Plant-available nitrogen supply from granulated biosolids: implications for land application guidelines

Soil Research ◽  
2008 ◽  
Vol 46 (5) ◽  
pp. 423 ◽  
Author(s):  
S. M. Eldridge ◽  
K. Y. Chan ◽  
Z. H. Xu ◽  
C. R. Chen ◽  
I. Barchia

Current State government guidelines attempt to ensure that the supply of plant available nitrogen (PAN) from land-applied biosolids does not exceed the crop’s requirement for mineral nitrogen (N), in order to minimise the risk of excess nitrate contaminating surface and groundwater. In estimating a suitable application rate, current guideline methodology assumes a fixed proportion of the organic N in the biosolids will be mineralised in the first year following the application for all situations. Our study included a field trial and a field incubation study to assess N mineralisation for both a granulated biosolid and a dewatered biosolid product, together with an additional laboratory incubation study for the granulated biosolid product. The application rates were 12, 24, and 48 dry t/ha for the granulated biosolids and 22 dry t/ha for the dewatered biosolids. Our results showed that the guideline procedure underestimated the supply of mineral N from the biosolid-treated soils, with more than 3 times the predicted amount being supplied by the biosolids at all application rates. The excess supply of mineral N was due to a much larger proportion of the biosolid organic N being mineralised than the assumed 25%, as well as a significant contribution of mineral N from the soil itself (which is ignored in the estimation calculation). The proportion of biosolid organic N mineralised in the 12-month field incubation study for the 3 granulated biosolid treatments (12, 24, and 48 dry t/ha) and the dewatered biosolid treatment (22 dry t/ha) were estimated to be 54%, 48%, 45%, and 53%, respectively, in our field incubation study. Both the laboratory and field incubation studies found that most of the biosolid mineralisable organic N was mineralised rapidly during the early stages of the incubation. In the field incubation, the 24 dry t/ha granulated biosolid treatment had 35% of its organic N mineralised within the first 2 months following application, while all granulated biosolid treatments in the laboratory incubations had by, day 29, supplied >50% of the mineral N they would supply for the whole 216-day incubation. This release pattern for the supply of PAN from biosolid organic N should be factored into fertiliser application strategies. Our study reveals some of the shortcomings of the currently recommended ‘one size fits all’ approach for estimating the PAN supply from land-applied biosolids. Further research on the development of an effective rapid assessment for the mineralisable N content in organic wastes and soils, in combination with modelling, may improve our capacity to predict PAN supply from land-applied organic wastes in the future.

Soil Research ◽  
2013 ◽  
Vol 51 (6) ◽  
pp. 529 ◽  
Author(s):  
Sami Al-Dhumri ◽  
Firew H. Beshah ◽  
Nichola A. Porter ◽  
Barry Meehan ◽  
Roger Wrigley

In the application of biosolids to land for agricultural purposes, the supply of plant-available nitrogen (PAN) should match the crop requirements. This ensures that the crop yield is maximised while minimising the environmental risk from over-application. In Victoria, the amount to be applied is usually calculated according to the State EPA guidelines using the nitrogen limited biosolids application rates (NLBAR). These guidelines specify the mineralisation rates to be used in the NLBAR calculation for different types of biosolids. However, these rates have not been validated for Victorian soils and agricultural production systems. To test the veracity of these rates, this study quantified the amount of PAN for two different biosolids (anaerobically digested biosolids, ANDB; and aerobically digested biosolids, ADB) added to two types of soils, a sandy loam at Lara and a clay loam at the Melton Recycled Water Plant, Surbiton Park, Melton. The PAN was calculated by determining the N fertiliser equivalence of the biosolids. To achieve this, two field calibration plots were prepared, one for the biosolids and one for urea as the N fertiliser. Biosolids were applied based on total N at six rates (0, 68, 136, 204, 340 and 510 kg N ha–1); urea was applied at six rates (0, 60, 120, 180, 240 and 280 kg N ha–1). Perennial ryegrass (Lolium perenne) was planted 1 day after the application of biosolids and harvested after 120 days. The calculated amount of mineralisable organic N in ANDB was estimated to be 41% and 39% when applied to the clay loam and sandy loam soils, respectively; for ADB, it was 12% and 9%, respectively. These values indicate that the organic N mineralisation rates provided in the EPA Victoria guidelines (15% for ANDB and 25% for ADB) might not always be applicable. Also of note is that the values obtained for the each of the biosolids appear to be independent of the soil type.


Author(s):  
Subin Kalu ◽  
Gboyega Nathaniel Oyekoya ◽  
Per Ambus ◽  
Priit Tammeorg ◽  
Asko Simojoki ◽  
...  

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.


1980 ◽  
Vol 94 (1) ◽  
pp. 183-193 ◽  
Author(s):  
K. K. S. Bhat ◽  
T. H. Flowers ◽  
J. R. O'Callaghan

SummaryA model for predicting the various transformations undergone in the soil by nitrogen applied in farm wastes, in response to variations in soil and climatic factors, is presented. The soil is divided into layers and a simple mass balance model is used to describe the movement and redistribution of water within the soil profile, as a function of rainfall, evapotranspiration and soil moisture characteristics.Ammonification of native and applied organic N is assumed to follow first-order reaction kinetics and nitrification and denitrification are treated as zero-order reactions. The rates or rate constants for all three reactions were related separately to soil temperature, moisture content and pH.Uptake of nitrogen by a grass crop, dry-matter production, removal of dry matter and N through harvests, addition to soil of C and N through dead plant material and stubble and the consequent immobilization of mineral N are allowed for. Some of the predictions of the model are compared with the results of a lysimeter experiment.


2006 ◽  
Vol 86 (4) ◽  
pp. 613-620 ◽  
Author(s):  
C G Cogger ◽  
T A Forge ◽  
G H Neilsen

Biosolids are municipal wastewater treatment solids that meet regulatory standards for land application. Most biosolids are a rich source of N, P, and micronutrients. Although the use of biosolids on food crops remains controversial in the public eye, decades of research have led to the development of regulations for the safe and beneficial use of biosolids in agriculture. Emerging areas of research include biosolids in commercial and home horticulture, the fate of pathogens and organics in biosolids, the use of biosolids in the remediation of contaminated sites, and biosolids effects on soil ecology. Nutrient management remains the most critical day-to-day issue for land application of biosolids. Recent research on plant-available nitrogen (PAN) in biosolids has found that N availability is similar over a range of biosolids processing types, and that growing-season climate is a key factor affecting available N. Regionally based predictions of PAN have been developed for the United States, and could be extended into Canada. Relatively little is known about the effects of biosolids applications on soil ecology, but soil nematodes offer an opportunity to evaluate the structure and function of the soil ecosystem following biosolids applications. We have studied responses of nematode communities to application of municipal biosolids and composts, in forage production systems and orchards. Both types of amendments increased the abundance of enrichment opportunists, for up to 3 yr after single applications. These data on the persistence of increased enrichment opportunists have provided insight into the longevity of amendment-induced enhancement of biological activity and nutrient cycling. Cumulative biosolids applications of 90 Mg ha-1 have caused reductions in abundance of pollutant-sensitive Dorylaimida. The extent to which this change is the result of metal or nutrient loading is unclear and deserves more detailed study. Key words: Biosolids, plant-available nitrogen, soil ecology, nematodes


Soil Research ◽  
2012 ◽  
Vol 50 (2) ◽  
pp. 91 ◽  
Author(s):  
Guixin Pu ◽  
Mike Bell ◽  
Glenn Barry ◽  
Peter Want

One major benefit of land application of biosolids is to supply nitrogen (N) for agricultural crops, and understanding mineralisation processes is the key for better N-management strategies. Field studies were conducted to investigate the process of mineralisation of three biosolids products (aerobic, anaerobic, and thermally dried biosolids) incorporated into four different soils at rates of 7–90 wet t/ha in subtropical Queensland. Two of these studies also examined mineralisation rates of commonly used organic amendments (composts, manures, and sugarcane mill muds). Organic N in all biosolids products mineralised very rapidly under ambient conditions in subtropical Queensland, with rates much faster than from other common amendments. Biosolids mineralisation rates ranged from 30 to 80% of applied N during periods ranging from 3.5 to 18 months after biosolids application; these rates were much higher than those suggested in the biosolids land application guidelines established by the NSW EPA (15% for anaerobic and 25% for aerobic biosolids). There was no consistently significant difference in mineralisation rate between aerobic and anaerobic biosolids in our studies. When applied at similar rates of N addition, other organic amendments supplied much less N to the soil mineral N and plant N pools during the crop season. A significant proportion of the applied biosolids total N (up to 60%) was unaccounted for at the end of the observation period. High rates of N addition in calculated Nitrogen Limited Biosolids Application Rates (850–1250 kg N/ha) resulted in excessive accumulation of mineral N in the soil profile, which increases the environmental risks due to leaching, runoff, or gaseous N losses. Moreover, the rapid mineralisation of the biosolids organic N in these subtropical environments suggests that biosolids should be applied at lower rates than in temperate areas, and that care must be taken with the timing to maximise plant uptake and minimise possible leaching, runoff, or denitrification losses of mineralised N.


2019 ◽  
Vol 11 (9) ◽  
pp. 1094 ◽  
Author(s):  
Marta Aranguren ◽  
Ander Castellón ◽  
Ana Aizpurua

It is difficult to predict the crop-available nitrogen (N) from farmyard manures applied to soil. The aim of this study was to assess the usefulness of the proximal sensors, Yara N-TesterTM and RapidScan CS-45, for diagnosing the N nutritional status of wheat after the application of manures at sowing. Three annual field trials were established (2014–2015, 2015–2016 and 2016–2017) with three types of fertilizer treatments: dairy slurry (40 t ha−1 before sowing), sheep manure (40 t ha−1 before sowing) and conventional treatment (40 kg N ha−1 at tillering). For each treatment, five different mineral N fertilization doses were applied at stem elongation: 0, 40, 80, 120, and 160 kg N ha−1. The proximal sensing tools were used at stem elongation before the application of mineral N. Normalized values of the proximal sensing look promising for adjusting mineral N application rates at stem elongation. For dairy slurry, when either proximal sensor readings were 60–65% of the reference plants with non-limiting N, the optimum N rate for maximizing yield was 118–128 kg N ha−1. When the readings were 85–90%, the optimum N rate dropped to 100–110 kg N ha−1 for both dairy slurry and conventional treatments. It was difficult to find a clear relationship between sensor readings and yield for sheep manure treatments. Measurements taken with RapidScan C-45 were less time consuming and better represent the spatial variation, as they are taken on the plant canopy. Routine measurements throughout the growing season are particularly needed in climates with variable rainfall. The application of 40 kg N ha−1 at the end of winter is necessary to ensure an optimal N status from the beginning of wheat crop development. These research findings could be used in applicator-mounted sensors to make variable-rate N applications.


Soil Research ◽  
2012 ◽  
Vol 50 (4) ◽  
pp. 348 ◽  
Author(s):  
Guixin Pu ◽  
Mike Bell ◽  
Glenn Barry ◽  
Peter Want

One major benefit of land application of biosolids is to supply nitrogen (N) for agricultural crops, and understanding mineralisation processes is the key for better N-management strategies. Field studies were conducted to investigate the process of mineralisation of three biosolids products (aerobic, anaerobic, and thermally dried biosolids) incorporated into four different soils at rates of 7?90 wet t/ha in subtropical Queensland. Two of these studies also examined mineralisation rates of commonly used organic amendments (composts, manures, and sugarcane mill muds). Organic N in all biosolids products mineralised very rapidly under ambient conditions in subtropical Queensland, with rates much faster than from other common amendments. Biosolids mineralisation rates ranged from 30 to 80% of applied N during periods ranging from 3.5 to 18 months after biosolids application; these rates were much higher than those suggested in the biosolids land application guidelines established by the NSW EPA (15% for anaerobic and 25% for aerobic biosolids). There was no consistently significant difference in mineralisation rate between aerobic and anaerobic biosolids in our studies. When applied at similar rates of N addition, other organic amendments supplied much less N to the soil mineral N and plant N pools during the crop season. A significant proportion of the applied biosolids total N (up to 60%) was unaccounted for at the end of the observation period. High rates of N addition in calculated Nitrogen Limited Biosolids Application Rates (850?1250 kg N/ha) resulted in excessive accumulation of mineral N in the soil profile, which increases the environmental risks due to leaching, runoff, or gaseous N losses. Moreover, the rapid mineralisation of the biosolids organic N in these subtropical environments suggests that biosolids should be applied at lower rates than in temperate areas, and that care must be taken with the timing to maximise plant uptake and minimise possible leaching, runoff, or denitrification losses of mineralised N.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Susan King ◽  
Michael Schwalb ◽  
David Giard ◽  
Joann Whalen ◽  
Suzelle Barrington

Swine manure subjected to in-storage psychrophilic anaerobic digestion (ISPAD) undergoes proteins degradation but limited NH3volatilization, producing an effluent rich in plant-available nitrogen. Accordingly, ISPAD effluent can offer a higher fertilizer value during land application, as compared to manure of similar age stored in an open tank. However, this additional nitrogen can also be lost by volatilization during land application. The objective of this study was therefore to measure NH3volatilization from both ISPAD and open tank swine manures when applied to 5 different soils, namely, washed sand, a Ste Rosalie clay, an Upland sandy loam, a St Bernard loam, and an Ormstown loam. This research was conducted using laboratory wind tunnels simulating land application. The five experimental soils offered similar pH values but different water holding capacity, cation exchange capacity, cation saturation, and organic matter. After 47 h of wind tunnel monitoring, the % of total available nitrogen (TAN orNH4 +and NH3) volatilized varied with both manure and soil type. For all soil types, the ISPAD manure consistently lost less NH3as compared to the open tank manure, averaging 53% less. Lower volatile solids content improving manure infiltration into the soil and a more complex ionic solution explain the effect of the ISPAD manure advantages. This was reinforced by the St Bernard sandy loam losing the same nitrogen mass for both manures, because of its higher pH and buffer pH coupled with an intermediate CEC resulting in more soil solution NH3. Within each manure type, % TAN volatilized was highest for washed sand and lowest for the clay soil. As a result, ISPAD manure can offer up to 21% more plant-available nitrogen fertilizer especially when the manure is not incorporated into the soil following its application.


2007 ◽  
Vol 87 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Bobbi L Helgason ◽  
Francis J Larney ◽  
H. Henry Janzen ◽  
Barry M Olson

The amount and pattern of plant-available nitrogen (N) release from composts are variable and not well-defined. We used a 425-d canola (Brassica napus L.) bioassay to follow the release of N from eight composted cattle manures applied to soil at 20 g kg-1. Two stockpiled manures, one inorganic fertilizer and an unamended control were also included for comparison. Eight consecutive 30-d growth cycles were conducted in a controlled environment chamber (20°C) and plant N uptake was measured. Total N uptake was greatest from the N fertilizer and least from the wood-chip bedded manure. Addition of compost increased N uptake by 27–99% compared with that in the control. Nitrogen uptake from compost was directly proportional to its inorganic N content (r2 = 0.98; P < 0.0001) showing that the initial inorganic N content of compost, analyzed prior to its application can be used to predict plant available N. In seven of the eight composts studied, less than 5% of organic N was mineralized over 425 d, suggesting that little of the organic N in compost becomes available in the year of application. Compost is a valuable organic amendment, but co-application of N fertilizer is recommended to supply adequate N and optimize the benefits of compost for crop growth. Key words: Plant-available nitrogen, compost, nitrogen mineralization, beef manure


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