Physiological Responses Of Four Shrubs To Saline-alkali Stress And Its Effect On Soil Fertility

Saline-alkali soil is widespread in our country and has the huge potential,but the salinization serious impact on agricultural production,soil improvement is an important way of promoting the efficient utilization of saline soil resources.Remediation and utilization saline-alkali soil is one of the hot issues for a long time in the world's areas of governance degraded land.And remediation and utilization saline-alkali soil is a long time,complex and systematic engineering,and the core is to reduce the harmful soil salinity,and to improve the soil environment for crop growth.At present,the halophyte availability as the core technology is generally considered a breakthrough of remediation and efficient utilization saline-alkali soil in the future.The objective of this article was to investigate further the effects of different halophytes growing in a saline-alkali soil.A saline-alkali soil was planted with four representative halophyte(Lycium ruthenicum,Hippophae rhamnoides,Shepherdia argentea and Tamarix chinensis)in the botanical garden of Yin Chuan City,Ning Xia Province,NaCl and NaHCO3 were used to simulate different saline-alkali stress condition,The experiment was conducted for 2 years,and soil chemical properties,microbiological properties,halophyte absorption and transportation salt and biological response of halophyte were systematically investigated and analyzed.Main results as below:(1)Different concentration of NaCl and NaHCO3 stress had different effects on growth and photosynthetic characteristics for four plants.Comparing with the decreasing of trees growth and their photosynthetic characteristics of four shrubs,NaHCO3 resulted in more serious salt injuries than NaCl in T.chinensis,S.argentea and H.rhamnoides,while NaHCO3 resulted in less serious salt injuries than NaCl in L.ruthenicum.In conclusion,our findings suggested that the ability of salt tolerance of the four plants were L.ruthenicum>T.chinensis>S.argentea>H.rhamnoides.(2)Soil organic matter showed an increasing trend,in the order of T.chinensis>S.argentea>H.rhamnoides>L.ruthenicum.Soil nutrients(N P K)in different halophyte treatments roots was improved.(3)The distribution of salt ions in root,stem and leaf of halophyte was in the order of L.ruthenicum.>T.chinensis>S.argentea>H.rhamnoides.The capacity of L.ruthenicum.absorption and transport Na+ was strongest in this four types of halophyte,so L.ruthenicum is more suitable for cultivation in the saline-alkali soil full of Na+.(4)With planting halophyte,microbial environment of saline-alkali soil was improved significantly.The ability of improvement was in the order of T.chinensis>S.argentea>H.rhamnoides>L.ruthenicum..In summary,halophyte-reclamation is an effective way of saline-alkali soil improvement,which not only can improve soil chemical and microbiological propoties,but also can absorb and migrate the salt,and which also can produce some economic benefit.Therefore,halophyte reclamation is irreplaceable.In addition,the complex halophyte reclamation,halophyte reclamation cooperating to farming measures would made more significant reclamation effect...