil K concentrations. fertilization. At the end of the experiment, soil ammonium acetateAlthough a survey of soil fertility and forage manageextractable K (K e ) increased little with K rates, and the differences ment specialists indicates that additional K is rarely were observed only in the first 30 cm of depth. Despite the uptake recommended when the concentration of exchangeable of 1546 kg K ha Ϫ1 , soil K e values did not change appreciably, suggesting K is greater than 300 kg ha Ϫ1 (about 150 mg K kg Ϫ1 ) in that much of the K uptake was derived from the fertilizer and from

The effects of plant harvest stage, autumn harvest dateand cultivars on alfalfa production and quality weredetermined in a 3‐year field experiment established in1992. Harvesting stage influenced annual yield andquality. Late bud‐first flower harvests increased harvestfrequency and forage quality in comparison with har‐vestingat the full bloom stage while decreasing dry‐matteryield by 18% (25·5 vs. 21·6 t ha 21 ). Harvestingstage significantly affected autumn forage productionand quality and yield at the first spring cut. Harvests atfull bloom allowed greater autumn and spring regrowththan cutting at the late bud stage, possibly because ofthe accumulation of higher root reserves. Autumn har‐vestsand cultivar significantly influenced the yields atthe first spring cut in any growing season. Cuttingbefore the first frost in autumn reduced the vigour ofboth cultivars, and the subsequent yield at the first cutin any year, in comparison with harvests taken after ornear the first autumn frost. It is concluded that theeffects of the stage of harvesting alfalfa on dry‐matterproduction and quality are important in theMediterranean environment of the Ebro Valley; theeffects of autumn management were observed mainlyon the yields of the subsequent first cut in spring but noton the total annual production.

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