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Sirvi Autor "Ounane, S.M." järgi

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  • Pisipilt
    Kirje
    Influence of inoculation and phosphorus regimes on symbiotic nitrogen fixation and phosphorus use efficiency of Algerian cowpea (Vigna unguiculata L. (Walp.)) landraces
    (2018) Benlahrech, S.; Kac, G.; Teffahi, M.; Ounane, S.M.
    To study the genotypic variation of cowpeas on plant growth and phosphorus (P) uptake which is a function of different P regimes in the soil rhizosphere , 6 landraces of cowpea commonly found in northern Algeria ( NE4, NE10, NE11, NKT5, NKT7, NKB7 ) and 4 landraces from Sahara in southern Algeria (NAG4, NAG5, NAT2 and ND3) were studied during 2013 – 2014 in greenhouse. They were inoculated with Mesorhizobium sp. (S1), Bradyrhizobium sp. (S2) and co – inoculation (S1 – S2) under three P treatments: no P supply (P0), soluble P (PP) and insoluble P (TCP). Only varieties commonly found in northern Algeria nodulated with soluble P (PP) and inoculation containing Mesorhizobium sp . (S1). As a result of the symbiosis, the use of S1 has significantly increased shoot dry weight by 22%, total P content by 20% and P use efficiency for symbiotic nitrogen fixation by 18% compared to no inoculation (T). The landraces from the northern of Algeria expressed a higher growth than those from Sahara in the south of Algeria, especially three of them (NE4, NE10 and NE11) who showed a high performance under all P regimes. We suggest that these three landraces may be useful for improving symbiotic nitrogen fixation in cowpeas when growth is limited by low – P soils and that they could contribute to sustainable farming systems through reduction of farm er’s dependence on fertilizers.
  • Pisipilt
    Kirje
    Variation of chickpea nodulation in a Mediterranean agroecosystem: relationship with soil characteristics and thresholds for significant contribution to plant growth
    (2021) Chenene, Y.; Blavet, D.; Belalmi, M.; Kaci, G.; Teffahi, M.; Ounane, S.M.
    This study was designed to investigate the influence of some environmental constraints on chickpea (Cicer arietinum L.) growth and nodulation in a reference agroecosystem. This multi-local field experiment, realized in the agroecosystem of Chlef in northern Algeria, involved 24 sites where the local well-adapted genotype Ain temouchent is grown. Determination of soil properties allowed the identification of three clusters of sites. Plant biomass (SDW) varied significantly among sites from 6.7 to 39.4 g SDW plant -1 and was highly correlated with nodule biomass (NDW). The slope of the regression function between NDW and SDW, defined as the efficiency in use of the rhizobial symbiosis (EURS) inside clusters ranged from 67 to 200 g SDW g-1 NDW. Analysis of the EURS highlighted the existence of a low nodulation threshold of 0.1 g NDW plant-1 below which the contribution of nodulation to the host plant growth was not significant and a high threshold above which the nodule biomass increase was not linked with an increase in shoot biomass. Thus, the significant regression of shoot growth as a function of nodulation ranged from 0.10 to 0.35 g NDW plant-1 (R 2 = 0.54, P < 0.001). Moreover, nodule biomass was positively correlated with soil Olsen-P, more particularly in cluster A (R 2 = 0.50, P < 0.05) and B (R 2 = 0.61, P < 0.01). This approach proved to be a rapid and efficient way to identify the major factors affecting nodulation in order to develop strategies to optimize nodule contribution to chickpea growth and yield.