Plant Soil Environment Research Articles

Crop Response to Iron Deficiency is Guided by Cross-Talk Between Phytohormones and their Regulation of the Root System Architecture

Agriculture plays a very important role in influencing major economic sectors of the developing and the developed world and is regarded as one of the most crucial factors in the country’s development. Sustaining quality agriculture production is a necessity particularly of the under-developed, the developing and those countries which are inclined to a demographic spurt in the near future. However, the growth in the agricultural sector is marred by abiotic and biotic threats which take toll not only on productivity but also on quality of the farm produce. Later is important to address the challenge of malnutrition in humans and animals. It is thus important to strategically approach the present and emerging challenges that hamper sustainability and growth of the agricultural sector for which it is important to understand the soil-plant environment interactions under a prevailing stressful condition and elucidate the mechanism that harbour tolerance against the stress and facilitate a favourable-synergistic-balanced influence of the stress on plant growth and development. Plant survival and performance under abiotic stress condition are mainly regulated by root proliferation and nutrient extraction from soil. Later is facilitated by a preferential allocation of resources to the roots and a favourable change in root system architecture (RSA), caused by an altered hormonal balance. The present paper critically reviews the available literature that marks the interactive influence of phytohormones in regulating the plant root characteristics and the iron nutrition of crop plants. The mechanisms governing these interactions, whether direct or indirect, are also elaborated.

Theoretical research of the work of technological equipment for lifting large planting material with a soil clod

Large woody plants are a promising type of planting material for use in landscaping and forestry. The most labor-intensive technological operation in the process of growing them is lifting. To increase efficiency, this type of work must be performed using special equipment. The aim of the study is to study the process of plantlets lifting with a soil clod based on mathematical modeling methods to determine the optimal design parameters of lifting equipment developed by the authors. For a theoretical study of the equipment working process, a mathematical description of the interaction of the digging working tool with the soil-plant environment is carried out. The research work with the model consisted in the implementation of computer experiments to solve the compiled differential equation of the working tool motion around a fixed axis. Moreover, within the framework of changing the parameters of the working tool and the medium being processed, the dependences of the moments created by the driving forces and resistance forces are recorded. According to the results of the study, patterns of changes in the power characteristics of the digging process were established depending on the parameters of the working tool and the soil-plant environment.

Recent Understanding of Soil Acidobacteria and Their Ecological Significance: A Critical Review.

Acidobacteria represents an underrepresented soil bacterial phylum whose members are pervasive and copiously distributed across nearly all ecosystems. Acidobacterial sequences are abundant in soils and represent a significant fraction of soil microbial community. Being recalcitrant and difficult-to-cultivate under laboratory conditions, holistic, polyphasic approaches are required to study these refractive bacteria extensively. Acidobacteria possesses an inventory of genes involved in diverse metabolic pathways, as evidenced by their pan-genomic profiles. Because of their preponderance and ubiquity in the soil, speculations have been made regarding their dynamic roles in vital ecological processes viz., regulation of biogeochemical cycles, decomposition of biopolymers, exopolysaccharide secretion, and plant growth promotion. These bacteria are expected to have genes that might help in survival and competitive colonization in the rhizosphere, leading to the establishment of beneficial relationships with plants. Exploration of these genetic attributes and more in-depth insights into the belowground mechanics and dynamics would lead to a better understanding of the functions and ecological significance of this enigmatic phylum in the soil-plant environment. This review is an effort to provide a recent update into the diversity of genes in Acidobacteria useful for characterization, understanding ecological roles, and future biotechnological perspectives.

Two-Dimensional Visualization and Quantification of Labile, Inorganic Plant Nutrients and Contaminants in Soil.

We describe a method for two-dimensional (2D) visualization and quantification of the distribution of labile (i.e., reversibly adsorbed) inorganic nutrient (e.g., P, Fe, Mn) and contaminant (e.g., As, Cd, Pb) solute species in the soil adjacent to plant roots (the 'rhizosphere') at sub-millimeter (~100 µm) spatial resolution. The method combines sink-based solute sampling by the diffusive gradients in thin films (DGT) technique with spatially resolved chemical analysis by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The DGT technique is based on thin hydrogels with homogeneously distributed analyte-selective binding phases. The variety of available binding phases allows for the preparation of different DGT gel types following simple gel fabrication procedures. For DGT gel deployment in the rhizosphere, plants are grown in flat, transparent growth containers (rhizotrons), which enable minimal invasive access to a soil-grown root system. After a pre-growth period, DGT gels are applied to selected regions of interest for in situ solute sampling in the rhizosphere. Afterwards, DGT gels are retrieved and prepared for subsequent chemical analysis of the bound solutes using LA-ICP-MS line-scan imaging. Application of internal normalization using 13C and external calibration using matrix-matched gel standards further allows for the quantification of the 2D solute fluxes. This method is unique in its capability to generate quantitative, sub-mm scale 2D images of multi-element solute fluxes in soil-plant environments, exceeding the achievable spatial resolution of other methods for measuring solute gradients in the rhizosphere substantially. We present the application and evaluation of the method for imaging multiple cationic and anionic solute species in the rhizosphere of terrestrial plants and highlight the possibility of combining this method with complementary solute imaging techniques.

Effectiveness of domestic rural wastewater treatment in soil-plant system

The characteristics of Polish rural agglomerations indicate that only 32% of these areas are villages typified by compact buildings where the use of a collective sewage system is economically justified. In other areas, it is necessary to apply solutions that allow for the sewage utilization in place of their creation and safe discharge into the environment, e.g. in the form of home systems based on biological processes, e.g. in soil-plant systems. The purpose of the work was to determine the soil-plant efficiency of wastewater treatment with the use of so-called energy plants. The experiment was conducted in 2012–2014 in lysimeters at a depth of 130 cm and 100 cm in diameter. These were submerged in the ground, filled with sand clay and equipped with installations enabling the drain-age of gravity water in the form of lysimeter effluents. Two species of plants were used: Miscanthu giganteus and Sida hermaphrodita (L.) Rusby. They were irrigated with pre-treated domestic sewage (variant I – 1200 mm · year−1 and variant II – 1600 mm · year−1). For irrigation, sewage from a group of buildings inhabited by six families was used. Raw domestic sewage was discharged into the tank, consisting of four chambers, which constituted a relatively good level of pre-cleaning. For the irrigation of plants in the experiment, pre-treated sewage was used. In order to determine the effectiveness of wastewater treatment in the soil-plant environment, the concentrations of the following components were determined in the effluents: TSS, BOD5, COD, Ntot. The quantities of pollutants contained in the sewage were characterized by considerable variability, especially in relation to COD (390.6–1583.0 mg O2· dm−3) and Ntot (47.0–250.2 mg N · dm−3).

Serratia marcescens BM1 Enhances Cadmium Stress Tolerance and Phytoremediation Potential of Soybean Through Modulation of Osmolytes, Leaf Gas Exchange, Antioxidant Machinery, and Stress-Responsive Genes Expression.

The heavy metal contamination in plant-soil environment has increased manifold recently. In order to reduce the harmful effects of metal stress in plants, the application of beneficial soil microbes is gaining much attention. In the present research, the role of Serratia marcescens BM1 in enhancing cadmium (Cd) stress tolerance and phytoremediation potential of soybean plants, was investigated. Exposure of soybean plants to two Cd doses (150 and 300 µM) significantly reduced plant growth, biomass, gas exchange attributes, nutrients uptake, antioxidant capacity, and the contents of chlorophyll, total phenolics, flavonoids, soluble sugars, and proteins. Additionally, Cd induced the stress levels of Cd, proline, glycine betaine, hydrogen peroxide, malondialdehyde, antioxidant enzymes (i.e., catalase, CAT; ascorbate peroxidase, APX; superoxide dismutase, SOD; peroxidise, POD), and the expression of stress-related genes (i.e., APX, CAT, Fe-SOD, POD, CHI, CHS, PHD2, VSO, NR, and P5CS) in soybean leaves. On the other hand, inoculation of Cd-stressed soybean plants with Serratia marcescens BM1 significantly enhanced the plant growth, biomass, gas exchange attributes, nutrients uptake, antioxidant capacity, and the contents of chlorophyll, total phenolics, flavonoids, soluble sugars, and proteins. Moreover, Serratia marcescens BM1 inoculation reduced the levels of cadmium and oxidative stress markers, but significantly induced the activities of antioxidant enzymes and the levels of osmolytes and stress-related genes expression in Cd-stressed plants. The application of 300 µM CdCl2 and Serratia marcescens triggered the highest expression levels of stress-related genes. Overall, this study suggests that inoculation of soybean plants with Serratia marcescens BM1 promotes phytoremediation potential and Cd stress tolerance by modulating the photosynthetic attributes, osmolytes biosynthesis, antioxidants machinery, and the expression of stress-related genes.

Presence and possible origin of positive Eu anomaly in shoot samples of Juncus effusus L

BackgroundThe rare earth elements (REE) are non-essential elements for plants. They stimulate plant growth at low doses, but at high levels are phytotoxic. There are differences in concentrations of REE in various organs of the same plant species, but the normalized REE patterns can be very similar in samples of the same species collected in different locations. Here we compare normalized REE curves in above-ground samples of Juncus effusus L. (common rush, soft rush) collected from sites with different land-use types. MethodsThe concentrations of rare earth elements were measured in 55 shoot samples of J. effusus L. The samples were collected from 15 sampling sites located in the Holy Cross Mts., south-central Poland and analyzed with the use of inductively coupled plasma mass spectrometry (ICP-MS). The results were normalized to the North American Shale Composite and anomalies of different elements were calculated. ResultsTotal REE concentrations varied from 0.028 mg/kg to 2.7 mg/kg. The samples were enriched in the light REE (from La to Eu) with the highest concentrations of La and Ce. The North American Shale Composite (NASC)-normalized REE curves were roughly similar in all samples except for two samples collected in the acid mine drainageaffected areas. ConclusionAll samples showed positive europium anomalies in NASC-normalized REE concentration patterns. The most probable explanation of this is that the uptake and translocation of Eu in J. effusus (and possibly in other wetland plants) is caused by a short-term decrease of the redox potential in a rhizosphere favoring reduction of Eu3+ to Eu2+ and thus enhancing Eu mobility in the soil-plant environment.

PH-Dependent Bioavailability, Speciation, and Phytotoxicity of Tungsten (W) in Soil Affect Growth and Molybdoenzyme Activity of Nodulated Soybeans

Increasing use of tungsten (W)-based products opened new pathways for W into environmental systems. Due to its chemical alikeness with molybdenum (Mo), W is expected to behave similarly to its “twin element”, Mo; however, our knowledge of the behavior of W in the plant–soil environment remains inadequate. The aim of this study was to investigate plant growth as well as W and nutrient uptake depending on soil chemical properties such as soil pH and texture. Soybean (Glycine max cv. Primus) was grown on two acidic soils differing in soil texture that were either kept at their natural soil pH (pH of 4.5–5) or limed (pH of ≥7) and amended with increasing concentrations of metallic W (control and 500 and 5000 mg kg–1). In addition, the activity of molybdoenzymes involved in N assimilation (nitrate reductase) and symbiotic N2 fixation (nitrogenase) was also investigated. Our results showed that the risk of W entering the food web was significantly greater in high-pH soils due to increased solubility of mainly monomeric W. The effect of soil texture on W solubility and phytoavailability was less pronounced compared to soil pH. Particularly at intermediate W additions (W 500 mg kg–1), symbiotic nitrogen fixation was able to compensate for reduced leaf nitrate reductase activity. When W soil solution concentrations became too toxic (W 5000 mg kg–1), nodulation was more strongly inhibited than nitrogenase activity in the few nodules formed, suggesting a more-efficient detoxification and compartmentalization mechanism in nodules than in soybean leaves. The increasing presence of polymeric W species observed in low-pH soils spiked with high W concentrations resulted in decreased W uptake. Simultaneously, polymeric W species had an overall negative effect on nutrient assimilation and plant growth, suggesting a greater phytotoxicity of W polymers. Our study demonstrates the importance of accounting for soil pH in risk assessment studies of W in the plant–soil environment, something that has been completely neglected in the past.

Effect of Fe-Glycine Aminochelate on Pod Quality and Iron Concentrations of Bean (Phaseolus vulgaris L.) Under Lime Soil Conditions

ABSTRACTIron (Fe) has very low solubility and plant availability in calcareous soils, and this generally results in restricted plant production and low quality. During last decades, various commercial chelated fertilizers have been used in agricultural systems to meet iron requirements of crops. However, despite extensive application of these commercial chelate fertilizers, there is real doubt and high concerns regarding many aspects of their action, dynamics, efficiency, and safety in plant-soil–environment systems. In the present study, growth and quality of green bean plants (Phaseolus vulgaris L.) were evaluated under foliar and soil applications of Fe-glycine chelate (iron glycine aminochelate) and commercial Fe-EDDHA chelate in a lime soil. The results showed that morphophysiological parameters were improved by the application of Fe-glycine and Fe-EDDHA treatments. Foliar application of Fe-glycine has significantly improved leaf area and Soil-Plant Analyses Development (SPAD) values compared to control and Fe-EDDHA treatments. Pod yield, shoot (but not root) dry weight, and iron concentrations in leaves and pods (but not in root) were significantly higher when plants were treated by Fe-glycine rather than Fe-EDDHA in both soil and foliar applications. Vitamin C and protein contents were significantly improved and phenolic compounds were reduced by foliar application of Fe-glycine and soil application of Fe-EDDHA. The results indicate that foliar application of Fe-glycine can significantly increase Fe concentrations and quality of beans under lime soils with restricted iron availability.

Analysis of moisture conditions in the lowland areas using high resolution spectral data from the Sentinel-2 satellite and the GIS tools

Research concerning agricultural drought issue mainly focuses on the methods based on long-term atmospheric data, temperature, precipitation and evaporation measurements. On the other hand, the scientific bibliography shows the possibilities of using spectral data for description the state of plants. The general availability and increasing resolution of the spectral and temporal data create a chance for monitoring and forecasting deficiencies of soil moisture based on spectral images. Paper presents the results of analysis of the moisture conditions in soil-plant environment in the lowland catchment area using the spectral data obtained from the Sentinel-2 European Space Agency satellite for period February-November 2016. These spectral data were used for the calculation the Normalized Differential Vegetation Index (NDVI) which provided information about moisture conditions in the soil-plant environment. Then, the values of NDVI index were compared with the data obtained from the field investigations. The analyses have showed the spatial and temporal variability of moisture conditions in the soil-plant environment determined on the background of the spectral indicators and the existence of some dependences between climatic and spectral indicators characterizing soil-plant environment.

Selenium in the Soil-Plant Environment: A Review

Selenium (Se) exhibits a “double-edged” behavior in animal and human nutrition. It is a micronutrient required in low concentrations by animals and humans, but toxic at high concentrations. Selenium deficiency has been associated with cancer and other health problems. Selenium requirements are commonly met through soils and plants such as wheat, rice, vegetables and maize in many countries. Selenium concentration in the soil generally ranges from 0.01-2.0 mg kg-1 but seleniferous soils usually contain more than 5 mg kg-1. Seleniferous soils have been reported in Ireland, China, India and USA. Weathering of parent rocks and atmospheric deposition of volcanic plumes are natural processes increasing Se levels in the environment. Anthropogenic sources of Se include irrigation, fertilizer use, sewage sludge and farmyard manure applications, coal combustion and crude oil processing, mining, smelting and waste incineration. Mobility of Se in the soil-plant system largely depends on its speciation and bioavailability in soil which is controlled by pH and redox potential. Plant uptake of Se varies with plant species and Se bioavailability in the soil. The uptake, translocation, transformation, metabolism, and functions of Se within the plant are further discussed in the paper. The release of Se in soils and subsequent uptake by plants has implications for meeting Se requirements in animals and humans.

Innovative Materials for Removal of New Generation Pollutants from Aquatic Environment

Wide spread application of Nanoparticles (NPs) for various uses like antibacterial materials, drug delivery systems, cosmetics, pesticides and electronic gadgets leads to developments in nanotechnology. Improvement in properties of these product due to NPs are leading to a rapid proliferation of new materials that are likely to become a source of Engineered Nanoparticles (ENPs) to the ambient environment, where their possible ecotoxicological impacts remain unknown. These ENPs can be termed as new generation pollutants in aquatic and terrestrial environment. The potential toxic effects of these nanoparticles on aquatic as well as soil-plant environment, have drawn much special attention due to their higher production, usage and unintentional release into the environment without any systematic regulation by government agencies as in case of conventional pollutants.

Do More Seeds per Panicle Improve Grain Sorghum Yield?

Seed number, rather than seed mass, is largely considered to be the most important yield component of grain sorghum [Sorghum bicolor (L.) Moench]. An experimental sorghum mutant line with enhanced seed number (tri‐seed) was grown at the Soil–Plant–Environment Research (SPER) facility, USDA–ARS, Bushland, TX, in 2014 and 2015 to provide field validation of the tri‐seed line's ability to increase yield. The SPER facility had a rain shelter to control the soil‐water balance. The parent inbred line BTx623 and the tri‐seed line MSD‐P5, which originated as a mutant of BTx623, were grown in weighing lysimeters with undisturbed soil profiles of four agriculturally productive soils (Pullman clay loam, Ulysses silt loam, Amarillo sandy loam, and Vingo fine sand) of the US Great Plains. Planting density was 16 plants m−2 and the crops received either 18 or 36 mm of irrigation weekly. The tri‐seed line produced significantly smaller grain yield, seed mass, and total biomass compared with the parent line. The mass per panicle was similar between lines, but a significantly larger proportion of the tri‐seed line panicle was non‐grain panicle mass compared with the parent line. Both hybrids exhibited some plasticity in seed mass to accommodate assimilate as it became available, but increased seed mass, along with increased seed number, also did not result in a significant increase in harvest index for the tri‐seed line compared with the parent line. The increase in seed number by the tri‐seed line did not compensate for the decreased seed mass, which consequently failed to increase grain yield or harvest index.

Precipitation as the most affecting factor on soil–plant environment conditions affects the mycorrhizal spore numbers in three different ecological zones in Turkey

ABSTRACTMycorrhizal symbiosis is the one of the most important relationship between microbiota and plants to sustain plant nutrition in relatively unfavourable conditions. Somehow this relation is threatened by time, therefore, definition of the factors effecting mycorrhizal symbiosis has become essential. The aim of this study was to determine the differences in specific mycorrhizal parameters such as sporulation and soil–plant environment conditions in three different regions of Turkey. During 1996−2002, 53 soil series were selected from natural and agricultural plant communities in three different agro-ecological zones of Turkey: Central Anatolia (CA), the Southeastern Anatolian (SA) project area and the Coast of Mediterranean (CM). The arbuscular mycorrhizal fungus (AMF), spore numbers and mycorrhizal root colonization were related to the annual average precipitation, soil characteristics and host plant identity.In the CM zone (average annual precipitation of 650 mm), soils found under natural vegetation contained a maximum value of 108 spores g−1, with bare soils containing a minimum number of 0.1 spores g−1. In the CA zone (330 mm annual average precipitation), the maximum number of spores in the soil samples was 46.5 spores g−1 with a minimum of 6.8 spores g−1 and in the SA soil samples (380 mm annual average precipitation), a maximum of 48.4 spores g−1 and a minimum of 14.2 spores g−1 were recorded. The overall mean number of mycorrhizal spores g−1 soil was 15.5 ± 14.4, 22.2 ± 8.6 and 27.9 ± 25.4 for the CA, SA and CM zones, respectively. Mean spore numbers differed in only two of the three zones, with the third zone being intermediate. Precipitation was the most affecting factor on the sporulation of AMF. Also host plant species and certain soil parameters, such as positive correlations with CaCO3 and N-min and a negative correlation with organic matter, have an influence on sporulation.The key finding is that the cropping system has a large impact on spore numbers/abundance. Seventeen standing crops as well as bare soil, fallow and natural areas were compared. There are a large number of factors which can affect mycorrhizal development; in the present work, it seems that soil and crop management, and environmental factors (such as precipitation) affect sporulation and root colonization. Covering land surface with mycorrhiza-dependent cover crop, irrigation and less soil till may increase indigenous mycorrhizal spores.

Effect of city waste compost applied alone and in combination with chemical fertilizer on the yield and nutrient uptake of wheat and subsequent maize crop

The use of city waste as compost can provide a two way benefits of increasing soil productivity along with preventing pollution associated with population pressure, industrialization and urbanization. This study was conducted to determine the effect of the compost applied with chemical fertilizer, its effect on NPK uptake and nutrient use efficiency by wheat and maize plant. In this context, the effect of city waste compost at 10 and 20 tone ha-1 was evaluated along the application of half and ¾ of the recommended NPK doses on wheat crop and their residual effect on maize crop. The experimental design was RCBD with 3 replication for both crops under the same layout at Pirsabak Research Institute, Nowshehra. Commerical compost was applied and mixed with the soil a month prior to sowing. The phosphatic and potash fertilizer are applied in the form of SSP and SOP at time of sowing while the N fertilizer are applied in three split doses half at sowing time while the remaining with the first and second irrigation. In the succeeding reason, maize was sown in the same layout without applying any compost and chemical fertilizers to evaluate the residual effect of previously applied fertilizers. The CWC significantly improved both the wheat and residual maize thousand grain weight, grain yield and biological yield over alone NPK with maximum values for 20 t CWC ha-1 with 75 % NPK. The CWC also promoted the NPK status of soil and their uptake by wheat and residual maize suggesting that integration of CWC with NPK could improve the nutrient use efficiency and save the use of chemical fertilizer 25 to 50 %. The higher yield and superior performance of CWC in conjunction with NPK over sole NPK or control even in the residual maize advocated that the use of CWC could help in maintaining the soil productivity for the long run. These results suggested that the use of CWC will not only promote the agricultural productivity but could also help in safe disposal of the city wastes and could manage the current pollution scenario with increasing population pressure in urban areas of the country. Based the present study the application of 20 t ha-1 CWC with 75 % NPK could maintain higher yields of wheat and maize for two seasons under prevailing soil and climatic conditions. However, for wide spread application the CWC must be checked for contaminants like heavy metals and pathogens for safe handling and disposals to soils and preventing any hazardous effects on soil plant environment. Keywords: City waste compost; Urea; Single super phosphate; Sulphate of potash; Wheat; Maize http://dx.doi.org/10.19045/bspab.2015.44004

Plant-based culture media: Efficiently support culturing rhizobacteria and correctly mirror their in-situ diversity

Our previous publications and the data presented here provide evidences on the ability of plant-based culture media to optimize the cultivability of rhizobacteria and to support their recovery from plant-soil environments. Compared to the tested chemically-synthetic culture media (e.g. nutrient agar and N-deficient combined-carbon sources media), slurry homogenates, crude saps, juices and powders of cactus (Opuntia ficus-indica) and succulent plants (Aloe vera and Aloe arborescens) were rich enough to support growth of rhizobacteria. Representative isolates of Enterobacter spp., Klebsiella spp., Bacillus spp. and Azospirillum spp. exhibited good growth on agar plates of such plant-based culture media. Cell growth and biomass production in liquid batch cultures were comparable to those reported with the synthetic culture media. In addition, the tested plant-based culture media efficiently recovered populations of rhizobacteria associated to plant roots. Culturable populations of >106–108cfug−1 were recovered from the ecto- and endo-rhizospheres of tested host plants. More than 100 endophytic culture-dependent isolates were secured and subjected to morphophysiological identification. Factor and cluster analyses indicated the unique community structure, on species, genera, class and phyla levels, of the culturable population recovered with plant-based culture media, being distinct from that obtained with the chemically-synthetic culture media. Proteobacteria were the dominant (78.8%) on plant-based agar culture medium compared to only 31% on nutrient agar, while Firmicutes prevailed on nutrient agar (69%) compared to the plant-based agar culture media (18.2%). Bacteroidetes, represented by Chryseobacterium indologenes, was only reported (3%) among the culturable rhizobacteria community of the plant-based agar culture medium.

Heavy Metals (Cd, Ni and Pb) Contamination of Soils, Plants and Waters in Madina Town of Faisalabad Metropolitan and Preparation of Gis Based Maps

Heavy metal pollution is a great threat to the environment. These metals are enters to the soil-plant environment through anthropogenic sources. A survey study was conducted to assess the heavy metals contamination of soils, plants and waters of Madina town of Faisalabad, Metropolitan area in 2010. Soil, plant and water samples were collected in the vicinity of Faisalabad following 4 × 4 Km grids. Soil samples were taken from 0-15 cm and 15-30 cm depths and prepared for the determination of metals (Cd, Pb and Ni). Plant samples were also taken from the same location and dried and digested in HClO4:HNO3 in the ratio of 1:3. AB-DTPA extract of soil, plants extract and water samples was analyzed on Atomic Absorption Spectrophotometer (Model Thermo S series). The results of the study showed the concentration of metals in Soils ranged from Cd (0.00-0.111 ppm), Pb (0.87-8.97 ppm) and Ni (0.017-1.72 ppm) at 0-15 cm while Cd (0.00-0.88 ppm), Pb (0.43-6.77 ppm) and Ni (0.055-0.852 ppm) at 15-30 cm respectively. Cd, Pb and Ni concentration in the plants ranged from 0.00-2.25 ppm 1.11-5.29 ppm and 1.51-4.96 respectively. Concentration of metal in the ground water ranged from Cd (0.00-0.06 ppm), Pb (0.10-11.10 ppm) and Ni (0.03-0.05). The concentration Pb and Ni was below the permissible limits while concentration of Cd in waters and plants above the permissible limits. Finally it was concluded that soil, plant and water of Madina town were in the safe limits with respect to metals. The use of city effluent is increasing the level of metals into the soils that ultimately contaminate the soils, plants and waters. So, it is suggested that city effluent must be treated for the detoxification of metals before use in irrigation purposes for crops.

Crop Water Productivity of Sugarbeet as Affected by Tillage

One of today's greatest challenges of irrigated agriculture is to produce more food and fiber with less water, which can be accomplished by maximizing crop water productivity (CWP). A study was conducted to evaluate and compare the effect of conventional tillage (CT) and strip tillage (ST) on crop water use (CWU) and CWP of sugarbeet (Beta vulgaris L.) on clay loam soil in the northern Great Plains (NGP). Seasonal CWU and CWP for sugarbeet root and sucrose yields were determined for the 2006, 2007, and 2008 growing seasons according to the water balance and CWP equations under CT and ST practices. No significant differences due to tillage were found for CWU of sugarbeet. In 2006, CWP for root yield was significantly greater in ST relative to CT due to wind damage early in the spring which reduced sugarbeet plant population in the CT. The mean CWP for root yield across three growing seasons was10% greater for ST than for CT due to the protected soil–plant environment under the ST. The ST greatly reduces wind erosion and the related plant damage. The ST system used 0.0093 m3 and 0.061 m3 of irrigation water less than CT system to produce 1 kg of sugarbeet root and 1 kg of sucrose yield, respectively, throughout the growing season. We concluded that ST can be used to produce sugarbeet root yield and CWP comparable to CT or even in some instances greater than CT in areas that are prone to wind damage to sugarbeet seedlings.

Zinc Isotope Fractionation during Early Dissolution of Biotite Granite

Stable metal isotopes show great promise as a novel technique to study fundamental processes underlying micronutrient dynamics in soils and uptake by plants in situ. An important step in the development of these isotope systems is to constrain the extent and mechanisms of the isotopic fractionation in the plant–soil environment. One of the prominent micronutrient sources that needs to be constrained is release from parent material. To this end, we tested the isotopic fractionation of Zn during the very early stages of proton- and ligand-controlled dissolution of a finely powdered, fresh biotite granite using batch experiments. The observed fractionation pattern was similar for both dissolution mechanisms (proton and ligand promoted). Isotope fractionations were highest in the early stages of dissolution and probably kinetically controlled. After a few days, isotope fractionation imparted isotopically light Zn in the soil solution.

Effective microorganisms and their influence on vegetable production – a review

SummaryThis review aims to describe the nature of effective microorganisms (EM) and how EM influence the growth, yield, quality, and protection of vegetable plants. EM comprise a mixture of live natural cultures of microorganisms isolated from fertile soils that are used to improve crop production. EM technology was developed over 40 years ago by Dr. Tero Higa in Japan. How EM act and interact in the soil-plant environment to suppress plant pathogens and disease, to conserve energy, to solubilise soil minerals, to aid the balance and ecology of soil microbes, and to improve photosynthetic efficiency and biological nitrogen fixation are described. In 70% of published studies, it was concluded that EM had a positive effect on the growth of vegetables, while, in the other 30%, they had no significant influence. In this investigation, among 22 reports on the effects of EM on the yields of vegetables, 84% were positive, 4% were negative, and 12% showed no significant influence. It is concluded that EM can improve the quality and yield of vegetables by reducing the incidence of pests and diseases, and by protecting against weeds, thereby contributing to sustainable agriculture.