Ghazal, F.M., Hassan, M.M.M., EL-Sayed, G.A.M. and Desoky, A.H.( 2013). Response Of Maize Crop To Cyanobacteria Applied Under Different Nitrogen Rates Nature and Science 2013;11(12)
Abstract: The present investigation was conducted in sandy soil at Ismailia Agricultural Research Station, Agric. Res. Center (ARC) (Latitude 30ᵒ 35′ 41.901″ N and Longitude 32ᵒ 16′ 45.843″ E), Egypt, during two successive summer seasons of 2011 and 2012.Maize hybrid SC10 was used to study the effect of cyanobacteria (Cyano) and nitrogen fertilizer on maize growth, grain yield, yield components, and their effects on the biological activity of the soil around the rhizosphere of maize plants. Four treatments of cyanobacteria: 1) soaking grains in Cyano filtrate for 24 h then sprayed with Cyano filtrate after 30 d from planting, 2) side dressing along the row (dry) then sprayed at 30 d from planting, 3) soaking grains for 24 h + dry Cyano + Cyano spray, 4) and control (untreated); and three rates of nitrogen: 107 (1/3 N), 214 (2/3 N), and 321 kg ha-1(full N rate) were used. Experimental design was split-plot with four replications, where Cyano treatments were assigned to main plots and nitrogen rates in the sub plots. Results showed significant differences among Cyano treatments for days to 50% tasseling and days to 50% silking in 2012 season. Early days to 50% tasseling and days to 50% silking and were associated with the application of Cyano treatment (dry + spray) in 2012 season. However, Cyano did not affect days to 50% tasseling and days to 50% silking in 2011 season. Treatment of Cyano (soaking + dry + spray) was accompanied with the tallest plants and the highest values of ear heights. While, the shortest plants and the lowest values of ear heights were associated with using Cyano (soaking + spray). Effect of Cyano inoculation on grain yield was significant in both years. The highest grain yield was associated with Cyano treatment (soaking + dry + spray).The highest values for any of ear length and ear diameter was recorded as a result of using Cyano treatment (soaking + spray). Number of kernels row-1 was significantly affected by Cyano inoculation in the two years. Nitrogen application hastened the time of tasseling and silking. The increase of nitrogen rate from 1/3 N to full N increased significantly the plant height. Application of 1/3 N ha-1 was accompanied with the shortest plants and the lowest values of ear height. Grain yield increased as N increased up to the highest rate. Regarding yield components, ear length, ear diameter, and number of kernels row-1 were significantly affected by N application. Increasing N levels up to full N rate (the highest N rate) was associated with the tallest ears and the highest values for number of kernel row-1 and ear diameter. Nitrogen x Cyano interaction had significant effect on days to 50% tasseling and days to 50% silking in the second season only. Applying full N ha-1 with Dry Cyano + Cyano spray accelerated days to 50% tasseling and days to 50% silking. Using Cyano (soaking+ spray) with 1/3 N ha-1 gave the shortest plants. The highest grain yield was achieved as a result of applying (full N + soaking in Cyano + dry Cyano and Cyano spray) in the two seasons. Furthermore, the use of cyanobacteria in combination with different nitrogen rates increased the rhizosphere soil biological activity of the maize rhizosphere soil.
Keywords: (Cyanobacteria, nitrogen fertilizer rates, maize (Zea mays L.), rhizosphere soil biological activity sandy soil.)
