Soil and crop responses following application of biosolids-derived organomineral fertilisers to ryegrass (Lolium perenne L.) grown in pots

Biosolids-derived organomineral fertilisers (OMF) were produced using a novel technique reported in earlier studies. This technique enables addition of N and potash to biosolids granules to form a balanced NPK fertiliser. Two fertiliser products; OMF10 (10:4:4) and OMF15 (15:4:4), were formulated and tested in a glasshouse facility on pot-grown ryegrass in comparison with urea and biosolids granules at N application rates ranging from 0 to 300 kg ha-1. The aim of this research was to contribute to the understanding of nutrients management and dynamics in grass crops fertilised with OMF. The study focused upon dry matter yield (DMY) and crop responses to applied fertiliser, nitrogen use efficiency (NUE) and fertilisers’ effect on soil fertility. Results indicated that ryegrass responds linearly to application of OMF increasing DMY by about 2% to 27% compared with biosolids but to a lesser extent than urea (range: 17% to 55%). NUE was related to the concentration of readily available N in the fertiliser; urea and OMF showed significantly greater (P<0.05) N recoveries than biosolids (26% to 75%, and 19% to 29%, respectively). Total nitrogen in soil and SOM increased (P<0.05) depending on the concentration of organic-N in the fertiliser applied. DMY was lower but more sustained overtime in biosolids-treated pots. OMF application did not result in significant changes in soil extractable-P levels whereas for urea, it decreased significantly while it showed a significant increase in biosolids-treated pots, where soil-P Index changed from 5 to 6. In OMF-treated soil, soil P Index remained close to constant overtime thereby supporting the purpose of the formulations tested

The fate and effects of triclosan in soils amended with biosolids

Many hydrophobic pollutants can be emitted to agricultural soils if sewage sludge is used as a fertiliser. The fate and effects of pollutants in such receiving environments are relatively poorly understood compared with our knowledge of chemical behaviour and impact in surface waters. One chemical of particular concern is triclosan because it has antimicrobial properties which could affect important soil functions. Triclosan is hydrophobic, which means it will sorb appreciably to organic solids and is not readily biodegradable. It is also used extensively in personal care products. These factors have prompted considerable attention in the literature with respect to its environmental profile. In recent years, this attention has shifted away from the water environment to terrestrial systems. This thesis bridges some of the knowledge gaps considering the fate (specifically mineralisation, primary degradation and the formation of bound residues) and the effects (to the soil function and phenotype) of triclosan in soils amended with biosolids. Cont/d.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Formulation, utilisation and evaluation of organomineral fertilisers

The water industry recognises significant cost advantages in recycling sewage sludge (biosolids) to agricultural land compared with alternative more expensive disposal options such as incineration or landfill. A recent technique was proposed by United Utilities plc for the production of organomineral fertilisers (OMF) from biosolids granules which adds additional nitrogen to the biosolids’ nutrients to form a balanced NPK fertiliser. The aim of this research was to determine the effects in cereal and grass crops of using organomineral fertilisers (OMF) made from nutrients-enriched biosolids granules and to contribute towards the understanding of nutrient management and dynamics in agricultural systems. The research included soil incubation, glasshouse, lysimeters and field studies which used winter wheat (Triticum aestivum L.) and ryegrass (Lolium perenne L.). A theoretical model was developed for fertiliser particle distribution studies which required the determination of key physical properties of the products. Two OMF formulations have been suggested: OMF10 and OMF15 which have the following NPK compositions: 10:4:4 and 15:4:4 respectively. These were suggested for use in grassland as well as arable cropping. The particle trajectory model showed that the particle size range for OMF10 and OMF15 should be between 1.10 and 5.50 mm and between 1.05 and 5.30 mm in diameter respectively. Cont/d.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Field-scale evaluation of biosolids-derived organomineral fertilizers applied to winter wheat in England

Field-scale experiments in four crop seasons established the agronomic performance of biosolids-derived organomineral fertilizers (OMF) for winter wheat (Triticum aestivum L.) production in England. Two OMF formulations (OMF10 10:4:4 and OMF15 15:4:4) were compared with urea and biosolids granules (≈5:6:0.2) to determine crop responses and fertilizer effects on soil chemical properties. Fertilizers were applied at N rates between 0 and 250 kg ha–1 at regular increments of 50 kg ha–1 N. Average grain yields with OMF10 and OMF15 were higher than with biosolids granules, but lower than with urea (P < 0.05). The optimum N application rates, and corresponding grain yields, were 245 and 7900 kg ha–1 for biosolids, 257 and 9100 kg ha–1 for OMF10, 249 and 9500 kg ha–1 for OMF15, and 225 and 10350 kg ha–1 for urea, respectively. Differences in grain yield between fertilizer treatments were explained by differences in yield components, particularly number of grains and thousand-grain-weight. Grain-N recoveries were 31% for biosolids, ≈40% for OMF, and 52% for urea. Organomineral fertilizers-induced changes in soil extractable P and soil P Index were not significant. Thus, application of OMF replenished P offtake by the crop and therefore supported the choice of the proposed OMF formulations. By contrast, extractable P increased in biosolids and decreased in urea-treated soils, respectively. Heavy metals in soil were unaffected by fertilizer treatment and lower than permissible limit values. The use of OMF for winter wheat production appears to be a sustainable approach to recycling biosolids to land

Why Agricultural Tools Work in Theory But Aren’t Adopted in Practice: A Grounded Theory Approach to ICT in Ghana and Kenya

Organic fertilisers could contribute to addressing the issues of declining soil fertility, food security and waste management by recycling human waste for use in sub-Saharan Africa. The variable nutrient content of such products can make targetted application more difficult than in chemical fertilisers. One solution to this could be the use of in-field soil testing and information, particularly with the expansion of mobile technology. This research investigated the role of information and soil testing in 43 farmers using human waste derived fertilisers in Kenya and Ghana. Interviews were conducted to understand the use and sources of information in farming and the perception of soil testing technologies. It was found that mobile based testing was unlikely to be adopted for reasons of low priority, the type of knowledge being shared and trust after failures of different projects. Farmers did not see soil testing as the major issue that they needed to solve. Mobile technology was mostly used for visual and oral communication whereas soil testing often provided information in an unsuitable way. Farmers also had limited trust in new projects as they had previously had project failures that did not help them. In order to achieve sustainable adoption of technology there needs to be improved methods of disseminating and learning from project failures to prevent repeated attempts at inappropriate technology in the future

Towards agro-environmentally sustainable irrigation with treated produced water in hyper-arid environments

Supplementary data: Supplementary data to this article is:available at https://ars.els-cdn.com/content/image/1-s2.0-S0378377420313408-mmc1.zip (338B).National Priorities Research Programme (NPRP) grant from the Qatar National Research Fund (QNRF), grant reference number NPRP8-1115-2-473

Efficacy of selected phosphorous sorbing materials (PSMs) to enhance the orthophosphate sorption capacity of filter socks

Agricultural phosphate (PO43‐) is a major cause of water quality compliance failures. Filter socks (FS) are a sediment‐control method proven to be effective at removing sediment and sediment bound‐P. Within the water and wastewater treatment industries phosphorous sorbing materials (PSMs) are widely used to remove reactive PO43‐. Combining PSMs with FS provides an opportunity to concomitantly remove sediment, sediment bound‐P and PO43‐ from agricultural runoff. A column experiment was undertaken to evaluate the efficacy of selected PSMs to remove PO43‐ across a range of PO43‐ concentrations (0.08, 0.26 and 1.3 mg/l) and contrasting FS fill media (PAS 100 Compost and Woodchip). The results indicate that Ca‐enriched ferrihydrite removed up to 99% of PO43‐, and was the only PSM to reduce PO43‐ to below the target value of <0.05 mg/l. An initial cost benefit analysis indicates that PSM‐enhanced FS are a viable option to remove PO43‐ from agricultural runoff

Residual N effects from livestock manure inputs to soils

Organic inputs including livestock manures provide nitrogen (N) to crops beyond the year of their application. This so-called residual N effect should be taken into account when making decisions on N rates for individual fields, but also when interpreting N response trials in preparation of recommendations. This paper addresses general principles of residual N effects, gives literature-based estimates of them, and reviews to which extent residual N effects are included in recommendations and regulations in selected countries

Prediction of organic combined sewer sediment release and transport

Accurate predictions of sediment loads released by sewer overflow discharges are important for being able to provide protection to vulnerable receiving waters. These predictions are sensitive to the estimated sediment characteristics and on the site-conditions of in-pipe deposit formation. Their application without a detailed analysis and understanding of the “initial conditions” under which in- sewer deposits were formed normally results in very poor estimations. In this study, in-sewer sediment samples deposited during dry-periods in a combined sewer system were collected, and their properties assessed. Parameters in the sediment transport relationship first proposed by Skipworth for in-pipe deposits were estimated based on simulating the in-pipe deposit formation conditions in laboratory erosion tests. The measured parameters were then used to simulate sediment transport through a small combined sewer network for a number of rain events for which rainfall, hydraulic and water quality data were available. Results showed that the model of Skipworth can provide good predictions of the sediment loads released from such in-sewer deposits. The experimentally-derived calibration parameters used with Skipworth’s model allowed for a realistic simulation of the in-sewer sediment behaviour and so can be used to accurately estimate the sediment load released from combined sewer systems during rainfall events

The value of manure - Manure as co-product in life cycle assessment

Research ArticleLivestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studiesinfo:eu-repo/semantics/publishedVersio