Dry Matter Analysis The analyses of forage quality

24 3.4 Result And Discussion 3.4.1 Plant Responses due to the level of irradiance, organic fertilizer and Defoliation Management Several treatments on Field Experimental research were design and the data regarding forage production was gained. Moreover, the levels of shade were assumed might influence strongly on forage yield. Levels of shade were connected directly with light availability. Light is electromagnetic radiation of wavelengths to which the human eye is sensitiveλ ≈ 400 to 700 nm. However, sometimes the word light is also used to refer to other nearby regions of thespectrum: ultraviolet shorter wavelengths than visible light and infra-red longer wavelengths. Light is both a source of energy and a source of information for green plants. It is a sourceof energy for photosynthesis, and a source of information for photoperiodism nightday length, phototropism light direction, and photomorphogenesis light quantity and quality Aphlaho 2006. Trees in some ecosystems, for example in forest, savanna, ect have been referred to as ‗islands of fertility‘ Belsky et al. 1989, because elevated soil nutrients are found beneath their crowns, together with decreased solar radiation, reduced evapotranspiration and reduced soil temperatures Ludwig et al. 2004. The use of organic fertilizer such as manure might be useful to increase SOM. Thelen et al. 2010 observed the manure effected to soil organic matter by using corn Stover. Based on the research, they were obtained that adding manure or compost were effective ways to build SOM even with complete removal of corn Stover. Therefore manure the organic fertilizer was used on this research. The availability of light might influence nutrient intake by plant. Light quality and irradiance incident on shoots could affect the growth of roots by indirectly affecting the photosynthetic availability in roots, either because of changes in allocation or changes in assimilation. In turn changes in the root growth, morphology and symbioses could affect the ability of plants to take up nutrients form the soil. Moreover, light quality can affect the enzymes involved in nitrogen metabolism. At the biochemical level light dependent light induction and modulation of enzyme activity has been studied in some detail. On the other hand, 25 effects of light quality on whole plant mineral nutrient uptake and status have been little studied Aphlaho 2006. In actual condition forage plantation was forced by the limitation of sun availability that could be influence forage production. This condition occurred as the impact of competition both the trees and its plant. In general, plants have two main strategies in response to light competition: overgrow and shade the competitors andor tolerate shade by maximizing growth under reduced light Humphreys 1981. The former was obviously not a viable strategy for pasture plants growing in association with trees. However, tropical grasses were differing in their tolerance of shade. Several data were gained as its responses regarding to different levels of solar radiance, the utilization of organic fertilizer and defoliation management. The information consists of variations including forage yield, plant architecture plant layer height, and leaf area also chlorophyll concentration. In the early respond was provided the measurement on forage yield production on P. purpureum. Table 7. The Measurement forage yield Mgha P. Purpurem on different levels of shade, organic fertilizer and defoliation management treatments. Levels of shade Organic Fertilizer Mgha Defoliation management 40d 50d 60d 30 47.8±4.9 35.6±18.5 28.7±4.4 20 26.8±5.9 29.0±10.0 19.2±3.2 10 25.0±7.3 27.9±3.8 29.5±11.1 60 30 35.7±5.6 35.4±0.8 23.1±5.7 20 21.7±2.0 26.4±5.9 25.9±4.2 10 21.4±1.4 22.9±1.8 15.1±4.8 80 30 18.9±6.3 23.9±4.1 14.3±2.8 20 13.5±2.8 14.6±5.5 16.8±5.1 10 8.1±2.8 14.3±2.7 11.8±7.4 Table 7 showed the measurement on forage yield P. purpureum on different treatments. The data illustrated that levels of shade, organic fertilizer and defoliation management were persuaded on forage yield on P. purpureum. The study showed that yield production depressed as the less number of irradiance accepted by plants. At the same time, the utilization of higher amount of organic fertilizer enlarged yield production compared with less organic fertilizer. It was observed underneath shading condition, the forage yield was reducing, but it could be enhance by adding the organic fertilizer. Underneath shading condition