Search Filter
- Publications
- Abstract of Theses and Dissertations
- Database
- Effect of Nitrogen and Phosphorus Fertilizers on the Growth Response...
Effect of Nitrogen and Phosphorus Fertilizers on the Growth Response of Themeda triandra Forsk.
Thesis Abstract:
A greenhouse experiment was conducted to determine the effects of varying levels of nitrogen and phosphorus on the growth responses of Thermeda triandra, using plants and soil taken from Carranglan, Nueva Ecija.
Phosphorus was applied in the form of superphosphate (18% P2O5) at rates of 0,25, 50, 75 and 100 kg/ha. Nitrogen was added in liquid form of ammonium sulphate (NH4)2SO4 (21% N) at rates of 0, 50, 100, 150, 200, 250 and 300 kg/ha.
Results showed that nitrogen and phosphorus separately increased herbage yield, but the highest yields were obtained from the 200N-100P kg/ha and 200N-50P kg/ha combination treatments. The greatest root and tiller production resulted from 150N-50P kg/ha and 100N-50P kg/ha combination, respectively. Phosphorus alone showed the most significant capacity for height. However, greater grass height did not mean higher herbage yield.
Fertilizaer effects on leaf area index (LAI) were assessed in terms of number of, leaves and leaf surface area, period of growth and rates of fertilizer application. A combination of 250N-75P kg/ha gave the highest LAI.
Forage quality was evaluated in terms of nutrient composition. Protein content of Themeda triandra increased with nitrogen fertilizer applied alone. Phosphorus alone and N-P combination had no effect on protein content. On the other hand, ether extract and in vitro fry-matter digestibility decreased, while crude fiber increased as the grass matured.
Ammonium sulphate decreased but superphosphate increased soil pH. Organic matter and potassium decreased with fertilizer application because fertilization always stimulates soil microorganism activity and plant uptake of soil nutrient. However, in the study, the addition of fertilizers increased available soil phosphorus.
