Response of nutritional components in Guimu No.1 hybrid with different cuttings to urea and ammonium bicarbonate

Taking red soil in Hengyang, Hunan province as research object, response of nutritional components in Guimu No. 1 hybrid(Guimu No. 1 Pennisetum urpureum) to urea and ammonium bicarbonate during hot seasons was discussed in this study. There were 3 cuttings and all in growth period of Guimu No. 1 hybrid, including June 5th-July 15th, July 16th-August 24th and August 25th-October 3rd. Set three fertilization treatments on Guimu No. 1 hybrid, including urea group, ammonium bicarbonate group and control group(no fertilizer), and the experiment was randomized designed. The results showed that: 1) Crude protein, soluble sugar and acid detergent fiber (ADF) contents of three groups presented unimodal curves during the period of June-October, and maximum values of these three items were all observed in the period with the highest temperature(July 16th-August 24th); 2) In the same period, applying nitrogen fertilizers(urea group and ammonium bicarbonate group) could significantly enhance the crude protein, amino acid and soluble sugar contents(P0.05), while decrease neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of Guimu No. 1. The highest crud protein contents were observed in ammonium bicarbonate group for the cutting of June 5th-July 15th, and in urea group for the cuttings of July 16th-August 24th and August 25th-October 3rd. For 3 cuttings, ammonium group had the highest amino acid content and urea group had the highest soluble sugar content; 3) For the same treatment, cuttings of July 16th-August 24th had the highest nutrient yield. Dry matter, crude protein, amino acid, soluble sugar, acid detergent fiber yield were ammonium bicarbonateureacontrol during the period of June-October. Therefore, applying ammonium carbonate is better than applying urea to Guimu No. 1 hybrid in red soil during hot seasons.