Only 20 % of our rural households in Bangladesh have more than 4 cattle heads and 21 % have more than 2 cattle heads. A 5-8 members family needs 4-6 cattle to run a biogas plant to meet their daily cooking energy. For wide spread dissemination of biogas technology throughout the country it becomes imperative to increase the number of biogas plant users by increasing the gas production rate with the present available cattle heads. It has been found that with the addition of urine to cow-dung gas production has been increased up to 30 % at a proportion of dung, urine and water (50:35:15) which will reduce the number of cattle heads and plant size and hence the construction cost. This will certainly increase the technology users up to 41 % with the present available cattle heads and thereby solve the cooking fuel and organic fertilizer crisis and maintain the hygienic condition. Bangladesh J. Sci. Ind. Res. 41(1-2), 23-32, 2006

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This study aimed to evaluate the biogas production from the manure of hybrid and local breed cows fed with different types of feeding practices. The feedstock and digestive composition were measured to determine their effects on biogas production. The batches were prepared form manure of hybrid and local breed cows fed with roughages and mixed ration (roughages and concentrate) adding Inoculum (I) and with a total weight of 200 g. Four experimental groups (T1, T2, T3 and T4) were set up using mixing ratios of CM: H2O: I (25: 25: 50). The digesters were set up at ambient temperature for 40 days of Hydraulic Retention Time (HRT) using a water displacement method to monitor biogas production in the proto-type digesters. The biogas yield from the manure was found 250.90 Nml/g VS for T1, 176.50 Nml/g VS for T2, 208.25 Nml/g VS for T3 and 180.88 Nml/g VS for T4, respectively. The average CH4 and CO2 concentration (% vol.) in biogas were found 53% and 47% for T1, 55% and 45% for T2, 52% and 48% for T3, 53% and 47% for T4, respectively. The content of H2S was not found in this study. The study concluded that the overall biogas production was higher in the manure of hybrid cows fed with roughages. However, the biogas production was also higher in the manure of local breed cows fed with roughages than mixed ration. The results indicated that C, N, P, K and S values were relatively lower in this study. Keywords: Biogas, CH4, hybrid and local breed cows, prototype digester, HRT.

The experiment was conducted at Central Cotton Research Farm, Sreepur, Gazipur during cotton growing season of 2009-2010. Cotton variety cv. CB-10 was used under experiment. Eight levels of boron (0.0, 0.25, 0.50, 0.75, 1.0, 1.25, 1.50 and 1.75, g L -1 of foliar B application of 1.75 g B L -1 water. The highest lint yield (0.47 t ha -1 ) was obtained in 1.00 g B L -1 water than that of control. The highest germination (95.58%) was recorded at 1.00 g B L -1 water than that of control. Foliar boron fertilizer increased seed oil and protein content but it was insignificant. Numerically, the highest oil content (19.06%) was found at 1.25 g B L -1 water and protein (23.75%) at 1.75 g B L -1 water foliar spray.

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