THE EFFECTS OF DIFFERENT NITROGEN DOSES AND IRRIGATION LEVELS ON YIELD, NUTRITIVE VALUE, FERMENTATION AND GAS PRODUCTION OF CORN SILAGE

Abstract

The study was conducted to investigate the effects of different irrigation levels and nitrogen doses on yield, yield parameters, silage characteristics, digestibility, gas and methane production of corn silage. Three different irrigation levels (50%, 75% and 100% of depleted water) and 3 different nitrogen doses (100, 200 and 300 kg ha-1 N) were applied to corn silage. Experiments were implemented in split-split plots design with three replications during the growing seasons of 2013-2014. Plants were harvested at milk-dough stage and yield and morphologic characteristics were determined. Then, harvested plants were silaged and chemical characteristics were investigated. Irrigation level x nitrogen dose interaction was not found to be significant. Increasing nitrogen doses increased plant height, plant diameter, green herbage yield, crude protein, metabolic energy, gas production and organic matter digestibility and decreased pH levels, ADF and NDF ratios. Increased irrigation levels positively affected green herbage yield, plant height, plant diameter and increased ADF and NDF ratios. Gas production, metabolic energy and organic matter digestibility decreased with increasing irrigation levels. Increasing irrigation levels improved corn yields, but reduced the quality. On the other hand, increasing nitrogen doses had positive contributions both to yield and quality characteristics.