Effects Of Seawater Irrigation On Grape Root System And Root Zone Environment

Our prevous studies have elucidated that moderate seawater irrigation favored inmproving the quality of grape fruit.Our previous focused on the aboveground part of gravevines.Additionally,the exploratory research showed that seawater irrigation did not cause deterioration of physical and chemical properties or soil salinization,but affected soil microbial community structure significantly.Therefore,this study aimed at exploring the regulatory effects of seawater irrigation on the development of roots in Vitis vinifera cv.‘Cabernet Sauvignon',and exploring the influence of seawater irrigation on the microbial communities and remedial measures.The results will provide theoretical basis and technical supports for production.The main results are as follows:1.Irrigation with 10%seawater had no significant effects on the biomass and root activity of‘Cabernet sauvignon'.In contrast,15%seawater significantly inhibited shoot growth,decreased aboveground biomass by 23.1%,decreased root activity by 14.8%,and increased the ratio of root to shoot?3.97?.However,10%plant fertilizer on the growth of the amount of water was higher than that of control 45.9%),the ratio of root to shoot decreased to 3.02 and the root activity increased by 51%.There was no significant difference between magnetized water and control.2.The root length,the number of primary root and the number of root and the number of capillary root increased in different seawater irrigation treatments.After 10%and 15%seawater irrigation,the root length increased by 23.9%,48.5%.The root diameter decreased by 28.5%?46.0%,and the primary roots increased by 13.2%?23%,he number of roots?bifurcation number was reduced by 13.7%,2.2%and 21.6%,13.4%;root lengthof adding fertilizer was significantly increased by 61.8%,the root diameter was reduced by 53.2%and the lateral roots were increased by 21.2%,the number of roots,bifurcation number were decreased by 2.4%?19.5%;The root length of magnetized water treatment and magnetized seawater increased by 63.7%,48.2%,the diameter of the root became thinner by 56.4%,41.5%.The root surface area and root volume of each treatment showed a decreasing trend.3.The level of ABA was increased in the early stage after 10%seawater irregulation,The shoots and roots increased significantly?67.5%,58.2%?,although the organs have various degree of fluctuation,the level of ABA in other organs was higher than that of control except that in the new leaf 46.5%lower than that of the control.4.Long-time seawater irrigation improved pH value of the acidic soil slowly.The pH value of soil irrigation for two years and four years were 0.18 and 0.08 units higher than control.The contents of total salt,Cl^-and SO₄^2-of soil,soil bulk density,specific gravity and total porosity did not change significantly.5.10%seawater irrigation affected the types and quantities of soil microbial communities.The abundance of Nitrospira,slow growing Rhizobium,Nodule increased after2 years of seawater irrigation,which increased by 23%,72.3%,and 50.4%,respectively.However the abundance of Nitrogen fixing bacteria and Lactobacillus decreased by 23.9%and 22.6%,respectively.The abundance of Nitrospira.The abundance of Nitrospira increased by 52.5%after 4 years of seawater irrigation;the slow growing rhizobia,nitrogen fixing bacteria and Lactobacillus decreased by 84.54%,20%,36.5%and 67.0%,respectively.The abundance of of the slow growing rhizobia,nitrogen fixing bacteria,Bacillus sp increased after the 10%seawater with fertilizer treatment.6.Long-time 10%seawater irrigation significantly improved the quality of Cabernet Sauvignon grape fruit which increased the soluble solids content and TSS/TA,improved the sugar acid composition,and reduced the titratable acid content after both 2 years and 4 years of seawater irrigation.The content of soluble solid increased after adding fertilizer.Compared with the control,the contents of anthocyanin and reducing Vc were increased by 42.7%and79.7%,respectively;The contents of total phenol and tannin in grape fruit increased by 44.1%and 30.2%respectively after 4 years of seawater irrigation.7.The aroma content,content and species of Cabernet Sauvignon grape were improved after 10%seawater irrigation.The total content of aroma compounds after 10%magnetization water,10%water and fertilizer,1 and 2 years of seawater irrigation increased by 76.1%,91.7%,25.8%and 28.8%respectively.The 33 kinds of aroma components were detected after long-time seawater irrigation and in the control.Aldehyde,2-Hexenal,diethyl phthalate,2-Octanone and other 20 kinds of components were detected in the control and seawater treatments.Compared with the control,13 kinds of aroma components were added after seawater irrigation,which were Butanoic acid,2-hexenyl ester,octanal,5-Hepten-2-one,6-methyl-,5-Hydroxymethylfurfural,and so on.The contents of alcohols,aldehydes,ketones content increased after adding microbial fertilizer.Compared with the control,the content of2-Hexenal increased by 46.9%,95.6%,0.5%and 17.8%respectively in the four treatments;and the content of 2-Hexenal?E?-increased by about 113.0%,105.6%,20.4%and 66.7%,the content of Nonanal increased by 285.8%,195%,34.2%and 49.2%.