Transgenic Bt-cotton affects enzyme activity and nutrient availability in a sub-tropical inceptisol

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

Arsenic phytoextraction by Pteris vittata improves microbial properties in contaminated soil under various phosphate fertilizations

A greenhouse study was conducted to evaluate the phytoextraction of arsenic (As) by Chinese brake fern (Pteris vittata L.) from a highly contaminated Typic Haplustept soil treated with different phosphatic fertilizers (di-ammonium phosphate (DAP) and single superphosphate (SSP)). The fern was grown in two repeated growing cycles and the resultant changes in soil biological activities were examined in pot culture experiments. The biomass yield of the fern was recorded 8.17–12.33 g pot−1 in the first growing cycle and 5.73–10.90 g pot−1 in the second growing cycle. The fronds of P. vittata accumulated the highest quantity of As ranging from 2884 to 4504 mg kg−1 in the first growing cycle and from 2254 to 3803 mg kg−1 in the second growing cycle. The total As removal form the contaminated soil ranged from 19.4 to 44.5 mg pot−1 and 10.4 to 32.1 mg pot−1 in the first and second growing cycles, respectively. All the studied soil microbiological parameters were improved as a result of As phytoextraction in two successive growing cycles of the fern, for example, microbial biomass carbon, carbon mineralization, dehydrogenase activity, acid phosphatase activity, alkaline phosphatase activity and arylsulfatase activity were increased by 46, 38, 77, 37, 12 and 49%, respectively. The soil biological activities were improved as a result of decrease in the bioavailable pool of As by the action of phytoextraction. The phosphatic fertilizer management practices played a critical role in mobilizing As in the contaminated soil and thus enhanced the process of phytoextraction

Thermoelectric switch from anilinic compounds

521-524Copper(II) ion can be embedded in the aggregates formed by anilinic compounds, such as 2,4-dimethoxyaniline, 2-aminophenol, 4-aminophenol, protonated polyaniline, through a reaction of catalytic amounts of copper complexes such as cis-bis (glycinato)copper(II) monohydrate and copper(II) acetate in the presence of hydrogen peroxide. These aggregates have the property of an irreversible thermoelectric switch.</span

Not Available

Not AvailableLong-term sustainability and a declining trend in productivity of rice–wheat rotation in the Indo-Gangetic plain, often direct towards the changes in soil quality parameters. Soil quality is decided through few sensitive soil physical, chemical and biological indicators as it cannot be measured directly. The present investigation was carried out to develop a valid soil quality index through some chosen indicators under long-term influences of tillage, water and nutrient-management practices in a rice–wheat cropping system. The experiment consisted of two tillage treatments, three irrigation treatments, and nine nutrient management treatments for both rice and wheat, was continued for 8 years. The index was developed using expert-opinion based conceptual framework model. After harvest of rice, the CFSQI-P (productivity) was higher under puddled situation, whereas CFSQI-EP (environmental protection) was more under non-puddled condition and 3-days of drainage was found promising for all the indices. No-tillage practice always showed higher soil quality index. The treatments either receiving full organics (100 % N) or 25 % substitution of fertilizer N with organics showed higher soil quality indices. Puddling, irrigation after 3 days of drainage and substitution of 25 % recommended fertilizer N dose with FYM in rice could be practiced for maintaining or enhancing soil quality. No-tillage, two irrigations, and domestic sewage sludge in wheat can safely be recommended for achieving higher soil quality.Not Availabl

Characterizing parallel file-access patterns on a large-scale multiprocessor

High-performance parallel file systems are needed to satisfy tremendous I/O requirements of parallel scientific applications. The design of such high-performance parallel file systems depends on a comprehensive understanding of the expected workload, but so far there have been very few usage studies of multiprocessor file systems. This paper is part of the CHARISMA project that intends to fill this void by measuring real file-system workloads on various production parallel machines. In particular, here we present results from the CM-5 at the National Center for Supercomputing Applications. Our results are unique because we collect information about every individual I/O request from the entire mix of jobs running on the machine. Analysis of the traces leads to various recommendations for parallel file-system design.

Not Available

Not AvailableInoculation of phosphate solubilizing bacteria (PSB) and phosphorus mobilizing arbuscular mycorrhiza (AM) with low quality rock phosphate (RP) can be an alternative source to one of the costliest phosphatic fertilizers in India, i.e. single superphosphate, by enhancing phosphorus influx and modification of root properties. Co-inoculation of PSB and AM may play a pivotal role to reduce phosphorus application through RP. Root properties and grain yield of irrigated soybean-wheat cropping system were evaluated with two levels of RP (100 and 50% recommended P (1.0 RP and 0.5 RP)) and different combinations ofPSB and AM with0.5 RP (0.5 RP + PSB, 0.5 RP + AM and 0.5 RP + PSB + AM) versus 100% recommended P application through soluble single superphosphate (1.0 SP) in the Indo-Gangetic plains. The P influx under 0.5 RP + PSB + AM and 1.0 SP were statistically at par with each other and the former treatment provided 0.6 and 3.2% higher value than the later in soybean and wheat, respectively. The root surface area density (RSAD) of soybean and wheat under 0.5 RP + PSB + AM (13.71 and 6.16m2 m−3, respectively) and 1.0 SP (13.70 and 6.37 m2 m−3, respectively) were non-significant and almost equal with each other. The values of root cation exchange capacity and other root properties under 0.5 RP + PSB + AM and 1.0 SP were also non-significant. The improved root properties under 0.5 RP + PSB + AM provided statistically at par grain yield with 1.0 SP for both soybean and wheat crops. The yield under 0.5 RP + PSB + AM of soybean crop was 3.4% higher than 1.0 SP. The net returns US$−1 invested was significantly higher under 0.5 RP + PSB + AM compared to 1.0 SP for both soybean and wheat crops. Coinoculation of PSB and AM with 50% of recommended P through RP could be recommended for better root properties and profitable grain yield of soybean-wheat cropping system in the Indo-Gangetic alluvial plains.Not Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Impact of Integrated Management on Yield Sustainability in Relation to Soil Quality Under a Rice–Wheat Cropping System

This study concentrates on developing a soil quality index (SQI), linking productivity to soil quality indicators, and SQI using grain yield of rice and wheat grown in a sequence for 8 years in an integrated tillage-water-nutrient management system. Rice yield was significantly better under puddling, 3 days of drainage, and both 150 % NPK and 100 % NPK + FYM treatments, and the yields were positively correlated with bulk density (BD), available Fe and soil respiration. The wheat yield was significantly higher under conventional tillage, five lots of irrigation, and 150 % NPK, and was positively correlated with BD, water stable aggregates (WSA) and available N. However, it was negatively correlated with mean weight diameter, soil organic carbon and hydraulic conductivity. Stepwise regression identified available Fe, WSA and microbial biomass carbon as the most important indicators that explained 42 % variability in rice yield, which further correlated significantly with the PCA-based SQI (r = +0.44). Thus, crop yield emerged as an important indicator for maintaining soil quality to sustain high productivity under integrated management systems