الفهرس 
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Abstract
The response of paspalum (Paspalum Vaginatum ) grass to four aeration levels [ A0: without aeration (Control), A1: The distance between the tines was 15 cm with three tines, A2: The distance between the tines was10 cm with four tines and A3: The distance between the tines was7.5 cm with five tines ] and two adding rates of NPK fertilizers [ F1: recommended and F2:75% from recommended ] in regard to vegetative growth and chemical constituents was investigated. The investigation was carried out in the experimental site of El- Delta Company for Fertilizers and Chemical Industries (ASMEDA) and the Laboratory of Vegetable and Floriculture Department, Faculty of Agriculture, Mansoura University, Egypt during the two successive seasons of 2016 and 2017 (from April -5th to October-5th of every season). The experiment included 32 plots (1.0×1.0 m2). The layout of this experiment during both seasons was split plot design with four replicates for each treatment. All agricultural operations were performed according to the traditional local agriculture management practices. Planting date was the 5th of April during the two seasons. Compaction was done by a metal cylinder. Coverage percentage have not been changed along the experiment due to the use of sods. Plots were aerated monthly from April to September. The number of holes were 66, 100and 130 for A1, A2and A3 treatments, respectively. The plants were cut at 4 cm height from the soil surface; 18 cuts were taken in each season every 10 days from April to October. The first cut was done on 15th of April and the final cut was done on the 5th of October. Fertilizers were applied at two treatments as following F1 (recommended): N was applied at the rate of 125 g N/ plot, P fertilizer was applied at the rate of 66 g P/ plot and K fertilizer was applied at a rate of 22 g K/ plot. F2: (75% from recommended): N fertilizer was applied at the rate of 93.75 g N/ plot, P fertilizer was applied at the rate of 49.5 g P/ plot and K fertilizer was applied at a rate of16.5 g K/ plot. Irrigation was applied as follows (7 liters/m2/day from April to 5st September, then 7 liters/m2/three days from 1st September till the mid- Octobe). The results could be summarized as follows: Vegetative growth parameters:- For individual effect of aeration, all values of shoots fresh and dry weight that obtained from the use of the fourth level of aeration (A3) were the biggest values while, the least values were resulted from the first level of aeration(A0) till October during 2016 and 2017 seasons. For the individual effect of fertilization, the second rate of fertilization (F2:75% from recommended) led to a significant increase in shoots fresh and dry weight of paspalum plants grown compared to the first rate of fertilization (F1: recommended) in all months during the two studied seasons. With regard to the effect of interaction between aeration and fertilization, the greatest significant values of shoot fresh and dry weight were occurred due to the use of the fourth level of aeration (A3) when fertilized with the second level of fertilization(F2:75% from recommended), where the highest values of fresh weight of paspalum shoots were at (A3F2) and the lower values of fresh weight of paspalum shoots were at (A0F1) during the two studied seasons. Chemical composition of leaves:- The same trend was found for Chlorophyll a, b and total Chlorophyll as well concentration of (N, P and K) Conclusion : Under the same condition of this investigation it could be concluded that the use of the fourth level of aeration (A3: The distance between the tines was7.5 cm with five tines) under the second level of fertilization(F2:75% from recommended) was the best treatment. Finally, the aeration led to improve the chemical and physical soil properties and consequently reduction of fertilizers usage, enhance the photosynthetic efficiency and increase plant growth.