Effect Of Nodule Bacteria Inoculation On Pea/Maize System

Inoculating appropriate rhizobium can increase the effect of symbiotic nitrogen fixation. One reason that incorporating leguminous crops into intercropping systems is to exptoit the rule of symbiotic nitrogen fixation on improvement N-nutrition of crop. But now, rhizobium inoculation in legume/cereal system is seldom studied. Pot experiment was used to study the rhizobium inoculation (Non-Inoculation, Inoculating XC3.1, Inoculating ACCC16101) and nitrogen application (Non-N,0.3gN/kg soil) on pea/maize system. The major results are as follows:(1) Nitrogen affected the number of rhizosphere microorganism in maize and peas, the number of rhizosphere microorganisms in pea is more than that of maize, the sensitivity of maize's rhizosphere microbial to nitrogen supply was higher than that of pea's. Nitrogen treatment significantly increased maize rhizosphere bacteria, fungi and actinomycetes, the quantity of rhizosphere microorganisms was highest in intercropping with N fereilization and lowest in mono-cropping with no N treatment, and the amplification of rhizospheric microorganism was higher in mono-cropping than that in intercropping when nitrogen was supplied. The sensitivity of the number of bacteria, fungi and actinomycetes to nitrogen in pea rhizosphere was significantly lower than that in maize, only the quantity of rhizosphere actinomycetes was increased in mono-cropping with nitrogen supply.(2) Cropping patterns affected the amount of rhizosphere microorganisms. Intercropping significantly increased the amount of rhizosphere bacteria, fungus and actinomyces of the two crops, and the intercropping promotion of maize was larger than that of pea. The effect of intercropping on microorganism amount changed with N level, and the multiplication of bacteria, fungus and actinomyces resulted from intercropping was more obvious under non-N condition.(3) Nodule bacteria inoculation affected the amount of rhizosphere microorganisms of pea and maize, the promotion was XC3.1>ACCC16101. Inoculation ACCC16101 and XC3.1 significantly increased the amount of rhizosphere bacteria of maize and pea; the amount of rhizosphere actinomyces of pea significantly increased only by inoculating XC3.1. Maize's actinomyces was significantly increased by inoculation ACCC16101 and XC3.1. Inoculated XC3.1 resulted higher increase of microorganism amount than that of ACCC16101.(4) Nitrogen application affected nodulation and symbiotic nitrogen fixation. XC3.1 had higher N fixiation under higher N level than ACCC16101. Higher nitrogen fertilization inhibited nodule bacteria infection, the ability of infection and N fixiation were also affected by bucteria's adaptability and stress resistance.(5) Planting patterns affected nodulation and symbiotic nitrogen fixation, nitrogen nutrition of maize and peas in intercropping was superior to that in mono-cropping. Inoculation XC3.1 not only strengthened competition of intercropped maize, but also increased the resistance of pea to maize's competition.(6) Nodule bacteria inoculation rates affected nodulation and nitrogen-fixiation, the promotion of XC3.1 was better than that of ACCC16101. Pea's nodulation character, N nutrition and dry matter accumulation of pea and intercropped maize were better with XC3.1 treatment than that with ACCC16101. ACCC16101's effects on nodulation and nitrogen nutrition were affected by nitrogen supply level and cropping patterns.(7) Inoculation XC3.1 under non-N significantly increased biomass of pea and maize, so did the grain yield of pea. Nitrogen application significantly inhibited the promoting effects on pea and maize growth.