Assessing hydroaeroponic culture for the tripartite symbiosis of mungbean (Vigna radiata L.) with arbuscular mycorrhizal fungi and rhizobia

Mungbean (Vigna radiata L.) has the potential to establish symbiosis with rhizobia that fix atmospheric dinitrogen (N2), and arbuscular mycorrhizal fungi (AMF) that improve the uptake of low mobile soil nutrients such as phosphorus. Both rhizobial and mycorrhizal symbioses can benefit plants synergistically. The tripartite symbiosis of mungbean with rhizobia and AMF was assessed in hydroaeroponic culture under sufficient versus deficient P supplies (250 versus 75 μmol P plant-1 week-1) by comparing the effects of three AMF species on the mycorrhizal root colonization, rhizobial nodulation, and plant growth. Although, Glomus intraradices colonized well the roots of mungbean in sand and hydroaeroponic cultures, Gigaspora rosea only established well under sand culture conditions, and Acaulospora mellea weakly colonized roots under both culture conditions. Though significant differences of mungbean growth were found with different AMF species in sand, only few differences were observed in hydroaeroponic cultures. It is argued that the later will probably be a valuable tool for scrutinizing the interactions among the three symbionts, as well as plant  physiology, and nutrient partitioning within the symbiotic system.Key words: Acaulospora mellea, arbuscular mycorrhizal, Bradyrhizobium, Gigaspora rosea, Glomus intraradices, mungbean, phosphorus, symbiotic nitrogen fixation

Assessing hydroaeroponic culture for the tripartite symbiosis of mungbean (<em>Vigna radiata</em> L.) with arbuscular mycorrhizal fungi and rhizobia

International audienceMungbean (Vigna radiata L.) has the potential to establish symbiosis with rhizobia that fix atmospheric dinitrogen (N(2)), and arbuscular mycorrhizal fungi (AMF) that improve the uptake of low mobile soil nutrients such as phosphorus. Both rhizobial and mycorrhizal symbioses can benefit plants synergistically. The tripartite symbiosis of mungbean with rhizobia and AMF was assessed in hydroaeroponic culture under sufficient versus deficient P supplies (250 versus 75 mu mol P plant-(1) week(-1)) by comparing the effects of three AMF species on the mycorrhizal root colonization, rhizobial nodulation, and plant growth. Although, Glomus intraradices colonized well the roots of mungbean in sand and hydroaeroponic cultures, Gigaspora rosea only established well under sand culture conditions, and Acaulospora mellea weakly colonized roots under both culture conditions. Though significant differences of mungbean growth were found with different AMF species in sand, only few differences were observed in hydroaeroponic cultures. It is argued that the later will probably be a valuable tool for scrutinizing the interactions among the three symbionts, as well as plant physiology, and nutrient partitioning within the symbiotic system

Introducing mungbean as a preceding crop to enhance nitrogen uptake and yield of rainfed rice in the north-east of Thailand

One possible management option for farmers to improve the soil nitrogen (N) supply for rice production is the cultivation of a prior legume. The objective of this study was to investigate the value of such an option in the lowland of the north-east of Thailand. Two experiments were established in 2 typical locations in a split-plot design with 4 replicates. The main plots included 3 nitrogen levels (0, 30, and 60 kg N/ha) and the subplots, 4 pre-rice managements: (i) fallow with weeds removed (FW-); (ii) with weeds incorporated before the rice crop (FW+); (iii) mungbean incorporated at flowering as green manure (MGM); or (iv) incorporated after grains harvest (MR+). In both experiments the difference in rice yield between MGM and MR+ was not significant. In Expt 1, in contrast to Expt 2, the rice yield increase due to MR+ was significant and significantly higher than that due to application of 60 kg N/ha. Moreover, significantly higher apparent recovery of N (ANR(m), kg N uptake increase/kg N supplied by residues), probably due to the continuous flooding of the soil surface, was achieved in this experiment. The low values of internal efficiency of N (IEN, kg total grains/kg total N uptake), ANR(f) (Delta kg N uptake/kg N supplied by fertiliser), and of ANUE(f) (Delta kg grains/kg applied N fertiliser) recorded in the MR+ treatment of Expt 1, suggest that no application of N fertiliser is needed where the soil water conditions allow high recovery of the N supplied by a preceding mungbean crop

Introduction du haricot mongo (Vigna radiata L.) comme précédent cultural pour améliorer la disponibilité de l'azote et le rendement du riz pluvial dans le Nord Est de la Thaïlande

La revue Australian Journal of Agricultural Research devient en 2009 la revue Crop & Pasture Science (nouvel ISSN-L 1836-0947)International audienceOne possible management option for farmers to improve the soil nitrogen (N) supply for rice production is the cultivation of a prior legume. The objective of this study was to investigate the value of such an option in the lowland of the north-east of Thailand. Two experiments were established in 2 typical locations in a split-plot design with 4 replicates. The main plots included 3 nitrogen levels (0, 30, and 60 kg N/ha) and the subplots, 4 pre-rice managements: (i) fallow with weeds removed (FW–); (ii) with weeds incorporated before the rice crop (FW+); (iii) mungbean incorporated at .owering as green manure (MGM); or (iv) incorporated after grains harvest (MR+). In both experiments the difference in rice yield between MGMand MR+ was not significant. In Expt 1, in contrast to Expt 2, the rice yield increase due to MR+ was significant and significantly higher than that due to application of 60 kg N/ha. Moreover, significantly higher apparent recovery of N (ANRm, kg N uptake increase/kg N supplied by residues), probably due to the continuous .ooding of the soil surface, was achieved in this experiment. The low values of internal efficiency of N (IEN, kg total grains/kg total N uptake), ANRf (_kgNuptake/kg N supplied by fertiliser), and of ANUEf (_kg grains/kg applied N fertiliser) recorded in the MR+ treatment of Expt 1, suggest that no application of N fertiliser is needed where the soil water conditions allow high recovery of the N supplied by a preceding mungbean crop