Feasibility of Nitrogen-Enriched Chars as Circular Fertilizers

Abstract Purpose Charred materials are low in bioavailable nitrogen (N) due to gaseous losses and the formation of recalcitrant structures during pyrolysis. Enriching chars with N from wastewaters offers a possibility to upgrade the agronomic value of the chars and manage the liquids. For assessing the practical feasibility of the approach, more information on the extent of the retention and release of the loaded N is needed. Methods The ammonium-N (NH4-N) retention capacity of chars derived from sewage sludge (SS_A-C), Salix wood (SA), broiler manure (BR) and coal (LG85) was determined via equilibrations in solutions containing 400, 1500 and 5000 mg NH4-N L−1. Plant availability of the loaded N in SS_C, SA and BR was studied in a pot experiment with ryegrass. Results Differences in the total N retention of moist chars were small. The amount of N retained increased with increase in the solution N and was at the highest 2–4 g NH4-N L−1 char. In four consecutive ryegrass harvests, the apparent N recoveries were 67, 47 and 34% for SA, BR and SS_C treatments. No slow release of N was observed. Conclusion Considering crop production, the amounts of N retained within the studied chars in bioavailable form were small. Chars with a higher N retention capacity would be needed for an efficient cascade from water purification to fertilizer use. Graphical Abstract

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Nitrogen-retention capacity in a fertilized forest after clear-cutting — the effect of forest-floor vegetation

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0281 ◽

2015 ◽

Vol 45 (1) ◽

pp. 130-134 ◽

Cited By ~ 2

Author(s):

Per-Ola Hedwall ◽

Johan Bergh ◽

Annika Nordin

Keyword(s):

Vegetation Cover ◽

Forest Floor ◽

Nitrogen Retention ◽

Tree Seedling ◽

Retention Capacity ◽

N Retention ◽

Clear Cutting ◽

Nitrate N ◽

Ammonium N ◽

Forest Floor Vegetation

Forest fertilization with nitrogen (N) has several benefits to society such as increased wood production and carbon sequestration. There are, however, concerns about N leakage, particularly following clear-cutting. The forest-floor vegetation may increase the N retention of forest ecosystems; however, very few studies have quantified the amount of vegetation required. We studied the relationship between vegetation cover and risk of N leakage, estimated by the amounts of ammonium-N and nitrate-N retained on ion-exchange capsules in the soil, during 4 years following the clear-cutting and harvesting of logging residues in a previously fertilized forest in southern Sweden. Previous fertilization increased the amount of nitrate-N captured on the capsules, whereas the amount of ammonium-N decreased. The vascular vegetation cover increased from almost zero to approximately 25% independent of fertilization. The amount of ammonium-N and nitrate-N retained on the capsules was already reduced by 50%–75% at 20% vegetation cover, and by 30%–40% cover, it approached zero, independent of the number of years since clear-cutting. The vegetation may impede tree-seedling establishment, implying a trade-off between seedling growth and N-retention capacity. However, our results indicate that maximum N retention may be achieved at a relatively low vegetation cover, which could be accomplished with less intrusive scarification methods than currently used.

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EFFECT OF ADDED MONOCALCIUM PHOSPHATE MONOHYDRATE AND AERATION ON NITROGEN RETENTION BY LIQUID HOG MANURE

Canadian Journal of Soil Science ◽

10.4141/cjss87-065 ◽

1987 ◽

Vol 67 (3) ◽

pp. 687-692 ◽

Cited By ~ 7

Author(s):

A. F. MACKENZIE ◽

J. S. TOMAR

Keyword(s):

Sus Scrofa ◽

Crop Production ◽

Nitrogen Retention ◽

N Losses ◽

N Content ◽

Total N ◽

N Retention ◽

Monocalcium Phosphate ◽

Hog Manure ◽

Sus Scrofa Domesticus

Retention of nitrogen in manure to be used for crop production and to reduce environmental pollution is an essential management component. The effects of monocalcium phosphate monohydrate (MCPM) and aeration on N retention in liquid hog (Sus scrofa domesticus) manure (LHM) were investigated under laboratory conditions. The manure received 0, 20 or 40 g of MCPM kg−1 of LHM (0, 250 or 500 g MCPM kg−1 manure solids) and was incubated over a 15-d period with and without aeration. Manure pH decreased with added MCPM and then remained constant, but pH increased with time when MCPM was not added. Losses of NH3 from hog manure were significantly reduced by added MCPM, but increased significantly with aeration where MCPM was not added to the manure. The NH4-N content of LHM was higher where MCPM was added to the manure. Conversely, the NH4-N content tended to decrease with aeration in the absence of MCPM. Total N content of LHM was significantly decreased where MCPM was not added to the manure. Aeration had no significant effect on total N. It was concluded that addition of MCPM can increase the NH4-N content of LHM by decreasing NH3-N losses through acidification of the manure. Key words: Aeration, Ca(H2PO4)2∙H2O, hog manure, pH reduction, NH3 loss

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Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan

Biogeosciences ◽

10.5194/bg-13-1787-2016 ◽

2016 ◽

Vol 13 (6) ◽

pp. 1787-1800 ◽

Cited By ~ 13

Author(s):

Jr-Chuan Huang ◽

Tsung-Yu Lee ◽

Teng-Chiu Lin ◽

Thomas Hein ◽

Li-Chin Lee ◽

...

Keyword(s):

Agricultural Land ◽

Eastern Coast ◽

N Availability ◽

N Saturation ◽

Agricultural Lands ◽

Retention Capacity ◽

Total N ◽

N Retention ◽

Nitrogen Inputs ◽

N Input

Abstract. Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities have substantially altered the N cycle, both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind of the most rapidly industrializing eastern coast of China, can be a demonstration site for extremely high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings but classified into low, moderate, and highly disturbed categories based on population density to illustrate their differences in nitrogen inputs (through atmospheric N deposition, synthetic fertilizers, and human emission) and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ∼ 3800 kg N km−2 yr−1, approximately 18 times the global average. The average riverine DIN export ratios are 0.30–0.51, which are much higher than the averages of 0.20–0.25 of large rivers around the world, indicating excessive N input relative to ecosystem demand or retention capacity. The low disturbed watersheds have a high N retention capacity and DIN export ratios of 0.06–0.18 in spite of the high N input (∼ 4900 kg N km−2 yr−1). The high retention capacity is likely due to effective uptake by secondary forests in the watersheds. The moderately disturbed watersheds show a linear increase in DIN export with increases in total N inputs and mean DIN export ratios of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watersheds is the greater proportion of agricultural land cover in the moderately disturbed watersheds. Thus, their greater DIN export could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have a lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratios of the highly disturbed watersheds are very high, 0.42–0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures.

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Sewage Sludge as N-Fertilizers for Crop Production Enabling the Circular Bioeconomy in Agriculture: A Challenge for the New EU Regulation 1009/2019

Sustainability ◽

10.3390/su132313165 ◽

2021 ◽

Vol 13 (23) ◽

pp. 13165

Author(s):

Mirko Cucina ◽

Patrizia De Nisi ◽

Simone Sordi ◽

Fabrizio Adani

Keyword(s):

Sewage Sludge ◽

Plant Growth ◽

Manufacturing Process ◽

Crop Production ◽

Organic Fertilizer ◽

Organic Fertilizers ◽

Physiological Status ◽

The European Union ◽

Total N ◽

Eu Regulation

The fertilizer framework in the European Union has recently been reviewed by EU Regulation 1009/2019 that excluded sewage sludge from the list of the possible constituents of organic fertilizers relying on their origin, not on their quality. This paper aimed to carry out a complete characterization of sewage sludge obtained from a pharmaceutical manufacturing process (PDSS) to demonstrate that sewage sludge obtained from a standardized and controlled manufacturing process can be safely recycled as organic fertilizer. The agronomic and environmental characteristics of the PDSS product were analyzed and compared to other organic fertilizers. Its fertilizing potential was also evaluated through plant growth trials. PDSS was characterized by a high concentration of total N (6.6% w/w), which was all present in organic form. PDSS also showed a low concentration of heavy metals, an absence of pathogens and low concentrations of organic contaminants. Plant growth trials showed that the PDSS was able to improve lettuce and carrot growth (+25 and +46% of dry weight compared to the unfertilized control), as well as their physiological status. Considering all the results, the exclusion of sewage sludge relying only on its origin and not on its quality appears to conflict with the principles of the circular bioeconomy.

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Nitrogen fertilizer replacement value of sewage sludge, composted household waste and farmyard manure

The Journal of Agricultural Science ◽

10.1017/s0021859603003010 ◽

2003 ◽

Vol 140 (2) ◽

pp. 169-182 ◽

Cited By ~ 14

Author(s):

J. PETERSEN

Keyword(s):

Sewage Sludge ◽

Farmyard Manure ◽

Application Rate ◽

Household Waste ◽

Organic Residues ◽

Sewage Sludges ◽

Total N ◽

Fertilizer Value ◽

Ammonium N ◽

High Application

Field experiments were undertaken during 1998–2000 at Askov Experimental Station and Lundgård Experimental Site, Denmark, to investigate the fertilizer value of anaerobic and aerobic sewage sludges (SS1 and SS2), composted household waste (Compost) and farmyard manure (FYM). The organic residues were applied at two rates with or without supplementary mineral nitrogen (N). The effects of residue application on spring cereal dry matter (DM) yield and N-offtake were related to reference treatments with increasing rates of calcium ammonium nitrate (CAN). DM yields at the high application rates of aerobic sewage sludge (198 kg N/ha/year) and farmyard manure (300 kg N/ha/year) were comparable to the reference treatments receiving 90 kg mineral-N/ha/year. The comparable high application rate of anaerobic sewage sludge was 138 kg N/ha/year only and the DM yield was less. In contrast, the yield effect of Compost was very poor; even the high application rate of 321 kg N/ha/year yielded less than the low application rates of aerobic sewage sludge and farmyard manure, 66 and 100 kg N/ha/year, respectively.The nitrogen fertilizer replacement value (NFRV) of the organic residues was estimated for all four combinations of the response variables DM-yield and N-offtake and the independent variables of total-N and ammonium-N applied. NFRV was in the range 49–68% for the sewage sludges and FYM based on the DM-yield[ratio ]total-N relation, and slightly smaller for the N-offtake[ratio ]total-N relation, 29–53%. The highest values were obtained for the aerobic sewage sludge, having a potential manurial value comparable to FYM. In contrast, the NFRV of Compost was low, about 10%.The concentration of ammonium-N in organic residues and manures is often used for predicting the fertilizer value. Ammonium-N based NFRV of 160–210% for the sewage sludges indicate that water extractable ammonium-N underestimates the NFRV, probably due to the content of easily degradable organic matter in digested sewage sludge. The estimated NFRV for Compost was above 100% but connected with high uncertainty. In contrast, the ammonium-N based NFRV for FYM was only 70–87%, probably due to ammonia volatilization caused by incomplete incorporation of large quantities and the high ammonium-N[ratio ]total-N ratio in this residue.

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Effects of different N sources on riverine DIN export and retention in subtropical high-standing island, Taiwan

Biogeosciences Discussions ◽

10.5194/bgd-12-16397-2015 ◽

2015 ◽

Vol 12 (19) ◽

pp. 16397-16430

Author(s):

J.-C. Huang ◽

T.-Y. Lee ◽

T.-C. Lin ◽

T. Hein ◽

L.-C. Lee ◽

...

Keyword(s):

N Saturation ◽

Agricultural Lands ◽

Retention Capacity ◽

Total N ◽

Input Quantity ◽

N Retention ◽

Export Ratio ◽

Nitrogen Inputs ◽

N Input ◽

Synthetic Fertilizers

Abstract. Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities has substantially altered N cycle both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind to the most rapidly industrializing east coast of China can be a demonstration site for extreme high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds classified into low-, moderate-, and highly-disturbed categories based on population density to illustrate their differences in nitrogen inputs through atmospheric N deposition, synthetic fertilizers and human emission and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ~ 3800 kg N km−2 yr−1, approximately 18-fold higher than the global average mostly due to the large input of synthetic fertilizers. The average riverine DIN export ratio is 0.30–0.51, which is much higher than the average of 0.20–0.25 of large rivers around the world indicating excessive N input relative to ecosystem demand or retention capacity. The low-disturbed watersheds, despite of high N input, only export 0.06–0.18 of the input so were well buffered to changes in input quantity suggesting high efficiency of nitrogen usage or high N retention capacity of the less disturbed watersheds. The high retention capacity probably is due to the effective uptake by secondary forests in the watersheds. The moderate-disturbed watersheds show a linear increase of output with increases in total N inputs and a mean DIN export ratio of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watershed is the relative proportions of agricultural land and forests, not the built-up lands. Thus, their greater DIN export quantity could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratio of the highly-disturbed watersheds is 0.42–0.53, which is very high and suggests that much of the N input is transported downstream and the need of improvement in wastewater treatment capacity or sewerage systems. The increases in riverine DIN export ratio along with the gradient of human disturbance indicates a gradient in N saturation in subtropical Taiwan. Our results help to understand factors controlling riverine DIN export and provide a sound basis for N emissions/pollution control.

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Impact of Nitrogen Management Practices on Total Nitrogen in the Fruits of High Productive Hamlin Orange Trees

HortScience ◽

10.21273/hortsci.33.3.498e ◽

1998 ◽

Vol 33 (3) ◽

pp. 498e-498

Author(s):

S. Paramasivam ◽

A.K. Alva

Keyword(s):

Crop Production ◽

Management Practices ◽

Fine Sand ◽

Fruit Production ◽

Perennial Crop ◽

Total N ◽

N Removal ◽

Leaf N Concentration ◽

N Rates ◽

Orange Trees

For perennial crop production conditions, major portion of nutrient removal from the soil-tree system is that in harvested fruits. Nitrogen in the fruits was calculated for 22-year-old `Hamlin' orange (Citrus sinensis) trees on Cleopatra mandarin (Citrus reticulata) rootstock, grown in a Tavares fine sand (hyperthermic, uncoated, Typic Quartzipsamments) that received various N rates (112, 168, 224, and 280 kg N/ha per year) as either i) broadcast of dry granular form (DGF; four applications/year), or ii) fertigation (FRT; 15 applications/year). Total N in the fruits (mean across 4 years) varied from 82 to 110 and 89 to 111 kg N/ha per year for the DGF and FRT sources, respectively. Proportion of N in the fruits in relation to N applied decreased from 74% to 39% for the DGF and from 80% to 40% for the FRT treatments. High percentage of N removal in the fruits in relation to total N applied at low N rates indicate that trees may be depleting the tree reserve for maintaining fruit production. This was evident, to some extent, by the low leaf N concentration at the low N treatments. Furthermore, canopy density was also lower in the low N trees compared to those that received higher N rates.

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Kinetics of slow release of nitrogen fertiliser from multi-layered nanofibrous structures

Scientific Reports ◽

10.1038/s41598-021-84460-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Leila Javazmi ◽

Anthony Young ◽

Gavin J. Ash ◽

Tobias Low

Keyword(s):

Crop Production ◽

Slow Release ◽

New Technology ◽

Single Layer ◽

Middle Layer ◽

Modern Agriculture ◽

Triple Layer ◽

Urea Release ◽

Electrospun Nanofibres ◽

Kinetics Of

AbstractFertilisers are essential in modern agriculture to enhance plant growth, crop production and product quality. Recent research has focused on the development of delivery systems designed to prolong fertiliser release. This study introduces a new technology to encapsulate and release molecules of fertilisers by using multi-layered electrospun nanofibre as a carrier. Single-layer poly L-lactic acid (PLLA) nanofibres loaded with urea were fabricated using electrospinning. Triple-layer nanofibrous structures were produced by electrospinning polyhydroxybutyrate (PHB) nanofibres as external layers with PLLA nanofibres impregnated with urea fertiliser as the middle layer. Scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR) were employed to characterize the morphology of electrospun nanofibres. Urea release dynamic was analysed using a total nitrogen instrument (TNM-1). The results indicated that triple-layered urea-impregnated nanofibrous structures led to lower initial rate of nitrogen release and slower release rate of cumulative nitrogen which extended for more than three months. It is concluded that triple-layer nanofibrous structures have the potential for slow release delivery of fertilisers.

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The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N2O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols

Soil Research ◽

10.1071/sr15286 ◽

2016 ◽

Vol 54 (5) ◽

pp. 604 ◽

Cited By ~ 23

Author(s):

G. D. Schwenke ◽

B. M. Haigh

Keyword(s):

Crop Yield ◽

Crop Production ◽

Field Experiments ◽

N2o Emission ◽

N2o Emissions ◽

N Loss ◽

N Losses ◽

Total N ◽

Tropical Regions ◽

The Impact

Summer crop production on slow-draining Vertosols in a sub-tropical climate has the potential for large emissions of soil nitrous oxide (N2O) from denitrification of applied nitrogen (N) fertiliser. While it is well established that applying N fertiliser will increase N2O emissions above background levels, previous research in temperate climates has shown that increasing N fertiliser rates can increase N2O emissions linearly, exponentially or not at all. Little such data exists for summer cropping in sub-tropical regions. In four field experiments at two locations across two summers, we assessed the impact of increasing N fertiliser rate on both soil N2O emissions and crop yield of grain sorghum (Sorghum bicolor L.) or sunflower (Helianthus annuus L.) in Vertosols of sub-tropical Australia. Rates of N fertiliser, applied as urea at sowing, included a nil application, an optimum N rate and a double-optimum rate. Daily N2O fluxes ranged from –3.8 to 2734g N2O-Nha–1day–1 and cumulative N2O emissions ranged from 96 to 6659g N2O-Nha–1 during crop growth. Emissions of N2O increased with increased N fertiliser rates at all experimental sites, but the rate of N loss was five times greater in wetter-than-average seasons than in drier conditions. For two of the four experiments, periods of intense rainfall resulted in N2O emission factors (EF, percent of applied N emitted) in the range of 1.2–3.2%. In contrast, the EFs for the two drier experiments were 0.41–0.56% with no effect of N fertiliser rate. Additional 15N mini-plots aimed to determine whether N fertiliser rate affected total N lost from the soil–plant system between sowing and harvest. Total 15N unaccounted was in the range of 28–45% of applied N and was presumed to be emitted as N2O+N2. At the drier site, the ratio of N2 (estimated by difference)to N2O (measured) lost was a constant 43%, whereas the ratio declined from 29% to 12% with increased N fertiliser rate for the wetter experiment. Choosing an N fertiliser rate aimed at optimum crop production mitigates potentially high environmental (N2O) and agronomic (N2+N2O) gaseous N losses from over-application, particularly in seasons with high intensity rainfall occurring soon after fertiliser application.

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