Influence of temperature on decomposition of wheat straw and nutrient release in mollisols
Loading...
Date
2004-08
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
A laboratory experiment was conducted to study the influence of temperature on decomposition of wheat straw and nutrient release in Mollisols. For this study representative samples of three soils viz. Phoolbagh clay loam, Haldi loam and Patherchatta sandy loam were taken and wheat straw was applied @ 4.544 g/kg soil. The soils were incubated at 15, 25 and 35°C for 90 days. The evolution of carbon dioxide from soils was measured quantitatively following the alkali trap method. The soils differed significantly with regard to CO2 evolution. Haldi loam showed the highest CO2 evolution while Patherchatta sandy loam recorded the lowest, irrespective of temperature. The rate of CO2 evolution from all the soils was highest during the first six days of incubation and lowest at the end of incubation period. The CO2 evolution at 35°C was significantly greater than at 25 and 15°C at all dates of observation. At the end of incubation period in Phoolbagh clay loam 24.6, 38.4 and 59.6 percent carbon from added wheat straw was lost at 15, 25 and 35°C, respectively. In Haldi loam the corresponding values of wheat straw carbon loss was 22.4, 37.9 and 52.7 percent and in Patherchatta sandy loam 21.1, 31.8 and 45.3 percent, respectively. Out of two mathematical models viz. power function model and first order kinetic model the power function model showed better fitness with wheat straw carbon loss data with lower RMSE and higher R2 values than first order kinetic model. The half life of wheat straw in Mollisols varied from 371 to 426 days at 15°C, 130 to 238 days at 25°C and 50 to 95 days at 35°C. After decomposition of wheat straw in soils available P and K content increased moderately whereas, the available N level decreased over initial level. The increase in available P and K of the soils due to wheat straw was more at 35°C than at 25 and15°C. It was concluded that decomposition of wheat straw in the soils was slow and temperature dependent. The rate of decomposition followed power function model. Available P and K status of the soils were moderately increased by wheat straw incorporation.
Description
Keywords
null