Raya (Brassica juncea) and spinach (Spinacia oleracea), grown as leafy vegetables, are known to accumulate large amounts of heavy metals in their shoots and roots because of their high biomass and root proliferation. In a pot experiment, a sandy loam soil was polluted with cadmium (Cd) at rates of 0, 5, 10, 20, 40 and 80 mg kg−1 soil to assess the accumulation pattern and its effect on the dry matter yield and mineral composition of these vegetables. There was a decrease in dry matter yield due to the phytotoxic effect of Cd. The rate of Cd application at which a significant decline in root and shoot dry matter yield occurred varied depending on the vegetable. It was 20 mg Cd kg−1 soil in the shoots for both crops. However, the roots of raya were found to be more tolerant of Cd toxicity than those of spinach, as is evident from the fact that a significant decline in dry matter yield occurred at 20 and 10 mg Cd kg−1 soil, respectively. Since no visual toxic symptoms were observed on the leaves of raya in any of the treatments, it is clear that the metal may accumulate in this vegetable without visual evidence of its presence. However, at application levels beyond 40 mg kg−1 soil, toxicity symptoms, in the form of interveinal chlorosis of the leaf lamina followed by necrosis and leaf rolling, were clearly evident in the case of spinach. The reduction in root and shoot growth corresponded with the amounts of extractable Cd in the soils. The total content of Cd in the crops increased gradually as the rate of applied Cd rose and the roots accumulated much higher amounts than the shoots. The relationship of Cd with Zn and Fe was synergistic in both roots and shoots at the lower rates, but antagonistic at higher Cd application rates for both the crops, while in the case of Mn and Cu, the relationship was negative and antagonistic.
In deserts, biological processes decrease at the end of the vegetation period by lack of soil moisture and increasing heat. Important processes for plant nutrient uptake are negatively affected like N fixation, litter decomposition and denitrification. Desert plants must therefore adapt their mineral household towards best use of available nutrients and storage of minerals in perennial organs. Here we studied this pattern by experiments of the effect of nitrogen nutrition on mineral concentration and plant growth of Retama raetam (Forssk.) Webb. Berth for two years in sand culture. In summary, the mineral household of R raetam seems to be well adapted to unfavourable desert habitat independent from the N source and N level.
The mineral composition of frozen food of taro [Colocasia esculenta (L.) Schott] was analyzed to categorize the geographical production place of taro. The concentrations of Co and H2PO4− were found to be useful to separate the producing place between Japan and China. The analysis was performed by instrumental
neutron activation analysis (INAA) and ion chromatography (IC). In the case of INAA, the samples were dried and sealed in
a vinyl bag and irradiated with thermal neutrons from JRR3M, installed at Japan Atomic Energy Agency (JAEA). The activated
samples were cooled down for a few weeks and the elements (Co, Cr, Fe, Rb, Zn) were determined. Cobalt concentration of frozen
taro from China was higher than that from Japan. The tendency was the same in the fresh sample of taro. When concentration
of H2PO4− of frozen sample was measured, taro from Japanese product was higher than that of Chinese one, contrary to fresh sample.
This result might be caused by the leakage of H2PO4− during freezing process, indicating that we should be careful to apply the discrimination indicators. In addition to Co,
there was a significant difference of Rb and Fe concentrations between frozen taro from Japan and China.
Bedrock has an essential role in the formation of soils, it fundamentally determines mineral composition. The present research focuses on the minerals in forest soils formed in the Bükk Mountains (NE Hungary). The composition of soil minerals was in accordance with the geological features as well as with the changes in climate and vegetation, which provide a basis for tracking the past of the soil formation mechanisms (Nemecz, 2006). Thus, by studying the mineral composition the formation processes and development of the soils can be unveiled.According to the findings it can be assumed that the investigated soils, although formed primarily on solid limestone, cannot be the products of the weathering of limestone solely, as they also contain significant amounts of silicates. The major part of the soil forming materials presumably originates from earlier dust fallings or from alluvial deposits by erosion. The former assumption is confirmed by the fact that the investigated area is located at a high altitude, thus significant amounts of eroded material could only originate from a short distance, where the bedrock also consists of limestone. Further research is needed for more detailed knowledge on the mineral composition of the soils, thus on the development of the soils and the bedrock of the investigated area.
Authors:J.S. Khokhar, S. Sareen, B.S. Tyagi, L. Wilson, I.P. King, S.D. Young and M.R. Broadley
Correlations between juvenile wheat root traits, and grain yield and yield component traits under optimal field conditions have previously been reported in some conditions. The aim of this study was to test the hypothesis that juvenile wheat root traits correlate with yield, yield components and grain mineral composition traits under a range of soil environments in India. A diverse panel of 36 Indian wheat genotypes were grown for ten days in ‘pouch and wick’ high-throughput phenotyping (HTP) system (20 replicates). Correlations between juvenile root architecture traits, including primary and lateral root length, and grain yield, yield components and grain mineral composition traits were determined, using field data from previously published experiments at six sites in India. Only a limited number of juvenile root traits correlated with grain yield (GYD), yield components, and grain mineral composition traits. A narrow root angle, potentially representing a ‘steep’ phenotype, was associated with increased GYD and harvest index (HI) averaged across sites and years. Length related root traits were not correlated with GYD or HI at most sites, however, the total length of lateral roots and lateral root number correlated with GYD at a sodic site of pH 9.5. The total length of lateral roots (TLLR) correlated with grain zinc (Zn) concentration at one site. A wider root angle, representing a shallow root system, correlated with grain iron (Fe) concentration at most sites. The total length of all roots (TLAR) and total length of primary roots (TLPR) correlated with grain S concentration at most sites. Narrow root angle in juvenile plants could be a useful proxy trait for screening germplasm for improved grain yield. Lateral root and shallow root traits could potentially be used to improve grain mineral concentrations. The use of juvenile root traits should be explored further in wheat breeding for diverse environments.
On the basis of the samples studied, which were gathered over the past
year, we were able to summarize the characteristics of red clays in Northern
Hungary. From the large selection of samples we chose 16 representative soil
profiles for our assessment. In order to characterize red clays we used data on
mechanical composition, cation exchange capacity and adsorption capacity as
well as the mineral composition identified by X-ray diffraction and
thermoanalytical studies. Following observations and conclusions drawn from our
study we were able to identify the categories of red clay in Northern Hungary:
1. Red clay of the Hegyalja region (Tokaj foothills); 2. Red soils of the
Cserhát and Szalonna Hills; 3. Red clays of the Aggtelek karst, the Torna Hills
and the Bódva Valley; 4. Red soils of the Bükk mountain range. 5. Red clays of
the Northern periphery of the Great Hungarian Plain. The following conclusions can be drawn from
the studies on the water permeability of the soils: Water permeability is
correlated with the pore space and the ratio of coarse pores. The bigger the
total pore space and the ratio of coarse pores, the better the water
permeability of the soil. If the clay content is higher the water permeability
is generally lower. In soils that contain montmorillonite the speed of water
permeability is lower than in soils containing kaolinite. Within the porous
system of bauxitic red clays containing kaolinite the volume of medium size and
coarse pores increases, resulting in better water permeability. In the upper
layers of soils covered with vegetation water permeability is much better. The
high amount of roots and root residues provides better soil structure and
porosity, thus improving water permeability.
Use of a short rotary kiln with a cyclone preheater allowed the internal recirculation of volatile constituents, essentially
consisting of compounds of potassium, chlorine and sulphur. These compounds underwent partial condensation on the raw material
grains, composed mainly of calcite. The increasing concentration of volatile constituents created convenient conditions for
the crystallization of new phases, particularly sylvite. Beautiful crystals of this phase were formed, probably by the VLS
mechanism. Thermal analysis revealed that a liquid phase was formed in the system at the relatively low temperature of about
630C, which enhanced the reaction of silica with calcium carbonate, and spurrite was formed. Thus, the build-ups were composed
mainly of calcite, sylvite and spurrite, and in some cases also of calcium oxide and anhydrite. Sulphospurrite, gehlenite,
calcium langbeinite, dicalcium silicate and calcium aluminate, 12CaO7Al2O3 were found as minor components.