Abstract:Coupling effects of water and nitrogen application on the growth of cucumber and the distribution andaccumulation of nitrate nitrogen in facility soil were studied under partial root-zone irrigation(PRI).The experimental factors included irrigation amount,irrigation method(whole root-zone irrigation;alternate partial root-zone irrigation,APRI;fixed partial root-zone irrigation,FPRI),and supply position of water and nitrogen in differentroot-zones.The results indicated that there was an interaction among the experimental factors studied regarding shoot biomass and cucumber yields.The shoot biomass and cucumber yield under deficient irrigationwere relative lower than that under full irrigation for the same irrigation method.The shoot biomass and cucumber yield were significantly higher in APRI than whole root-zone irrigation if same amount of water wassupplied.The highest shoot biomass and cucumber yield were observed in the APRI treatment with rotatedirrigation and application of nitrogen,reaching 1 143kg/hm2(dry weight)and 1.75×105 kg/hm2(freshweight),respectively.Cucumber growth decreased in FPRI,especially when nitrogen fertilizer was suppliedto the non-irrigated furrow.In terms of both shoot biomass and cucumber growth,no significant differencewas observed between the treatment with fully irrigated root-zone and APRI under deficient irrigation condition.Nitrate distribution in soil profile was examined under APRI and FPRI with sufficient irrigation.Theresults revealed that nitrogen fertilizer application could cause nitrate accumulation in soil,and vertical movement of water down soil profile was the main factor affecting nitrate leaching.Nitrate leaching was reduced inPRI treatment with nitrogen fertilizer applied to non-irrigated furrow in comparison to applied to the irrigatedfurrow.Nitrate nitrogen was mainly accumulated in upper 110cm of the soil profile for the APRI treatmentwith nitrogen fertilized to the non-irrigated furrow,and its nitrate accumulation in deep soil profile was relatively significantly lower than the other treatments.In conclusion,APRI with nitrogen fertilizer applied tothe non-irrigated furrow is a better strategy balancing both cucumber growth and nitrate leaching.