Browsing by Author "Mandal, R."

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A study of availability of soil nitrogen by various extractants
(Bangladesh J. Sci. Res., 1989) Hossain, A. K. M. A.; Hoque, S.; Mandal, R.; Khan, T. H.
Available nitrogen was determined using 11 extractants on 29 soils covering a wide range of physical and chemical properties. Assessment of 2M KCI (p H 7.0), IN NaCI, IN NaCI (pH 1.0), 2N NaCI, IN Na2S04 ( p H l .O ) , 0.5N NaHCOa ( pH 8.5 ), Morgan’s reagent, O.IN C a C h , 0.5N HCl, 0.7N HCI and 0.5N H2SO4 extractable nitrogen showed that the best efficiency was obtained by IN NaCI. IN NaCI and 2M KCI extractable nitrogen bear significant relationship with soil organic matter and total nitrogen were found to be dependent on the type of soil. Correlation study with nitrogen uptake by BR-4 rice reveals that 2M KCI is superior to IN NaCI and closely followed by IN NaCI. Compared to these two extractants both aerobic and anaerobic incubation methods produced less satisfactory results.
A study of slow-release N-carrters on rice
(Journal of Bangladesh Academy of Sciences, 1987) Rashid, M. H.; Islam, A.; Ahmed, I. U.; Islam, M. S.; Mandal, R.
A field experiment was carried out to monitor the relative efficiency of urea, urea formaldehyde (UF), sulphur coated urea (SCU) and isobutylidene diurea (IBDU) each at the rate of 40, 80 and 120 kg N/ha on growth, yield and chemical composition of rice grown during aman season. Application of nitrogen caused a significant increase in number of tillers, height and yields of straw and grain irrespective of the sources. Among the chemical composition (N, P, K, Ca and Mg) of straw and grain only N content was significantly improved. All these components increased with nitrogen rate. The effectiveness of the N-carriers in increasing the parameters followed the order: SCU> Urea> IB DU > UF. Percent recovery of added nitrogen generally decreased with increasing amount of nitrogen. SCU was found to be superior to conventional urea whereas IBDU and UF were inferior due to slow release of nitrogen. Anaerobic incubation of urea, UF, SCU and IBDU for 4 weeks caused a significant release of NH4-N from 59.9 to 78.2%. An initial rapid production of NH4-N was followed by a gradual release with time. More than 75% urea and SCU decomposed to NH4-N within 2 and 4 weeks respectively. UF was more resistant to decomposition as compared to SCU and IBDU. However, the trend of degradation was similar for all the compounds. Accumulation of a small quantity of NO3-N disappeared rapidly within 2 weeks time.
Abundance of indigenous cyanobacteria in saline rice field ecosystem of ganges tidal floodplain as influenced by K and Zn
(J. Phytol. Res., 2011) Mandal, R.; Begum, Z. N. Tahmida; Amin, Farzana Binte
Amounts and mineralization of organic phosphorus compounds and derivatives in some surface soils of Bangladesh
(Elsevier Scientific Publishing Company, 1977) Islam, A.; Mandal, R.
Concentrations of a few organic phosphorus compounds and their hydrolysis products have been determined in a number of Bangladesh soils. The amounts of DNA and its derivatives, inositol penta- and hexaphosphates, ranged from 0.16 to 1.30, and 18.5 to 130.0 ppm, respectively. The hydrolysis products of phospholipids such as choline, ethanolamine and glycerophosphate ranged from 0.36 to 3.29, 0.28 to 2.52 and 0.20 to 1.05 ppm, respectively. Multiple correlation suggested that pH, organic matter, organic phosphorus and total phosphorus were collectively related to the amounts of different organic phosphorus fractions in soil samples. Individually, DNA and its derivatives were found to be significantly related to total phosphorus and inositol penta- and hexaphosphates to organic phosphorus. Choline was significantly related to organic matter, organic phosphorus and total phosphorus; ethanolamine to organic matter and total phosphorus; and glycerophosphate to organic phosphorus. Moisture and lime promoted progressive mineralization of organic phosphorus with time. Potassium dihydrogen phosphate, glucose and ammonium sulphate showed rapid initial and final mineralization. In contrast, the application of compost caused an initial luxury immobilization followed by a marked increase in mineralization with time. Maximum mineralization was observed when ammonium sulphate was added to samples in submerged conditions. The least mineralization occurred when lime was added to samples at 50% of field moisture capacity.
Availability of soil organic phosphorus to crops
(Nuclear science and applications, 1984) Mandal, R.; Islam, A.
The influence of each of potassium dihydrogen phosphate, ammonium sulphate, compost and glucose at the rate of 100 kg ha -i and liming of soil to pH 7.0, on the uptake of phosphorus from organic fraction by rice, jute, wheat, soybean and tomato plants has been studied. All the crops absorbed mineralized soil organic phosphorus signiBcantly. Plants absorbed more organic phosphorus from soil treated with ammonium sulphate and lime.
Characterization and categorization of Azotobacter and related microorganisms of Bangladesh soils
(Bangladesh J. Sci. Res., 1989-12) Mandal, R.; Parsons, J. W.
Free.living nitrogen fixing bacterial isolates were purified from eleven soil samples representing eight typical zones of Bangladesh. The isolates were categorized on the basis of their colonial, morphological and physic-biochemical characteristics. Only one isolate could not be fitted into any recognized group. The rest were the members of Azotobacter and Azomona.i genera.
Comparative performance of modern wheat varieties in different salinity
(The Journal of Noami, 1994-12) Aich, A. C.; Mandal, R.; Ahmed, A. H. M.
Comparison of methods to evaluate k availability in rice soils
(Srilankan Journal of Agricultural Sciences, 1988) Islam, A.; Hoque, S.; Mandal, R.; Chowdhury, S. A.
tions have been used to evaluate K availability from 29 rice soils. Of the methodsy boiling IN HNO^ extracted the highest amount of available K. The methods may be arranged as boiling IN HNO2 > hot 1.4N H^SO > IN Na^SO. (pH 1) > modified IN NaCl (pH 1) > 0.7N HCl > 0.5N HCl > Morgan’s reagent > 0.5M NaHCO^ (pH 8.5) > IN NaCl > IN NH^OAa > Water according to their relative efficiency. Extractants having acidic character were found to he superior over other methods. pH fluctuations possibly accentuated K release from the soils. All the methods correlated significantly with 60 days plant K. Highly significant correlation at 0.1% level was revealed by boiling 1 N HNO^j hot 1.4N H^SO^, IN NaCl (pH 1) and 0.5M NaHCO. (pH 8.5) with plant K. Only IN NaCl (pH 1) extractable K showed significant correlation with 90 days plant K.
Contribution of blue-green algae on fertility of rice soil fertilized with NPKSZn
(J. Phytol. Res., 2001) Hossain, Md. Jakir; Mandal, R.; Begum, Z. N. Tahmida
Conversion of urea placed at different depths and its subsequent impact on growth and yield of rice
(Indian J. of Agric. Sci., 1980-11) Islam, A.; Mandal, R.; Ahmed, Z.; Rashid, M. H.
In a study on the effect of urea with depths in rice {Oryza sativa Linn.), conversion of urea into NHj-N was maximum at 15 days in most of the treatments and into NOj-N was at 7 days. But with surface placement of urea it continued up to 15 days of placement and thereafter the concentrations of both declined with time in all the treatments. Fertilizers @ 80 kg N + 60 kg P + 40 kg K/ha placed 8-cm depth produced the highest dry matter and grain yield. At this treatment, the rice plants also accumulated highest amount of N in the shoot and grain.
Cyanobacteria in rice soils
(World Journal of Microbiology & Biotechnology, 1994) Khan, Z. U. M.; Begum, Z. N. Tahmida; Mandal, R.; Hossain, M. Z.
Direct absorption of organic phosphate by rice and jute plants
(International Journal of Plant Nutrition, Plant Chemistry, Soil Microbiology and Soil-Borne Plant Diseases, 1979-10) Mandal, R.; Islam, A.; Osman, K. T.
Appreciable amounts of organic phosphate from calcium glycerophosphate, lecithin, sodium phytate and inosine-5-monophosphate were absorbed directly by rice plants and that from calcium glycerophosphate and lecithin by jute plants under sterile and non-sterile conditions. The plants absorbed phosphate both in organic and inorganic combinations and the deficit of one form in the media made the other 'more available' to the roots. Sterilization of jute roots with 0.r„ HgCl^ stopped the absorption of phosphate upto 4 days while the treatment mixture of CjHjOH and HtOj indicates inhibitory effects on roots of neither plants.
Distribution o f hydrolysis products o f inositol penta- and hexaphosphates in some humid tropical soils
(Journal of Trop. Agric., 1978-04) Mandal, R.; Islam, A.
'I'he proportions of' inositol jjentaphosphate (IPb) and hexaphospliate (IPa) varied significantly and were found to be related to the organic matter and organic P contents of the soils sampled. Esters of myo + D-chiro IPf, together accoimted for 48 to 81 per cent and scylloinositol represented about 19 to 52 per cent of the total hcxaphosphate. Simple correlation revealed that alkaline conditions probabK’ favoured the synthesis of scyllo //■’e by phytase and multiple correlation suggested that organic matter, organic P and pH were collectively related to the amounts of different inositol polyphosphate fractions in soil samples. The ratio of IP^ to IP;, varied between 0-7 and 4-3 and that of myo + D-chiro to scyllo IP^ between 0-9 and 4-3.
Distribution of organic phosphate compounds in some soil profiles of Bangladesh
(Bangl. J. Sci. Res., 1980) Mandal, R.; Islam, A.; Osman, K. T.
Inositol phosphate, phospholipid^ ribonucleic acid and deoxyribo nucleic acid along with their derivatives decreased gradually with depth in the profiles, while their variable amounts were jointly correlated with organic phosphate, total phospate, organic matter, total nitrogen, pH and clay content of the soil. However, individually inositol phosphate was significantly correlated with organic phosphate, organic matter, pH and clay at the 0,1% level, and ribonucleic and deoxyribonucleic acids and their derivatives with organic phosphate and organic matter at the 5 and 10% level respectively while phospholipids with none of the factors studied.
Distributional pattern of nitrogen fixing cyanobacteria in rice field of Bangladesh
(Phykos, 1993) Begum, Z. N. T.; Khan, Z. U. M.; Mandal, R.; Hossain, M.Z.
Economic feasibility of bamboo subsurface drain-age in coastal saline soils of Bangladesh
(Intern. J. Trop. Agric., 1997-12) Aich, A.C.; Ahmed, A. H. M.; Mandal, R.
Effect of aluminum, iron and manganese on nitrification in peat
(Srilankan Journal of Agricultural Sciences, 1989) Mandal, R.; Parsons, J. W.
Nitrification in the presence of 0 to 3000 pg of each of Al, Fe and Mn as chlorides in peat (g ) has been studied. About up to 40 days the added elements could not produce any appreciable change in the processes of N mineralization and transformation. However, thereafter the salts suppressed nitrification and encouraged ammonification. The interalia transformation of N increased with concentration having the threshold value of 2000 \xg peat. The divergence of two trend (ammonification and nitrification) in the presence of metals attained the maximum at about 80 days. Addition of elements in freshly prepared peat was found to be more responsive than the aged one.
Effect of blue-green algae and urea-N on growth and yield performance of traditional variety of rice
(J. Phytol. Res., 2009) Mandal, R.; Begum, Z. N. Tahmida; Islam, Saiful
Effect of brackish water, organic matter, lime and gypsum on grain yield of wheat in salt affected soils of Bangladesh
(Journal of Indian Soc Coastal agric Res., 1995) Aich, A.C.; Mandal, R.; Ahmed, A. H. M.
Effect of chlorides of cobalt, nickel and copper on nitrification in peat
(Pak. J. Sci. Ind. Res., 1989-09) Mandal, R.; Parsons, J. W.
Mineralization of N in ihe presence ofO to 2000 mg kg ' each of Co. Ni and Cu as chlorides in peat was studied. Tliese s;dts of metals did not produce any significant change in tlie proccss of niLrificalion and ammonificalion up to 40 and 50 days respectively. However, lliereafter tlie general trend was forNH^-N to decrease up to 110 days as (NOj+NOj)- N accumulated. Nitrificaiion was increasingly sujipressed as tlie Co, Ni and Cu were increa.