Effects Of Water Stress And Microbial Fertilizer Addition On The Growth And Development Of Protected Grape And Soil Microbial Environment

The research on management of water and soil microbial communities of grape protected cultivation in Hexi area of Gansu Province is insufficient,which result in the lower water-fertilizer utilization efficiency and inferior soil microbial environment of grape cultivation.In this study,the effect of synergistic regulation of water and bacterial fertilizer on rhizosphere soil microbial community structure during the whole growth period of grape drip irrigation was carried out in Yongdeng County,Gansu Province.There were three levels of water regulation,namely,moderate water stress(the lower limit of soil moisture was 55%FC),mild water stress(the lower limit of soil moisture was 65%FC)and sufficient water supply(the lower limit of soil moisture was 75%FC);the a mount of the of bacterial manure addition was set to three levels:no addition(0g),a small amount of addition(75 g)and a large amount of addition(150 g),a total of9 water and bacterial regulation treatments.The main research results are as follows:(1)The addition of a small amount of bacterial fertilizer under mild water stress increased the shoot length at the fruit expansion stage,while under moderate water stress,the growth of shoot diameter was inhibited by a large amount of bacterial fertilizer,and the growth of longitudinal and transverse stems were prmoted by a small amount of bacterial fertilizer addition at the fruit expansion stage.(2)The addition of a small amount of bacterial fertilizer under mild water stress could increase the content of malondialdehyde(MDA)in grape leaves throughout the whole growth period,and promote the synthesis of chlorophyll content(SPAD)in the fruit period.Light and moderate water stress inhibited the synthesis of chlorophyll a and total chlorophyll content under a small amount of bacterial fertilizer.(3)With the addition of a small amount of bacterial fertilizer,the grape yield under mild water stress reached the maximum of 46505.56 kg/hm~2,which was 56.34%higher than that under sufficient water supply,Under the sufficient water supply level,the grape yield under the treatment with a large amount of bacterial fertilizer was also relatively high,reaching 43661.11 kg/hm~2,which was 42.48%higher than that without bacterial fertilizer.The total water consumption of sterile fertilizer treatment with sufficient water supply during the whole growth period was 5135.44 m~3/hm~2.Under the condition of water-bacterial interaction,the water production efficiency of the treatments with medium water stress and large amount of bacterial fertilizer addition and small amount of bacterial fertilizer addition under mild water stress was relatively high,which were 11.30 kg/m~3 and 11.17 kg/m~3.The irrigation water use efficiency under sufficient water supply was significantly lower than that under moderate and mild water stress treatments.(4)A small amount of bacterial fertilizer addition under moderate water stress could increase the soluble solid(SSC)content of grape fruit at coloring maturity stage;the fruit p H reduced under the full water supply of bacteria fertilizer treatment condition;the vitamin C content was increased under light water stress condition;the anthocyanin content was increased under the condition of large amount of bacterial fertilizer addition with moderate water stress and small amount of bacterial fertilizer with mild water stress at the coloring maturity stage.The total sugar and glucose content increased under the condition of small amount of bacterial fertilizer treatment in the whole growth period,and the addition of bacterial fertilizer under mild water stress could promote fructose content.With the extension of stress time,mild and moderate water stress inhibited sucrose synthase(SS)activity;Moderate water deficit and less fertilizer promoted acid invertase(AI)activity during fruit enlargement,whilewith the increase of stress time,moderate water deficit inhibited AI activity under the same bacterial fertilizer addition condition.Under moderate water stress,athe activity of sucrose phosphate synthase(SPS)was promoted with small amount of bacterial fertilizer treatment d uring the whole growth period of fruit,while the activity of neutral invertase(NI)was promoted with a large amount of bacterial fertilizer treatment.And through the membership function analysis of fruit quality,the comprehensive index evaluation coefficient of light water stress with a small amount of bacterial fertilizer was the highest.(5)Under the condition of mild water stress,the activity of invertase in fruit enlargement stage was improved with a small amount of bacterial fertilizer addition,and the urease activity in germination stage and coloring maturity stage was improved with a large amount of bacterial fertilizer additon.Under the condition of moderate water stress,the catalase activity was increased with less fertilizer treatment at germination stage,and the urease activity decreased without fertilizer treatment additionat fruit enlargement stage.(6)There was no significant change in soil total phosphorus and total nitrogen content under the regulation of water and bacteria at each growth stage.However,the contents of organic matter,organic carbon and water-soluble carbon was improved under the condition of sufficient water supply and multi-amount bacterial fertilizer treatment.The content of available phosphorus and microbial entropy(SMQ)was promoted under the treatment with mild water stress and high amount of bacterial fertilizer addition at fruit expansion stage.The content of ammonium nitrogen at shoot stage was reduced with the condition of moderate water stress and low amount of bacterial fertilizer,while the microbial biomass C/N ratio(MBC/MBN)increased.nitrate nitrogen content in fruit enlargement period was inhibited with continuous mild and moderate water deficit,and the accumulation of available phosphorus in grape shoots was inhibited with moderate water deficit and excessive bacterial fertilizer addition.(7)The aggregation of non-hydrolyzable nitrogen content was inhibited with the condition of water stress.Under mild water stress,the percentage of acid-hydrolyzable amino acid nitrogen,acid-hydrolyzable amino sugar nitrogen,acid-hydrolyzable ammonium nitrogen and acid-hydrolyzable unknown nitrogen accounted for the largest percentage of total nitrogen.The results of redundancy analysis(RDA)showed that nitrate nitrogen and ammonium nitrogen were the most important environmental factors affecting the change of soil organic nitrogen components.Based on the comprehensive analysis,mild water stress during the whole growth period was the best water regulation treatment for delayed cultivation grapes in local facilities,namely,the soil moisture reached 65%?80%of the field water holding rate,and the irrigation quota of 270 m~3/hm~2 could achieve the effects of water saving and improve the soil micro-ecological environment of facility farmland.Under the condition of water and bacteria interaction,added a small amount of bacterial fertilizer under mild water stress could optimize fruit quality and improve rhizosphere soil microbial environment.