Ground water quality assessment for irrigation in Palwal block of Palwal district, Haryana, India

The present study examined the quality of groundwater for agriculture purpose in a 49785 ha region comprising Palwal block of Palwal district of Haryana state by focusing on spatial variability of electrical conductivity (EC), cationic and anionic composition of CO32-, HCO3-, Cl-, SO42-, Ca2+, Mg2+, Na+ and K+ of the ground water. It was found 75% of the samples showed EC values up to 4 dS/m and the maximum value of EC was found as 10.55 dS/m. Out of one hundred thirty three ground water samples 34.8 % were of good quality, 49.2 % saline and 16.0 % alkali in nature. Out of the saline water, 24.2, 1.5 and 23.5 % were marginally saline, saline and high SAR saline, respectively. In alkali group, 2.3, 2.3 and 11.4 % were marginally alkali, alkali and high alkali, respectively. Residual sodium carbonate (RSC) and sodium adsorption ratio (SAR) varied from nil to 5.50 me L-1 and 2.50 to 23.41 (m mol L-1)½, respectively. Counter map maps of EC, SAR, RSC and water quality of groundwater used for irrigation in the block were prepared through GIS to study spatial variability

Agricultural Information's Impact on the Adaptive Capacity of Ghana's Smallholder Cocoa Farmers

Ghanaian smallholders grow one quarter of the world's cocoa, but climate change, individual extreme weather events, such as droughts, as well as deforestation increasingly threaten cocoa production. Pertinent information could bolster adaptive capacity. However, in Ghana's cocoa sector, relevant agricultural information is not available to all farmers, which can exacerbate power asymmetries. This paper focuses on how (i) agricultural and drought-adaptive information and (ii) socio-economic characteristics shape a cocoa farmer's adaptive capacity. We conducted our study in the aftermath of 2015–16's prolonged El Niño-induced drought that negatively impacted the livelihoods of cocoa smallholders across Ghana. In 48 semi-structured interviews and 12 focus groups, we asked smallholders how they responded to the drought to decipher how adaptive capacity compares between farmers receiving four different sources of agricultural information, and of diverse socio-economic status. Overall, agricultural information improved cocoa farmers' adaptive capacity compared to those who received no formal agricultural information. Smallholders detailed adaptive techniques that would be accessible to, and thus replicable by, other poorly-resourced cocoa farmers. Shade tree management and income diversification were identified as pertinent adaptive actions. However, we identified a divergence between exposure to agricultural information and its transformation into substantive adaptive action. Additionally, informal information sharing between smallholders represents an underutilized resource by extension programmes. We found that adaptive capacity is also determined by socio-economic characteristics: particularly gender, and to a lesser extent formal education level, proximity to asphalt roads, and land tenure. Finally, we present evidence that framing adaptive techniques in relatable terms that resonate with farmers' immediate livelihood concerns could narrow the adaptation deficit prevalent in Ghana's cocoa sector

From Agroforestry to Agroindustry: Smallholder Access to Benefits From Oil Palm in Ghana and the Implications for Sustainability Certification

Oil palm production in Ghana—which is primarily cultivated by smallholders (60%+)—plays an important role in local economies and rural livelihoods. As a multi-functional crop, it is embedded in the everyday life of rural and urban Ghanaians both by individual households and on an industrial level. The sector is currently experiencing a resurgence under Ghana's New Patriotic Party (NPP) rule and is being targeted by the Roundtable on Sustainable Palm Oil (RSPO) for yield intensification and increased export production. End goals of these efforts include poverty alleviation, environmentally responsible development efforts, and agricultural diversification in rural areas. We apply Ribot and Peluso's “theory of access” (2003) to assess the barriers and opportunities for smallholder oil palm farmers, and the degree to which these are addressed by RSPO interventions. Our results highlight how Ghanaian smallholders gain many benefits from palm oil production as a source of regular income, a drought-resilient crop, and a source of cooking oil for household use. However, they also report different levels of access to finance, markets, land, and technical support, along with differing views and visions of the oil palm sector's development. The focus of governmental and RSPO initiatives on international trade-based incentives overlooks this diversity and, in particular, the importance of local markets for Ghanaian livelihoods. This poses a threat to women millers and traders, poorer producers, and the local markets they supply who risk losing access to the palm oil supply chain. More generally, these findings illustrate the importance of understanding how markets interact at multiple local to international scales, in order to design interventions that will more equitably reach and benefit local communities

Bayesian Methods for Exoplanet Science

Exoplanet research is carried out at the limits of the capabilities of current telescopes and instruments. The studied signals are weak, and often embedded in complex systematics from instrumental, telluric, and astrophysical sources. Combining repeated observations of periodic events, simultaneous observations with multiple telescopes, different observation techniques, and existing information from theory and prior research can help to disentangle the systematics from the planetary signals, and offers synergistic advantages over analysing observations separately. Bayesian inference provides a self-consistent statistical framework that addresses both the necessity for complex systematics models, and the need to combine prior information and heterogeneous observations. This chapter offers a brief introduction to Bayesian inference in the context of exoplanet research, with focus on time series analysis, and finishes with an overview of a set of freely available programming libraries.Comment: Invited revie

A HARPS-N mass for the elusive Kepler-37d::a case study in disentangling stellar activity and planetary signals

To date, only 18 exoplanets with radial velocity (RV) semi-amplitude <2 m s−1 have had their masses directly constrained. The biggest obstacle to RV detection of such exoplanets is variability intrinsic to stars themselves, e.g. nuisance signals arising from surface magnetic activity such as rotating spots and plages, which can drown out or even mimic planetary RV signals. We use Kepler-37 – known to host three transiting planets, one of which, Kepler-37d, should be on the cusp of RV detectability with modern spectrographs – as a case study in disentangling planetary and stellar activity signals. We show how two different statistical techniques – one seeking to identify activity signals in stellar spectra, and another to model activity signals in extracted RVs and activity indicators – can each enable a detection of the hitherto elusive Kepler-37d. Moreover, we show that these two approaches can be complementary, and in combination, facilitate a definitive detection and precise characterization of Kepler-37d. Its RV semi-amplitude of 1.22 ± 0.31 m s−1 (mass 5.4 ± 1.4 M⊕) is formally consistent with TOI-178b’s $1.05^{+0.25}_{-0.30}$ m s−1, the latter being the smallest detected RV signal of any transiting planet to date, though dynamical simulations suggest Kepler-37d’s mass may be on the lower end of our 1σ credible interval. Its consequent density is consistent with either a water-world or that of a gaseous envelope ($\sim 0.4{{\ \rm per\ cent}}$ by mass) surrounding a rocky core. Based on RV modelling and a re-analysis of Kepler-37 TTVs, we also suggest that the putative (non-transiting) planet Kepler-37e should be stripped of its ‘confirmed’ status

An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star

Although several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long-period, low-mass exoplanets with measured masses and a corresponding lag in our understanding of such planets. In this paper we report the mass estimation and characterization of the long-period exoplanet Kepler-538b. This planet orbits a Sun-like star (V = 11.27) with M_* = 0.892 +/- (0.051, 0.035) M_sun and R_* = 0.8717 +/- (0.0064, 0.0061) R_sun. Kepler-538b is a 2.215 +/- (0.040, 0.034) R_earth sub-Neptune with a period of P = 81.73778 +/- 0.00013 d. It is the only known planet in the system. We collected radial velocity (RV) observations with HIRES on Keck I and HARPS-N on the TNG. We characterized stellar activity by a Gaussian process with a quasi-periodic kernel applied to our RV and cross correlation function full width at half maximum (FWHM) observations. By simultaneously modeling Kepler photometry, RV, and FWHM observations, we found a semi-amplitude of K = 1.68 +/- (0.39, 0.38) m s^-1 and a planet mass of M_p = 10.6 +/- (2.5, 2.4) M_earth. Kepler-538b is the smallest planet beyond P = 50 d with an RV mass measurement. The planet likely consists of a significant fraction of ices (dominated by water ice), in addition to rocks/metals, and a small amount of gas. Sophisticated modeling techniques such as those used in this paper, combined with future spectrographs with ultra high-precision and stability will be vital for yielding more mass measurements in this poorly understood exoplanet regime. This in turn will improve our understanding of the relationship between planet composition and insolation flux and how the rocky to gaseous transition depends on planetary equilibrium temperature

Transitioning to more sustainable, low-emissions agriculture in Brazil

KEY FINDINGS Cattle producers joined sustainability initiatives primarily to increase production, reduce production costs, learn new practices and access innovations, and because of their interest in sustainability. Farmers who shifted to sustainable intensification practices increased their productivity. Some also accessed new markets and a minority earned higher prices. Producers sought farming advice mostly from nearby farmers and technicians promoting sustainability initiatives. The cost of changing farm practices, insufficient technical assistance or capacity, and difficulty in complying with legal standards were the major barriers preventing other cattle producers from participating in sustainability initiatives. The greenhouse gas (GHG) emissions per kg of beef of cattle farmers in sustainable intensification programs were 18% lower compared to neighboring farms not in the programs. Early life-cycle cattle ranching (e.g. calving, early rearing), commonly associated with deforestation, has been more engaged with NGO initiatives providing support and agronomic outreach rather than formal standards and reporting. Coffee Coffee farmers joined a certification program because of requests from buyers, potential for receiving price premiums on their coffee, and to access new markets with certified products. Coffee farmers producing certified coffee increased their economic efficiency, mainly due to higher productivity, compared to before they certified. Coffee producers' connections to technicians and access to information mostly revolved around their participation in cooperatives.POLICY RECOMMENDATIONS Build on market development lessons from the coffee sector to enhance sustainability, quality, traceability, and branding in the cattle sector. Expand sustainability initiatives’ capacity to deliver market access, technical assistance, and finance services to more cattle farmers. Continue support to producers in sustainability initiatives over multiple years, as they are likely to increase the sustainability of their practices with time. Expand agronomic outreach and sustainability initiatives to calving and early rearing operations to reduce associated deforestation and GHG emissions

The GAPS Programme at TNG XXXVII. A precise density measurement of the young ultra-short period planet TOI-1807 b

Context. Great strides have been made in recent years in the understanding of the mechanisms involved in the formation and evolution of planetary systems. Despite this, many observational findings have not yet been corroborated by astrophysical explanations. A fine contribution to the study of planetary formation processes comes from the study of young, low-mass planets, with short orbital periods (.100 days). In the last three years, the NASA/TESS satellite has identified many planets of this kind and their characterization is clearly necessary in order to understand how they formed and evolved. Aims. Within the framework of the Global Architecture of Planetary System (GAPS) project, we performed a validation and characterization (radius and mass) of the ultra-short period planet TOI-1807 b, which orbits its young host star BD+39 2643 (∼300 Myr) in only 13 h. This is the youngest ultra-short period planet discovered so far. Methods. Thanks to a joint modeling of the stellar activity and planetary signals in the TESS light curve and in new HARPS-N radial-velocity measurements, combined with accurate estimation of stellar parameters, we validated the planetary nature of TOI-1807 b and measured its orbital and physical parameters. Results. By using astrometric, photometric, and spectroscopic observations, we found that BD+39 2643 is a young, active K dwarf star and a member of a 300 ± 80 Myr old moving group. Furthermore, it rotates in Prot = 8.8 ± 0.1 days. This star hosts an ultra-short period planet, exhibiting an orbital period of only Pb = 0.54937 ± 0.00001 days. Thanks to the exquisite photometric and spectroscopic series, along with the accurate information on its stellar activity, we measured both the radius and the mass of TOI-1807 b with high precision, obtaining RP,b = 1.37 ± 0.09 R⊕ and MP,b = 2.57 ± 0.50 M⊕. These planet parameters correspond to a rocky planet with an Earth-like density (ρb = 1.0 ± 0.3 ρ⊕) and no extended H/He envelope. From the analysis of the age-RP distribution for planets with well measured ages, we inferred that TOI-1807 b may have already lost a large part of its atmosphere over the course of its 300 Myr lifetime