Advanced search

Accumulation of varying quality soil organic matter in sub tropical paddy soils under different land use management

Author
Organization
Abstract
Soil organic carbon (SOC) content of wetland rice cropped soils in subtropical Asia is evolving due to i) decades of very depleted organic matter (OM) returns (commonly even removal of stubble) and ii) due to a general more recent intensification towards two rice cropping seasons per year. Improved OM management of sub-tropical wetland rice soils may steadily improve their low SOC levels through the inhibited decomposition of added OM under flooded conditions, particularly so for now double cropped rice soils. This accumulated soil organic matter (SOM) will improve soil fertility depending on its quality which is of great importance for food security in the densely populated and vulnerable sub-tropical rice growing areas. The quality of SOM is largely influenced by the cropping pattern and its management but experimental evidences for sub-tropical paddy soils on this topic are limited. Therefore, in the first step, changes in SOC in surface soil layer (0-15cm) were studied from two long-term field experiments in Bangladesh running since 1978 and 1982 on a loamy, mixed, non-acid Aeric Haplaquept and a clayey, kaolinitic, Ultic Ustocrept soil (USDA Soil Taxonomy) with rice – rice and rice – wheat cropping pattern, respectively. Both experiments involve combinations of mineral fertilizer dressings and OM application. Results from both experiments showed accumulation of SOC in all treatments including no application of fertilizer and OM (control). The accumulation of SOC was higher with an increasing rate of N fertilizer and also with the quality of added OM, i.e. OM having lower C:N ratios. Most SOC was accumulated in compost, green manure and farmyard manure amended plots compared with rice straw amended plots and control. Accumulation of SOC is still showing a linear trend in both experiments since their establishment by 0.5 t OC ha-1 yr-1 (SOC (g kg-1 soil) = 0.243 X year + 7.49, R2 = 0.78; N=7) in the very young Aeric Haplaquept soil and 2.5 t ha-1 yr-1 (SOC (g kg-1 soil) = 1.29 X year + 39.90, R2 = 0.99; N=4) in the highly weathered clayey, kaolinitic, Ultic Ustocrept soil. Results from these experiments demonstrate SOC sequestration improved with OM amendment on paddy soils having high clay content and initial low carbon content. In the 2nd step, soils were collected from four pairs of fields having vegetable-rice and rice-rice cropping pattern in addition to two long-term field experiments and all the soil samples were subjected to physico-chemical fractionation to investigate the effect of soil management including cropping pattern on SOM quality. Soils were first physically fractionated into particulate organic matter (POM) and silt and clay sized OM. The silt and clay sized OM was further chemically fractionated by oxidation with 6% NaOCl to isolate an oxidation-resistant OM fraction, followed by extraction of mineral bound OM with 10% HF. The results show that there is a slight increase in POM in less fertilized soils representing nearly one third and one fifth of SOC in Aeric Haplaquept and Ultic Ustocrept soil, respectively. The silt and clay sized OM of the both soils receiving only organic amendments were susceptible to oxidation by NaOCl. In the cropping pattern experiment, there was also a small increase in POM in vegetable compared with rice soils. NaOCl oxidized the largest amount of silt and clay sized OM from the vegetable soils. The silt and clay N in vegetable soil was more selectively removed by NaOCl treatment compared with OC. Both the HF-extracted and HF-resistant OM fractions were lower in vegetable soils compared with rice soils. Results from the fractionations suggest that SOM accumulated in organic amended plots and vegetable-rice cropped soils are more labile and prone to loss in any change of land use.

Citation

Please use this url to cite or link to this publication:

Chicago
Kader, MD Abdul, Steven Sleutel, Shamim Ara Begum, Sabina Yeasmin, and Stefaan De Neve. 2011. “Accumulation of Varying Quality Soil Organic Matter in Sub Tropical Paddy Soils Under Different Land Use Management.” In SOM 2011, Abstracts, 79–80.
APA
Kader, M. A., Sleutel, S., Begum, S. A., Yeasmin, S., & De Neve, S. (2011). Accumulation of varying quality soil organic matter in sub tropical paddy soils under different land use management. SOM 2011, Abstracts (pp. 79–80). Presented at the 3rd International symposium on Soil Organic Matter (SOM 2011) : Organic matter dynamics : from soil to oceans.
Vancouver
1.
Kader MA, Sleutel S, Begum SA, Yeasmin S, De Neve S. Accumulation of varying quality soil organic matter in sub tropical paddy soils under different land use management. SOM 2011, Abstracts. 2011. p. 79–80.
MLA
Kader, MD Abdul, Steven Sleutel, Shamim Ara Begum, et al. “Accumulation of Varying Quality Soil Organic Matter in Sub Tropical Paddy Soils Under Different Land Use Management.” SOM 2011, Abstracts. 2011. 79–80. Print.
@inproceedings{1860555,
  abstract     = {Soil organic carbon (SOC) content of wetland rice cropped soils in subtropical Asia is evolving due to i) decades of very depleted organic matter (OM) returns (commonly even removal of stubble) and ii) due to a general more recent intensification towards two rice cropping seasons per year. Improved OM management of sub-tropical wetland rice soils may steadily improve their low SOC levels through the inhibited decomposition of added OM under flooded conditions, particularly so for now double cropped rice soils. This accumulated soil organic matter (SOM) will improve soil fertility depending on its quality which is of great importance for food security in the densely populated and vulnerable sub-tropical rice growing areas. The quality of SOM is largely influenced by the cropping pattern and its management but experimental evidences for sub-tropical paddy soils on this topic are limited. Therefore, in the first step, changes in SOC in surface soil layer (0-15cm) were studied from two long-term field experiments in Bangladesh running since 1978 and 1982 on a loamy, mixed, non-acid Aeric Haplaquept and a clayey, kaolinitic, Ultic Ustocrept soil (USDA Soil Taxonomy) with rice -- rice and rice -- wheat cropping pattern, respectively. Both experiments involve combinations of mineral fertilizer dressings and OM application. Results from both experiments showed accumulation of SOC in all treatments including no application of fertilizer and OM (control). The accumulation of SOC was higher with an increasing rate of N fertilizer and also with the quality of added OM, i.e. OM having lower C:N ratios. Most SOC was accumulated in compost, green manure and farmyard manure amended plots compared with rice straw amended plots and control. Accumulation of SOC is still showing a linear trend in both experiments since their establishment by 0.5 t OC ha-1 yr-1 (SOC (g kg-1 soil) = 0.243 X year + 7.49, R2 = 0.78; N=7) in the very young Aeric Haplaquept soil and 2.5 t ha-1 yr-1 (SOC (g kg-1 soil) = 1.29 X year + 39.90, R2 = 0.99; N=4) in the highly weathered clayey, kaolinitic, Ultic Ustocrept soil. Results from these experiments demonstrate SOC sequestration improved with OM amendment on paddy soils having high clay content and initial low carbon content. In the 2nd step, soils were collected from four pairs of fields having vegetable-rice and rice-rice cropping pattern in addition to two long-term field experiments and all the soil samples were subjected to physico-chemical fractionation to investigate the effect of soil management including cropping pattern on SOM quality. Soils were first physically fractionated into particulate organic matter (POM) and silt and clay sized OM. The silt and clay sized OM was further chemically fractionated by oxidation with 6\% NaOCl to isolate an oxidation-resistant OM fraction, followed by extraction of mineral bound OM with 10\% HF. The results show that there is a slight increase in POM in less fertilized soils representing nearly one third and one fifth of SOC in Aeric Haplaquept and Ultic Ustocrept soil, respectively. The silt and clay sized OM of the both soils receiving only organic amendments were susceptible to oxidation by NaOCl. In the cropping pattern experiment, there was also a small increase in POM in vegetable compared with rice soils. NaOCl oxidized the largest amount of silt and clay sized OM from the vegetable soils. The silt and clay N in vegetable soil was more selectively removed by NaOCl treatment compared with OC. Both the HF-extracted and HF-resistant OM fractions were lower in vegetable soils compared with rice soils. Results from the fractionations suggest that SOM accumulated in organic amended plots and vegetable-rice cropped soils are more labile and prone to loss in any change of land use.},
  author       = {Kader, MD Abdul and Sleutel, Steven and Begum, Shamim Ara and Yeasmin, Sabina and De Neve, Stefaan},
  booktitle    = {SOM 2011, Abstracts},
  language     = {eng},
  location     = {Leuven, Belgium},
  pages        = {79--80},
  title        = {Accumulation of varying quality soil organic matter in sub tropical paddy soils under different land use management},
  year         = {2011},
}