Root Cation Exchange Capacity Research Articles

Ameliorating effects of phosphorus, lime and animal manure on wheat yield and root cation exchange capacity in degraded alfisols of north-west himalayas

A field experiment over the two years was conducted to study the ameliorating effects of P, lime and animal manure on wheat (cv s-308) yield, root CEC and on economic doses of P. Phosphorus was applied as single superphosphate at the rate of 0, 13, 26, 39, 52, 65 and 78 kg P per ha; lime as CaCO3 at 0 and 1 t/ha, and well cured animal manure at 0 and 8 t/ha. The application of P, to the extent of 65 kg/ha, increased the root CEC of wheat up to bloom stage only whereas nutrient concentration, uptake and; grain and straw yield were found to increase up to maturity. Similarly, addition of 8t/ha of animal manure resulted in a significant increase in root CEC up to bloom, nutrient concentration and uptake, vis-a-vis grain and straw yield of wheat were found to enhance up to maturity. However, the application of lime, though, increased the root CEC and nutrition of crop during both years, it did so in cases of wheat yield only during the first year of the experiment. Root CEC, particularly, at early growth stages, was very well correlated with N, P, K, Ca and Mg concentrations and uptake, and wheat yield at maturity. The economic dose of P for wheat in association with 8 t/ha of animal manure under the present conditions was found to be 39.4kg p/ha.

Root Cation Exchange Capacity (CEC) and Yield-Contributing Parameters in Rice in Normal and Alkali Soils

Root Cation Exchange Capacity (CEC) and Yield-Contributing Parameters in Rice in Normal and Alkali Soils

Determination of cation exchange capacity of ryegrass roots by summing exchangeable cations

Cations were desorbed from root exchange sites of ryegrass (Lolium multiflorum Lam. cvs. Gulf, Marshall, Urbana, and Wilo) using BaCl2, BaCl2-triethanolamine, NH4OAc, and KCl. Results were analysed using multivariate analysis of variance. Ba2+-containing desorbents displaced more Ca2+ while monovalent desorbents displaced more exchangeable monovalent cations. The sum of adsorbed cations was significantly correlated with root exchange capacity (CEC) as determined by the H+ titration procedure, although slightly larger values were obtained with all desorbents. Lower CEC values were obtained for ryegrass cultivars less sensitive to Al.

Effects of simulated acid precipitation on cadmium- and zinc-amended soil and soil-pine systems

In order to determine the effect of acid precipitation on the movement of Cd and Zn in metal-contaminated systems, Cd- and Zn-amended soil systems, with and without eastern white pine seedlings, were treated with solution at pH levels of 2, 3, 4, and 5.3 for a 10-week period. While the soil parameters measured were not significantly altered by the higher pH treatments, treatment at pH 2 decreased soil pH, base saturation, and leachate pH, and increased leachate metal content. The presence of the seedlings moderated the effects of the pH 2 treatment by a probable combination of root cation exchange capacity and plant uptake. Seedlings receiving the higher pH treatments exhibited the expected metal distribution pattern (roots ≫ stems = leaves), while the pH 2 seedlings exhibited a different pattern (roots = stems = leaves). Cadmium and Zn levels in the stems and needles of the pH 2 plants were significantly higher than levels in those of the higher pH seedlings, while levels in the roots treated with pH 2 solution were significantly lower. This unusual distribution pattern may be the result of root injury due to the highly acidic solution. Although metal distribution was clearly affected by the acid treatments, increased toxicity symptoms were not observed in seedlings subjected to soil applications of acidified solutions.

Aspects of the phosphorus nutrition of white clover populations. IIII cation exchange capacity

Abstract Relationships between plant cation exchange capacity (CEC) and the ability of plants to tolerate low phosphorus (P) soils have been suggested. To investigate this the CEC of roots, leaves and stolons of 17 semi‐natural populations and three cultivars of white clover (Trifolium repens L.) were measured. Plants were grown in sand culture and solution culture with low phosphorus (P) supply (≍ 50 μM P) or high P supply (825–1291 μM P). The CEC of leaf was greater than that of stolon which in turn was greater than that of root material. Leaf CEC was closely correlated with stolon CEC (r=+0.80∗∗), and leaf CEC was correlated with root CEC (r=+0.69∗) but stolon CEC and root CEC were not significantly correlated (r=+0.48). Significant differences in CEC were found both between populations and between genotypes within populations. When plants were grown at high‐p root CEC and, to a lesser extent, stolon CEC, were correlated with plant growth rate. Leaf CEC tended not to be correlated with plant growth att...

Root cation exchange capacity of cotton cultivars in relation to aluminum toxicity

Abstract Root cation exchange capacity (CEC) was analyzed for four cotton cultivars (Pima S‐5, Stoneville 825, Deltapine 41 and Auburn 56) within tvo species (Gossypium barbadense and G. hirsutum) grown in control (O Al) and Al (1.5 mg/l) solution. Pima S‐5, a G. barbadense variety, had significantly (P < 0.10) lower root CEC than G. hirsutum cultivars in control (O Al) solution. Root CEC of Stoneville 825 was numerically but not significantly lower than Auburn 56 and Deltapine Al in control solution. Root CEC was significantly reduced in all cultivars when grown in Al solution. Compared to controls, Pima S‐5 and Stoneville 825 had either numerically or significantly less reduction in root CEC than Auburn 56 or Deltapine 41 in Al solution. Aluminum content of roots after CEC analysis was numerically greater in the former cultivars than the latter. The lower root CEC of Pima S‐5 and Stoneville 825 in non‐toxic conditions could provide an initially greater Al tolerance when roots grow into marginally Al tox...

Cation exchange capacity of roots: Titration, sum of exchangeable cations, copper adsorption

Abstract The cation exchange capacity of roots (CECR) has been measured according to three different methods : titration of H‐roots with NaOH in the presence of CaCl2, MgCl2, or NaCl 0.1 N, saturation of roots with mixed Ca‐Mg‐Na solutions of eight different compositions and extraction of the adsorbed cations with copper, saturation of roots with Cu‐ions and extraction with HC1. Two types of roots were studied : roots of ryegrass (Lolium multiflorum Lm.) and roots of clover (Trifolium pratense L.) The very good coincidence of the results from the three methods tends to prove the reliability of the experimental procedures. The simplicity and the reproducibility of the Cu‐method renders it recommendable in view of possible standardization of the methods in the future.

Comparison of methods of expression and measurement of cation exchange capacity of plant roots

Cation exchange capacity (CEC) of roots of fifteen genetically different tea clones was measured and the values were expressed on surface area and weight basis. The precision of the two methods is almost identical. The weight basis is, however, preferred as it is more convenient and less time consuming.

Potassium uptake of rye-grass (Lolium perenne) and red clover (Trifolium pratense) as related to root parameters

Rye-grass (Lolium perenne) is known to be a strong competitor to red clover (Trifolium pratense) for soil K+ under conditions of low K availability in the soil. The objective of this study was to clarify whether this competitive behaviour of the two species can be explained by root morphology. Total K+ uptake ofL. perenne andT. pratense was studied under field conditions in relation to root fresh weight, root density, root cation exchange capacity, root surface and root length. The soil was an Alfisol, Udalf. All root parameters, when calculated per unit soil surface (M2), were higher inL. perenne than inT. pratense. In addition,L. perenne had longer root hairs and a denser root hair system thanT. pratense. The greatest difference in root morphology between species was root length, withL. perenne roots averaging 4–6 times longer than those ofT. pratense. Significant correlations were found between the total K+ uptake and all root parameters examined, with highest correlationsforroot fresh weight (r,0.92***T. pratense; 0.94***L. perenne) and root length (r, 0.91***T. pratense;r, 0.93***L. perenne). Potassium uptake per unit root fresh weight, root surface and root length were all significantly higher forT. pratense than for L. perenne. Differences in the rate of K+ uptake between species were particularly high when expressed per unit root length. Because of its greater root length and surface area,L. perenne can take up more soil K+ thanT. pratense, particularly where there is a low K− supply in the soil. Under such conditionsL. perenne will be a particularly strong competitor toT. pratense.

Studies on the potassium requirements of different crops

A field experiment on a potassium deficient Typic ustochrept soil of the University Farm at Pura, Kanpur compared the responses of wheat, chickpea, mustard and Egyptian clover to added potassium for two consecutive years commencing in 1979–80. All the crops responded to potassium fertilization. Sensitivity of various crops to potassium deficiency was in the order: Egyptian clover > chickpea > wheat > mustard. Higher sensitivity of Egyptian clover and chickpea compared to wheat was in agreement with their comparatively high root cation exchange capacity. Mustard by contrast showed higher root cation exchange capacity and exhibited least potassium sensitivity because of its higher potassium utilization efficiency. Leaf K content and total uptake of potassium by all crops was increased by applying potassium upto the highest level.

The effect of growth regulators on root cation exchange capacity of young clonal tea plants

A sand culture experiment was conducted under glasshouse conditions to study the effect of gibberellic acid (GA3), indol-3yl-acetic acid (IAA) and 2,4-dichlorophenoxy acetic acid (2,4-D) on root cation exchange capacity (CEC) of two genetically different tea clones. Results showed that application of GA3 and IAA progressively increased root CEC in both clones when their concentration was raised from 0 to 100 mgl−1. 2,4-D at its lower concentration (<25 mg l−1) produced the same effect, while at higher concentration (100 mg l−1) there was a decrease in root CEC. The root CEC was correlated negatively with brown: white root ratio and positively with top growth of clonal tea plants.

An ecological consideration of the significance of cation-exchange capacity of roots of some Utah range plants

Root cation-exchange capacities (CEC) are related to tissue nutrient content of several native Utah range plants. The root CEC values for dicotyledonous species were found to be significantly larger than for monocotyledonous species (grasses). The relative amounts of monovalent and divalent cations taken up are strongly correlated with root CEC. Dicot species tend to take up divalent ions more efficiently than monocots, but monocots take up relatively more monovalent cations than dicots. The relationship of root CEC to cation uptake helps explain differential distribution of grass lands and shrublands in common climatic zones and has important implications for range revegetation programs.

Competitive adaptation by plants to nutrient shortage through modification of root growth and surface charge

Abstract Plants respond to lowering Nand P nutrition by increasing their relative root growth (lowering S:R ratio) and decreasing their root cation exchange capacity (CEC); the 2 responses were correlated. The smaller the normal CEC of the plant the greater these changes were. Part of the competitive advantage of low CEC plants may lie in their greater increase in relative root growth in response to limiting concentrations of phosphate.

Root CEC determinations to establish root biomasses of two plant species grown in mixtures

The use of measurements on the cation exchange capacity (CEC) of roots in competition experiments with two plant species is suggested. If the root-CEC differences between the two species are not too small, measurement of this parameter offers a very simple way to determine the separate contributions of the two plant species in the total root biomass of the mixture. This ‘root-CEC method’ can be applied to total root yields as well as to detailed root-zone studies.

Cation‐exchange capacity of clonal tea roots and its implications on fertiliser responses

AbstractFifteen genetically different tea clones showed no variation in their root cationexchange capacity (CEC) values when assessment was made separately on white (including creamy white and cream) and brown (including creamy brown and reddishbrown) portions of roots. But CEC values determined on the whole root system of the same clones were significantly different. This was true for plants varying in age from 8 to 18 months. Clones of Assam types gave lower root CEC values throughout the experimental period than China types, while clones of the Southern form of tea (Cambod) gave high root CEC values initially, which dropped rapidly as the plants became older. Root CEC of different clones was found to be negatively correlated with the brown: white root ratio and with the K: √Ca ratio of the plant tops. Ageing of plants decreased root CEC by increasing the proportion of brown roots, as a result of which the K: √Ca ratio also decreased with age.

Determination of cation exchange capacity of woody plant roots using ammonium acetate extractant

A rapid exchange procedure using ammonium acetate as an extractant was developed for measurement of cation exchange capacity (CEC) of plant roots. The CEC values obtained with 1∶100 and 1∶200 root/solution ratios were almost equal, though the values increased with length of the time of immersion in both the root/solution ratios. The method gave higher CEC values with fresh roots as compared to dried roots. However, dried milled and dried unmilled roots gave identical values.

Cotton growth and nutrient uptake following Temik aldicarb application

SUMMARYThe feasibility of enhancing cotton (Gossypium hirsutum L.) growth and nutrient uptake with Temik aldicarb was investigated using sand culture with a continuous flow of 1/5 strength of Hoagland solution. Aldicarb was incorporated in the nutrient solution at different rates, and was applied to the plants when they were 30 days old for a period of 1, 3, 5, or 7 days. The cation exchange capacity of the fresh roots of treated plants as well as the ionic permeability of the untreated plants as influenced by aldicarb application were also studied. Low rate of aldicarb provided a stimulus effect on the plant and enabled it to grow faster and to take up more N, P, K, Ca, Mg, and Na than the control. This suggested a direct effect of aldicarb on mineral metabolism especially those processes involving N and P. Maximum dry-matter yield and nutrient uptake occurred at the 5 mg aldicarb rate for all times of treatments. At a rate of 7middot;5 mg aldicarb, growth and nutrient uptake were inhibited, suggesting a toxicity of assimilatory processes within the plant which might have reduced its ability to take up and assimilate nutrients. Aldicarb facilitated the transfer of Na to the stem and leaves resulting in a more uniform distribution of Na throughout the treated plants compared with the control.

Some effects of herbicide-selection onAlopecurus myosuroïdes Huds

Four-year selection ofAlopecurus myosuroides by simazine has led to an increase of yield potential and root proportion, but has no effect on root cation-exchange capacity. Correlation between C.E.C. and yield potential is discussed. It is suggested that these characteristics provide selected plants with a better competitive ability; this competitive ability, however, may be considered as a side effect of certain herbicide selective effects.

Cation exchange capacity of plant roots in relation to nutrients uptake by shoot and grain as influenced by age

Four varieties of each paddy and wheat crops were grown in pots to see their cation exchange capacities of roots and their relationships with the uptake of nutrients by shoot and grain at different physiological growth stages. The results are summarised, as follows:

Calcium uptake and distribution in plants

Abstract Calcium uptake and distribution in plants are influenced by many factors. Root uptake seems to be independent of metabolic inhibitors but transfer to shoots is drastically reduced by such inhibitors. K uptake increases with root temperature which in turn results in depressed Ca uptake. Plant species differences in the proportion of K vs Ca uptake are often related to root cation exchange capacity. The cations K, Mg, Na, NH4+, and H+ directly and indirectly depress Ca uptake and distribution. Their effects are more pronounced at low Ca concentrations than at high. Lime‐induced chloros.is is associated with depressed Ca levels in leaves and tests under controlled conditions indicate that bicarbonate results in root retention of Ca and a decrease of Ca in leaves. Nitrate as a complementary ion promotes Ca uptake by plants. Trace metals in excess inhibit calcium uptake. Aluminum in particular greatly depresses Ca retention by roots as well as Ca uptake and transport to shoots. Leaves generally increase in Ca with age. Magnesium can result in phytotoxiciiy when Ca levels are low and this may be involved in crop Ca disorders. Leaf fruit or seed transfers of Ca can be related to concentration of Ca in leaves.