APPLICATION OF CLAY MINERALS FOR SOIL IMPROVEMENT

Background and Aims Phosphorus(P)deficiency is one of the main factors that influence plant productivity in agricultural and forestry systems. Fertilization and soil improvement are the primary practices used to meet the P demands of crops in traditional agriculture and of trees in forestry management. Chinese fir (Cunninghamia lanceolata), a fast_growing, evergreen coniferous tree with high yield and quality of wood, is the most important tree species of timber plantations in subtropical China. Since Chinese fir plantations range from about 20° to 30° N in latitude and 100° to 120° E in longitude, there are many different genotypes of Chinese fir among the forests in south China. Therefore, it is possible to select the Chinese fir clone with high phosphorus use efficiency. Methods Based on the pot experiment under the different phosphorus deficiency stress (heavy, medium, slight phosphorus deficiency and normal phosphorus supply), the dry matter accumulation, phosphorus absorption efficiency, and phosphorus use efficiency of eight different Chinese fir clones were analyzed to compare their phosphorus characteristics. Key Results There were significant differences in the dry matter accumulation, phosphorus absorption efficiency and phosphorus use efficiency among different clones under phosphorus stress. The dry matter accumulation and phosphorus absorption efficiency of different clones decreased whereas phosphorus use efficiency increased with increasing phosphorus stress. The dry matter accumulation of Clone 8, 9, 24 and 37 were influenced by phosphorus stress less than those of the other clones. Phosphorus stress significantly affected the dry matter accumulation of Clone 23. Higher phosphorus absorption and use efficiency in Clone 8, higher phosphorus absorption efficiency in Clone 24 and 37, and higher phosphorus use efficiency Clone 9 were found under phosphorus stress. However, the phosphorus absorption efficiency and phosphorus use efficiency of Clone 23 were lower than those of the other 7 clones. Conclusion High phosphorus absorption and use efficiency of Chinese fir are the major adaptive strategy under environment with low phosphorus availability.

The root–microbe–soil interface: new tools for sustainable plant production

The human eye does not have sufficient resolution to unravel the mysteries of soil and plant health. Corn is one of the major grains grown in Canada. The proposed maximum theoretical yield of corn is 450-500 bu/acre, but average growers are producing 150 bu/acre. The main aim of this study is to understand the factors associated with soil health and plant productivity beyond the cropping system and practices. We measure the aspects of soil physical, chemical properties and differences in microorganism communities will be related to yield responses collected from plants harvested from 40 diverse sites across Ontario using aerial infrared photography to identify sections of fields where plants appear healthy or stressed (as we discovered that when corn plants were randomly selected for testing, their microbiomes were quite similar). In this way, we hope to identify some of the primary reasons that confer the unevenness in crop yield seen across the same field when the same farm inputs had been applied. Such findings will be used to improve low production sites, thereby increasing overall yields significantly. Based on results from our previous studies we hypothesized that the difference in the plant productivity at different sites are due the abundance and diversity of microbial communities, and the impacts of their specific activities such as nitrogen fixation, phosphorous solubilisation, root growth promotion, and suppression of plant pathogens. The ratio of different soil chemical parameters affects microbial community richness and diversity in many ways. The study results will be integral in our understanding of the microbial community structures that influence crop productivity either negatively or positively. We expect to find out who are the key microorganisms and their roles in corn growth and productivity. Our initial analysis of data generated through TRFLP and next generation based sequencing of microbial communities showed, the endophytic microbial communities were distinct between low and high producing sites across most of the field sites tested. The high producing area had significantly higher bacterial richness and less diversity than the low producing area. Initial correlation analysis revealed potential positive interactions between the general fertility index, potassium to magnesium ratio, the gram negative and nitrogen fixer bacterial communities with yield and yield related parameters. Taken together, the corn sap bacterial community composition and richness was greatly influenced by soil chemical properties, which may indicate shifts in their functionality despite equal levels of total bacterial loads. The talk will identify factors associated with high and poor yielding sites and how this relates to soil and crop health.

Chapter 3 - Clay Minerals—Organic Matter Interactions in Relation to Carbon Stabilization in Soils

Environment-friendly growth enhancers for rice are being promoted to reverse the negative impact of intensive chemical-based and conventional rice farming on yield sustainability and environmental problems. Several rhizosphere microorganisms and pyroligneous acids (PA) had demonstrated beneficial influence on growth, yield and grain quality of rice. Since most of the previous study had evaluated the effect of PGPR and PA on paddy rice singly, the effect of combined application of these on the growth and yield of paddy rice and on some soil chemical properties were determined. A four factorial pot experiment was conducted to evaluate the effect of PGPR, PA in combination with fertilizers and on different soil types. There were 54 treatment combinations including the control with three replications under complete randomized design. Plant growth parameters were evaluated using standard procedures during tillering and heading stages. Rice yield and some soil chemical properties were determined at harvest. Results showed that inoculation of Bacillus licheniformis and Fusarium fujikuroi enhanced plant growth by increasing the plant height which could be ascribe to its ability to promote IAA and GA production in plants. Inoculation of Rhizobium phaseoli enhanced chlorophyll content indicative to its ability to improve the N nutrition. However, these plant growth benefits during the vegetative stage were override by the fertilizer application effect especially during the maturity stage and grain yield. High fertilization rates on coarse-textured soil without nutrient loss resulted to high available nutrients and consequently high yield. Wood vinegar application however improved nutrient availability in soil which could be beneficial for improving soil quality. Further evaluation is necessary to fully assess the potential benefits that could be derived from inoculation of these organisms and wood vinegar application in different soil environment especially under different field conditions.

Purpose of the article is to identify the impact of automobile transport emissions and industry to physical and chemical properties of soils of Odessa.Data & Methods. These materials obtained as a result of their own field and analytical researches carried out during 2014-2015 years concerning the impact of automobile transport and industry on physical and chemical properties of soil in the city. In the research it is used common methods of field and laboratory analytical investigations, physical and chemical studies and assessments of soils of Odessa. Soil profiles were laid in areas with different types of urban phytocenosis, such as park area, botanical garden, roadside lawn, industrial zone. Analytical researches of physical and chemical properties of soil were carried out by generally standardized methods.Results. Conducted researches indicate that motor vehicle and industry emissions significantly affect the change in physical and chemical properties of urban soils, impairing their ecological condition. Physical and chemical properties of soils of Odessa are much different from their natural counterparts. The main differences are: shift pH to the alkaline reaction, increased toxic salts, high rate of humus, uneven distribution of nutrients, high content of natrium cations as part of the soil-absorbing complex. Especially unfavorable conditions for plant growth in the city have soils that are located within the joint impact of industrial and road transport emissions, which can negatively affect as the growth and development of plants as the health of urban populations.

Value of dehydrated food waste fertiliser products in increasing soil health and crop productivity

The long-term use of mineral fertilizers has decreased the soil fertility in papaya (Carica papaya L.) orchards in South China. In situ earthworm breeding is a new sustainable practice for improving soil fertility. A field experiment was conducted to compare the effects of four treatments consisting of the control (C), chemical fertilizer (F), compost (O), and in situ earthworm breeding (E) on soil physico-chemical properties and soil enzyme activity in a papaya orchard. The results showed that soil chemical properties, such as pH, soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), and total phosphorus (TP) were significantly improved with the E treatment but declined with the F treatment. On 31 October 2008, the SOM and TN with the O and E treatments were increased by 26.3% and 15.1%, respectively, and by 32.5% and 20.6% compared with the F treatment. Furthermore, the O and E treatments significantly increased the activity of soil urease and sucrase. Over the whole growing season, soil urease activity was 34.4%~40.4% and 51.1%~58.7% higher with the O and E treatments, respectively, than that with the C treatment. Additionally, the activity of soil sucrase with the E treatment was always the greatest of the four treatments, whereas the F treatment decreased soil catalase activity. On 11 June 2008 and 3 July 2008, the activity of soil catalase with the F treatment was decreased by 19.4% and 32.0% compared with C. Soil bulk density with the four treatments was in the order of O ≤ E < F < C. The O- and E-treated soil bulk density was significantly lower than that of the F-treated soil. Soil porosity was in the order of C < F < E < O. Soil porosity with the O and E treatments was 6.0% and 4.7% higher, respectively, than that with the F treatment. Meanwhile, the chemical fertilizer applications significantly influenced the mean weight diameter (MWD) of the aggregate and proportion of different size aggregate fractions. The E treatment significantly increased the MWD, but the F treatment decreased it. The MWD with the E treatment was 14.5% higher than that with the F treatment. The proportion of >2 mm size aggregates in the O and E treatments was vastly improved. In conclusion, in situ earthworm breeding in orchards performed better than traditional compost and chemical fertilizer in improving soil aggregation, chemical properties, and enzyme activity. This is a new, organic fertilizer application for improving soil structure, chemical properties, and soil enzymes due to the activities of the earthworms and the production of vermicomposting.

تأثیر مدیریت تلفیقی محصول بر کربن و اشکال نیتروژن خاک

Gunungkidul Regency is one of the areas facing agricultural challenges, including the threat of drought and extremely low soil fertility. Low soil fertility is characterized by thin soil solum, sandy texture, and low organic matter content. Several efforts to improve soil fertility have been carried out using organic materials, particularly cow manure, which is abundantly available in the local community of Gunungkidul. This study aimed to evaluate the impact of organic fertilizer application on soil fertility. Soil samples were taken from Mediterranean soil that had developed on limestone formations in Gunungkidul. The research method used was an experimental approach, analyzing the changes in the soil's physical and chemical properties following the application of organic fertilizer. The experimental design included various ratios of Mediterranean soil material (K) to cow manure fertilizer (S) as follows: (i) Control (100% Mediterranean soil material and 0% cow manure); (ii) K1S3 (25%:75%); (iii) K2S2 (50%:50%); (iv) K3S1 (75%:25%). The results showed that the K1S3 treatment demonstrated the best performance during the incubation period and significantly improved soil fertility. The K1S3 treatment resulted in enhanced soil aggregate stability, an increase in pH to 7.73 (alkaline), an increase in soil organic carbon (C-organic) to 3.55% (high), an increase in total nitrogen (N-total) to 0.49% (medium), and an increase in total phosphorus (P-total) to 0.33% (medium). The study indicates that a higher application of organic material leads to greater improvements in soil chemical properties. Therefore, the use of cow manure as organic fertilizer can be an effective solution for improving the quality of calcareous soils in Gunungkidul.

Changes in wetland soil morphological and chemical properties after 15, 20, and 30 years of agricultural production

An expanding population with an increasing demand for alimentation exerts considerable stress on the agricultural system. This system depends on maintaining robust and fertile soils, typically achieved through the application of synthetic inputs such as fertilizers to preserve soil productivity. However, the availability of these fertilizers is finite, or their production and application have a negative impact on the environment. Consequently, the exploration of alternative, sustainable sources to ensure continued production minimizing the detrimental environmental effects are necessary. Therefore, alternative recycled organic wastes are potential soil fertilizers and / or amendment becomes an appealing choice, contributing to the establishment of a sustainable ecosystem and fostering soil health. Specifically, their phosphorus content has a specific relevance not only for the European Union but also for the rest of the world.The aim of this research is to focus on evaluating the influence of applying various composted valorized organic wastes and by-products on enhancing soil productivity. Moreover, their influence on both soil composition and plant growth were evaluated. The characterization of physicochemical composition of soils and Durum wheat plant as well as crop yield were carried out. Heavy metals content was specially monitored.With these purposes an experimental design under controlled conditions was built. Three soils (factor 1) with different physical-chemical characteristics were evaluated: a sandy non calcareous soil, Entisol (ENT), a calcareous Inceptisol (INC) and a calcareous Vertisol (VER). The soils were treated with different mineral products and organic valorized wastes, guaranteeing that the same quantity of phosphorus (P) was added with each by-product (50 mg  kg-1i.e,: C, a negative control with no P application,; DAP (Di-ammonium Phosphate), which was used as a positive control; EST (Estruvite), OMP (composted Olive Mill Pomace), OMP+EST; USW (composted Urban Solid Waste); USW+EST; S (composted Sludge from wastewater treatment plants) and S+EST. When combinations of composted wastes were used, each one was applied at a rate to add 50 % of the total P added. The main results showed that the OMP produced the lowest yield and biomass of the crop; however, EST, USW, and USW+EST produced the highest yields and biomass, which were similar or even higher than those produced with the application of DAP. In addition, the added organic treatments promoted enzymatic activity in the soil. Moreover, none of the added organic amendments significantly increased the heavy metal contents to critical levels. Finally, the added valorized products being used in agricultural conditions in Mediterranean soils had a positive effect on enhancing soil health and productivity depending on the soil type.

<p>Sewage sludge production from wastewater treatment plants (WWTP) progressively exceeds 60 Million m<sup>3</sup> p.a. in the EU. Although it is rich in organic matter (OM) and essential nutrients for crop production, sewage sludge is mainly disposed in landfills. Under the framework of Cyclic Economy and EU Green Deal, sewage sludge represents an ideal soil amendment and fertilizer with a potential to increase soil OM, provide nutrients and reduce chemical fertilization. Nonetheless, its agronomic use comes with limitations due to the presence of heavy metals and pathogenic microorganisms. Several stabilization technologies, including composting, thermal treatment and liming, aim to produce safe sewage sludge products suitable for agronomic use.</p><p>This incubation study investigated the effects of municipal sewage sludge (stabilized by alternative and common methods) on nutrient and microbial dynamics in two soils; an acidic (pH 5) and an alkaline (pH 8). Stabilized sewage sludge (Thessaloniki WWTP, Greece) with clay minerals (bentonite and vermiculite), biochar (pine residues), Ca(OH)<sub>2</sub> and air-drying, was applied at 1% and 3% dw, in soil mesocosms (300 g). Non-amended soils were also included as control. Soils were incubated (15 days; 25<sup>o</sup>C) and equilibrated with periodic wetting and air-drying. Then, chemical soil properties, heavy metal concentrations and microbial abundance were determined using standard methods.</p><p>Treated sewage sludge addition in the acidic soil, noticeably increased soil pH (pH 5.2 – 8.5), compared to the control treatment (pH 5.0). In the alkaline soil, pH remained at similar levels (pH 8.1 – 8.6). Interestingly, EC increased from 0.42 up to 4.10 and 0.80 up to 3.08 dS m-1 for the acidic and alkaline soils, respectively. The C/N ratio was approx. 10 for all treatments, except biochar (C/N=16). Higher NO<sub>3</sub><sup>-</sup> concentrations were observed for (CaOH)<sub>2</sub>, biochar and vermiculite stabilized sewage sludge treatments, and higher NH<sub>4</sub><sup>+</sup> concentrations were observed for air-dried, bentonite and vermiculite stabilized sewage sludge treatments, in both soils, when compared to the control. Heavy metal concentration increased in all treatments, yet, it remained below legislative critical levels. Sewage sludge amendment increased total heterotroph abundance in all treatments (5.4 – 7.5 log<sub>10</sub> CFU g<sup>-1</sup>) compared to the control. Antibiotic resistant prokaryote abundance ranged between 3.9 – 7.0 log<sub>10</sub> CFU g<sup>-1</sup> and no persistent pattern was found. Pathogens remained below legislative critical levels in all treatments.</p><p>Our preliminary results show that stabilized sewage sludge has the potential to be a safe soil conditioner and fertilizer under the framework of Cyclic Economy and EU Green Deal. A desirable increase in soil fertility and organic C was observed for both soils, and an advantageous pH increase for acidic soil. Though, care should be taken not to exceed EC>2 dS m<sup>-1</sup> when amending agricultural soils with sewage sludge products. Also, further experimentation is required to understand the effects of soil amendments on plant nutrition and productivity.</p><p> </p><p>Funding Acknowledgement: The research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project Number: HFRI-FM17-1907).</p>

It is impossible to achieve the planned yields, product quality, and economic efficiency in agricultural production using only organic fertilizers. joint application of organic and solid mineral fertilizers solves the problem of replenishing the soil content of nitrogen, phosphorus and other elements used by plants. The authors have carried out the research of new methods of variable-rate application of mineral fertilizers in plant growing, allowing to increase the profitability of agricultural production. (Research purpose) is to develop new methods of variable-rate application of mineral fertilizers in crop production, which will allow increasing the profitability of crop production as compared with the conventional methods of applying fertilizers basing on average field indicators. (Materials and methods) The authors have developed a calculation technique implemented in the VBA Excel computer program for determining the main indicators: gross output, fertilizer saving, profit, etc. The main variable to change in the calculations is the planned yield based on average field parameters. At the end of the calculation process, the values of the best result for gross harvest output and profit are displayed on the screen. The research objects for the calculation were represented by elementary areas of crop areas of three farms – “Prodresurs”, Agropoligon VIUA, and “Murminskoye” with different soil types: chernozem, loamy, and sandy-loam. (Results and discussion) The method of proportional variable-rate application of fertilizers on three types of soils gives a stable increase in profit as compared with the application of fertilizers basing on the average field indicators. (Conclusions) Calculations have shown that under the specified conditions and at the equal yield of 30 c/ha the application of organomineral fertilizers is the most effective, profitability has accounted for 40 percents – on mesopodzol sandy-loam soils; 8.7 percents – on sod-podzolic soils; and 1.3 percents – on black soils. The method of proportional variable-rate application of mineral fertilizers accompanied with variable-rate application of organic fertilizers makes it possible to reduce the amount of mineral fertilizers applied by half.

Each soil has unique nature of the characteristics and its properties are beyond the control of the designer. Since the soil parameters varies from site to site or location to location, thus selecting the reliable properties of soil is always a challenge for the Geotechnical Engineers. One of the option is intense soil investigations. However, there are various soil properties whose determination is time consuming and expansive. Geotechnical Engineer usually tries to develop mathematical equations specific to a particular soil type. However, a mathematical formula that is more reliable for the type of soil in which the link is genuine. In the light of above discussion, index and chemical properties were not investigated in most of the areas of Hyderabad region. Also correlation between chemical and index properties were not investigated. Correlation between chemical and index properties were not well understood. Thus it is important to develop the appropriate mathematical equations to be able to access the local area. The aim of this study is to determine index and chemical properties of soil selected from different locations of Hyderabad Region and also develop correlation between chemical and index properties of soils of Hyderabad region. Regression analysis have been carried out between Index and chemical properties. Such correlations may be of use to geotechnical engineers, in preliminary estimates of index and chemical properties of soils Hyderabad region and perhaps reduce testing requirements. The data obtained from independent laboratory tests on soils sourced from several locations in Hyderabad region were subjected to regression analysis after the samples had been grouped in A-4, A-6, and A-7-6 using AASHTO classification system. The derived Regression equations can be used to estimate the index and chemical properties of soils in Hyderabad region.