Organic Soil Fertility Research Articles

Production of artificial humic acid from biomass residues by a non-catalytic hydrothermal process

Humic substance is vital for soil fertility and has wide applications such as soil remediation agents, organic fertilizer and adsorbents. The results of pH effect on artificial humic acids (AHAs) production demonstrated that acid hydrothermal conditions are favorable for biomass waste dissolution and formation of AHA precursors such as saccharides, furans, organic acids and phenols; whereas alkaline hydrothermal conditions are suitable for AHAs production from these precursors. Enhanced humification from biomass waste with a combined acid - alkaline hydrothermal process was proposed. The solid product known as hydrochar was reduced to only 5 wt% after this process indicating the significant improvement of dissolution and transformation. The AHAs concentration of 28.28 ± 0.98 wt% obtained from corn stalk was the highest yield so far, 10 times higher than ever reported. The carbon flow analysis indicated that the selectivity of AHA-C was 43.2% of the initial carbon in corn stalk. Our study provides a new way of mass production of AHAs in short period, which has great potential for industry application.

Effects of the Rapid Construction of a High-Quality Plough Layer Based on Woody Peat in a Newly Reclaimed Cultivated Land Area

To implement the balance system of cultivated land in occupation and supplement and to adhere to the principle of “supplement the occupied cultivated land of high quality with the one bearing same quality”, in the thesis, a field experiment was conducted to study the effects of woody peat on soil physical, chemical, and biological properties of the plough layer and its crop yield. Furthermore, the correlation between soil indexes and crop yield under the best fertilization mode through the addition of the natural material of woody peat instead of lengthy cultivation of the plough layer to rapidly construct a high-quality plough layer and solve the practical problem that the natural endowment of newly reclaimed cultivated land is far less than the occupied high-quality cultivated land was explored. The land remediation project of Fuping County, Hebei Province, was taken as the experimental area, and the five most representative and effective datasets were selected and studied. The results demonstrated that the addition of woody peat and rotten straw could reduce soil particle size and bulk density and alleviate soil viscosity and acidification. An increase in soil organic matter, soil microbial biomass carbon (MBC), alkali-hydrolyzable nitrogen, available phosphorus, and available potassium and a decrease in the heavy metal content were also observed. The results indicated that the application of woody peat achieved the expected effect of the rapid construction of a high-quality plough layer. The best mode of fertilization was A2, which provided a good reference for the rapid construction of a high-quality plough layer in the future. The analysis of the correlation between soil indexes and crop yield illustrated that the organic matter content, soil available nutrients, and crop yield had a significant positive correlation; the organic matter content and soil available nutrients showed the same tendency, which suggests that soil organic matter content and soil fertility level are closely related and that soil fertility plays a decisive role in crop yield under the same external conditions. Woody peat exerted an eminent influence on the organic matter content and soil available nutrients to determine the change in crop yield, which provides a reliable basis for future research on land improvement projects to increase crop yield.

Effect of Integrated Nutrient Management on Okra Production in Acid Soil

Integrated Nutrient Management (INM) is a novel strategy to achieve sustainable crop production in degraded soils through judicious and balanced plant nutrients utilization. Sole application of chemical fertilizers in crop production causes soil and environmental pollution. The present study was designed to assess the effects of application of organic manures conjointly with chemical fertilizers on growth and yield of okra in acid soil. The experiment was consisted of four treatments viz. T0 [Control], T1 [Recommended dose of chemical fertilizers (RDF)], T2 [Dolomite (D) @ 1t ha-1 + RDF], T3 [Poultry manure (PM) @ 3t ha-1 + RDF], T3 [Cow dung (CD) @ 5t ha-1 + RDF] with six replications in a randomized complete block design. The results indicated that the use of PM with RDF showed better performance in the growth and yield attributes of okra. Compared with others plots, the highest plant height (114.10 cm), fresh weight plant-1 (591.58 g) and dry weight plant-1 (86.73 g) were observed in the PM-treated plot. Similarly, the highest number of fruits plant-1 (20.33) and fruit yield (13.58 t ha-1) were also found in PM-treated plants. Therefore, under acidic soil conditions, organic and inorganic fertilization may have a significant positive impact on the growth and yield of Okra.

A novel method for measuring and evaluating spatial distribution of straw incorporated by rotary tillage

AbstractStraw incorporation after tillage plays an essential role in soil organic matter and fertility. Despite the importance of understanding the effect of tillage on straw distribution in the soil, an accurate method to measure and evaluate the spatial distribution of straw has not been developed. In this work, we proposed a method for quantifying straw distribution in soil following tillage. The approach uses a straw spatial coordinate digitizer, Pro/Engineer drawing software, and MATLAB visualization software. Straw of four different lengths was mixed into soil by a rotary tillage. Results indicated that the uniformity of straw spatial distribution decreased with the increase of straw length. T50 (50‐mm straw length) had the greatest uniformity. As a result, it is recommended that straw be cut to 50 mm or shorter. This work offers a new insight into the quantitative analysis of straw spatial distribution in soil.

Glasshouse Evaluation of the Black Soldier Fly Waste Product HexaFrass™ as an Organic Fertilizer

Simple SummaryIn recent years farmers have relied on highly efficient synthetic nitrogen fertilizers to achieve increased yields. However, the extensive application of nitrogen-based fertilizers is now associated with several negative impacts on the environment, such as pollution of waterways and eutrophication of lakes and estuaries. To promote more sustainable food production, less environmentally damaging methods of adding nutrients and organic matter to soils are needed. One potential organic fertilizer has arisen recently as a by-product of insect farming. Mass production of the black soldier fly (BSF; Hermetia illucens L.) results in the production of waste or frass, which is high in organic matter and contains essential plant nutrients such as nitrogen, phosphorous and potassium. In this study, it was found that one such product, HexaFrass™, improved the shoot and root growth of several herb and vegetable plants when grown under glasshouse conditions, and had similar effects to other commonly-used organic fertilizers, such as chicken manure pellets. As HexaFrass™ is a waste by-product, and the BSF are themselves raised on other food or organic wastes, the use of BSF frass has good potential as a sustainable, more environmentally-friendly, organic soil amendment.The mass farming of the black soldier fly (BSF; Hermetia illucens L.), to produce insect-based feed for livestock and fish, results in considerable amounts of insect frass, which contains substantial amounts of organic matter and bioavailable nutrients. Insect frass has shown good potential as a soil amendment and organic fertilizer. This study examined the effects of HexaFrass™ on the growth of common vegetables and herbs under glasshouse conditions. In an organically-rich potting mix, HexaFrass™ increased shoot dry weight by an average of 25%, although this effect was variable among test plants. In other trials, application of HexaFrass™ caused an increase in plant growth similar to that obtained by applying chicken manure and a commercial organic fertilizer. Increases in shoot and root dry weight showed quadratic relationships with HexaFrass™ dose, indicating that application of excessive quantities could lead to plant inhibition. Shoot:root dry matter ratio tended to increase with HexaFrass™ dose suggesting there was no specific stimulation or enhancement of root growth. Overall, these results provide further evidence of the potential of insect frass as an effective organic fertilizer for vegetables and herbs.

Influence of Organic Fertilization on the Physico-Chemical and Organoleptic Quality of Attiekes of Three Varieties of Cassava (Manihot esculenta C.)

Cassava occupies an important place in the food security of populations in Côte d'Ivoire. There are many products derived from cassava but«attiéké» remains the flagship product in Côte d'Ivoire. Faced with the productivity challenges, organic fertilization is increasingly used by farmers in order to sustainably increase cassava production. The perspective of our study is to assess the effects of the uncombined use of cowpea and poultry manure as organic soil fertilizers on certain physicochemical and sensory characteristics of «attiékés» of three varieties of cassava. To do this, on an experimental plot installed, cowpea fertilization was tested at planting densities of 62,500; 250,000 and 125,000 plants/ha and poultry manure at rates 5; 15 and 5 t/haon, respectively, the cassava varieties Yavo, BoCou1 and Yacé.The results obtained show that cowpea and poultry manure increased the dry matter content respectively by 3.99 and 3.53 % in the Yavo variety by 3.57 and 18.06 % in the BoCou 1 as well as by 17.43 and 17.64 % in the Yacé. For the other parameters of pH, titratable acidity, total carbohydrates and free glucose, the variations depended on the variety and the level of fertilization. The sensory attributes of attiekes from these varieties grown on fertilized soil have been accepted by consumers in terms of color, smell, taste and consistency. In addition, they were rated less good than the controls obtained without fertilizer due to color, taste and consistency, while in terms of odor, it would be the same rating.

Sustainable applications of rice feedstock in agro-environmental and construction sectors: A global perspective

Rice is second only to maize among the world's most important cereal crops, with a global harvested area of approximately 158 million hectares and an annual production of more than 700 million tonnes as paddy rice. At this scale, rice production generates vast amounts of waste in the form of straw, husk, and bran. Because of high cellulose, lignin, and silica contents, rice biowaste (RB) can be used to produce rice biochar (RBC) and rice compost (RC). Furthermore, RB can be used as sorbents, soil conditioners, bricks/concrete blocks, flat steel products, and biofuels, all of which make significant contributions to meeting United Nations Sustainable Development Goals (UNSDGs). Although previous reviews have explored individual applications of rice feedstocks, inadequate attention has been paid to multifunctional values and potential multi-utilities. Here, we offer a comprehensive review of RBC and RC with respect to: (1) preparation and characterization; (2) applications as soil conditioners and organic fertilizers and their effects on soil-carbon sequestration; (3) remediation of toxic element–contaminated soils and water; (4) removal of colors, dyes, endocrine-disrupting chemicals, personal-care products, and residual pesticides from water; and (5) applications in the construction industry. Specifically, we describe the opportunities for the sustainable use of RBC and RC in the management of contaminated soils and water as well as the construction industry. Overall, this review is expected to lengthen the list of possible multifunctional applications of RBC and RC.

Economic evaluation and socioeconomic drivers influencing farmers’ perceptions on benefits of using organic inputs technologies in Upper Eastern Kenya

Declining soil fertility in Sub-Saharan Africa (SSA) is a significant constraint towards increasing agricultural productivity. Soil fertility decline coupled with rapid population growth and low use of organic soil fertility technologies has threatened the population's economic status that lives in the rural area and relies on rain-fed agriculture. We conducted a cross-sectional household survey in the Central Highlands of Kenya (Gatanga and Meru South sub-counties) to determine farmers’ perception of the benefits of using organic resources technologies, socioeconomic drivers influencing their perceptions, and financial returns from the technologies. The selected technologies were; sole animal manure and a combination of animal manure with inorganic fertilizer. We based the benefits of using the selected soil fertility management technologies on four variables; potential to improve soil fertility, crop yields, profitability, and labor requirement. The majority of the farmers strongly agreed that using the selected technologies improved soil fertility, crop yields and were profitable. On the contrary, they agreed it was labor-intensive. Gender of the household head, household size, Tropical Livestock Unit (TLU), access to external labor, access to credit, total land cultivated, age, and years of farming experience were the socioeconomic drivers that significantly influenced farmers’ perception of the use of sole animal manure and animal manure combined with inorganic fertilizer. Results showed that animal manure had the highest financial returns of US$ 440.74 in Gatanga, while in Meru South, animal manure combined with inorganic fertilizer had the highest returns of US$ 456.25. The study highlights that the use of sole animal manure and animal manure combined with inorganic fertilizer is perceived positively by the smallholder farmers and has better financial returns than sole inorganic fertilizer. Thus, the use of selected organic resource technologies should be encouraged by creating more awareness through farmers’ training programs.

Effects of organic fertilizer application on crop yield and soil properties in rice-wheat rotation system: A meta-analysis

To clarify the effects of organic fertilizer application on crop yield and soil properties in rice-wheat rotation system in China, we carried out a meta-analysis to quantitatively evaluate the effects of organic fertilizer types (ordinary organic fertilizer, biochar, and straw), fertilization regimes (organic fertilizer alone, organic fertilizer + partial chemical fertilizer, and organic fertilizer + full amount of chemical fertilizer), and experiment duration (short term, medium term, and long term) on soil properties and the yield of rice and wheat, as well as their responses to soil conditions (acid, neutral, basic). Results showed that the application of organic fertilizer had similar yield-increase effect on rice yield (3.1%) and wheat yield (3.0%) compared to chemical fertilizer application alone. The effect of organic fertilizer application on soil quality was more obvious, significantly reducing soil bulk density by 5.7%, and increasing the concentrations of soil organic matter, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, available phosphorus, available potassium, microbial biomass carbon, and microbial biomass nitrogen by 11.7%-38.4%. Among different types of organic fertilizer, the effects of ordinary organic fertilizer and biochar on soil properties improvement were better than straw. Compared to the organic fertilizer application alone, the effects of organic fertilizer combined with chemical fertilizer on crop yield was better, but poorer on soil property improvement. With the increasing duration of organic fertilizer application, crop yield and soil fertility gradually increased. Under the condition of acid soil, the effect of organic fertilizer application on crop yield was the best. The annual yield of rice and wheat showed significant negative correlation with soil bulk density, but a significant positive correlation with the concentrations of soil total nitrogen, available phosphorus, available potassium, and microbial biomass nitrogen.

Moving niche agroecological initiatives to the mainstream: A case-study of sheep-vineyard integration in California

Across the world, an increasing number of farmers are piloting agroecological systems. The recoupling of crops and livestock is one type of agroecological practice that has potential to help reduce the use of off-farm inputs, improve soil quality, and reduce costs for farmers. Yet, a major part of the world's agricultural landscapes remain dominated by conventional specialized crop and livestock practices. In particular, grazing animals in perennial cropping systems may reduce pesticide and fuel use, decrease labor, and build soil organic carbon and soil fertility. In this study, we examined adopters and non-adopters’ perceptions of a niche system, integrated sheep-vineyard systems (ISVS) in California. We aimed at understanding the conditions under which ISVS, a specific case of ICLS (integrated crop-livestock systems), could be mainstreamed. We then contextualized these interviews using the Multi-Level Perspective framework to analyze the levers favoring or impeding mainstreaming of this niche system. We considered both pull factors arising from changes in the landscape, and push factors arising through decentralized, grassroot processes. Our inductive analysis is a promising first insight into farmers’ perceptions and motivations toward ISVS adoption in California, considering both vineyard managers and contractors (i.e. shepherds renting their sheep to vineyard managers). We found a positive perception of ISVS among both current adopters and non-adopters regarding the potential agronomic, environmental and economic benefits of these practices. All adopters were satisfied with this system as they experienced labor and fuel savings, soil quality improvement and marketing advantages. Local push factors (bottom-up levers emerging from the niche systems) were highlighted by interviewees as contributing to adoption. Push factors identified include knowledge exchange and networking between vineyard managers and developing marketing pathways for “carbon-positive” wool, meat and wine products. However, some pull factors (macro-economic and policy levers acting as top-down levers) could help move the system beyond limited adoption. We point out biotechnical and socio-economic research avenues to encourage the scaling-up of ISVS and ICLS more broadly. On the biotechnical dimension, we recommend continuing and scaling-out system experiments to redesign vineyards considering sheep integration and evaluate the effect of grazing on soil quality and fire management. On the socio-economic dimension, we encourage the exploration of relevant spatial scenarios through co-design of collaborative arrangements between vineyard managers and contractors at the landscape level. Greater research on the social, environmental and economic services provided by ISVS is urgently needed to inform state and federal agricultural policies, including whether such systems should be supported through payment for ecosystem services and as part of environmental good practices and fire safety recommendations.

Impact of Wastes on Some Properties of Soil around an Active Dumpsite in Ibadan, Southwestern Nigeria

Recently most farmers in developing country like Nigeria has resulted to the use of solid wastes as compost to replenish the deteriorated soils while some are farming on the abandoned waste dumpsite due to their richness in organic matter. This study assessed the soil nutrient and fertility status by investigating the influence of wastes (if any) on physical and chemical properties of soils in and around Lapite dumpsite for environmental sustainability. Ten soil samples each collected from three locations: dumpsite, downslope and upslope sites at depth of 0-20cm were analyzed for soil texture, bulk density, porosity, electrical conductivity, pH, organic carbon, organic matter content (OMC), total nitrogen (TN), available phosphorus (AP), Na, K, Ca, Mg, Fe, Zn, Cu, Pb and Ni. Significant differences were observed on soil physical: moisture content (18.05-38.11 %); Bulk density (1.01-1.54 g/cm3); porosity (49.09-74.56 %) and chemical properties: : OMC (1.39-5.98 %);TN (0.58-1.60 %); AP(0.35-1.09 %) among others in soils from the studied location sites at p ≤ 0.05; however, no remarkable impact was noticed on soil texture. This study has shown that deposition of wastes has impacted the physical and chemical properties by improving soil organic matter contents and increasing nutrient contents such as exchangeable bases and micronutrient, thus enhancing soil organic matter, fertility and productivity status of the soil for maximum plant growth. However, increase in heavy metal concentrations in dumpsite soils call for incessant assessment and monitoring, thus sorting, reuse and recycling should be encouraged to reduce the metal loads over time.

DIRT/3D: 3D root phenotyping for field-grown maize (Zea mays)

The development of crops with deeper roots holds substantial promise to mitigate the consequences of climate change. Deeper roots are an essential factor to improve water uptake as a way to enhance crop resilience to drought, to increase nitrogen capture, to reduce fertilizer inputs, and to increase carbon sequestration from the atmosphere to improve soil organic fertility. A major bottleneck to achieving these improvements is high-throughput phenotyping to quantify root phenotypes of field-grown roots. We address this bottleneck with Digital Imaging of Root Traits (DIRT)/3D, an image-based 3D root phenotyping platform, which measures 18 architecture traits from mature field-grown maize (Zea mays) root crowns (RCs) excavated with the Shovelomics technique. DIRT/3D reliably computed all 18 traits, including distance between whorls and the number, angles, and diameters of nodal roots, on a test panel of 12 contrasting maize genotypes. The computed results were validated through comparison with manual measurements. Overall, we observed a coefficient of determination of >0.84 and a high broad-sense heritability of> 0.6 for all but one trait. The average values of the 18 traits and a developed descriptor to characterize complete root architecture distinguished all genotypes. DIRT/3D is a step toward automated quantification of highly occluded maize RCs. Therefore, DIRT/3D supports breeders and root biologists in improving carbon sequestration and food security in the face of the adverse effects of climate change.

Could cattle ranching and soybean cultivation be sustainable? A systematic review and a meta-analysis for the Amazon

Abstract: Tropical forests are being destroyed to make space for agricultural activities with the assumption that they are required to feed the growing global population. Consequently, more sustainable practices are needed to guarantee food security and environmental protection of highly threatened natural biodiversity hotspots like the Amazon rainforest. Cattle ranching and soybean cultivation are by far the greater drivers of land use change and deforestation in the Amazon region. We performed a systematic review of papers related to these two main drivers and a meta-analysis on the effects of sustainable practices on different ecosystem services. The results of the review highlight a large concern about the negative impacts of cattle ranching and soybean crops on the ecosystem dynamics and functionality of the Amazon biome, in addition to the clear relationship with deforestation. Another relevant finding is the large gap in empirical research concerning the effects of sustainable practices on different ecosystem services. Such a gap is evident since only 13 studies from the initial database met the requirements for a meta-analysis. Of the 171 comparisons between the ecosystem services provided in conventional land-uses and those adopting sustainable practices, the overall model indicated a non-significant effect, although the results were heterogeneous. Crop yield and herbage biomass were negatively affected, while livestock productivity, soil organic carbon, soil fertility and woody biomass were positively affected. Also, the six sustainable practices evaluated showed different outcomes, from a predominance of positive effects in silvopastoral systems, to a predominance of negative effects on agrosilvicultural systems. Our systematic review and meta-analysis indicate that cattle ranching and soybean cultivation can indeed be conducted in a more sustainable way, enhancing the provision of ecosystem services while avoiding deforestation. In turn, our results also highlight the lack of empirical data and the need to standardize the methodologies used to deeply assess the effects of such practices. In conclusion, we suggest a way to advance research into the real effects of sustainable practices aimed at reducing the negative impacts of cattle ranching and soybean crops in the Amazon.

Comparative Study of Biostimulant Properties of Industrially and Experimentally Produced Humic Substances

Demand for new biological technologies in agriculture is ever growing, particularly with respect to the need of restoring the soil organic matter and soil fertility. Products of natural origin are developed to stimulate plant growth and productivity. Humic substances (HS) are the decay products of living matter, with high molecular weight and complex structure. Nowadays, HS are industrially produced from various materials like peat, lignin, soil and compost. The objective of this study is to make a comparison of the impact of HS of different origin on plant development. In total, eight different HS were used; four were extracted from various materials and four were commercially available products. To evaluate the stimulating effect, three different species of plants were used (Triticum aestivum, Sinapis alba, Lepidum sativum). The tests were carried out on Phytotestkit plates, germinating the seeds in different solutions of HS in various concentrations in dark, with or without added nutrient solution. Then, the growth parameters were measured. All tested products showed increase in at least some concentrations compared with the control sample. Significant differences in the stimulating effect of HS depending on their origin were found.

Organic soil fertility amendments enhance surface-dwelling beetle diversity in a sub-humid tropical environment under conservation agriculture

ABSTRACT Surface-dwelling beetles offer ecosystem services in agro-ecosystems including biological pest control and organic matter decomposition. This study was conducted to investigate beetle community response to six years of tillage, crop residue application, crop rotation and soil fertility amendments (low fertiliser, high fertiliser, manure, manure + low fertiliser and manure + 60 kg N ha−1) treatments. Reduced tillage increased beetle abundance by 4.6% relative to soil inversion tillage. Crop residue application increased the abundances of Platynus assimilis, Zophosis boei and total beetles by two to three times. Meanwhile, Renatiella reticulata increased by 628.6% in high fertiliser compared to manure + 60 kg N ha−1, manure + low fertiliser and the control. In crop rotation + crop residue retention plots, application of sole manure at 10 t ha−1 increased the Shannon index by 360–365% relative to manure + 60 kg N ha−1 and manure + low fertiliser. Based on the findings in this study, it can be concluded that reduced tillage, retention of crop residues on the soil surface and application of manure increase surface-dwelling beetle abundance and diversity.

English

Farmers can play an important role in climate change mitigation through sustainable soil management practices. Semi-structured interviews were conducted in the Atwima Nwabiagya municipality of Ashanti region, Ghana, to explore farmers' knowledge and perceptions of their soils, soil fertility, applied management practices, and climate change on soil organic carbon. The interviews included topics related to farmers’ access to training and its impact in adopting and changes in management strategies. Summary for interviews was prepared based on notes and recordings and analyzed with the Qualitative Content Analysis (QCAmap) software using emergent codes. Results show that farmers had a lot of knowledge on soil organic matter (SOM) and how it affects climate and the relationship between SOM and soil fertility. They also acknowledged that their management practices affect quantities of SOM in topsoil and subsoil and soil fertility. The adoption of current and new management practices including, the use of organic and inorganic fertilizers, manure, mulching, and shade management, is a reflection of their newly acquired knowledge and understanding of fertility sustaining processes. The study highlights the relationship between farmers' training and changes in their adopted practices and how management practices affect SOC influencing climate change and soil fertility. Key words: soil organic carbon, cocoa farmers, perception, soil management, soil fertility and climate change.

Fluoride and nitrate contamination of groundwater in the Loess Plateau, China: Sources and related human health risks

Fluoride (F−) and nitrate (NO3−) in groundwater have caused serious health problems worldwide. However, in the Chinese Loess Plateau where groundwater is the primary source of drinking water, previous studies have rarely reported the health risks from fluoride and nitrate in groundwater. Therefore, we collected 105 groundwater samples (78 from shallow aquifers and 27 from deep aquifers) from the western district of the Loess Plateau for physicochemical and isotopic analysis to investigate the sources of F− and NO3− in groundwater and associated health risks. Fluoride concentration in 73.1% of shallow groundwater and 22.2% of deep groundwater exceeds 1.5 mg/L, while NO3− content in 76.3% of shallow groundwater and 51.9% of deep groundwater surpasses 50 mg/L. High-F- groundwater is associated with HCO3–Na, SO4–Na·Mg and Cl–Na·Mg types water. Fluorine-bearing minerals dissolution, cation exchange, calcite precipitation, evaporation, and anthropogenic activities contribute significantly F− in groundwater. Mixing with shallow groundwater is an important source of F− in deep groundwater. The NO3− content is highest in Cl type water, followed by SO4 type and HCO3 type water. NO3− mainly originates from soil organic nitrogen (SON), chemical fertilizers (CF), and manure and sewage (M&S). Nitrification is the dominant transformation process of nitrogen nutrients in groundwater. The hazard index (HI) values for shallow groundwater are 0.203–9.232 for adults, 0.253–11.522 for teenagers, 0.359–16.322 for children, and 0.507–23.043 for infants, while those for deep groundwater are 0.713–5.813 for adults, 0.890–7.254 for teenagers, 1.261–10.277 for children, and 1.780–14.508 for infants. Approximately 96.2% of shallow groundwater poses non-carcinogenic risks to infants and children, followed by 92.3% to teenagers, and 89.7% to adults. All deep groundwater poses non-carcinogenic risks to infants and children, followed by 92.6% to teenagers, and 74.1% to adults. This study is helpful to develop strategies for the integrated management of high fluoride or nitrate groundwater in arid areas.

Arbuscular mycorrhizal fungal communities of topsoil and subsoil of an annual maize-wheat rotation after 15-years of differential mineral and organic fertilization

Arbuscular mycorrhizal fungi (AMF) could improve crop yield by nutrient uptake from soil. However, how AMF of topsoil and subsoil respond to long-term differential application of mineral and organic fertilizers and how they are influenced in presence of different crops and growth stages have never been assessed together. Next generation sequencing was applied to profile soil AMF communities in both topsoil and subsoil from a typical arable soil (Eutric Regosol) in the Sichuan Base, southwest China. Soils were collected at anthesis and harvest of winter wheat and maize after 15-years of differential fertilization of an annual maize-wheat rotation (same inputs of nitrogen, N; but different in carbon, C; phosphorus, P; and potassium, K): (i) no-fertilization control (CT), (ii) 100% mineral NPK fertilizer (NPK), (iii) 60% mineral N and 100% mineral PK plus 40% N as crop residues (NPKCR); and (iv) 60% mineral N and 100% mineral PK plus 40% N as pig (organic) manure (NPKOM). Compared to CT, AMF diversity significantly decreased in topsoil, but increased in subsoil for both wheat and maize under NPK, NPKCR and NPKOM. The AMF community composition differed between NPK and CT in both topsoil and subsoil of maize and wheat. Both distance-based redundancy analysis (db-RDA) and structural equation modeling (SEM) suggested that AMF communities in topsoil and subsoil of maize and wheat responded in differences in soil available P, soil organic carbon, fertilization and climate (temperature and/or rainfall). Fertilization and available N, not AMF community, had significantly positive effects on wheat and maize aboveground dry matter and grain yield. Results from the present study shed light on how AMF communities in topsoil and subsoil respond to different soil fertility management over the long-term. Insights of this study are valuable in managing an important part of biological soil fertility.

Comprehensive review on agricultural waste utilization and high-temperature fermentation and composting

Due to the high demand for food and meat for the world's growing population, the agricultural sector is expanding every year. Timely and effective treatment is of utmost importance to utilize organic matter in agricultural waste and avoid environmental pollution. Composting or aerobic fermentation is an effective way to treat agricultural waste and produce organic fertilizer. Improving the application rate of organic fertilizer in soil needs time to reduce dependence on chemical fertilizers. This review article presented the current status and traditional agricultural waste (livestock manure and crop straws) utilization methods, the art of aerobic fermentation process including ultrahigh temperature fermentation and composting. The selection of livestock manure and crop straws as agricultural waste for this review article is due to high nutrients contents and massive generation of them worldwide. This article also included the development of aerobic fermentation technology and listed the high-temperature fermentation tanks. Based on high-temperature aerobic fermentation process performance and quality compost production, recently, some researchers have started working on hyperthermophile pretreatment-assisted high temperature composting, also discussed. Finally, this article gave brief knowledge about compost maturity, which is very important to measure before its application as an organic fertilizer. This art of literature could provide comprehensive knowledge about agricultural waste utilization and high-temperature composting to researchers.

Application of Organic Waste Compost in Seyhan Region

In this study aims to recycle farmers market and garden waste into compost and bring it back to soil as a useful and valuable organic fertilizer thanks to natural processes in Seyhan Region. With the compost production, it is aimed to promote both soil improvement and organic fertilizer use and recycling. The compost has many benefits for agricultural activities. This review, the main challenges of the process of organic waste compost and explores the crucial aspects related to the quality of the produced the importance of compost. Although the importance of compost production is known, the importance of composting and more information are needed. Therefore, in this study, innovative approaches with different methods have been investigated. Environmental and biodiversity impacts related to organic waste composting detailed in this study. This study investigated the application of blue-green algae to enhance the quality of composts composed from multiple organic waste. This research provides an innovative method for using algae the compost products. The importance of using algae in order to achieve rapid results in innovative and sustainable agriculture areas in composting was explained. A pilot project application was established to optimize organic waste collection and composting for agriculture in Compost Production facility in Seyhan Municipality. In addition, also in this study contributed to the environmental and biodiversity awareness and zero waste projects research of applicability. Studying areas should be created for composting in municipalities.