Response of bio-regulators to yield and quality of Indian mustard (Brassica juncea L. Czernj. and Cosson) under different irrigation environments

A field study was conducted during rabi seasons of 2008 and 2009 to evaluated of productivity of Indian mustard (Brassica juncea L.) by foliar spray of bio-regulators under different irrigation environments. Amongst treatments, the application of sufficient irrigation water (four irrigations) recorded the highest number siliqua per plant, higher number of seeds per siliqua, 1000 seed weight and yields as compared to all other irrigation treatments. Results show that an increased in seed yield of 92.40 and 39.37 % under sufficient irrigation and limitedwater condition in 2008 and 93.34% and 40.31% in 2009, respectively over deficient irrigation conditions, foliar sprays of 100 ppm thioglycollic acid at initiation of branching were recorded highest yield attributes and yields. Similarly, 500 ppm of thiourea at initiation of branching and flowering stages also gave second best highest yield attributes and yields as compared to all other bio-regulators spray stages. However, bio-regulators sprays were not recorded any significant effect on oil and protein content. The results were concluded that economic feasibility to improve productivity of Indian mustard with four irrigations levels and sprays of 100 ppm thioglycollic acid and 500 ppm of thiourea at initiation of branching and flowering stages under hyper arid environment

Studies on nutrient management and seed rate on growth and herbage yield of fenugreek (Trigonella corniculata L.) cv. Kasuri in Rajasthan

A field experiment was conducted at Bikaner and Jalore (Rajasthan) to study the effect offertilizer and vermicompost and four levels of seed rate on growth attributes of fenugreek(Trigonella corniculata) cv. Kasuri.  The results showed that application of fertilizer (20 kg N+ 4 kg P2O5 ha-1) increased plant height, number of branches plant-1, dry matter accumulationand number of root nodules, over control.  Vermicompost @ 4 t ha-1 significantly improvedgrowth attributes.  Growth parameters such as plant height, herbage yield and dry weightof leaves, increased significantly with increasing levels of seed rate up to 7.5 kg ha-1, whereas,nodules plant-1, fresh root weight and number of branches plant-1 decreased significantly upto 7.5 kg ha-1. &nbsp

Multivariate Prediction of Total Water Storage Changes Over West Africa from Multi-Satellite Data

West African countries have been exposed to changes in rainfall patterns over the last decades, including a significant negative trend. This causes adverse effects on water resources of the region, for instance, reduced freshwater availability. Assessing and predicting large-scale total water storage (TWS) variations are necessary for West Africa, due to its environmental, social, and economical impacts. Hydrological models, however, may perform poorly over West Africa due to data scarcity. This study describes a new statistical, data-driven approach for predicting West African TWS changes from (past) gravity data obtained from the gravity recovery and climate experiment (GRACE), and (concurrent) rainfall data from the tropical rainfall measuring mission (TRMM) and sea surface temperature (SST) data over the Atlantic, Pacific, and Indian Oceans. The proposed method, therefore, capitalizes on the availability of remotely sensed observations for predicting monthly TWS, a quantity which is hard to observe in the field but important for measuring regional energy balance, as well as for agricultural, and water resource management.Major teleconnections within these data sets were identified using independent component analysis and linked via low-degree autoregressive models to build a predictive framework. After a learning phase of 72 months, our approach predicted TWS from rainfall and SST data alone that fitted to the observed GRACE-TWS better than that from a global hydrological model. Our results indicated a fit of 79 % and 67 % for the first-year prediction of the two dominant annual and inter-annual modes of TWS variations. This fit reduces to 62 % and 57 % for the second year of projection. The proposed approach, therefore, represents strong potential to predict the TWS over West Africa up to 2 years. It also has the potential to bridge the present GRACE data gaps of 1 month about each 162days as well as a—hopefully—limited gap between GRACE and the GRACE follow-on mission over West Africa. The method presented could also be used to generate a near real-time GRACE forecast over the regions that exhibit strong teleconnections

Earth's water reservoirs in a changing climate

International audienceProgress towards achieving a quantitative understanding of the exchanges of water between Earth's main water reservoirs is reviewed with emphasis on advances accrued from the latest advances in Earth Observation from space. These exchanges of water between the reservoirs are a result of processes that are at the core of important physical Earth-system feedbacks, which fundamentally control the response of Earth's climate to the greenhouse gas forcing it is now experiencing, and are therefore vital to understanding the future evolution of Earth's climate. The changing nature of global mean sea level (GMSL) is the context for discussion of these exchanges. Different sources of satellite observations that are used to quantify ice mass loss and water storage over continents, how water can be tracked to its source using water isotope information and how the waters in different reservoirs influence the fluxes of water between reservoirs are described. The profound influence of Earth's hydrological cycle, including human influences on it, on the rate of GMSL rise is emphasized. The many intricate ways water cycle processes influence water exchanges between reservoirs and thus sea-level rise, including disproportionate influences by the tiniest water reservoirs, are emphasized

Tracking Sea Surface Salinity and Dissolved Oxygen On a River-Influenced, Seasonally Stratified Shelf, Mississippi Bight, Northern Gulf of Mexico

River discharge, and its resulting region of freshwater influence (ROFI) in the coastal ocean, has a critical influence on physical and biogeochemical processes in seasonally stratified shelf ecosystems. Multi-year (2010–2016) observations of satellite-derived sea surface salinity (SSS) and in situ water column hydrographic data during summer 2016 were used to investigate physical aspects of the ROFI east of the Mississippi River Delta to better assess regional susceptibility to hypoxia in the summer months. Time series of SSS data indicate that the shelf region impacted by the seasonal expansion of freshwater can be as extensive as the well-known “dead zone” region west of the Delta, and hydrographic observations from a shelf-wide survey indicate strong stratification associated with the ROFI. Peak buoyancy frequencies typically ranged between 0.15 and 0.25 s−1 and were concentrated in a 2–3 m layer around 4–10 m deep across much of the shelf. This ROFI is expected to be influenced by local freshwater sources which, while individually small, make a notable contribution in aggregate to the region (annually averaged daily discharge of approximately 2880 m3 s−1). The dissolved oxygen (DO) conditions under this freshwater cap were spatially and temporally variable, with areas of hypoxia and near-hypoxic conditions over portions of the shelf, demonstrating the utility of satellite-derived SSS in identifying coastal areas potential vulnerability to hypoxia. These regions of low bottom dissolved oxygen persisted throughout the peak summer season at several sites on the shelf, with the northeastern corner of Mississippi Bight having the most intense and persistent hypoxia

Comparisons of observed and modeled elastic responses to hydrological loading in the Amazon basin

International audienceIn large hydrological basins, water mass loading can produce significant crustal deformation. We compare the monthly vertical component of 18 GPS sites located in the Amazon basin, with the deflection models derived from Gravity Recovery and Climate Experiment (GRACE) observations on the one hand and derived from HYDL, a global hydrological model, on the other hand. The GPS data set includes the largest deflections by hydrological loading ever recorded at two stations located in the center of the basin. The main result of the study is that the GRACE solution produced by GRGS (Groupe de Recherche en Géodesie Spatiale, Toulouse, France) produces the best agreement with the Global Navigation Satellite Systems series with a correlation coefficient up to 0.9 in the center of the basin, although 70% at best of the RMS variation in the GPS series is accounted for