Suchergebnisse

Department of Agricultural Chemistry & Soil Science, Institute of Agricultural Science, University of Calcutta, 51/2, Hazra Road, Kolkata-700 019, India E-mail : priyamaroy@gmail.com College of Agriculture, Orissa University of Agriculture and Technology, Bhubaneshwar-751 003, Odisha, India Water Management Research Centre, Department of Agriculture, Ranaghat, Government of West Bengal, India Manuscript received 08 April 2015, revised 24 June 2015, accepted 01 July 2015 The interaction study between potassium and zinc was conducted with an inceptisol under submerged soil condition at ambient laboratory conditions with their nine different treatment combinations. It was found that exchangeable K increased gradually till 42 days of incubation before decreasing and was maintained highest (189.20 mg kg–1) in the treatment T6 where both K and Zn were applied combinedly at 60 and 5 mg kg–1 respectively. But regarding changes with respect to the cationic micronutrients it was observed that the amount of Fe, Mn, Cu and Zn was highest with the values 152.94, 64.94, 2.64 and 10.18 mg kg–1 respectively in the treatment T9 where K and Zn were applied combinedly at their highest level (K @ 60 mg kg–1 soil and Zn @ 10 mg kg–1 soil) at 42 days of incubation for Fe and Mn, 35 days of incubation for Cu and 14 days of incubation for Zn. From the present investigation it is concluded that both Zn and K has a positive synergistic effect on one another under submerged soil conditions.

The mining of soluble potassium salts (potash) is essential for manufacturing fertilizers required to ensure continuous production of crops and hence global food security. As of 2014, potash is mined predominantly in the northern hemisphere, where large deposits occur. Production tonnage and prices do not take into account the needs of the farmers of the poorest countries. Consequently, soils of some regions of the southern hemisphere are currently being depleted of potassium due to the expansion and intensification of agriculture coupled with the lack of affordable potash. Moving away from mined salts towards locally available resources of potassium, such as K-bearing silicates, could be one option to improve this situation. Overall, the global potash production system and its sustainability warrant discussion. In this contribution we examine the history of potash production and discuss the different sources and technologies used throughout the centuries. In particular, we highlight the political and economic conditions that favored the development of one specific technology over another. We identified a pattern of needs driving innovation. We show that as needs evolved throughout history, alternatives to soluble salts have been used to obtain K-fertilizers. Those alternatives may meet the incoming needs of our century, providing the regulatory and advisory practices that prevailed in the 20th century are revised. ; Terrativa Minerais S.A.

The ubiquitous calcium transducer calmodulin (CaM) plays a pivotal role in many cellular processes, regulating a myriad of structurally different target proteins. Indeed, it is unquestionable that CaM is the most relevant transductor of calcium signals in eukaryotic cells. During the last two decades, different studies have demonstrated that CaM mediates the modulation of several ion channels. Among others, it has been indicated that Kv7.2 channels, one of the members of the voltage gated potassium channel family that plays a critical role in brain excitability, requires CaM binding to regulate the different mechanisms that govern its functions. The purpose of this review is to provide an overview of the most recent advances in structure–function studies on the role of CaM regulation of Kv7.2 and the other members of the Kv7 family. ; This research was funded by grants from the Department of Industry, Tourism and Trade of the Government of the Autonomous Community of the Basque Country (Elkartek BG2015) and from the Spanish Ministry of Economy, Industry and Competitiveness (BFU2015-66910-R and CSD2008-00005). ; Peer reviewed

Complex research of the most important physico-chemical and mechanical properties (granulometric composition, hygroscopicity, caking, dusting, compactability, friability) of model system based on potassium sulfate and experimental samples of potassium sulfate and potassium-magnesia has been conducted. The experimental samples of potassium sulphate and potassium-magnesia were obtained in the processing of polymineral ore in the presence of various amounts of impurity inorganic salts (magnesium sulfate and chloride, sodium chloride). The obtained chlorine-free fertilizers have low hygroscopicity and low caking, but they are characterized by high dusting. Studies of the influence of dust-suppressors of different chemical nature on dusting of model and experimental samples of potassium sulfate and potassium-magnesia have shown that polyethylene glycol PEG-400 has the highest dust suppression effect on these fertilizers. Using PEG-400 has no negative influence to the friability, caking and compactability of fertilizers.

Using the patch-clamp method in the whole-cell configuration, it was shownthat external potassium ions play an important role in the regulation of calcium-activated chloride currents. A clear dependence of the amplitude of chloride currents on changes in the concentration of external potassium is shown. Changes in concentration of sodium, magnesium and calcium ions from membrane outside have no so significant effect, like outside potassium ions. The effect of potassium on the amplitudes of chloride currents is significantly greater than the effect it has on other cell ionic currents — sodium, potassium, cation. There is reason to believe that a change in the amplitudes of chloride currents contributes to the pathophysiological processes characteristic of hypokalemia and hyperkalemia.