Biochar: A Sustainable Approach for Improving Plant Growth and Soil Properties

Soil is the most important source and an abode for many nutrients and microflora. Due to rapid depletion of agricultural areas and soil quality by means of ever-increasing population and an excessive addition of chemical fertilizers, a rehabilitated attention is a need of the hour to maintain sustainable approaches in agricultural crop production. Biochar is the solid, carbon-rich material obtained by pyrolysis using different biomasses. It has been widely documented in previous studies that, the crop growth and yield can be increased by using biochar. This chapter exclusively summarizes the properties of biochar, its interaction with soil microflora, and its role in plant growth promotion when added to the soil

SN 2016B a.k.a. ASASSN-16ab: a transitional Type II supernova

We present photometry, polarimetry, and spectroscopy of the Type II supernova ASASSN-16ab/SN 2016B in PGC 037392. The photometric and spectroscopic follow-up commenced about 2 weeks after shock breakout and continued until nearly 6 months. The light curve of SN 2016B exhibits intermediate properties between those of Type IIP and IIL. The early decline is steep (1.68 ± 0.10 mag 100 d-1), followed by a shallower plateau phase (0.47 ± 0.24 mag 100 d-1). The optically thick phase lasts for 118 d, similar to Type IIP. The 56Ni mass estimated from the radioactive tail of the bolometric light curve is 0.082 ± 0.019 M☉. High-velocity component contributing to the absorption trough of H α and H β in the photospheric spectra are identified from the spectral modelling from about 57-97 d after the outburst, suggesting a possible SN ejecta and circumstellar material interaction. Such high-velocity features are common in the spectra of Type IIL supernovae. By modelling the true bolometric light curve of SN 2016B, we estimated a total ejected mass of ∼15 M☉, kinetic energy of ∼1.4 foe, and an initial radius of ∼400 R☉

SN 2017gmr: An Energetic Type II-P Supernova with Asymmetries

We present high-cadence UV, optical, and near-infrared data on the luminous Type II-P supernova SN2017gmr from hours after discovery through the first 180 days. SN2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical light-curve evolution suggests that an extra energy source from circumstellar medium (CSM) interaction must be present for at least 2 days after explosion. Modeling of the early light curve indicates a ∼500 Re progenitor radius, consistent with a rather compact red supergiant, and latetime luminosities indicate that up to 0.130±0.026 Me of 56Ni are present, if the light curve is solely powered by radioactive decay, although the 56Ni mass may be lower if CSM interaction contributes to the post-plateau luminosity. Prominent multipeaked emission lines of Hα and [O I] emerge after day 154, as a result of either an asymmetric explosion or asymmetries in the CSM. The lack of narrow lines within the first 2 days of explosion in the likely presence of CSM interaction may be an example of close, dense, asymmetric CSM that is quickly enveloped by the spherical supernova ejecta

Exploring the biochar as a suitable carrier for a bioinoculant Aspergillus niger K7 and its consequence on Eleusine coracana in field studies

Carriers are not only important in providing a protective niche for microbial inoculants but also act as delivery vehicles. In the present investigation, the aim is to study the suitability of biochar as a carrier for Aspergillus niger K7 as well as its impact on the growth and productivity of Eleusine coracana, if any. In this experiment, the spores of the K7 strain were used as bioinoculant with biochar as a carrier for growth studies of finger millet in the agriculture field. Soil and biochar were analyzed for their physiochemical properties. After that, inoculum preparation was done, and the inoculum was incubated for six months with biochar to examine the viability of K7 strain with biochar. At last, for field trials, the seeds were sown, the mixture was amended to the soil, and growth and yield parameters were measured at 60 and 130 days. The soil amended with K7 strain and biochar separately showed significant enhancement in the growth and yield of plants over control, but the combination of the fungal strain with biochar as a carrier gave the best results in our study. It can be inferred from the results that biochar can protect microbial inoculants, improve soil properties, and make nutrients available for plant growth

On the paleoseismic evidence of the 1803 earthquake rupture (or lack of it) along the frontal thrust of the Kumaun Himalaya

The foothills of the Himalaya bordered by the Main Frontal Thrust (MFT) continue to be a locus of paleo-seismological studies. One of such recent studies of trench stratigraphy near the central (Indian) Himalayan foothills (Malik et al., (2016) has reported multiple ruptures dated at 467-570, 1294-1587 and 1750-1932 CE. The last offset has been attributed to the Uttarkashi earthquake of 1803 and the penultimate faulting, with lesser confidence to an earthquake in 1505 CE. We tested these claims by logging an adjacent section on a shared scarp, and the new trench site, however, revealed a stratigraphic configuration partially in variance with from what has been reported in the earlier study. Our findings do not support the previous interpretation of the trench stratigraphy that suggested multiple displacements cutting across a varied set of deformed stratigraphic units leading up to the 1803 rupture. The current interpretation posits a single episode of a low-angle displacement at this site occurred between 1266 CE and 1636. Our results suggest a single medieval earthquake, conforming to what was reported from the previously studied neighboring sites to the east and west. The present study while reiterating a great medieval earthquake questions the assumption that the 1803 earthquake ruptured the MFT. Although a decollement earthquake, the 1803 rupture may have been arrested midway on the basal flat, and fell short of reaching the MFT, somewhat comparable to a suite of blind thrust earthquakes like the 1905 Kangra and the 1833 Nepal earthquakes

Optical studies of two stripped-envelope supernovae-SN 2015ap (Type Ib) and SN 2016P (Type Ic)

We present the photometric and spectroscopic studies of a Type Ib SN 2015ap and a Type Ic SN 2016P. SN 2015ap is one of the bright (MV =-18.04 mag) Type Ib while SN 2016P lies at an average value among the Type Ic SNe (MV =-17.53 mag). Bolometric light-curve modelling of SNe 2015ap and 2016P indicates that both the SNe are powered by 56Ni + magnetar model with 56Ni masses of 0.01 and 0.002 M⊙, ejecta masses of 3.75 and 4.66 M⊙, spin period P0 of 25.8 and 36.5 ms, and magnetic field Bp of 28.39 × 1014 and 35.3 × 1014 G, respectively. The early spectra of SN 2015ap show prominent lines of He with a 'W' feature due to Fe complexes while other lines of Mg ii, Na i, and Si ii are present in both SNe 2015ap and 2016P. Nebular phase [O i] profile indicates an asymmetric profile in SN 2015ap. The [O i]/[Ca ii] ratio and nebular spectral modelling of SN 2015ap hint towards a progenitor mass between 12 and 20 M⊙.BK acknowledges the Science and Engineering Research Board (SERB) under the Department of Science & Technology, Government of India, for financial assistance in the form of National Post-Doctoral Fellowship (Ref. no. PDF/2016/001563). LT is partially supported by the ‘PRIN-INAF 2017’ with the project ‘Towards the SKA and CTA era: discovery, localization, and physics of transient objects’. The work made use of the Swift Optical/Ultraviolet Supernova Archive (SOUSA). SOUSA is supported by NASA’s Astrophysics Data Analysis Program through grant NNX13AF35G. SBP and KM acknowledge BRICS grant DST/IMRCD/BRICS/Pilotcall/ProFCheap/2017(G) for this work. NER acknowledges support from the Spanish MICINN grant ESP2017-82674-R and FEDER funds