ABSTRACT-The influence of intensive crop rotation on the distribution of potassium forms and clay mineralogy was assessed under a Mediterranean condition in the Piranshar region, northwest of Iran. For this purpose, surface soil samples in relation to six soil sub-groups from crop rotationfiled (sugar beet, wheat, pea, and barley) over five decades and the adjacent uncultivated lands were descr...

introduction: intensified agriculture over a long-term is an important factor in soil change phenomena that can cause some unwanted effects on soil properties. to examine this hypothesis, chemical properties of the soils under sunflower cultivation over five decades and adjoining virgin lands were investigated in order to monitor changes caused by long-term cropping. the studied soils are influ...

ABSTRACT- The present research was conducted to study K forms and fixation in soils of southern Iran (Hormozgan Province) with aridic and aridic-ustic regimes and to address the relations between soil mineralogy and potassium forms. Thirteen surface soil samples (0-25 cm) were collected from different regions and analyzed in laboratory. Illite and feldspar and mica are the major clay and soil m...

Pesticide adsorption by soil clays can be dramatically influenced by the exchangeable cations present. Among the common exchangeable base cations in soils (Ca2+, Mg2+, K+, and Na+), K+-saturated clays frequently demonstrate the strongest affinity for pesticides. In the presence of multiple exchangeable cations in the system, we hypothesize that the magnitude of pesticide sorption to soil minera...

Any exchangeable, time-homogeneous Markov processes on [k] with cadlag sample paths projects to a Markov process on the simplex whose sample paths are cadlag and of locally bounded variation. Furthermore, any such process has a de Finetti-type description as a mixture of independent, identically distributed copies of time-inhomogeneous Markov processes on [k]. In the Feller case, these time-inh...

The renin-angiotensin-aldosterone system and electrolyte levels in 11 patients with heart failure controlled on digoxin and frusemide were investigated after separate periods of Slow K, spironolactone, and amiloride therapy. When spironolactone or amiloride replaced Slow K, distinct parallel increments in the levels of renin, angiotensin II, and aldosterone resulted. Though plasma potassium was...

Acute hyponatremia is a serious condition, which poses major challenges. Of particular importance is what determines plasma sodium concentration ([Na(+)]). Edelman introduced an explicit model to describe plasma [Na(+)] in a population as [Na(+)] = alpha.(exchangeable Na(+) + exchangeable K(+))/(total body water) - beta. Evidence for the clinical utility of the model in the individual and in ac...