Abstract
Animal manure is an important source of nutrients for crop production. Bio-slurry is a by-product
of biogas production that generates from anaerobic digestion of animal wastes. Integrated use of
bio-slurry and chemical fertilizer could be profitably used in cultivating crops. With this concept
in view, the present study was undertaken to evaluate the mineralization pattern of nitrogen (N)
and sulphur (S) from bio-slurry and to see its field performances for crop production.
Mineralization study was accomplished under anaerobic (55% water holding capacity) condition
for 84 days at 200 ± 20 C at the University of Aarhus, Denmark. Nitrogen mineralization reached its
peak within 56-84 days. The maximum amount of 169.8 mg N/kg with 71.3% net N was recorded
with the digested alfalfa green manure. The S mineralization increased up to 49 days and then
decreased with time. The maximum amount of 6.84 mg SO42--S/kg was released in the treatment
Cattle manure 1 and net SO42--S mineralization of 26.0% was found in wheat straw. The treatments
with slurry released lower amount of S compared to original cattle manure. Field experiments
with the single vegetable crops (cauliflower, cabbage, carrot and brinjal) and with the T. Aman -
Potato-Boro rice cropping pattern were carried out at Bangladesh Agricultural University (BAU)
farm, Mymensingh for consecutive two years. The experiments were laid out in a randomized
complete block design with three replications. The crop varieties were White corona for
cauliflower, Atlas70 for cabbage, Kuruda 35 for carrot, Uttara for brinjal, BINA dhan7 for T. Aman
rice, Diamant for potato and BRRI dhan28 for Boro rice. For single crop experiments, there were
seven treatments viz. T1: 100% PM (poultry manure) slurry, T2: 75% PM slurry + CF, T3: 50% РМ
slurry + CF, T4 100%NPKS, T5: 75%NPKS, T6: 50%NPKS and T7: control. Treatment T3 (50% PM
slurry + CF) in both years produced significantly the highest yield of cabbage, cauliflower, carrot
and brinjal. For T. Aman,-potato-boro rice pattern, the field trials comprised seven treatments such
T1: control, T2: 100%NPKS, T3: 70%NK, T4: 70%NK+PM slurry, Ts: 70%NK+CD (cowdung)
slurry, T6: 70%NK+PM and T7: 70%NK+CD. After harvest of the first T. Aman rice, the plots were
divided into two parts. In one part of the plot, manure and bio-slurry were applied to each crops
while in another part of the plot, manure or bio-slurry was added to alternate crops. Chemical
fertilizers were applied to each crop in both parts of the plots. Treatment T4 (70%NK+PM slurry)
produced the highest crop yield in both parts of the plot. The highest yield was followed by the
yield recorded by the treatments T6 (70%NK+PM) and Ts (70%NK+CD slurry). The use of manure
and fertilizer in each crop produced higher annual productivity, and increased the rice equivalent
yield of about 3.0 t/ha/yr compared to the crop yield where manure was applied to alternate crop
and fertilizer to every crop. The fertilizer-manure combined treatments slightly increased the pH,
OM, N, P, K and S contents of soil after two crop cycles. This study clearly indicates that use of
poultry manure slurry in combination with chemical fertilizers can give higher crop yield than the
use of chemical fertilizer alone and it can also improve nutrient status of soil which has significant
value for sustainable crop production.