Effects Of Partial Root-Zone Irrigation On Water And Nutrients Use Of Sweet Corn Under Different Fertilization Condition

A pot experiment was conducted to investigate the effects of partical root-zone irrigation on physiological characteristic, plant height, leaf area, dry matter accumulation, water and nutrients use of sweet corn (Zea mays L.) under different fertilization condition. Three irrigation methods, i.e. conventional irrigation (CI), fixed irrigation (FI) and alternate irrigation (AI), three fertilization methods, i.e. even fertilization (EF), fixed fertilization at one side (FF) and fixed fertilization at one side with half fertilization (SF), and two fertilization levels, i.e. higher fertilization (HF) and lower fertilization (LF), were designed in this experiment. The results indicated:(1) Compared to CI, partial root-zone irrigation (PRI) such as fixed irrigation (FI) and alternate irrigation (AI) reduce transpiration greatly, and slightly reduce photosynthesis rate, and stomata conductance. Under EF, FF and SF, mean transpiration rate reduced by 18.26%, 28.28% and 25.39%, mean photosynthesis rate 6.69%,16.38% and 0.84%, mean stomata conductance 4.53%, 19.83% and 16.67%, respectively. The reduction of transpiration rate was greater than that of photosynthesis rate.(2) The difference of leaf area for different irrigation treatments narrowed with the advance of maize growth. The effect of fertilization method and fertilization level on leaf area of sweet corn became smaller at later growing stage.(3) Compared to CI, total dry matter, shoot dry matter, root dry matter and root mass ratio for PRI reduced. Under EF, FF and SF, mean total dry matter reduced by 18.26%, 22.94% and 23.72%, respectively.(4) Compared to CI, PRI reduced the invalid evaporation and evapotranspiration, the reduction of evapotranspiration was greater than that of total dry matter, so PRI can increase more canopy WUE. Under EF, FF and SF, mean evapotranspiration reduced by 30.43%, 30.52% and 29.88%, respectively, but canopy WUE and leaf WUE increased by 15.44%, 10.93% and 8.87%, 13.17%, 17.94% and 33.68%, respectively.(5) The SF combined with LF treatment can increase dry mass per fertilizer amount. Compared to EF and FF, the SF treatment increased dry mass per fertilizer amount from 78.19%~126.46%. Compared to HF, fertilization productivity increased 43.64% for LFunder SF.(6) Compared to CI, leaf N, P and K concentrations for FI under HF were increased by 2.32%, 0.72% and 57.26%, respectively.(7) Compared to CI, PRI increased soil available P content from 3.31% to 16.44%, and soil available K content from 16.67% to 56.91%.(8) The PRI-SF-LF water fertilizer coupling can increase more WUE and dry mass per fertilizer amount in the experimental condition.