Abstract
A study was undertaken to see the effects of integrated use of fertilizer and manure on the crop yields and soil properties in the wheat rice and rice rice cropping patterns. The wheat- rice pattern experiments were conducted at the Regional Agricultural Research Station (RARS) and the Farming System Research (FSR) site of Jamalpur during 1994-97 and the rice rice pattern at Bangladesh Agricultural University (BAU) farm, Mymensingh during 1995-98. Cowdung and dhaincha (Sesbania) were used as manure treatments. The experiments were laid out in a randomized complete block design with four replications. In the wheat-rice pattern, the highest grain yield of wheat was obtained with the 100% of NPKSZn fertilizers treatment which was comparable to the yield observed with the treatment containing 75% of NPKSZn fertilizers plus cowdung. In both locations, the treatments containing 50% or 75% of N plus 50%, 75% or 100% of PKS fertilizers along with GM gave the highest or an identical grain yield of T.Aman rice compared to the rate of 100% NPKS fertilizers. The highest N, P, K, S and Zn uptake by wheat were found in the treatments receiving full rate of NPKSZn fertilizers, and it was statistically similar to that noted with 75% N plus full rate of PKSZn fertilizers, and 75% NPKSZn fertilizers plus cowdung. For T. Aman rice, the highest uptake of these nutrients were recorded with 50 or 75% N plus 50%, 75% or 100% of PKS fertilizers along with GM and occasionally with cowdung. In the rice-rice pattern, the highest grain yield of Boro rice was recorded in the soil test basis (STB) NPKSZn fertilizers treatment while in T. Aman rice the 75% or 100% of NPKS(STB) fertilizers plus GM with or without cowdung gave the highest or a comparable yield. The mean yearly N, P, K, S and Zn uptake by rice (Boro + T.Aman) increased with increasing supply of nutrients. Application of cowdung along with NPKSZn(STB) resulted in markedly higher uptake of nutrients in Boro rice. In T. Aman rice, application of NPKS(STB) with GM and/or CD showed higher N, P, K, S and Zn uptake than that with NPKS(FRG) and NPK(FP) treatments. The total N content and the available P, K, S and Zn status in soils increased slightly due to manuring. The whole. results suggest that the integrated use of fertilizer with manure (viz. Sesbania, cowdung) can be an efficient practice for ensuring higher crop yields without degradation of soil fertility.