Alternatives for Circular Bioeconomy in Organic Farming under Excessive Nutrients (Goat manure and Arbuscular Mycorrhizal Fungi): A Case Study in Indonesia

A case study in Indonesia of circular bioeconomy implementation was investigated by managing livestock wastes, especially goat manure (GM), which an excess of its availability may be adverse to the environment. The efficacy of this scenario to control pollution or to increase productivity still needs to be proven. Hence, this research aimed to study the possibility of circular bioeconomy implementation using biotic and abiotic resources in Indonesia under excessive nutrients (GM and mycorrhizal) on P. angulata production. Outdoor factorial container experiment was carried out using a randomized complete block design in Central Java, Indonesia. Treatments included four levels of GM (0, 10, 20, 30 g plant−1) and four levels of mycorrhizal (0, 10, 20, 30 g plant−1) applied in the soil with six replications. This case study revealed that the use of mycorrhizal inoculant and GM indicated no significant difference to most of P. angulata’s growth and yield parameters. The implementation of circular bioeconomy through integrated farming of P. angulata was not an instant solution for economic and environmental optimization, but can be considered as a way to tackle environmental problem due to the excessive livestock wastes. The environmental sustainability can be achieved step by step, without hindering farmers’ income.

KNOWLEDGE, ATTIUTDE AND PRACTICES OF HEALTH CARE PROFESSIONALS ON USING ZINC TO TREAT CHILDHOOD DIARRHOEA

To assess knowledge, attitude and practice (KAP) related to zinc use by healthcare professionals (HCPs) for diarrhoea in children. (2) To check the availability/non availability of zinc formulations in community pharmacies. Childhood diarrhoea is one of the leading cause of morbidity and deaths globally. Excessive nutrients loss occurs as an aftermath of the diarrhoea. Zinc supplementation to children aid in replenishing lost micronutrients and improves overall health during episodes of diarrhoea. A pre-tested, self-administered questionnaire was developed and distributed among 100 practitioners that included general physicians and paediatricians and 50 community pharmacists in different localities of Delhi. A presentation containing therapeutic role of zinc in childhood diarrhoea was administered to non-prescribers of zinc. Majority of prescribers reported already using zinc as an adjunct to ORS yet believed ORS alone can meet the demand of lost nutrition from the body. Non-prescribers disagreed that ORS alone meets the demand of lost nutrition yet believed zinc is safe for managing childhood diarrhoea. Their practice rely on prescribing anti-diarrhoeals and antibiotics to treat diarrhoea in infants. Community pharmacists believed that zinc is safe and beneficial for children under 5 years of age however, the rate of dispensing zinc formulations from pharmacies is low. The study displayed a gap of knowledge among HCPs and recommends conduction of educational programs to ensure adequate consumption of zinc supplements among children.

Nutrient Solution Deprivation as a Tool to Improve Hydroponics Sustainability: Yield, Physiological, and Qualitative Response of Lettuce

Hydroponics growing systems often contain excessive nutrients (especially nitrates), which could lead to a quality loss in ready-to-eat leafy vegetables and posing a health risk to consumers, if managed inadequately. A floating raft system was adopted to assay the production and quality performance of lettuce (Lactuca sativa L. cv ‘Maravilla De Verano Canasta’) deprived of the nutrient solution by replacement with only water, three and six days before harvest. Yield and quality parameters, mineral composition, pigments, organic acids, amino acids profile, soluble proteins, and carbohydrate content were determined. Nutrient solution deprivation six days before harvest resulted in a significant reduction in leaf nitrate (−53.3%) concomitant with 13.8% of yield loss, while plants deprived of nutrient solution three days before harvest increased total phenols content (32.5%) and total ascorbic acid (102.1%), antioxidant activity (82.7%), anthocyanins (7.9%), sucrose (38.9%), starch (19.5%), and γ-aminobutyric acid (GABA; 28.2%), with a yield reduction of 4.7%, compared to the control. Our results suggest that nutrient solution deprivation three days before harvest is a successful strategy to reduce nitrate content and increase the nutritional quality of lettuce grown in floating raft systems with negligible impact on yield. These promising results warrant further investigation of the potential effect of nutrient solution deprivation on the quality attributes of other leafy vegetables cultivated in floating raft systems and in a “cascade” growing system.

Isolation and Selection of Purple Non-Sulfur Bacteria for Nutrient Rich Biomass Production from Wastes

Purple nonsulfur bacteria (PNSB) are anoxygenic photosynthetic bacteria, which are able to photoheterotrophically grow in the presence of excessive nutrients. Hence, PNSB can convert organic components, in waste waters into nutrient rich biomass. This suggests the feasibility of converting wastes into valuable products. In this research, method for isolation of PNSB was optimized, and subsequently used for the isolation of PNSB from domestic waste and pond water samples taken in Hanoi. In addition, the effects of carbon and nitrogen sources and types of waste on biomass and nutrients (protein and carotenes) were also investigated. Four PNSB strains were isolated and based on comparative 16S rDNA analysis and their morphological characteristics, they were identified as Rhodobacter (Rb.) capsulatus, Rhodobacter (Rb.) sphaeroides, Rhodobacter (Rb.) sediminis and Rhodopseudomonas (Rp.) palustris. In terms of the effects of carbon and nitrogen sources on their biomass and nutrient production, glucose or maltose and ammonium chloride or urea were found to be more enhancive than starch and peptone, respectively. Among the studied strains, Rb. capsulatus MD1 and Rb. sphaeroides MD3 showed significantly higher biomass production (up to 0.7 g/l) when growing with various carbon and nitrogen sources, in comparison with the other strains. Moreover, MD1 and MD3 also produced at least four-fold more carotenoid and up to two-fold more protein in tofu processing wastewater compared with the other wastewater. The results suggest potential applications of the PNSB strains for efficient conversions of organic compounds in wastes into biomass of high nutritional values.

Linear and nonlinear effects of nutrient enrichments on the diversity of macrobenthos in lowland watercourses

The study concerns the relationships between taxonomic, functional and phylogenetic diversity of benthic invertebrates inhabiting watercourses and abiotic parameters associated with excessive nutrients load (concentration of Kjejdahl nitrogen, nitrates, phosphorus, organic carbon and dissolved oxygen, values of BOD5 and electrolytic conductivity). The research used data on the species composition of leeches, molluscs and larval forms of odonates and chironomid dipterans. Their description using mathematical functions allowed to determine whether the diversity reaches maximal values at extreme or moderate values of nutrients enrichment. In most cases, statistically significant relationships were unimodal—the highest diversity was observed at intermediate values of nutrients content and associated parameters, however the different patterns of relationships, monotonic and inverse quadratic, were also observed. Indirect impacts of nutrients enrichment on diversity were found as the most significant relationships. Significant responses of functional diversity were clearer and stronger than responses of taxonomic and phylogenetic diversity. The identification of fauna to the species level allowed for obtaining precise results that could enable selection of appropriate parameters for effective assessment of environmental degradation.

Giving the Land a Kick

When it became clear that nutrients cause the rise of dead zones, scientists next examined the possible sources of the nutrients. This chapter argues the biggest source today is agriculture. The expansion of the Gulf of Mexico dead zone directly follows the huge increase in agricultural productivity, especially for corn. Yields increased over six times since 1930 in part because farmers used more fertilizer, “to give the land a kick.” As the chapter explains, Nancy Rabalais and Gene Turner found a direct link between fertilizer use and nutrient levels in the Mississippi River. In spite of opposition from agribusinesses, their work led to the formation of a White House committee and passage of legislation to support work on the hypoxia problem. Agriculture is also the main source of nutrients feeding dead zones in other regions of the world. The chapter later points out that the biggest user of fertilizer is now China, where excessive nutrients have caused massive harmful algal blooms and other environmental problems.

Trend Analysis of Nitrate Concentration in Rivers in Southern France

Excessive nutrients in rivers, lakes and aquifers are still threatening environmental health in Europe. Stringent regulations have led to progress in water quality, however hotspots with high nitrate concentrations still exist in Europe and understanding the impact of management on the nitrate concentrations and trends in these critical areas is still challenging. In this paper, we use the Exploration and Graphics for RivEr Trends (EGRET) statistical tool to eliminate the impact of flow variation, both short- and long-term, on nitrate concentration. We apply this tool to the south of France where water quality and quantity monitoring data is readily available. We compare the Mann–Kendall non-parametric approach to estimate trend and a methodology commonly used by Member States of the European Union when they report their progress in implementing the Nitrates Directive (referred to MSD approach hereafter). We showed that using the latter approach for the period 2008–2015 and the Mann–Kendall test leads to similar results in percentage of stations exhibiting trends, however with a significant disagreement on the stations exhibiting these trends. We further showed that when using flow-weighted nitrate concentrations instead of the simple mean nitrate concentration, the MSD approach results in a significant underestimation of the stations with an increasing trend. We also demonstrated that most of nitrate concentration time series are characterized by a bell-shaped curve with an increase of concentration from 1990 to mid-2000 and then a significant decreasing trend due to the implementation of management measures from mid-2000 to 2017. Most of the significant decreasing nitrate concentration trends are localized in Nitrate Vulnerable Zones that correspond to areas where strict nutrient management is required, highlighting the efficiency of the policy in place.

Effects of Biochar to Excessive Compost-Fertilized Soils on the Nutrient Status

Positive effects of a biochar–compost mix on soil nutrient status in infertile soil have been reported, but the potential effect of biochar amendments in excessive compost-fertilized soils has not been extensively studied. Excessive application of compost can result in the accumulation of nutrients and heavy metals (Cu and Zn). Thus, the objective of this study is to investigate the effect of biochar–excessive compost co-application on soil nutrient status. We hypothesized that biochar co-application could have positive effects on the absorption of excessive nutrients of Cu and Zn. A 371-day laboratory incubation study was conducted to evaluate the effects of the lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C on the dynamics of the soil nutrients. Three Taiwan rural soils were selected, including slightly acidic Oxisols (SAO), mildly alkaline Inceptisols (MAI), and slightly acid Inceptisols (SAI). The biochar treatments include control (0%) and 0.5%, 1.0%, and 2.0% (w/w). In each treatment, 5% (w/w) poultry-livestock manure compost was added to test excessive application. The results indicated that the biochar treatments had a significant increase effect on soil pH, total carbon (TC), total nitrogen (TN), C:N ratio, and available K concentration. The effect of biochar on electrical conductivity (EC) and available P, Ca, Mg, Fe, Mn, Cu, Pb, and Zn was insignificant. The effect of biochar, with relatively low application rates (<2% by wt), low surface area, and less surface function group, was eliminated by excessive compost (5% by wt). In addition to carbon sequestration and nitrogen conservation, biochar addition has no effect on the absorption of the excessive nutrients Cu and Zn in three studied soils.

Hydrothermal Carbonization and Pellet Production from Egeria densa and Lemna minor

Biofuels are seen as a potential option for mitigating the effects of fossil fuel use. On the other hand, nutrient pollution is accelerating eutrophication rates in rivers, lakes, and coastal waters. Harvesting aquatic plants to produce biofuels could mitigate this problem, though it is important to attack the problem at source, mainly as regards the contribution of nutrients. For the first time, solid biofuels were obtained in the forms of carbon and pellets from the aquatic plants Egeria densa, which is classed as an invasive plant under the Spanish Catalogue of Exotic Invasive Species, and Lemna minor, both of which can be found in the Umia River in north-west Spain. The essential oils and macro- and microelements present in both these plants were also extracted and analyzed. The higher heating values (HHVs) of the carbon products obtained ranged from 14.28 to 17.25 MJ/kg. The ash content ranged from 22.69% to 49.57%. The maximum yield obtained for biochar for Egeria densa at 200 °C was 66.89%. Temperature significantly affects solid hydrochar yield. The HHVs of the pellets obtained ranged from 11.38 to 13.49 MJ/kg. The use of these species to obtain biofuels through hydrothermal carbonization (HTC) and pellets is a novel and effective approach that will facilitate the removal of nutrients that cause eutrophication in the Umia River. The elements extracted show that harvesting these plants will help to remove excessive nutrients from the ecosystem.

Synechococcus sp. Strain PCC7002 Uses Sulfide:Quinone Oxidoreductase To Detoxify Exogenous Sulfide and To Convert Endogenous Sulfide to Cellular Sulfane Sulfur

ABSTRACT Eutrophication and deoxygenation possibly occur in coastal waters due to excessive nutrients from agricultural and aquacultural activities, leading to sulfide accumulation. Cyanobacteria, as photosynthetic prokaryotes, play significant roles in carbon fixation in the ocean. Although some cyanobacteria can use sulfide as the electron donor for photosynthesis under anaerobic conditions, little is known on how they interact with sulfide under aerobic conditions. In this study, we report that Synechococcus sp. strain PCC7002 (PCC7002), harboring an sqr gene encoding sulfide:quinone oxidoreductase (SQR), oxidized self-produced sulfide to S0, present as persulfide and polysulfide in the cell. The Δsqr mutant contained less cellular S0 and had increased expression of key genes involved in photosynthesis, but it was less competitive than the wild type in cocultures. Further, PCC7002 with SQR and persulfide dioxygenase (PDO) oxidized exogenous sulfide to tolerate high sulfide levels. Thus, SQR offers some benefits to cyanobacteria even under aerobic conditions, explaining the common presence of SQR in cyanobacteria. IMPORTANCE Cyanobacteria are a major force for primary production via oxygenic photosynthesis in the ocean. A marine cyanobacterium, PCC7002, is actively involved in sulfide metabolism. It uses SQR to detoxify exogenous sulfide, enabling it to survive better than its Δsqr mutant in sulfide-rich environments. PCC7002 also uses SQR to oxidize endogenously generated sulfide to S0, which is required for the proper expression of key genes involved in photosynthesis. Thus, SQR has at least two physiological functions in PCC7002. The observation provides a new perspective for the interplays of C and S cycles.