Coupling Effects Of Patrial Root-zoon Drying And Deficit Irrigation With Phosphatic Fertilizer On Maize (Zea Mays L.) Growth

This pot experiments with maize （Zea mays L.） of Zheng Dan958were conducted to studythe coupling effects of two irrigation methods-PRD （Partial root-zone drying irrigation） and DI（Deficit irrigation）with amount and local application of phosphatic fertilizer on photosynthetic rate,transpiration rate, dry matter accumulation, distribution of root biomass, phosphorus absorption,soil available phosphorus content, P utilization rate, as well as relative enzymatic activity,in orderto explore the best soil water content and phosphatic fertilizer conditions and, additionally, explainthe possible mechanism. Following are the main conclusions.1. Coupling effects of irrigation methods—PRD and DI, with different phosphorus amount:（1） Phosphorus amount had a significantly positive effect on plant height, leaf area, totalplant dry weight, shoot dry weight and root dry weight ratio. The effect of phosphorus amount onChlorophyll content had a same trend. The more the phosphorus fertilizer applied, the higher thephotosynthetic rate and Chlorophyll content were found. Water use efficiency was positivelyeffected only by phosphorus amount. Compared with DI, PRD treatment could significantlyimproved the phosphorus concentration of plant absorbed from soil.（2） Irrigation methods effected root acid phosphatase activity significantly,which treated inDI were higher than that in PRD by10.32%,6.68%,12.90%, at three different amount ofphosphorus application, such as low, medium and high levels. All the treatments, had no effectson leaf acid phosphatase activity and leaf superoxide dismutase activity.2. Coupling effects of irrigation methods—PRD and DI, with different phosphorus applingdepth:（1） Irrigation methods, phosphorus depth and their interaction effected plant heightextremely significantly. The leaf area and Chlorophyll content of PRD treatment were higher thanDI. In addition, transpiration rate, stomatal conductance and water-use efficiency were effected byirrigation method significantly on which PRD treatment had an enhance effort compared with DI.Finally, no elements show any significant effect on photosynthetic rate, intercellular CO₂ concentration and stomatal density.Shoot and root dry weight in PRD were heavier significantlythan ones in DI.（2） For local application treatments of phosphatic fertilizer such as averagely,depth10cm,depth30cm,plant of PRD shared higher phosphorus content than one of DI at12.86%、10.74%and10.61%respectively, the leaf acid phosphatase activity of plant of DI were higherthan one of PRD,and the content of available phosphorus remained in soil of PRD by65.30%、48.16%and5.93%were found higher than one of DI significantly.