Effect of NPK Fertilization in the Newly Reclaimed Soil on Productivity of Grain Sorghum

A field experiment was conducted in the Agricultural Research Station at Arab El-Awamer, Assiut Governorate, during the two growing seasons of 2014 and 2015 to investigate the effect of NPK fertilization in newly reclaimed soil on grain sorghum productivity. The randomized complete block design using split-split-plot with four replications was arrangement, where nitrogen fertilizer rates (100, 120 and 140 kg N/fed. i.e. N₁, N₂ and N₃, respectively) were allocated in the main plots, while phosphorus fertilizer rates (22.5 and 30 kg P₂O₅/fed. i.e. P₁ and P₂, respectively) were assigned in the sub-plots and potassium fertilizer rates (24 and 36 kg K₂O/fed. i.e. K₁ and K₂, respectively) were fixed in the sub-sub-plots. The grains of sorghum Hybrid 305 was sown on 13^th and 17^th June in the first and second seasons, respectively. The plot area was 12 m² including 4 ridges of 60 cm apart with 4 m length. The results could be summarized as the following:
-   The plant height in both seasons and the panicle length, 1000 grain weight and grain yield/fed. in the second season only, were increased with increasing N fertilizer rates up to 120 kg N/fed., as well as the highest mean values for panicle width, grains weight/panicle in both season and panicle length, 1000 grain weight and grain yield/fed. in the first season were recorded by 100 kg N/fed.
-   Also, the mean values for all the studied traits were increased by increasing P fertilizer rates in both seasons.
-   Here too, the lowest K fertilizer rate (24 kg K₂O/fed.) gave the highest mean values of grains weight/panicle, 1000-grain weight and grain yield/fed. in the first season, while the highest K fertilizer rate (36 kg K₂O/fed.) gave the highest mean values for the same traits in the 2^nd season.
-   In general, the first order interaction either N₃xP₁ or N₃xP₂ and N₃xK₁ or N₃xK₂ as well as P1xK1 or P1xK2 interaction treatments gave the lowest mean values for all the studied traits.

-   Also, the maximum grain yield/fed. (21.46 and 22.78 ard.) were recorded by N₁xP₂xK₁ and N₂xP₂xK₁ interaction treatments in the 1^st and 2^nd seasons, respectively.