160 research outputs found

    Effects of Supplemental Irrigation on Berseem Seed Crop in a Semi-Arid Mediterranean Environment

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    Berseem seed production in Mediterranean environments is strongly influenced by soil water availability, particularly during spring growth. A long-term study (11 years) in Sicily recorded seed yields of between 0 and 1600 kg/ha, for an annual rainfall range of 289 to 867 mm (Stringi et al., 2001). It was proposed that water irrigation during sensitive growth stages could increase and stabilize seed yield. This research investigated the response of berseem seed crop to low levels of irrigation applied at different growth stages

    Influence of Arbuscular Mycorrhizae on Biomass Production and Nitrogen Fixation of Berseem Clover Plants Subjected to Water Stress.

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    Several studies, performed mainly in pots, have shown that arbuscular mycorrhizal symbiosis can mitigate the negative effects of water stress on plant growth. No information is available about the effects of arbuscular mycorrhizal symbiosis on berseem clover growth and nitrogen (N) fixation under conditions of water shortage. A field experiment was conducted in a hilly area of inner Sicily, Italy, to determine whether symbiosis with AM fungi can mitigate the detrimental effects of drought stress (which in the Mediterranean often occurs during the late period of the growing season) on forage yield and symbiotic N2 fixation of berseem clover. Soil was either left under water stress (i.e., rain-fed conditions) or the crop was well-watered. Mycorrhization treatments consisted of inoculation of berseem clover seeds with arbuscular mycorrhizal spores or suppression of arbuscular mycorrhizal symbiosis by means of fungicide treatments. Nitrogen biological fixation was assessed using the 15N-isotope dilution technique. Arbuscular mycorrhizal symbiosis was able to mitigate the negative effect of water stress on berseem clover grown in a typical semiarid Mediterranean environment. In fact, under water stress conditions, arbuscular mycorrhizal symbiosis resulted in increases in total biomass, N content, and N fixation, whereas no effect of crop mycorrhization was observed in the well-watered treatment

    Plant Arrangement Effects on Dry Matter Production and Nitrogen Fixation of Berseem Clover: Annual Ryegrass Mixture

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    Agronomic factors affect the productivity and efficiency of cereal-legume intercropping systems (Ofori & Stern, 1987). This research aimed to determine the effects of different plant arrangement on hay yield, nitrogen (N) content and N fixation of berseem clover-annual ryegrass mixture in a Mediterranean semi-arid environment

    Effect of defoliation management and plant arrangement on yield and N2 fixation of berseem-annual ryegrass mixture

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    The research was carried out in a Mediterranean semi-arid environment on berseem clover, annual ryegrass and their mixture to study the effect of defoliation management [date of \ufb01rst cut (FC) 85, 119, 140, 169 days after sowing] and different plant arrangements (sowing the two components in alternate rows or in the same row) on yields, N content, N2 \ufb01xation and N transfer. The experimental design was a split-plot with four replications. The 15 N isotope dilution technique was used (8 kg N ha \u20131 as ammonium sulphate at 10 atom% 15 N excess) to evaluate the N2 \ufb01xation. Total seasonal DM yield was, on average, signi\ufb01cantly higher for FC119 and FC140 (approx. 12.3 t ha \u20131 ) than for FC85 and FC169 (approx. 10.6 t ha \u20131 ). Plant arrangement did not signi\ufb01cantly in\ufb02uence total yield of the mixture. However, the legume yield was higher (+20%; P<0.0001) in the same row than in alternate rows arrangement. N content of ryegrass was signi\ufb01cantly higher in the mixtures than in pure stand and in the \u2018same row\u2019 plant arrangement than in the \u2018alternate rows\u2019. Intercropped berseem always had a signi\ufb01cant higher % of Ndfa than the monocropped one (on average 74.7% and 57.7% respectively). The apparent transfer of \ufb01xed N from berseem to ryegrass was not detected in either plant arrangement

    Forage Quality and Yield of Berseem Clover and Annual Ryegrass Grown in Pure and Mixed Stands in Relation to Different N Application Rates

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    Grass-legume mixtures offer several advantages over monocultures in forage-animal production systems (Haynes, 1980). In fact, in grass-legume mixtures forage yield and quality are generally higher compared to grass monocultures also due to more efficient soil N-utilisation (Ta & Faris, 1987); furthermore grasses often utilise some of the N fixed by legumes (Malhi et al., 2002). Legumes do not generally require the addition of N fertiliser due to symbiotically fixed N, but the yield of the grass component in a mixture may be further improved with N application. The objective of this study was to investigate forage yield and quality of berseem and annual ryegrass grown in pure stands, and in mixture, at different N fertiliser rates

    Agroecosystem Performances of Livestock Farms in a Mountain Area of Sicily

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    Agroecosystem performance indicators (APIs) represent instruments for studying agroecosystem performance via an input/output approach and a knowledge base, with the aim of improving the sustainability level of the farm\u27s activity (Tellarini & Caporali, 2000). This research used APIs to evaluate the influence of stocking rate on the performance (in terms of energy) of farms in a mountainous area of northern Sicily, Italy

    The Timing of Daily Grazing on Annual Ryegrass or Sulla Forage: The Effects on Milk Yield and Composition of Comisana Ewes

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    The timing and duration of grazing greatly affect the response of animals. Night grazing, in addition to grazing during the day, seems to be one of the most important practices for improving animal performance (Bayer et al., 1987). Many authors have already underlined the major benefits of night grazing, such as improved body condition, reduced heat stress, increased forage intake and milk production. However, labour constraints, insecurity, damage to crops by animals are considered as the main reasons for not practising day and night grazing. The aim of this research was to improve knowledge about the effects of daily grazing time in ryegrass or sulla forage on milk yield and composition of Comisana ewes
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