Nitrogen Rates and Hybrids Influence as Affected on Maize (Zea mays L.) Silage Yield and Quality

摘要

A field experiment was conducted in 2008 and 2009 summer seasons to evaluate six maize hybrids; namely, SCI24, SC155, TWC310, TWC324, TWC327 and TWC352, under three nitrogen rates; viz., 90, 135 and 180 kg N fa~(-1), for their silage yield and quality. The results showed that nitrogen had a significant effect on mean squares for fresh and dry silage yields, crude protein and digestible crude protein. Also, hybrids had a significant effect on mean squares for all studied traits, except for crude fiberand total digestible nutrient. Hybrids significantly yielded more fresh silage of 2.86 and 4.81 tons fa~(-1) at 135 and 180 kgN fa~(-1), compared with 90 kgN fa~(-1). Silage dry matter yield, under 135 and 180 kgN fa~(-1), gave 0.94 and 1.56 tons fa~(-1) more than that under 90 kg N fa~(-1). Nitrogen rates of 135 and 180 kg fa~(-1) produced crude protein of 0.49 and 1.4 % more than 90 kg N fa~(-1). Hybrids significantly differed for all studied traits, except for crude fiber and total digestible nutrients. Fresh silage yield ranged from 23.21 to 28.34 ton fa~(-1), where, hybrid ranks were TWC324 > TWC327 > TWC310 > TWC352 > SC124 > SC155. Silage dry matter yield ranged from 8.09 to 9.74 ton fa~(-1). Hybrids significantly varied for their dry matter yield, where TWC324 > TWC310 > TWC327 > SC155 > TWC352 > SC124. For crude protein, TWC327 was the best, followed by TWC324, then, TWC310. Mean of crude fiber ranged from 21.71 to 23.38 %, where TWC310 had the lowest mean. Significant positive correlation was found for FSY with DMY (0.90), CP and DCP (0.83). Significant positive correlation was detected for CP with DCP (0.99). Crude fiber (CF) had a negative correlation with FSY, DM, CP, DCP and TDN. Also, ASH had a negative correlation with FSY, DM, CP, DCP and TDN. Finally, nitrogen affected fresh silage yield, silage dry matter yield, crude protein and digestible crude protein. TWC324, TWC327 and TWC310 hybrids had the highest fresh silage yield, silage dry matter yield, crude protein and digestible crude protein. Accordingly, these hybrids might be used for high silage production.