| In recent years,the sustainable development of the production of plant and soil are severely affected by soil salinization.The injury of salinization to the plants can be effectively alleviated by applying nitrogen fertilizer.This experiment was conducted for two varieties salt-tolerant of peas(' Yin Wan NO1 ',Ha)seedlings to analysis the interaction of NaCl and urea on plant growth,rhizosphere respiration,rhizosphere soil physical and chemical properties,biological properties.the results that were got whether alleviated the injury of salinization to peas seedlings and promote mineralization of the rhizosphere soil.It provides the theory basis for soil improvement,the mechanism of plant salt resistance,soil organic C loss.1.With the increase concentration of the salt,the dry weight of shoots,aboveground water content,the root-shoot ratio were significantly decreased.Under the medium NaCl-nutrient interaction treatments,the root-shoot ratio was has been increased.the dry weight of shoots,aboveground water content,the root-shoot ratio of ' Yin Wan NO1 ' was greater than Ha.Under the medium NaCl-urea sources interaction treatments,the the dry weight of roots,root length and root surface area of two varieties salt-tolerant of pea seedlings has been increased.Under 300 mgN,the plant height and of two varieties salt-tolerant of pea seedlings were inhibited.The root length and root surface area of Ha was greater than' Yin Wan NO1 '.The injury of plants coming from salt stress can be alleviated by appropriate N applying.2.The ions balance was disrupted by NaCl treatment.The ions of Na+,Cl–,K+ and Ca2+ were accumulated in the shoots of the two varieties salt-tolerant of pea seedlings by salt stress.The ratio of K+ / Na+ and Ca2+ / Na+ were decrease by NaCl treatments.The accumulation of Na+ and Cl– in the shoots of two varieties salt-tolerant of peas seedlings were decreased by N applied,especially under the medium NaCl-urea sources interaction treatments.Under 150 mgN,the ratio of K+ / Na+ of the shoots was increased significantly compared to 0 mg N,and the ratio of K+ / Na + and Ca2+ / Na+ of Ha is significantly higher than ' Yin Wan NO1 '.3.Under the same salt concentration,the amount of the total soil respiration and rhizosphere respiration showed a trend of increase and decreases followed with the increase of N application rate.Under the same N concentration,the amount of the total respiration and rhizosphere respiration shows the same trend.Compared to control treatments,the amount of the total respiration and rhizosphere respiration were increased under moderate salt and 150 mgN interaction treatment.While the total respiration and rhizosphere respiration were inhibited under severe salt stress and 300 mgN interaction treatment.The total soil respiration from high to low is: Ha,' Yin Wan NO1 ' and the soil without plant.With the increase of cultivate time,the respiration rate of ' Yin Wan NO1 ' and the soil without plant were showed a trend of gradually reduce the soil respiration rate.4.Under 150 mg N treatments,the content of soil microbial biomass C and urease activity,total CO2 of the soil were the highest,especially medium salt-N interaction.Soil microbial biomass C and soil organic C mineralization can be promoted by a moderate amount of NaCl and N interaction,and positive priming effect may be greater than other treatments.Compared to the soil of ' Yin Wan NO1 ' planted,the content of soil microbial biomass C and urease activity of Ha were higher.Positive priming effect from Ha may be stronger.Compared with the soil with plants,soil microbial biomass C and reduced enzyme activity were decreased,soil organic C increased and less the total CO2 in the soil without plants.The result is speculated that the negative priming effect may be produced. |
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