STRUCTURE FORMATION UPON MIXING Na-MONTMORILLONITE WITH BI- AND TRIVALENT ION-CLAYS1

The light transmittance of montmorillonite suspensions saturated with Na⁺, Mg⁺⁺, Ca⁺⁺, Al⁺⁺⁺, Fe⁺⁺⁺ or La⁺⁺⁺ and with known mixtures of these ions was investigated. Also, the kinetics of bi- and trivalent ion montmorillonite tactoid formation and breakdown was followed by recording changes in light transmission as a function of time when M-montmorillonite suspensions (M = Mg⁺⁺, Ca⁺⁺, Al⁺⁺⁺, Pe⁺⁺⁺ or La⁺⁺⁺) were added to Na-montmorillonite suspensions of the same concentration in a titrating vessel placed in the light path of a spectrophotometer. Introduction of a small fraction of Na⁺ onto the exchange complex of M-clay had no effect on the size of the M-tactoids. The breakdown of Mg⁺⁺ and Ca⁺⁺ tactoids occurred as the equivalent fraction of adsorbed Na⁺ increased from 0.2 to 0.5, with mixed Na-M montmorillonite particles having an equivalent fraction of adsorbed Mg⁺⁺and Ca⁺⁺ less than 0.3 remaining as single platelets. Conversely, introducing even a small fraction (<10%) of trivalent onto the exchange complex of Na-montmorillonite caused the formation of tactoids. Instantaneous formation of an intermediate unstable structure occurred upon mixing Na-montmorillonite with M-montmorillonite. It is proposed that edge-to-face association stabilizes this intermediate structure, whereas face-to-face association stabilizes the eventual tactoids.     

Zur Bestimmung der Kationenaustauschkapazität von Böden mittels Barium

Regarding the Determination of Cation Exchange Capacity of Soils with Barium Very often the cation exchange capacity (CEC) of soils is determined using Ba⁺⁺ as exchange cation. In soils with high contents of organic matter, Ba⁺⁺ cannot be desorbed completely by Mg⁺⁺ or H⁺ but by Ca⁺⁺. Soils containing vermiculite adsorb Ba⁺⁺ in non exchangeable form. The fixed Barium can only be determined by total digestion. Therefore in soils containing vermiculite the exchange with Ba⁺⁺ leads to an underestimation of the CEC.     

Eignung von 0,1 M BaCl2-Lösung zur Bestimmung der Kationenaustauscheigenschaften kalkhaltiger Böden

Determination of the CEC of carbonate soils with unbuffered 0.1 M BaCl₂ Soils containing carbonates and precipitated calcium carbonate, respectively, were percolated with unbuffered 0.1 M BaCl₂ followed by 0.1 M MgCl₂ and anorganic acids of the same concentration. The measured concentration of bases (including Ba⁺⁺) in the percolates indicates, that precipitation of Ba⁺⁺ or exchange with Ca⁺⁺/Mg⁺⁺ on carbonate surfaces occurs during percolation, which leads to an overestimation of exchangeable bases. From the total amount of Ba⁺⁺ bounded in such a way the less part is dissolved/exchanged by MgCl₂ solution in the following leaching step. So the CEC of carbonate soils seems to be generally overestimated too, by the method applied in a not exactly measurable degree.     

Suitability of Immobilized Pseudomonas fluorescens SM1 Strain for Remediation of Phenols, Heavy Metals, and Pesticides from Water

Immobilized microbial cells for the biological treatment have the potential to degrade toxic chemicals faster than conventional wastewater treatment systems. In the present study, suitability of immobilized Pseudomonas fluorescens SM1 strain in calcium alginate beads for remediation of the major toxicants in Indian water bodies was tested by means of GC/HPLC and AAS techniques. Roughly 80% reduction in the concentration of phenols was observed by immobilized SM1 cells compared with 60% by the free cells. Also, in the case of the bioremediation of heavy metals, immobilized SM1 cells were found to be more efficient compared with the free cells. Suspension of P. fluorescens SM1 cells in the test model water for 24 h brought down the concentrations of Cu⁺⁺, Cd⁺⁺, Ni⁺⁺, and Pb⁺⁺ by more than 75% under free cell state and 7?C9% better efficiency under the immobilized conditions. However, Cr(VI) could show only 44% removal by the cell immobilized system, whereas a mere 35% reduction in the Cr(VI) levels was shown in the test model water by the free SM1 cells under the same conditions. Moreover, a model water containing 2,000 ppb of BHC, 1,248 ppb mancozeb, and 312 ppb 2,4-D passed through the cell immobilized column resulted in the decline in their concentrations up to 362 ppb, 750 ppb, and 126 ppb, respectively. Generally, AAS, HPLC, and GC analyses of treated test model waters with the free and immobilized SM1 cells exhibited high potential of immobilized SM1 in detoxification of test water. From the results, we conclude that immobilized cells of P. fluorescens SM1 strain were quite effective in bioremediation of major toxicants present in Indian water bodies, and we also recommend the use of immobilized bacterial cells rather than the free cells for the bioremediation/detoxification process.     

Effects of Supplemental Calcium on Ion Accumulation,Transport and Plant Growth of Salt Sensitive Brassica Rapa Landrace

ABSTRACT

Effects of three supplemental calcium (Ca⁺⁺; 2.5, 5.0, and 10 mole m^?3) concentrations on ion accumulation, transport, selectivity, and plant growth of salt-sensitive species, Brassica rapa ‘Sani’ in saline medium were investigated. Supplemental Ca⁺⁺ in the presence of 125 mol m^?3 sodium chloride (NaCl) did not improve the dry weight and leaf area indicating no role played by Ca⁺⁺ in the alleviation of salinity induced growth inhibition. However, calcium chloride (CaCl₂) did significantly affect sodium (Na⁺), potassium (K⁺), and Ca⁺⁺ contents of roots and shoots. The ion contents of shoots were significantly greater than those of roots per g dry weight, indicating ion transportation to shoots is greater than ion accumulation in roots. Use of CaCl₂ in 125 mol m^?3 NaCl reduced the Na⁺ content but increased K⁺ and Ca⁺⁺ contents in shoots. Sodium contents in shoots differed among the supplemental Ca⁺⁺ treatments indicating the role of CaCl₂ in Na⁺ ions transportation. Calcium content in shoots declined significantly in the control treatment (0 CaCl₂) but increased significantly in 10 mol m^?3 CaCl₂. The root also showed the effects of Ca⁺⁺ on the reduction of Na⁺ content and the increase of K⁺ and Ca⁺⁺ content. Unexpectedly, 5 mol m^?3 CaCl₂ induced the highest Na⁺ content in roots at 16 days after treatment. Supplemental CaCl₂ application influenced the K⁺ or Ca⁺⁺ selectivity over Na⁺ in two ways, ion accumulation at roots and transport to shoots. However, high CaCl₂ treatments allowed greater Ca⁺⁺ selectivity over Na⁺ than low CaCl₂. Likewise, high supplemental CaCl₂ showed higher K⁺ selectivity over Na⁺ than low CaCl₂. A marked increase in K⁺ versus Na⁺ selectivity for the transport process occurred at 10 mol m^?3 CaCl₂ treatments. The roots and shoots exhibited higher K⁺/Na⁺ and Ca⁺⁺/Na⁺ ratios in high CaCl₂ treatment than in low. The results are discussed in context to supplemental Ca⁺⁺ concentrations, ions accumulation, transportation and selectivity of salt sensitive Brassica rapa cultivar.     

Etude de la nutrition potassique du sorgho I‐ incidence du remplacement du potassium par le sodium sur la teneur en cations des feuilles

Abstract

Grain sorghum plants were grown in nutritive solution culture under variable potassium concentrations from 0.5 to 6.0 meq/l, Na replacing K in deficient solutions. Leaves were analysed for K⁺, Na⁺, Ca⁺⁺ and Mg⁺⁺.

Potassium deficiency has no effect on the total amount of cations, but the decrease of K in deficient leaves is correlated with an increase of Na⁺, Ca⁺⁺ and Mg⁺⁺. Evidence of antagonism between K and divalent cations in given, but, in the most deficient leaves, magnesium instead of calcium balances for the diminution of potassium.     

Effects of the sodium and calcium concentrations on the in vitro growth of Atriplex halimus L. plantlets

The objective of this work is to analyse the sodium (Na⁺) and calcium (Ca⁺⁺) importance in the in vitro morphogenesis of a halophile species the Atriplex halimus. The experiments have been made on plantlets coming from a seed population collected in a natural area (Algeria). Twenty medium, all different by their sodium chloride (NaCl) and calcium chloride (CaCl₂) content, have been tested. For five Na⁺ concentrations, four [Na⁺]/[Ca⁺⁺] ratios have been tested. The [Na⁺]/[Ca⁺⁺] ratio has a significant effect on the studied criteria (stem length, longest root length and leaf number). The ratio equal to two is the one which gives the lowest values and the ratio equal to one (for the same [Na⁺] quantity and a double quantity of [Ca⁺⁺]) gives the strongest ones. A new doubling of the [Ca⁺⁺] (ratio equal to 0.5) induces a decrease of the values. These results are remarkable if we take into account the low cation concentrations used in the experiments. The morphogenetical events observed here will be explained when results about cation ratios inside the plant and the enzyme activity will have been obtained.     

H+, Ca++, and Mn++ influence on sorghum seedling shoot growth

Plant response mechanisms for acid soil tolerance adaptability are generally unknown. Sorghum [Sorghum bicolor (L.) Moench] cultivars (Funk G522DR, GP 140, SC 599, TAM 428, SC 283, and SC 574) were grown in white quartz flintshot sand and watered with 0.01 M sodium acetate buffer at pH 4.0, 4.5, 5.0, 5.5, or 6.0 with concurrent treatments of Ca⁺⁺ (0, 10, 100 mgl^‐1 as CaCl₂) or Mn⁺⁺ (0, 1.4, 140.0 mgl^‐1 as MnCl₂). At the acid soil tolerance impact response phase (<10 days old), Ca⁺⁺ or Mn⁺⁺ did not influence seed germination (i.e., radicle exsertion). Ca⁺⁺ did not influence initial shoot growth. Increased H⁺ concentration greatly inhibited juvenile shoot growth equivalently in all six cultivars. This inhibition was explicable as an influence of gibberellic acid (GA) availability to the aleurone layer and was explained as an accumulation (partitioning) of GA into lipid cellular constituents. Excess Mn⁺⁺ further exacerbates this condition by limiting GA biosynthesis.     

Cesium- und Strontiumaustauscheigenschaften von Marschböden

Cesium and Strontium Exchange Properties of Marsh Soils The cesium and strontium exchange properties of some typical marsh soils of the estuary and lower river Weser region were described. Soil samples were taken according to the existing soil maps 1:25000 of Lower Saxony e.g. a “sea marsh soil”. a “brackish marsh soil”, and a “river marsh soil”. The exchange properties were determined by Cs/Ca and Sr/Ca exchange curves (Q/I relations) as generally used in soil potassium research. In addition to the Q/I relations the following investigations were carried out: - Cs and Sr desorption experiments (one time equilibration with Ca⁺⁺ solutions) - Cs and Sr reexchange experiments (eight times equilibration with water, Ca⁺⁺, Ba⁺⁺, and K⁺ solutions) - the naturally-occuring Cs and Sr contents of the soils including amounts caused by imissions or fallout, respectively - clay mineral composition and swelling of layer silicates due to saturation with Ca⁺⁺, Sr⁺⁺, Cs⁺, and K⁺ ions. Q/I relations as well as desorption and reexchange experiments indicated strong cesium and low strontium fixation by the soils investigated. This was considered the reason for the stronger transfer of Sr from soil to plants as compared with Cs. Furthermore, the reexchange experiment revealed nearly complete reversibility of the Sr sorption reactions by equilibration with the divalent cations Ca⁺⁺ and Ba⁺⁺ and some Sr fixation after treatment with K⁺ solutions. However, cesium was much better reexchanged by K⁺ than by Ca⁺⁺ and Ba⁺⁺ ions. This led to the conclusion that Cs fixed in interlayer positions of clay minerals could be remobilized by potassium and ammonium fertilization. The naturally-occuring Cs contents of the soils were found to be below the detection limit of the analytical methods used. The contents of naturally-occuring exchangeable Sr, however, was in agreement with the amounts of “labile Sr” as derived from the Sr/Ca exchange curves. Concerning the cesium exchange properties a clear distinction between “sea and river marsh soils” on the one hand and “brackish marsh soils” on the other hand was established due to differences in clay mineral composition and swelling state of 1:2 layer silicates. The different cesium exchange properties of the two soil groups could also be verified by more or less pronounced hysteresis effects of sorption (Q/I relation) and desorption curves.     

The acidifying potential of atmospheric deposition in Canada

It is proposed that the value of ([SO₄ ^??] - [Ca⁺⁺ + Mg⁺⁺]) in precipitation is a suitable way to describe the acidifying potential (AP) of the wet desposition. In eastern North America, the AP of precipitation varies from 20 to 85% of the total sulphate, the remainder of the sulphate being neutralized H₂SO₄, sulphate from salts in dust or from sea salt. The AP ranges from 20 to 80% of the H⁺ in the wet deposition. The rest of the H⁺ is contributed by the net effect of N compounds. Ammonium and nitrate ions from ammonia and NO_Xemissions do not represent a net acidic loading to the terrestrial ecosystem if they are taken up by vegetation. However, when N leaches from watersheds in the form nitrate, it constitutes an acidifying demand on the ecosystem. Therefore, the overall net acidifying potential (NAP) applied to the terrestrial ecosystem is defined by the value of ([SO₄ ^??] - [Ca⁺⁺ + Mg⁺⁺]) in precipitation plus [NO₃ ^??] in runoff from the watershed.     

Influence of H+ Ca++, and Mn++ on the development of amylase in the endosperm of several sorghum cultivars 1

Sorghum [Sorghum bicolor (L.) Moench] seeds (Funks G522DR) were planted in ‘white quartz flintshot’ and watered with 0.01 M NaAc buffer at pH 4.0, 4.5, 5.0, 5.5, or 6.0 ± Ca⁺⁺ (0, 10, 100 ppmw) or Mn⁺⁺ (0, 1.4, 140.0 ppmw) and grown for seven days in a growth chamber. Endosperm amylase contents, quantitatively and qualitatively, were dependent upon the environmental conditions during germination. H⁺ concentration at pH 4.0 strongly induced a decrease in amylase activity which was relieved as the pH was raised to pH 6.0. Ca⁺⁺ greatly increased endosperm amylase contents. Mn⁺⁺ (1.4 ppmw) tended to increase endosperm amylase contents while Mn⁺⁺ (140.0 ppmw) strongly decreased endosperm amylase content. In the cultivar SC283, endosperm amylase contents were nearly double those found in Funks G522DR while SC574 had, at most, one half the endosperm amylase content of Funks G522DR endosperm. Endosperm amylase contents of SC283 were pH tolerant while those of Funks G522DR and SC574 were highly pH sensitive. These data further demonstrate the plasticity of plants growing under adverse environmental conditions.     

Nutrient uptake and yield of sweet pepper as affected by stage of development and N form

Uptake of NO₃ ^‐, NH₄ ⁺, P, K⁺⁺, Ca⁺⁺ and Mg⁺⁺, as influenced by the stage of plant development and three NO₃ ^‐: NH₄ ⁺ ratios (1: 0, 1: 1, and 0: 1), was determined for sweet pepper (Capsicum annuum L. cv. ‘California Wonder'). Uptake was highest during fruit development and immediately after fruit harvest, indicating that fruit removal promotes nutrient uptake. When NO₃ ^‐ and NH₄ ⁺ were supplied in equal concentrations, NO₃ ^‐ was absorbed more readily. Each increment in NH₄ ⁺ decreased the uptake of K⁺, Ca⁺⁺, and Mg⁺⁺ by fruit tissue, while no significant effect on the N and P content of the fruit was observed. Ammonium nutrition reduced plant dry weight and fruit yield in comparison to NO₃ ^‐. Results from this study suggest that NO₃ ^‐ is the preferred N form, and that fertilizer application should be scheduled according to specific physiological stages to maximize nutrient uptake. Nutrient content of vegetative tissue was not indicative of potential yield.     

Influence of plant age on calcium stimulated ammonium absorption by radish and onion

Abstract

The efficient use of N for crop production is important because N is normally the most expensive fertilizer input. Past research has suggested that Ca⁺⁺ can be used to stimulate NH₄+ absorption by plants. The importance of plant growth stage in relation to this phenomenon has not been examined previously. The objectives of this study were to examine Ca⁺⁺ ‐ stimulated NH₄ ⁺ absorption and to examine the effect of Ca⁺⁺ concentration on N content and growth in plant tops, bulbs and roots at different growth stages. Ammonium absorption experiments were conducted in the greenhouse in 4‐L pots containing 3.5 kg of calcareous Gila sandy loam (Typic Torrifluvents) (CEC <1 cMol kg^?1). Plants (Radish, Raphanus sativas L., and onion, Allium cepa L.) were grown with a uniform nutrient solution (1/2 strength nutrient solution, all N as NO₃) to the desired growth stage at which time the soil was leached with deionized water. Afterwards, the soils were fertilized with 1/2 strength nutrient solutions (5 mol m^?3 NH₄) with Ca⁺⁺: NH₄ ⁺ molar ratios of 0, 0.25, 0.50, 1.00, and 2.00 for a period of 30 h. As Ca⁺⁺ concentration increased, NH₄ ⁺ absorption and plant growth increases were greatest with young seedlings. In the intermediate and mature growth stages, Ca⁺⁺ stimulated ¹⁵NH₄ ⁺ absorption was less rapid than in the earlier growth stages but frequently exhibited a different response (i.e., altered metabolite translocation) to the added Ca⁺⁺ ‐ concentration. However, at the intermediate and mature growth stages significantly increased N contents and plant growth also were noted in most cases. The Ca⁺⁺ ‐ increased N content in leaves and bulbs of the older plants had much less ¹⁵N suggesting that the newly absorbed ¹⁵NH₄ ⁺ was being deposited in the roots replacing older N forms that were then translocated to the bulbs or leaves. Thus, increasing Ca⁺⁺ appeared to have anadditional function of increasing the mobility of metabolites (dry matter) from the roots. Since more above‐ground plant products were produced with the same amount of N, plant N use efficiency was increased.     

Diltiazem influence on calcium and aluminum absorption by roots of three sorghum cultivars

Calcium (Ca⁺⁺) (10 mM) and Al⁺⁺⁺ (10 mM) ions were applied unilaterally in agar to primary roots of sorghum [Sorghum bicolor (L.) Moench.]. Both Ca⁺⁺ and Al⁺⁺⁺ caused unilateral growth “inhibitions and induced root curvature in cv Funk G522DR, SC574, and SC283 (acid soil stress sensitive, tolerant, and tolerant, respectively). Diltiazem (0.1 mM) [3‐(acetyloxy)‐5‐[2‐(dimethylamino)ethyl]‐2,3‐dihydro‐2‐(4‐methoxyphenyl)‐l‐5‐benzothiozepin‐4 (5H)‐one] inhibited Ca⁺⁺ absorption in Funk G522DR and SC283 but only partially influenced Ca⁺⁺ absorption by roots of SC574. Aluminum ion absorption by roots was inhibited in SC283 and SC574 but not in Funk G522DR.     

Growth,yield and antioxidant capacity of strawberry under various K+:Ca++ ratios in hydroponic culture

Optimisation of the mineral composition of the nutrient solution is one of the most important factors affecting crop productivity and quality under hydroponic cultivation. Considering the role of minerals in nutrition and the lack of studies on the K⁺:Ca⁺⁺ ratio of nutrient solution on fruit quality, a study was carried out to evaluate the effects of K⁺:Ca⁺⁺ ratios on growth, yield, vitamin C content of the fruit and total carbohydrate and phenolic compounds of the ‘Paros’ strawberry under hydroponic conditions. The highest total phenolic compounds, photosynthetic capacity, including leaf area, photosynthetic pigments, stomatal conductance and yield were observed at the 1.4 ratio (K > Ca). Enzymatic (peroxidase, superoxide dismutase and catalase) and non-enzymatic (total phenol, phenolic compounds and anthocyanin) antioxidant capacities were affected significantly by the K⁺:Ca⁺⁺ ratio. The highest antioxidant capacity was observed in ratios with K > Ca in the solution. We recommend growers to maintain an appropriate K⁺:Ca⁺⁺ ratio in the nutrient solution, as this affects growth parameters, productivity and strawberry quality.     

Sorghum seedling root growth as influenced by H+, CA++, and MN++ concentrations 1

Root response mechanisms for acid soil tolerance adaptability are generally unknown. Sorghum [Sorghum bicolor (L.) Moench] cultivars (Funk G522DR, GP140, SC599, TAM428, SC283, and SC574) were grown in white quartz flintshot sand and watered with 0.01M sodium acetate buffer at pH 4.0, 4.5, 5.0, 5.5, or 6.0 and Ca⁺⁺ (0, 10, 100 mgl^‐1 as CaCl₂) or Mn⁺⁺ (0, 1.4, or 140.0 mgl^‐1 as HnCl₂). At the acid soil tolerance impact response phase (< 10 days old), Ca⁺⁺ did not influence initial root growth. Increased H⁺ concentration inhibited juvenile root growth equivalently in all six cultivars. This inhibition was reversed by exogenous GA₃ in Funks G522DR but not in SC283 or SC574. Excess Mn⁺⁺ (140 mgl^‐1) further decreased root growth. Induction of an auxinase inhibitor by GA₃ would support a hypothesis of H⁺ concentration influence on IAA transport and/or availability. Root growth matched IAA water partitioning and exogenous IAA (10^‐10 and 10^‐9 M) reversed the H⁺ concentration influence on root growth of SC283. We suggest that low pH (<4.8) soil influence on root growth is explicable as an influence on IAA synthesis and/or transport and that excess Mn⁺⁺, which is known to induce IAA oxidation, further exacerbates the deleterious growing conditions.     

外加盐对凉粉草胶溶液的耐盐性和分子链刚性度的影响

在有盐环境下贮藏和加工凉粉草胶必须了解其多糖分子对盐的敏感性,该文绘制了凉粉草胶多糖在不同离子强度NaCl、KCl、MgCl₂和CaCl₂溶液中的Huggins'图,分别计算其分子链在这4种离子溶液中的耐盐度S、链刚性度B等值,结果发现：凉粉草胶多糖在4种离子溶液中,其耐盐性由强到弱的顺序为:K⁺>Na⁺>Mg⁺⁺>Ca⁺⁺,其分子链的构象在4种离子溶液中由柔到刚的顺序为:K⁺>Na⁺>Mg⁺⁺>Ca⁺⁺,这说明凉粉草胶多糖适合在KCl溶液中贮藏和加工。与其他多糖分子链在NaCl溶液中的B值比较后发现,凉粉草胶多糖的分子链构象较海藻酸钠要刚,较黄原胶要柔,这说明凉粉草胶比黄原胶更适合在NaCl溶液中贮藏和加工。     

江苏省滨海盐土向潮土演化过程中水溶性氟含量变化原因的探讨

江苏滨海盐土向潮土演化过程中，水溶性Ｆ＾－含量经历了由少变多，再由多变少的过程。水溶性氟含量变化受控于水溶性Ｃａ＾＋＋变化（Ｆ＾－＝ａ＋ｂＣａ＾＋＋－１／２），同时，由于土壤胶体和溶液中ＯＨ＾－与Ｆ＾－含量可能ＣａＦ２的活度积起控制作用，而ｐＨ值的变化起叠加作用。江苏沿海土壤中影响水溶性氟含量的矿物主要是ＣａＦ２。     

Review of beneficial uses of calcium and ammonium salts for stimulating plant growth and metabolite translocation

Abstract

Numerous investigations have been conducted to quantify Ca‐stimulated ammonium (NH₄ ⁺) absorption by plants [this technology is covered under U.S. patent 4,500,335, patent licensee is Tetra Technologies, 250251–45 North, The Woodlands, TX 77380]. Greenhouse and field studies on vegetable crops, field crops and ornamental foliage crops show significant growth increases from increasing Ca⁺⁺:NH₄ ⁺ ratios in the growth media. Increased root growth was normally the first plant response, with especially large root and bulb responses observed in onion (Allium cepa L.), beets (Beta vulgaris.), radish (Raphanus sativus L.), and bermudagrass (Cynodon dactylon Pers.). Direct measurements of Ca‐stimulated NH₄ ⁺ absorption were obtained with isotopic nitrogen (¹⁵N) in greenhouse trials. As Ca⁺⁺ concentrations were increased an increase in ¹⁵NH₄ ⁺ absorption was obtained in all plant species tested. The Ca⁺⁺ stimulated NH₄ ⁺ absorption phenomenon in plants is best explained by the “Viets Effect”;, which describes the use of Ca⁺⁺ or magnesium (Mg⁺⁺) to increase plant absorption of potassium (K⁺). Although, increased NH₄ absorption effectively increases plant growth, increasing K⁺ absorption does not. Increased NH₄ ⁺ absorption has been associated with enhanced photosynthetic rates as well as increased proportions of new metabolites (compounds initially produced from newly captured carbon dioxide) translocated to the nutrient sinks (seeds, bulbs, roots, etc.). The integrity of the plasmalemma is maintained by the presence of extra Ca⁺⁺, leading to greater turgor pressure (higher water content) and nutrient retention in cells which produce greater growth potential in plants.     

The effect of potassium chloride on ion dynamics and – budget in a slightly acidic forest soil

In a laboratory study, KCI- a neutral salt - equivalent to 300kg K/ha and 272 kg CI/ha was applied to the surface of undisturbed columns of a forest soil (Terra Fusca Rendzina) under steady state unsaturated flow conditions (1.0 cm/day). The effluent of the five soil columns was collected daily, and pH, cation- and anion concentrations were measured. Most of the applied K ions were retained in the top 10cm of the soil and moved in decreasing amounts further down the column. Among the cations studied Ca⁺⁺, Mg⁺⁺, and Na⁺ were lost from the system, K⁺, NH₄, Fe⁺⁺⁺, Mn⁺⁺, H⁺, and Al⁺⁺⁺ were retained. Nitrate and sulfate concentrations in the leachates showed a temporary decrease when CI passed through the columns. This decrease was accompanied with a decrease in pH. CI^?, NO₃^?, and SO₄^? exhibited leaching losses. Besides these anions, HCO₃^? played an important role.