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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Transgenic Bt-cotton affects enzyme activity and nutrient availability in a sub-tropical inceptisol
AU - Sarkar, B.
AU - Patra, A. K.
AU - Purakayastha, T. J.
PY - 2008/8/1
Y1 - 2008/8/1
N2 - We investigated the dynamics of N and P availability in the rhizosphere of Bt and non-Bt cotton crops during their growth. In a net-house pot culture experiment at the Indian Agricultural Research Institute, New Delhi, Bt-cotton (cv. MRC-6301Bt) and its non-transgenic near-isoline (MRC-6301) were grown on a sandy loam soil until maturity. A control (no-crop) treatment was also included. Rhizosphere soil and root samples were collected at 60, 90, and 120 days after sowing (DAS). Soil samples were analysed for dehydrogenase activity, soil respiration, mineral-N and Olsen-P. Results have revealed a significant reduction in dehydrogenase activity (-17 %) and soil respiration (-3.5 %) in the rhizosphere of Bt-cotton over non-Bt isoline. Total mineral-N (NH 4+-N + -N) in soil was reduced by 14 %, whereas Olsen-P was increased by 8 % because of Bt-cotton. Root biomass yields were not different (P > 0.05), but root volume was significantly higher in Bt than non-Bt isoline. Time of sampling strongly (P < 0.05) affected the above parameters, showing their highest values at 60 or 90 DAS. A significant interactive effect of sampling time and treatments was also indicated. Our results suggest that Bt-cotton may constrain the availability of N, but enhances P-availability in these soils.
AB - We investigated the dynamics of N and P availability in the rhizosphere of Bt and non-Bt cotton crops during their growth. In a net-house pot culture experiment at the Indian Agricultural Research Institute, New Delhi, Bt-cotton (cv. MRC-6301Bt) and its non-transgenic near-isoline (MRC-6301) were grown on a sandy loam soil until maturity. A control (no-crop) treatment was also included. Rhizosphere soil and root samples were collected at 60, 90, and 120 days after sowing (DAS). Soil samples were analysed for dehydrogenase activity, soil respiration, mineral-N and Olsen-P. Results have revealed a significant reduction in dehydrogenase activity (-17 %) and soil respiration (-3.5 %) in the rhizosphere of Bt-cotton over non-Bt isoline. Total mineral-N (NH 4+-N + -N) in soil was reduced by 14 %, whereas Olsen-P was increased by 8 % because of Bt-cotton. Root biomass yields were not different (P > 0.05), but root volume was significantly higher in Bt than non-Bt isoline. Time of sampling strongly (P < 0.05) affected the above parameters, showing their highest values at 60 or 90 DAS. A significant interactive effect of sampling time and treatments was also indicated. Our results suggest that Bt-cotton may constrain the availability of N, but enhances P-availability in these soils.
KW - Nutrient availability
KW - Rhizosphere
KW - Root characteristics
KW - Transgenic Bt-cotton
U2 - 10.1111/j.1439-037X.2008.00312.x
DO - 10.1111/j.1439-037X.2008.00312.x
M3 - Journal article
AN - SCOPUS:46749156728
VL - 194
SP - 289
EP - 296
JO - Journal of Agronomy and Crop Science
JF - Journal of Agronomy and Crop Science
SN - 0931-2250
IS - 4
ER -