scholarly journals Conditioning with Lime and Fertilizer Improves Ionic Rare Earth Mine Tailings

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Qin Zhang ◽  
Dongmei Shen ◽  
Jie Luo ◽  
Guanyue Wan ◽  
Caiyun Zhou ◽  
...  
Keyword(s):  
Rare Earth ◽  
Plant Growth ◽  
Chinese Cabbage ◽  
Mine Tailings ◽  
Soil Acidification ◽  
Heavy Metal Contamination ◽  
Pore Space ◽  
Soil Nutrient ◽  
Nutrient Content ◽  
Rare Earth Mine

To explore rare earth mine tailings improvement technology without soil dressing, we planted Chinese cabbage in pots to determine the effect of different amounts of lime combined with fertilizer on the improvement of ionic rare earth mine tailings, aiming to provide a scientific basis for the reclamation of abandoned ionic rare earth mines. The results showed that the soil substrate of the tested rare earth tailings exhibited four forms of degradation: soil acidification, soil desertification, nutrient depletion, and heavy metal contamination by rare earth elements (REEs). The application of fertilizer alone (CK treatment) did not support Chinese cabbage growth, whereas different amounts of lime combined with fertilizer supported plant growth and significantly reduced the activity of the rare earth heavy metals. The height, fresh weight, and REE content of the Chinese cabbage plants were significantly reduced with an increase in the amount of lime applied. Addition of lime not only significantly improved the soil pore space and reduced soil acidification but also significantly increased the soil nutrient content. Our findings suggest that lime combined with fertilizer can improve ionic rare earth mine tailing soil degradation, thus promoting plant growth and achieving the improvement of ionic rare earth mine tailings without soil dressing.

scholarly journals Effects of Two Trichoderma Strains on Plant Growth, Rhizosphere Soil Nutrients, and Fungal Community of Pinus sylvestris var. mongolica Annual Seedlings

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 758 ◽  
Author(s):  
Saiyaremu Halifu ◽  
Xun Deng ◽  
Xiaoshuang Song ◽  
Ruiqing Song
Keyword(s):  
Enzyme Activity ◽  
Community Structure ◽  
Plant Growth ◽  
Soil Nutrients ◽  
Fungal Community ◽  
Rhizosphere Soil ◽  
Soil Nutrient ◽  
Nutrient Content ◽  
Root Structure ◽  
Soil Nutrient Content

Trichoderma spp. are proposed as major plant growth-promoting fungi that widely exist in the natural environment. These strains have the abilities of rapid growth and reproduction and efficient transformation of soil nutrients. Moreover, they can change the plant rhizosphere soil environment and promote plant growth. Pinus sylvestris var. mongolica has the characteristics of strong drought resistance and fast growth and plays an important role in ecological construction and environmental restoration. The effects on the growth of annual seedlings, root structure, rhizosphere soil nutrients, enzyme activity, and fungal community structure of P. sylvestris var. mongolica were studied after inoculation with Trichoderma harzianum E15 and Trichoderma virens ZT05, separately. The results showed that after inoculation with T. harzianum E15 and T. virens ZT05, seedling biomass, root structure index, soil nutrients, and soil enzyme activity were significantly increased compared with the control (p < 0.05). There were significant differences in the effects of T. harzianum E15 and T. virens ZT05 inoculation on the growth and rhizosphere soil nutrient of P. sylvestris var. mongolica (p < 0.05). For the E15 treatment, the seedling height, ground diameter, and total biomass of seedlings were higher than that those of the ZT05 treatment, and the rhizosphere soil nutrient content and enzyme activity of the ZT05 treatment were higher than that of the E15 treatment. The results of alpha and beta diversity analyses showed that the fungi community structure of rhizosphere soil was significantly different (p < 0.05) among the three treatments (inoculated with T. harzianum E15, T. virens ZT05, and not inoculated with Trichoderma). Overall, Trichoderma inoculation was correlated with the change of rhizosphere soil nutrient content.

scholarly journals Halotolerant Rhizobacteria for Salinity-Stress Mitigation: Diversity, Mechanisms and Molecular Approaches

2022 ◽  
Vol 14 (1) ◽  
pp. 490
Author(s):  
Alka Sagar ◽  
Shalini Rai ◽  
Noshin Ilyas ◽  
R. Z. Sayyed ◽  
Ahmad I. Al-Turki ◽  
...  
Keyword(s):  
Plant Growth ◽  
Salinity Stress ◽  
Crop Production ◽  
Germination Rate ◽  
Soil Nutrient ◽  
Nutrient Content ◽  
Shoot Elongation ◽  
Plant Growth Promoting Bacteria ◽  
Molecular Approaches ◽  
Plant Growth Promoting

Agriculture is the best foundation for human livelihoods, and, in this respect, crop production has been forced to adopt sustainable farming practices. However, soil salinity severely affects crop growth, the degradation of soil quality, and fertility in many countries of the world. This results in the loss of profitability, the growth of agricultural yields, and the step-by-step decline of the soil nutrient content. Thus, researchers have focused on searching for halotolerant and plant growth-promoting bacteria (PGPB) to increase soil fertility and productivity. The beneficial bacteria are frequently connected with the plant rhizosphere and can alleviate plant growth under salinity stress through direct or indirect mechanisms. In this context, PGPB have attained a unique position. The responses include an increased rate of photosynthesis, high production of antioxidants, osmolyte accumulation, decreased Na+ ions, maintenance of the water balance, a high germination rate, and well-developed root and shoot elongation under salt-stress conditions. Therefore, the use of PGPB as bioformulations under salinity stress has been an emerging research avenue for the last few years, and applications of biopesticides and biofertilizers are being considered as alternative tools for sustainable agriculture, as they are ecofriendly and minimize all kinds of stresses. Halotolerant PGPB possess greater potential for use in salinity-affected soil as sustainable bioinoculants and for the bioremediation of salt-affected soil.

scholarly journals Design and Build a Soil Nutrient Measurement Tool for Citrus Plants Using NPK Soil Sensors Based on the Internet of Things

2021 ◽  
Vol 1 (2) ◽  
pp. 67-74
Author(s):  
Haristian Pratama ◽  
Amsar Yunan ◽  
Rudi Arif Candra
Keyword(s):  
Plant Growth ◽  
Alluvial Soil ◽  
Soil Nutrient ◽  
Nutrient Content ◽  
Measurement Tool ◽  
Soil Sensors ◽  
Dry Soil ◽  
Citrus Seeds ◽  
The Internet Of Things

A suitable planting medium is a medium of good quality soil that can support plant growth quickly. Fertile soil is the primary need for plants. The quality of the planting medium dramatically affects plant growth. The types of soil needed for plant growth vary, namely sandy soil, red soil, alluvial soil, and humus soil. Using an NPK sensor that functions to detect nutrients in the soil and can work if the tip of the sensor is plugged into the soil they want to detect, the results detected by the sensor will be sent in the form of analog signal data to nodemcu, which will be processed and displayed on the screen. Thingspeak. This tool is controlled by nodemcu with an NPK sensor to detect nutrients in the soil with output to thingspeak. The function of the NPK sensor tool will measure the nutrients in the soil for citrus seedlings, and the results read by the Npk sensor will be sent to the Thingspeak web, making it easier for farmers to seed citrus seeds. The data read by the sensor will be sent to thingspeak, making it easier to monitor nutrients in the soil. From the results of the tests carried out, it is found that the nutrient content in wet soil is higher than in dry soil; from the tests carried out, the NPK sensor accuracy rate is 90%.

The ameliorating effects of biochar and compost on soil quality and plant growth on a Ferralsol

Soil Research ◽  
2015 ◽  
Vol 53 (1) ◽  
pp. 1 ◽  
Author(s):  
Getachew Agegnehu ◽  
Michael I. Bird ◽  
Paul N. Nelson ◽  
Adrian M. Bass
Keyword(s):  
Plant Growth ◽  
Soil Fertility ◽  
Root Biomass ◽  
Soil Nutrient ◽  
Principal Component ◽  
Nutrient Status ◽  
Nutrient Content ◽  
Shoot Biomass ◽  
Plant Nutrient ◽  
Control Value

Deteriorating soil fertility and the concomitant decline in agricultural productivity are major concerns in many parts of the world. A pot experiment was conducted with a Ferralsol to test the hypothesis that application of biochar improves soil fertility, fertiliser-use efficiency, plant growth and productivity, particularly when combined with compost. Treatments comprised: untreated control; mineral fertiliser at rates of 280 mg nitrogen, 70 mg phosphorus and 180 mg potassium pot–1 (F); 75% F + 40 g compost pot–1 (F + Com); 100% F + 20 g willow biochar pot–1 (F + WB); 75% F + 10 g willow biochar + 20 g compost pot–1 (F + WB + Com); 100% F + 20 g acacia biochar pot–1 (F + AB); and 75% F + 10 g acacia biochar + 20 g compost pot–1 (F + AB + Com). Application of compost with fertiliser significantly increased plant growth, soil nutrient status and plant nutrient content, with shoot biomass (as a ratio of control value) decreasing in the order F + Com (4.0) > F + WB + Com (3.6) > F + WB (3.3) > F + AB + Com (3.1) > F + AB (3.1) > F (2.9) > control (1.0). Maize shoot biomass was positively significantly correlated with chlorophyll content, root biomass, plant height, and specific leaf weight (r = 0.99, 0.98, 0.96 and 0.92, respectively). Shoot and root biomass had significant correlations with soil water content, plant nutrient concentration, and soil nutrient content after harvesting. Principal component analysis (PCA) showed that the first component provided a reasonable summary of the data, accounting for ~84% of the total variance. As the plants grew, compost and biochar additions significantly reduced leaching of nutrients. In summary, separate or combined application of compost and biochar together with fertiliser increased soil fertility and plant growth. Application of compost and biochar improved the retention of water and nutrients by the soil and thereby uptake of water and nutrients by the plants; however, little or no synergistic effect was observed.

scholarly journals Effect of calcination temperature on rare earth tailing catalysts for catalytic methane combustion

2020 ◽  
Vol 9 (1) ◽  
pp. 734-743
Author(s):  
Ran Zhao ◽  
ZiChen Tian ◽  
Zengwu Zhao
Keyword(s):  
Rare Earth ◽  
Mine Tailings ◽  
Photoelectron Spectroscopy ◽  
Methane Combustion ◽  
Space Velocity ◽  
High Catalytic Activity ◽  
Reduction Peak ◽  
X Ray ◽  
Different Temperatures ◽  
Bayan Obo

AbstractBayan Obo tailings are rich in rare earth elements (REEs), iron, and other catalytic active substances. In this study, mine tailings were calcined at different temperatures and tested for the catalytic combustion of low-concentration methane. Upon calcination at 600°C, high catalytic activity was revealed, with 50% CH4 conversion at 587°C (space velocity of 12,000 mL/g h). The physicochemical properties of catalysts were characterized using thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS). Compared to the raw ore sample, the diffraction peak intensity of Fe2O3 increased post calcination, whereas that of CeCO3F decreased. A porous structure appeared after the catalyst was calcined at 600°C. Additionally, Fe, Ce, Ti, and other metal elements were more highly dispersed on the catalyst surface. H2-TPR results revealed a broadening of the reduction temperature range for the catalyst calcined at 600°C and an increase in the reduction peak. XPS analysis indicated the presence of Ce in the form of Ce3+ and Ce4+ oxidation states and the coexistence of Fe in the form of Fe2+ and Fe3+. Moreover, XPS revealed a higher surface Oads/Olatt ratio. This study provides evidence for the green reuse of Bayan Obo mine tailings in secondary resources.

The effect of combined ecological remediation (plant microorganism modifier) on rare earth mine wasteland

2020 ◽  
Vol 27 (12) ◽  
pp. 13679-13691
Author(s):  
Qiao Yang ◽  
Zhongqiu Zhao ◽  
Hong Hou ◽  
Zhongke Bai ◽  
Ye Yuan ◽  
...  
Keyword(s):  
Rare Earth ◽  
Ecological Remediation ◽  
Rare Earth Mine

scholarly journals Effect of different levels of humic acids on the nutrient content, plant growth, and soil properties under conditions of salinity

2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy
Keyword(s):  
Plant Growth ◽  
Humic Substances ◽  
Humic Acids ◽  
Foliar Application ◽  
N Uptake ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Nutrient Content ◽  
Nutrient Elements ◽  
A Minor

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.

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