Experimental Study On Rotating Irrigation Mode With Saline And Fresh Water For Wolfberry In The Salinization Irrigation District

To study the brackish water irrigation mode for wolfberry under the condition of salinity soil, the brackish water irrigation experiments of the wolfberry grown field were conducted in Hong Wei test field where is the water-saving irrigation experiment demonstration garden of Hetao Irrigation district, Inner Mongolia for three consecutive years.To conventional irrigation for local control, study the impact of the different combination brackish-water irrigation mode (salty-salty-fresh,salty-fresh-salty, fresh-salty-salty and salty-salty-salty) on soil water and salt, wolfberry growth, yield and quality, discussed the optimal model of rotating irrigation with saline and fresh water for local wolfberry, thus provide the basis and reference to employ irrigation with saline and fresh water for wolfberry in Hetao Irrigation District. The main conclusions in this paper are as follows:(1) The influence of different rotation irrigation modes to farmland soil environment: (a) The soil water content of different treatments increased during the end of wolfberry growth period; The soil moisture in the root zone of treatment fresh-salty-salty、treatment salty-salty-salty and treatment local irrigation is higher,it is good for improve the wolfberry production.The treatment fresh-salty-salty’s water use efficiency of wolfberry is the highest in the rotation irrigation with saline and fresh water. (b) the different treatments of soil salinity occurred the phenomenon of surface assembly; Soil salinity was influenced by irrigation and rainfall mostly among the depth of 0～80cm, it had little influenced below the depth of 0～80cm; Rotation irrigation with saline and fresh water would cause the variability of soil saturated conductivity increased, according to the size of the different treatments of saturated conductivity arranged as follows:salty-salty-salty > salty-salty-fresh> salty-fresh-salty> fresh-salty-salty> local irrigation; salty-salty-fresh and salty-salty-salty treatments occurred salification after the autumn water irrigation,others have different degrees of desalination, fresh-salty-salty treatment of desalination rate reached 12.1%,and fresh-salty-salty treatment would not lead to the secondary salinization of soil.(2) The influence of different rotation irrigation modes to wolfberry growth:the growth rate of fresh water irrigation was significantly higher than the growth rate of saline water irrigation. the growth rate of growth index which in the mild saline land were higher than which in the middle saline land, This shows that the size of soil salinity is one of the important indicator which influences the growth of wolfberry. With the increase of soil salinity, The growth of the wolfberry’s growth indexs was inhibited in different degrees;In the mild saline land and the middle saline land, the order of the growth rate of the growth indexs in the whole growth period was:local irrigation> fresh-salty-salty >salty-salty-fresh> salty-fresh-salty> salty-salty-salty.The different treatments of plant height, young shoots, crown diameter and growth of ground diameter consistented with the growth rate; The highest degree of fitting on relationship of soil salinity and wolfberry’s growth indexs is cubic curve.(3)The influence of different rotation irrigation modes to wolfberry production:the order of wolfberry production no matter in the mild saline land or in the middle saline land was:local irrigation> fresh-salty-salty> salty-salty-fresh> salty-fresh-salty> salty-salty-salty; Under the same conditions of irrigation, the amount of saline water irrigation increased would cause the decrease of wolfberry production. The soil moisture in the root zone of treatment fresh-salty-salty is the lowest in full productive age of wolfberry.The impact on yield is the least. The crown diameter was the main factor which influenced the wolfberry production, the growth of young shoots was the second, the influence on plant height and ground diameter was smaller for wolfberry production. Soil salinity and wolfberry production had negative correlation significantly, the highest degree of fitting on regression equation is cubic curve.In the mild saline land,the plant fruit production of wolfberry is the largest during soil electric conductivity is 0.55ms/cm and the plant fruit production is 6.82 kilogram per plant. In the middle saline land,the plant fruit production of wolfberry is the largest during soil electric conductivity is 1.31ms/cm and the plant fruit production is 4.37 kilogram per plant.(4)The influence of different rotation irrigation modes to wolfberry quality:(a)the order of the change rule of hundred-grain weight of fresh fruit and fruit length under different rotation irrigation modes was local irrigation> fresh-salty-salty> salty-salty-fresh> salty-fresh-salty> salty-salty-salty no matter in the mild saline land or in the middle saline land,and had negative correlation significantly with soil salinity.(b)With the soil salinity increased,the content of polysaccharides, total sugar and amino acids increased in varying degrees in the wolfberry fruit, and had positive correlation significantly with soil salinity. The order of the change rule of the content of polysaccharides, total sugar and amino acids under different rotation irrigation modes was salty-salty-salty> salty-salty-fresh> salty-fresh-salty> fresh-salty-salty> local irrigation no matter in the mild saline land or in the middle saline land. (c) In the mild saline land, the hundred-grain weight of fresh fruit and fruit length were the largest during soil electric conductivity is 0.59ms/cm, they were 69.04g and 19.29mm respectively; the content of amino acids was the largest during soil electric conductivity is 0.72ms/cm, it was 8.174mg/100mg; the content of polysaccharides and total sugar were the largest during soil electric conductivity is 0.71ms/cm, they were 9.141% and 53.330% respectively. In the middle saline land, the hundred-grain weight of fresh fruit and fruit length were the largest during soil electric conductivity is 1.23ms/cm, they were 67.09g and 18.90mm respectively; the content of amino acids,polysaccharides and total sugar were the largest during soil electric conductivity is 1.54ms/cm, they were 7.821mg/100mg,11.800%and 67.257% respectively.Comprehensive the state of soil salinity, growth of wolfberry and yield and quality to analysis, fresh-salty-salty treatment is the optimal scheme of irrigation for local wolfberry.It’s mean that the irrigatin times is three during the growing season of wolfberry,the total irrigation water is 225mm.Among them,the first time irrigation is fresh water which degree of mineralization is 0.608g/L and the irrigation water is 75mm.Irrigation is saline water which degree of mineralization is 3.84g/L and the irrigation water is 75mm in the rest of the 2 times.