Abstract
Both field and pot experiments were conducted in consecutive two years (2002 and 2003) at a
farmer's field in Bogra District and at the net-house of the Department of Agricultural Chemistry, BAU, Mymensingh to evaluate the effects of composted municipal waste (MW), press mud (PМ),
sewage sludge (SS), cow dung (CD) and chemical fertilizers (CF) on rice. Two levels each of above-mentioned wastes (5 and 10 t ha¹) individually or in combination with two levels of CF (NPKSZn) at the rate of 50 and 75% of the recommended dose were applied. One control and one
100% CF were also included. RCBD experimental design in field and CRD in pot experiments
were followed with four replications. SS at the rate of 5 or 10 t ha¹ in conjunction with 50 or 75%
CF performed the best results producing grain, straw and total dry matter (TDM) yields as well as
nutrient contents of rice in both field and pot experiments during two consecutive years. Press mud
also recorded similar results in respect of grain, straw and TDM yields in both the experiments.
The highest grain (5.62 t ha¹) and straw (6.96 t ha¹) yields in 2002 field experiment were obtained
from PM 10 t ha¹ + 75% CF with second highest net return and moderate marginal benefit cost
ratio (MBCR) against control (2.2 and 2.64 t ha¹). In 2003, the highest grain (6.81 t ha¹) and straw
(8.24 t ha¹) yields were recorded by the treatment CD 10 t ha¹ + 75% CF with the highest net
return and moderate MBCR whereas lowest recorded in MW 5 t ha¹ (2.61 t ha¹) and control (3.20
t ha¹), respectively. SS at the rate of 5 and 10 t ha¹ plus 75% CF produced the tallest plants
(113.3 cm), the highest effective tillers hill (38.33), the highest grain (57.18 g pot') and straw
(69.0 g pot¹) yields in 2nd pot experiment. Rice yield and yield attributes significantly increased
with the increasing amount of composted wastes in combination with 50 or 25% reduced
recommended rate of CF. Among the different wastes, SS imparted superior role on yield attributes and was followed by MW and CDCDAn field experiment, SS with CF application resulted
higher uptake of N (73.42 -117.76 kg ha'), K (86.84 - 142.28 kg ha¹), Na (10.25 -15.65 kg ha') Notand Cu (220.94 - 333.37 g ha¹); PM with CF influenced the uptake of P (15.33 - 33.03 kg ha¹), Ca
(16.86 -109.35 kg ha°¹), As (4.09 - 9.62 g ha¹) and S (17.67 - 30.71 kg ha¹); CD with CF resulted
the uptake of B (91.85 - 308.17 g ha¹) and Mg (16.77 - 33.10 kg ha¹); MW with CF influenced the highest Zn (245.54 - 572.18 g ha¹) and CF alone imparted the highest amount of S (21.57 - 30.92 kg ha¹) and Fe (16.58 -18.97 kg ha¹). In pot experiments, the highest uptake of almost all nutrient elements including heavy metals and trace elements observed in SS with CF and PM with CF imparted the highest uptake of S, Ca, B and As. Arsenic uptake by grain was below statutory limit. Nutrients and OM content were significantly increased in post harvest soils over initial value. The overall findings suggest that the composted wastes combined with 50 or 75% CF can be an efficient practice for ensuring higher rice yield without deteriorating soil fertility.