Study On Application Of Microbiological Fertilizer Afforestation On Songnen Plain Saline Alkali Land

The saline soil area in Songnen plain is one of the three large saline soil areas in northeast inland of China.It is in the first place for its large area,wide spread,fast development and deeply hazard in northeast of our country.The leading content of this saline soil is NaHCO₃ and Na₂CO₃,which belongs to inland soda-saline soil.It is not only harmful to agricultural production but also harmful to afforestation.Microbiological Fertilizer contains large amount of organic substances and soil available microbe.During life activities process of soil available microbe,a great deal of organic acid was produced,available form of N,P and K were released continually.These effects could improve soil physical,chemical,biological properties and soil fertility,take positive role for afforestation trees in soda-saline alkali soil and amendment of soda-saline alkali land.So research and application of Microbiological Fertilizer is important for saline land amendment and usage.In this field test,during forestation Microbiological Fertilizer was added in soda-saline alkali soil.tree and soil samples were collected in different time.There were sixteen main forestation tree species used in this experiment.Seven physiological and biochemical indexes (osmoregulation substance in cells,protective enzyme activity and chlorophylls etc.),,twenty-seven soil parameters such as physico-chemical parametersof soil,organic substances,soil humus,nitrogen,phosphorous,available K,microbios etc.) were determined. Organic carbon changes of soils,carbon dioxide release flux and carbon equilibrium were studied along with the physical-chemical and biological properties of soils.Microbiological Fertilizer showed different effect to trees tolerance ability to salinization and physical, chemical,biological properties and carbon pool of soil.The study observed in field and analysed in lab four years from 2004 to 2007,The results are as follows:1.After four years afforestation with Microbiological Fertilizer,reduced effectively groundwater level in experiment area,physical and chemical properties of saline alkili soil were improved obviously,soil configuration were improved,bulk density and soil incorruptibility was reduced,soil porosity was enhanced,soil aggregates increased in quantity,soil permeability was enhanced.2.Microbiological Fertilizer could increase organic substances,humus and reduce pH in soda-saline alkali soil experiments.The increase of organic substance increased obviously with addition of Microbiological Fertilizer.Liquid and thermal properties were also improved,and the biological activity was increased,pH of soil,the salinity and CO₃^2-,HCO₃^-,Cl^-,Na⁺were all decreased,SO₄^2-,Ca²⁺ was increased and the chemical properties were improved. 3.Microbiological Fertilizer could alleviate decrease of nutrient in soil during the tree growth,soil N indexes and related enzyme activity were all enhanced.Microbiological Fertilizer could also activate underlying N,P and K in soil,improve microbial environmental.4.Microbiological Fertilizer could alleviate decrease of nutrient in soil during the tree growth,soil P and K indexes and related enzyme activity were all enhanced.Microbiological Fertilizer could also activate underlying P and K in soil,improve microbial environmental.5.After Microbiological Fertilizer was added in soda-saline alkali soil,soil microbios such as bacteria and actinomyces increased in quantity with tree growth year by year. Microbiological Fertilizer could activate underlying nutrient in soil during the tree growth, improve microbial environmental.6.The content of chlorophylls in trees leaf increased with the addition of fertility,but different afforestation tree species the increased quantity of chlorophylls was different. Microbiological Fertilizer could improve afforestation tree species tolerance ability to salinization,transforming of soluble sugar and activity of protective enzyme like POD,SOD; and reduce the content of Proline,salinization damage to afforestation tree species and MDA content,and decrease damage to membrane system,which caused by membrane lipid peroxidation due to salinity stress,make stability to membrane system.7.Afforestation with could improve the characteristics of soda-saline alkali soil by increasing the total organic carbon content and active carbon content of soil with a better quality of organic carbon.8.Afforestation with Microbiological Fertilizer could remarkably increase the respiratory intensity of soda-saline alkali soil.the respiratory,and actively organic carbon content correlated positively at a significant level with the total organic carbon content.9.Afforestation with Microbiological Fertilizer could remarkably increase the biomass in the soil-plant system,thus the carbon sequestration of soil,and reduce relatively the release of carbon of soil,playing a role of carbon sink.10.The fertilized plants including the arbors and shrubs were showed strong growth potentialities in contrast with that of non-fertilized,plants,for example survival rate and preservation rate,biomass,diameter at breast height,shoot growth,root length and root surface area,appearance of the arbors and shrubs.This experiment indicated that Microbiological Fertilizer could be widely used in saline land,it could accelerate afforestation tree growth process.Results of several years systematical studies in Songnen plain showed that afforestation with Microbiological Fertilizer biological rehabilitation might remarkably improve the physical and chemical characteristics and biological properties of soda-saline alkali soil,thus the soil fertility was elevated.Based on the former studies,this work studied the changes of carbon pool of soda-saline alkali soil after the biological rehabilitation in order to supply valuable referential data and basic research documents to the carbon pool changes and carbon cycling for the rehabilitation of soda-saline alkali soils.