Experimental site and climatic condition The experiment was carried out at the Dairy Farm under the Department of Dairy Science, Bangladesh Agricultural University, Mymensingh during the period from December, 2003 to April, 2004. The climate of the experimental site was characterized by scant rainfall and low temperature during December to April (Biswas, 1987). The experimental site was in the old Brahmaputra flood plain agro-ecological zone having a non-calcareous dark grey flood plain. The soil is loam in texture, neutral in reaction (pH 7.0) and contained 0.12% nitrogen (N) and 1.76% organic matter (FAO and UNDP, 1988). The land was flat, well-drained, and above flood level.
Preparation of compost and farmyard manure (FYM) Compost and composting: Compost is organic manure prepared by mixing different types of plant residues and animal waste. It is a product of the decomposition of plant and animal waste with various additives. The method of preparing compost is termed as composting. Composting denotes allowing a mixture of organic materials to decompose under more or less controlled conditions to produce a stable .end product, which is used as a manure soil conditioner. It is a biological process in which composting materials are decomposed by different aerobic and anaerobic microorganisms.
The method followed in this experiment to prepare compost was the heap method and the materials which used were cow dung, water hyacinths and soil. Size of heap was length - 3m, breadth - 1.25m and height - 1.25m. The substrate was minted with water (soak substrate about 30 minutes) with a spading fork the soil where to build the compost pile was loosened at about 18 inches depth. The composting materials were piled layer by layer and each layer had 15 cm height. This layer consists of three sub —layers-bottom (water hyacinth 5 cm), middle (cow dung 5 cm) and top (sandy soil 5 cm). The substrates were piled up loosely and contused until the compost heap reached 1.25 m height. In this experiment about 100 g of urea fertilizer was added at the top of each layer to increase microbiological activities for decomposition, Finally whole body of the heap was covered with clay soil. When the composting heap reached at 1.25m this heap had been saddled and the pile was covered completely at all sides with polythene except at the bottom. Four weeks after piling the pile was funned for rapid and proper decomposing. Eighty days after piling the compost were used as organic fertilizer in the fodder plot ready for this experiment.
Farmyard manure: Farmyard manure was produced in the farm from animal excreta. There are three main systems of collecting and storing cattle manure. In this experiment, the commonest system, the dry earth system was used for the preparation of farmyard manure. A manure pit was prepared by the measurements of 3 m long, 1.25 m breadth and 1.25 m depth. A shed was constructed over the pit with bamboo and polythene. At the bottom of the pit dry, loose, loamy soil was spread at a depth of 15 cm. for absorbing the urine, excreta of farm animals, the litter, leftover materials and miscellaneous farm by-products were stored in the manure pit. After filling up the manure pit, it was covered with a layer of soil to a thickness of 8 cm.
Experimental design and treatments There are two factors (F) in the experiment. Fl was considered for compost and F2 for FYM while FO was considered for the control group. Every factor had three treatments. The fodder crop was cultivated using three levels of each of compost and FYM (10 ton/ha, 12 ton/ha, 14 ton/ha) in a 2 x 3 factorial arrangement. The experiment was laid out in Completely Randomized Design (CRD). The whole experimental area was divided into twenty-one unit plots. The size of each unit plot was 4 m x 2.5 m (10 sq. m). Three treatments {T 1: 10 kg/plot (10 ton/ha.), T2: 12kg/plot (12 ton/ha.), T3: 14 kg/plot (14 ton/ha.)) were randomly distributed into eighteen plots and the remaining three plots were considered as controlled group. The Zamboo grass (Hybrid Jowar) was cultivated in different plots of-each factor and randomly applied compost and FYM so that each fodder in the same factor and same treatment could receive three different levels of compost and FYM uniformly. In this way, each factor treatment was replicated three times.
Land preparation and sowing The land was ploughed and cross ploughed four times with bullock-drawn country plough followed by laddering to obtain the desirable tilth. The corners of the land were spaded and visible larger clods were broken into small pieces. Weeds and stubbles .of the previous crop was removed from the soil. Towards the final stage of land preparation, compost and FYM were applied as organic' fertilizers at the rate of 10, 12, 14 ton/ha. Finally, the experimental plots were prepared by leveling properly and the seeds were sown after 15 days of the land preparation.
The seeds were sown following line sowing method. with a row spacing of 25 cm and plant spacing of 5 cm. The seed rate was 20 kg/acre. A light laddering was done for better soil covering of seeds. Different species of natural weeds were grown in experimental plots. Weeding was done once during the experimental period. No irrigation and no insecticides were used. The height of fodder was measured every fortnightly. Ten fodder plants were randomly selected from each plot and full lengths of the plant were measured by a measuring tape. Fodder height was measured in cm from the base of the plant. Zamboo fodder of all the plots were harvested at the pre-flowering stage (60 days after sowing). Immediately after harvesting, all the fodders were weighed and average forage production under different levels of organic manure were expressed in metric ton/ha (MT/ha). The plots were harvested above the ground level.
Statistical analyses The data were analyzed using the MSTAT statistical program for a Completely Randomized Design (CRD), and differences among the treatment means were determined by the least significant difference method (Gomez and Gomez, 1984).