Research Works

Effect of liming, phosphorus and ammonium sulphate on ammonification and nitrification in peat

Fri, 01 Sep 1989 00:00:00 GMT

Effect of liming, phosphorus and ammonium sulphate on ammonification and nitrification in peat Mandal, R.; Parsons, J. W. Mincralizalion of native N in an cxticmcly acid [x^l following liming and addition of P and (NH^)jSO^ was ijivesligalaJ. All Uic UcaUncnLs increased NM^-N uplo 20 days inculiation followed by a rapid d c c T e a s e lo a tniniinum at 35 days.'I hc trend, Uiereafler, mainly followed a slow increase at 45 days. Released of NHj-N increased significanlJy witJi ])H and added (NH^)jSO^ specially where lime and N were applied together.

Influence of aluminum on pH and recovery of exchangeable aluminum from peat

Wed, 01 Mar 1989 00:00:00 GMT

Influence of aluminum on pH and recovery of exchangeable aluminum from peat Mandal, R.; Parsons, J. W. Incubation experiment was conducted to obtain infomiation on tlie extent of acidity developed due to added AlCI, (0, 25, 50 and 100 tig g ') at different pH levels and changes in exchangeable A1 in peat. Results showed that A1 at high pH is hydrolysed causing an increased acidity by releasing H* from hydroxy aluminium compounds. Concentration of exchangeable A! is tremendously reduced with increasing pH possibly due to formation of mono-aluminium compounds or polynuclcar complexes of hydroxy aluminium. Extractable Al in IM KCI was very low Ix-cause of the presence of organic binding sites in peat. Thus, the recovery of exchangeable Al from Fisoii peat (I) containing more humified material was extremely low (1.0-2.1%) in comparison to Re^i Mo,‘?s peat (47.6-52.8%).

Amounts and mineralization of organic phosphorus compounds and derivatives in some surface soils of Bangladesh

Sat, 01 Jan 1977 00:00:00 GMT

Amounts and mineralization of organic phosphorus compounds and derivatives in some surface soils of Bangladesh 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.

Effect of chlorides of cobalt, nickel and copper on nitrification in peat

Fri, 01 Sep 1989 00:00:00 GMT

Effect of chlorides of cobalt, nickel and copper on nitrification in peat 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.