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

Phosphorus Release Characteristics from Biosolids-Derived Organomineral Fertilizers

This study investigated the availability of phosphorus (P) following soil application of a novel biosolids-derived organomineral fertilizer (OMF15; 15:4:4) in comparison with single superphosphate (0:18:0). Two soil types of contrasting characteristics were incubated over a period of 90 days at 25 °C and maintained near field capacity. Phosphorus was applied at rates equivalent to 0 (control), 150, and 300 kg ha−1 of P2O5, respectively. Availability of P from OMF15 was low throughout the experiment accounting for less than 6.5% of total OMF15-P applied. It was shown that after the 90 days incubation period, the overall increase in soil extractable P in OMF15-treated soil was marginal in both soil types. For single superphosphate (SSP), P availability ranged from 16% to 46% of total SSP-P applied. Application of SSP increased soil extractable P levels significantly (P < 0.001) compared with unfertilized control soils. The results of this study aided the development of fertilization strategies for the best use of OMF produced from nutrient-enriched biosolids granules for applications in winter cereal and grass crops in England

Nitrogen release characteristics from biosolids-derived organomineral fertilizers

is study investigated the availability of nitrogen (N) following soil application of a novel biosolids-derived organomineral fertilizer (OMF15—15:4:4) in comparison with urea (46% N). OMF15 is produced by coating biosolids granules (particle size range: 1.10–5.50 mm in diameter) with urea and potash [60% potassium oxide (K2O)], which increase the concentration of mineral N and potassium (K), respectively, resulting in a balanced fertilizer material suitable for application in cereal and grass crops. The study comprised two soil types of contrasting characteristics which were incubated over a period of 90 days at 25 °C and maintained near field capacity. Nitrogen was applied at rates equivalent to 0 (control), 150, and 300 kg ha−1, and soil mineral N measured routinely using standard laboratory techniques. Results showed that the majority of N was released from OMF15 within 30 days from application (range: 40% to 72% of total OMF15-N applied) with a further 10% to 28% in the following 60–90 days. OMF15 required an accumulated thermal time of 2250 degrees-day to release between 68% and 79% of the total OMF15-N applied. From this, it was inferred that mineralization of the organic-N fraction in OMF15 is likely to progress beyond harvest of winter cereal crops in-field conditions in England. The results of this study aided the development of fertilization strategies for the best use of OMF in winter cereal and grass crops

An investigation into the fertilizer particle dynamics off-the-disc

The particle size range specifications for two biosolids-derived organomineral fertilizers (OMF) known as OMF10 (10:4:4) and OMF15 (15:4:4) were established. Such specifications will enable field application of OMF with spinning disc systems using conventional tramlines spacing. A theoretical model was developed, which predicts the trajectory of individual fertilizer particles off-the-disc. The drag coefficient (Cd) was estimated for small time steps (10-6 s) in the trajectory of the particle as a function of the Reynolds number. For the range of initial velocities (20 to 40 m s-1), release angles (0° to 10°) and particle densities (1000 to 2000 kg m-3) investigated, the analysis showed that OMF10 and OMF15 need to have particle diameters between 1.10 and 5.80 mm, and between 1.05 and 5.50 mm, respectively, to provide similar spreading performance to urea with particle size range of 1.00 to 5.25 mm in diameter. OMF10 and OMF15 should have 80% (by weight) of particles between 2.65 and 4.30 mm, and between 2.55 and 4.10 mm, respectively. Due to the physical properties of the material, disc designs and settings that enable working at a specified bout width by providing a small upward particle trajectory angle (e.g., 10°) are preferred to high rotational velocities. However, field application of OMF with spinning discs applicators may be restricted to tramlines spaced at a maximum of 24 m; particularly, when some degree of overlapping is required between two adjacent bouts. The performance of granular fertilizers can be predicted based on properties of the material, such as particle density and size range, using the contour plots developed in this study

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

Effect of traffic with a light-weight tractor on physical properties of an Aridisol soil in Almeria, Spain

The objective of this work was to evaluate the effect of repeated traffic with a light-weight tractor on the physical/mechanical properties of an Aridisol soil from eastern Almería (Spain). The soil has been used for almond (Prunus amigdalus L.) production for the past 29 years. A light modal tractor (≈15 kN overall load) and different traffic frequencies or treatments; namely, 0 (control, no traffic), and 1, 5, 7, and 10 passes, respectively, were used. The following variables were measured: cone Index (CI); bulk density (BD); total soil porosity (TSP); water infiltration into soil (I), and ruth depth (RD). The results showed that, only treatments 7 and 10 led to significant increases in CI and BD throughout the soil profile (0-450 mm). Changes in TSP in those treatments were consistent with changes in soil bulk density. No significant differences in RD were found when the tractor passed 1 or 5 times. All traffic treatments resulted in significant compaction in the topsoil layer (0-150 mm) and soil physical conditions that would be regarded as unsuitable for establishment of most arable crops.The objective of this work was to evaluate the effect of repeated traffic with a light-weight tractor on the physical/mechanical properties of an Aridisol soil from eastern Almería (Spain). The soil has been used for almond (Prunus amigdalus L.) production for the past 29 years. A light modal tractor (≈15 kN overall load) and different traffic frequencies or treatments; namely, 0 (control, no traffic), and 1, 5, 7, and 10 passes, respectively, were used. The following variables were measured: cone Index (CI); bulk density (BD); total soil porosity (TSP); water infiltration into soil (I), and ruth depth (RD). The results showed that, only treatments 7 and 10 led to significant increases in CI and BD throughout the soil profile (0-450 mm). Changes in TSP in those treatments were consistent with changes in soil bulk density. No significant differences in RD were found when the tractor passed 1 or 5 times. All traffic treatments resulted in significant compaction in the topsoil layer (0-150 mm) and soil physical conditions that would be regarded as unsuitable for establishment of most arable crops

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