Effect Of Different Rhizosphere Regulations On The Rhizosphere Microbial Activity And Arbuscular Mycorrhiza Fungal Phosphate Of Maize In Intensive Farming

To understand the distribution and function of AM fungi in intensive farmland ecosystem soil and the effect of mycorrhizal late-term inoculation on crop growth and the difference of mycorrhizal dependence of maize genotypes with different phosphorus efficiency, we completed two field trials and an indoor pot experiment from January 2009 to September 2010. Results were as follows:1. Under intensive farming condition, the activity of mycorrhizal fungi varied in different time and space, the regulation of different phosphorus fertilization style on hyphae is greater than the regulation of root. It has been thought that the mycorrhizal fungi in surface soil have the greatest effet on plant, but the results of this experiment showed that the hyphae absorption of available phosphorus and organic phosphorus in 20-60cm depth accounted for 50% and 73.13% of total phosphorus absorption.2. In the late-mid period of intensive farming,the mycorrhizal fungi innoculation significantly increased 66% production of P-treatment and declined the normal production of P- treatment. With the increased amount of P fertilizer, the infection of inoculum to plant root is abate,even worse,the possible reason may be that high P concentration restricted mycorrhizal fungi to infect roots.3. Infection in sterile root conditions,incresing P appication result in the P-efficient and P-inefficient genotypes maize showing different trend in P concertraton in shoots ;on the contrary,under the condition of mycorrhizal infection with two genotypes maize,the trend is the same;The existence of mycorrhizal fungi narrowed the P-efficient and P-inefficient genotype itself on the P uptake in shoot4. Mycorrhizal responsiveness of maize genotypes with different phosphorus efficiency under different phosphorus levels conditions were significantly differences. Mycorrhizal dependence of genotype with high phosphorus efficiency was higher than genotype with low phosphorus efficiency under the conditions of the higher phosphorus input. The result illustrate that 181 is a good breeding material and more adapted to high P efficiency and mycorrhizal dependency requirements under the current agricultural intensification mode. However, because of the differences of mycorrhizal effects with different maize genotypes under the different phosphorus levels conditions, mycorrhizal dependency and mycorrhizal effects should be as important factors to consider in the future breeding work.Through the above results, we can conclude that: Under intensive farming condition,AM fungi has a large distribution in 20-60cm depth and played a positive role in phosphorus uptake. In the late-mid period of intensive farming,the mycorrhizal fungi innoculation significantly increased 66% production of P-treatment and declined the normal production of P- treatment. The mycorrhizal dependency of P efficient maize 181 is more adapt to the current agricultural ecosystem of intensive production.