This document describes a study that developed a quick and easy incubation method to measure nitrogen mineralization from soils and organic residues. The method involves extracting mineral nitrogen from soil and residue mixtures using water and incubating the mixtures at 37°C for 10 days. Mineral nitrogen levels were measured over time. Polynomial equations provided a good fit for modeling nitrogen mineralization curves, particularly for soils mixed with secondary pulp mill sludge. The highest mineralization occurred in soils with the highest organic matter contents. The method effectively simulated the release of easily mineralizable organic nitrogen from soils and residues.
Environmental impact of biosolids land applicationSilvana Torri
Como citar este trabajo
Torri S, Cabrera M. 2017 Environmental impact of biosolids land application. In: Organic Waste: Management Strategies, Environmental Impact and Emerging Regulations, Editor: M Collins, Nova Science Publishers, Inc., Hauppauge, NY 11788, ISBN: 978-1-53610-936-8, 185-208, 226 pp
This presentation was presented during the Plenary 1, Opening Ceremony of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. Luca Montanarella from EU Commission’s Joint Research Centre, in FAO Hq, Rome
Soil Fertility, Fertilizer, and Fertiizization. Chapter 5 THE OM AND SOMPurwandaru Widyasunu
This material is part of my lecturing on soi fertility, fertilizer, and fertilization namely Chapter 6 The OM and SOM written down based on the book of Benjamin Wolf and George H. Snyder. 2002. This material is only for lecture purpose of my class.
Substances containing carbon are organic matter.
Soil organic matter consists of decomposing plant and animal residues.
It also includes substances of organic origin either leaving or dead.
Assessing the potential of soil organic carbon sequestration in African soilsExternalEvents
This presentation was presented during the 2 Parallel session on Theme 2, Maintaining and/or increasing SOC stocks for climate change mitigation and adaptation and Land Degradation Neutrality, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Ms. Tantely Razafimbelo, from University of Antananarivo and CASA - Madagascar, in FAO Hq, Rome
Downward movement of potentially toxic elements in biosolids amended soils,Silvana Torri
Como citar este trabajo
Torri S.I., Corrêa R.S. 2012. Downward movement of potentially toxic elements in biosolids amended soils, Special issue: Biosolids Soil Application: Agronomic and Environmental Implications, Applied and Environmental Soil Science (ISSN: 1687-7667), Volume 2012, Article ID 145724, 7 pages, doi:10.1155/2012/145724.
Effects of Soil Organic Matter in the Soil, Benefits of soil organic matter, Amount of Soil organic matter, Maintenance or improvement of SOM, Factors affecting formation and decomposition of SOM
Environmental impact of biosolids land applicationSilvana Torri
Como citar este trabajo
Torri S, Cabrera M. 2017 Environmental impact of biosolids land application. In: Organic Waste: Management Strategies, Environmental Impact and Emerging Regulations, Editor: M Collins, Nova Science Publishers, Inc., Hauppauge, NY 11788, ISBN: 978-1-53610-936-8, 185-208, 226 pp
This presentation was presented during the Plenary 1, Opening Ceremony of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Mr. Luca Montanarella from EU Commission’s Joint Research Centre, in FAO Hq, Rome
Soil Fertility, Fertilizer, and Fertiizization. Chapter 5 THE OM AND SOMPurwandaru Widyasunu
This material is part of my lecturing on soi fertility, fertilizer, and fertilization namely Chapter 6 The OM and SOM written down based on the book of Benjamin Wolf and George H. Snyder. 2002. This material is only for lecture purpose of my class.
Substances containing carbon are organic matter.
Soil organic matter consists of decomposing plant and animal residues.
It also includes substances of organic origin either leaving or dead.
Assessing the potential of soil organic carbon sequestration in African soilsExternalEvents
This presentation was presented during the 2 Parallel session on Theme 2, Maintaining and/or increasing SOC stocks for climate change mitigation and adaptation and Land Degradation Neutrality, of the Global Symposium on Soil Organic Carbon that took place in Rome 21-23 March 2017. The presentation was made by Ms. Tantely Razafimbelo, from University of Antananarivo and CASA - Madagascar, in FAO Hq, Rome
Downward movement of potentially toxic elements in biosolids amended soils,Silvana Torri
Como citar este trabajo
Torri S.I., Corrêa R.S. 2012. Downward movement of potentially toxic elements in biosolids amended soils, Special issue: Biosolids Soil Application: Agronomic and Environmental Implications, Applied and Environmental Soil Science (ISSN: 1687-7667), Volume 2012, Article ID 145724, 7 pages, doi:10.1155/2012/145724.
Effects of Soil Organic Matter in the Soil, Benefits of soil organic matter, Amount of Soil organic matter, Maintenance or improvement of SOM, Factors affecting formation and decomposition of SOM
The Changing of Soil Reaction and Exchangeable Aluminum on two Different Soil...Agriculture Journal IJOEAR
The objective of the experiment was to know the effect of Dolomite application on soil reaction and exchangeable Aluminum in two different soil orders. The method was experimental using Factorial Randomized Block Design, which consists of two Factors. The First factor were soil orders consist two levels, i.e. T1= Ultisols Kentrong, dan T2 = Inseptisols Jatinangor, while the second were dolomite dosages, consist four levels, i.e. dO = 0 ton ha-1 , d1 = 1 ton ha-1 , d2 = 2 ton ha-1 , d3 = 3 ton ha-1 , d4 = 4 ton ha-1 .The result of the experiment showed that on Ultisols Kentrong, dolomite applications significantly increased the value of soil reaction (pH) after two weeks incubation. The treatment of 3 ton/ha showed pH 4.73 or 8 % higher that control. Otherwise, the applications of dolomite also decreased the exchangeable Aluminum. The treatment of 3 ton/ha showed value 7.01 of exchangeable aluminum or 21 % lower than control. In Inceptisols Jatinangor, dolomite applications increased the value of soil reaction (pH) after two weeks incubation and the treatment of 3 tonha-1 showed pH 5.83 or 11 % higher than control. Otherwise, the application of dolomite decreased the exchangeable aluminum although were not significantly different for that parameters in this soil order. Based on statistical analysis, it proved that liming unable applied effectively on whole soil types or orders due to its relation with the level of soil acidity.
Physical fractionation techniques have often relied on the breakdown of soil structure into its textural classes or density fractions in order to study SOM dynamics. This appears to be inappropriate for investigating how soil structure is maintained. The bonding agents responsible for structure have been well defined, although the effects of farming systems on them are not fully understood. Techniques which can rapidly assess the impacts of management on bonding agents and structure are required in order to develop sustainable farming systems.
Mineralization of Carbon from Sewage sludge in three soils of the Argentine p...Silvana Torri
Como citar este trabajo
Torri S, Alvarez R, Lavado R. 2003. Mineralization of Carbon from Sewage sludge in three soils of the Argentine pampas. Commun. Soil Sci. and Plant Anal. (Taylor & Francis, Inc., 325 Chestnut Street, Suite 800, Philadelphia, PA 19106) 34 (13-14): 2035-2043. ISSN (impresa): 0010-3624. ISSN (electronica): 1532-2416.
Determination of the Soil Organic Carbon (SOC) and Measurement of the Biodive...Shariful Islam
Soil organic carbon is one of the important elements and the major component of the soil. A complex biogeochemical cycle in the soil mostly dependent on the soil organic carbon (SOC). However, this experimental method measure the soil organic carbon in the Chandpai range, Sundarbans. The research has been found the soil organic carbon at very low portion in the study area and the different diversity index of different study plots of the forest. The sampling area contaminated with oil spill and affected by different human activities. Most of the studied focused on the different parameters of the forest soil such as soil pH, soil water holdings capacity, soil moisture etc. However, this study analyzes the soil to measure the soil organic carbon and calculate the biodiversity index in the Sundarbans
Feasibility of using a mixture of sewage sludge and incinerated sewage sludge...Silvana Torri
Como citar este trabajo:
Torri S. 2009. Feasibility of using a mixture of sewage sludge and incinerated sewage sludge as a soil amendment. In: Sludge: Types, Treatment Processes and Disposal. Editor: Richard E. Baily, Nova Science Publishers, Inc., Hauppauge, NY 11788. ISBN: 978-1-60741-842-9. pp. 187-208, 317p.
Soil carbon sequestration resulting from biosolids application, Silvana Torri
Como citar este trabajo
Torri S.I., Corrêa R.S., Renella G. 2014. Soil carbon sequestration resulting from biosolids application, Applied and Environmental Soil Science (ISSN: 1687-7667), Volume 2014 (2014), Article ID 821768, 9 pages. doi:10.1155/2014/821768.
Biosolids application to agricultural land: a contribution to global phosphor...Silvana Torri
Torri S.I., Corrêa R.S., Renella G. 2017. Biosolids application to agricultural land: a contribution to global phosphorus recycle, Pedosphere 27(1): 1–16, doi:10.1016/S1002-0160(15)60106-0, ISSN 1002-0160/CN 32-1315/P
The Changing of Soil Reaction and Exchangeable Aluminum on two Different Soil...Agriculture Journal IJOEAR
The objective of the experiment was to know the effect of Dolomite application on soil reaction and exchangeable Aluminum in two different soil orders. The method was experimental using Factorial Randomized Block Design, which consists of two Factors. The First factor were soil orders consist two levels, i.e. T1= Ultisols Kentrong, dan T2 = Inseptisols Jatinangor, while the second were dolomite dosages, consist four levels, i.e. dO = 0 ton ha-1 , d1 = 1 ton ha-1 , d2 = 2 ton ha-1 , d3 = 3 ton ha-1 , d4 = 4 ton ha-1 .The result of the experiment showed that on Ultisols Kentrong, dolomite applications significantly increased the value of soil reaction (pH) after two weeks incubation. The treatment of 3 ton/ha showed pH 4.73 or 8 % higher that control. Otherwise, the applications of dolomite also decreased the exchangeable Aluminum. The treatment of 3 ton/ha showed value 7.01 of exchangeable aluminum or 21 % lower than control. In Inceptisols Jatinangor, dolomite applications increased the value of soil reaction (pH) after two weeks incubation and the treatment of 3 tonha-1 showed pH 5.83 or 11 % higher than control. Otherwise, the application of dolomite decreased the exchangeable aluminum although were not significantly different for that parameters in this soil order. Based on statistical analysis, it proved that liming unable applied effectively on whole soil types or orders due to its relation with the level of soil acidity.
Physical fractionation techniques have often relied on the breakdown of soil structure into its textural classes or density fractions in order to study SOM dynamics. This appears to be inappropriate for investigating how soil structure is maintained. The bonding agents responsible for structure have been well defined, although the effects of farming systems on them are not fully understood. Techniques which can rapidly assess the impacts of management on bonding agents and structure are required in order to develop sustainable farming systems.
Mineralization of Carbon from Sewage sludge in three soils of the Argentine p...Silvana Torri
Como citar este trabajo
Torri S, Alvarez R, Lavado R. 2003. Mineralization of Carbon from Sewage sludge in three soils of the Argentine pampas. Commun. Soil Sci. and Plant Anal. (Taylor & Francis, Inc., 325 Chestnut Street, Suite 800, Philadelphia, PA 19106) 34 (13-14): 2035-2043. ISSN (impresa): 0010-3624. ISSN (electronica): 1532-2416.
Determination of the Soil Organic Carbon (SOC) and Measurement of the Biodive...Shariful Islam
Soil organic carbon is one of the important elements and the major component of the soil. A complex biogeochemical cycle in the soil mostly dependent on the soil organic carbon (SOC). However, this experimental method measure the soil organic carbon in the Chandpai range, Sundarbans. The research has been found the soil organic carbon at very low portion in the study area and the different diversity index of different study plots of the forest. The sampling area contaminated with oil spill and affected by different human activities. Most of the studied focused on the different parameters of the forest soil such as soil pH, soil water holdings capacity, soil moisture etc. However, this study analyzes the soil to measure the soil organic carbon and calculate the biodiversity index in the Sundarbans
Feasibility of using a mixture of sewage sludge and incinerated sewage sludge...Silvana Torri
Como citar este trabajo:
Torri S. 2009. Feasibility of using a mixture of sewage sludge and incinerated sewage sludge as a soil amendment. In: Sludge: Types, Treatment Processes and Disposal. Editor: Richard E. Baily, Nova Science Publishers, Inc., Hauppauge, NY 11788. ISBN: 978-1-60741-842-9. pp. 187-208, 317p.
Soil carbon sequestration resulting from biosolids application, Silvana Torri
Como citar este trabajo
Torri S.I., Corrêa R.S., Renella G. 2014. Soil carbon sequestration resulting from biosolids application, Applied and Environmental Soil Science (ISSN: 1687-7667), Volume 2014 (2014), Article ID 821768, 9 pages. doi:10.1155/2014/821768.
Biosolids application to agricultural land: a contribution to global phosphor...Silvana Torri
Torri S.I., Corrêa R.S., Renella G. 2017. Biosolids application to agricultural land: a contribution to global phosphorus recycle, Pedosphere 27(1): 1–16, doi:10.1016/S1002-0160(15)60106-0, ISSN 1002-0160/CN 32-1315/P
Plants response to high soil Zn availability. Feasibility of biotechnological...Silvana Torri
Como citar este trabajo
Torri S, Cabrera M, Torres- Duggan. 2013. Plants response to high soil Zn availability. Feasibility of biotechnological improvement. En: Biotechnologic Techniques of Stress in Plants, Editor: M. Miransari, Stadium Press LLC USA, ISBN : 1-62699-031-X, 101-118.
Quantification of annual soil greenhouse gas emissions under different land u...ILRI
Prepared by Sheila Wachiye , Lutz Merbold, Timo Vesala, Janne Rinne, Matti Räsänen and Petri Pellikka for the General Assembly 2019 of the European Geosciences Union (EGU), Vienna, Austria, 7–12 April 2019.
Fate of cadmium, copper, lead and zinc on soils after the application of dif...Silvana Torri
Como citar este trabajo
Torri S, Lavado R. 2009. Fate of cadmium, copper, lead and zinc on soils after the application of different treated sewage sludge in soils of the Pampas region. In: Sewage Treatment: Uses, Processes and Impact. Editors: Anna Stephens and Mark Fuller, Nova Science Publishers, Inc., Hauppauge, NY 11788. ISBN: 978-1-60692-959-9. 95-123. 394p.
ORGANIC MATTER AND ITS DECOMPOSITION.pptxVanangamudiK1
ORGANIC MATTER AND ITS DECOMPOSITION
Organic matter
Composition of organic residues
Organic matter classification
Decomposition of soil organic matter
C: N ratio
Role of organic matter
Factors affecting soil organic matter
Factors affecting organic matter decomposition
Distribution and mobility of lead and zinc atmospheric depositions in industr...INFOGAIN PUBLICATION
Heavy metal contamination is a severe environmental problem. Knowledge of the total heavy metals contents of soils is a necessary step for making an accurate appraisal and quantitative evaluation of the extent of contamination, indeed, wet and dry atmospheric deposits, plays an important role in the cycle of semi-volatile contaminants [1]. Metallurgical industries release heavy metals into the atmosphere, these last, clump together to form fines particles suspended in the air, these metals can be transported by wind via aerosol or aqueous pathway and deposited in the soil. The main aim of this work was to study the mobility and fate of lead and zinc from atmospheric deposits in contaminated soil from the foundry (ALFET) in industrial zone of Tiaret (Western Algeria) and to determine the effect of physicochemical parameters of the soil on their mobility in the topsoil. Physicochemical analysis of 35 soil samples have shown that zinc and lead levels contents in the surface layer soil (0-30 cm) vary depending on the pH, total limestone (CaCO3) and the soil water content. Results clearly show that soil texture and fine fraction (clay and sand) significantly influence mobility of Pb and Zn in soil.
Monitoring of Selected Heavy Metals Uptake by Plant around Fagbohun Dumpsite,...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
1. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
An easy incubation method for measuring nitrogen
mineralization from soils and organic residues
Teixeira T. ,Kokkonen A., Cordovil C.M.d.S. Instituto Superior de Agronomia, DQAA,
Contact: Prof. Claudia M.d.S. Cordovil, Instituto Superior de Agronomia, TU Lisbon, Dep. Environmental
Chemistry DQAA, Tapada da Ajuda, 1349-017 Lisboa, Portugal, +351 213653424, cms@isa.utl.pt
EXECUTIVE SUMMARY
The growth of the population in the last century, and the acknowledgment that the growth will continue, lead to various
problems. One of the problems is the need to produce enough food to the entire population, witch will lead to an
excessive use of the land, and to its impoverishment in nutrients and organic matter, soil physical conditions
degradation, increasing problems with plagues and diseases, and environmental pollution due to fertilizers applications,
among others (Cordovil, 2004). Other problem is the increasing amount of residues produced by the population. These
residues may be faced as a product that might help increase the soil value in organic matter, nutrients, water holding and
erosion resistance, and at the same time solving the problem of what to do with them.
Nitrogen (N) is an essential element to all organisms’ survival and growth, being present in essential compounds such
as proteins, nucleic acids and other molecules, and it’s a very large part of organic residues composition.
The application of organic residues to agricultural soils as a source of nitrogen (N) needs a better understanding of the
processes involving N organic compounds mineralization. A good prediction of the amounts of N mineralized from the
residues is an interesting issue, and also a valuable tool for the sustainable and rational use of these sources of nutrients
to plants growth, while preserving the environment.
Having all that into consideration, the objective of the present work is to know more about nitrogen mineralization, and
finding if it’s possible to predict its availability from organic residues applied to soil.
A quick and easy to perform waterlogged incubation experiment was developed, to investigate mineralization of
nitrogen compounds in several different soils, with and without application of different organic residues (poultry
manure and secondary pulp mill sludge). Soils tested were differed in texture, organic matter content as well as in pH. A
mild solubilising agent (H2O) was used to extract easily mineralizable N. After, the extraction suspensions were further
incubated at 37ºC for 10 days and sampled over this period. Mineral N (NH4-N and NO3-N) was determined in all the
soils tested. Both soils and soil – residues mixtures were analysed after 0, 2, 5 and 10 days.
N mineralization curve was well adjusted to polynomial equations and was better fitted for soil with secondary pulp
mill sludge mixture. The r-squared values of the polynomial trend lines fitted to the results of the experiment showed
good values. The less favourable results were obtained for soil with poultry manure, and this effect was particularly
visible in soils with lower sand content. When secondary pulp mill sludge was added to the soils, all r-squared values
were excellent.
The highest mineralization percentages were observed in soils with the highest organic matter (OM) contents, showing
the presence of significant amounts of easily mineralizable compounds. Soils that were poorer in OM, had a low
mineralization potential during the time of the experiment, as expected, due to the more recalcitrant nature of the
organic matter itself. The amounts of N mineralized from soil organic matter (SOM), were more related to OM content
of soils than to the texture itself. Sand and clay contents were poorly correlated to the N mineralization potential in all
the soils tested. The addition of organic residues to the soil enhanced the N mineralization potential as expected.
The correlation between the r-squared and the final amount of N, was only favourable for soil-secondary pulp mill
sludge mixture. It was also possible to encounter a correlation between the initial amount of N (Nkj) and the N
mineralization evolution, being the best result once again for soil-secondary pulp mill sludge mixture.
This simple incubation procedure was efficient, on the simulation of the release of the easily mineralisable organic N,
both from soil and residues. However, further studies are to be made, in order to understand the N mineralization from
this and other residues more deeply.
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 1
2. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
1 INTRODUCTION
Nitrogen (N) is an essential element to all organisms’ survival and growth, and it is present in essential compounds such
as proteins, nucleic acids and other molecules. N is a 79% part of our atmosphere but, despite that, for most organisms it
is only obtained from other sources. This means that molecular nitrogen in the atmosphere cannot be used directly by
either plants or animals, and needs to be converted into mineral nitrogen compounds, or "fixed," in order to be used by
living organisms. This means that plant and animal production depend mostly on the N pool in the soil and its
availability.
On the other hand, the increasing world population, is giving rise to the need for more food producing, in particular
vegetables and cereals, in quantity and quality enough to supply man’s needs. It is therefore necessary to supply more
and more nutrients to the soil in order to achieve the production levels required to reduce world hunger. Having this into
consideration is easy to understand that the intensive and somewhat indiscriminate growing use of commercial
fertilizers will not be environmentally sustainable. In fact, the excessive application of N, as mineral fertilizers, may
lead to many environmental problems such as nitrate pollution of water resources, amongst others.
• Air pollution as far as fertilizers are concerned, arises mostly from fertilizers industries that discharge SO2, N2O,
NOx and NH3 to the atmosphere. NOx air pollution contributes to acidifying nitrate deposition. Nitrate deposition
changes water and soil chemistry and can also results in excess nitrogen in ecosystems, which can cause changes in
vegetation, loss of biodiversity, and increased greenhouse gas emissions.
• Soil pollution has to do with the amount of fertilizer applied to soil as well as how it’s applied. Soil reaction can
change, the level of ions in soil solution can rise, and nutrient’s unbalance can take place.
• Water pollution is a very important problem because, as said earlier, nitrogen is present in soils as nitrate ion,
ammonium ion, and as a component of soil organic matter. In all soils, except in very wet or dry soils, the
ammonium form is readily converted into the nitrate form. This nitrate form is completely soluble and not tightly
held into soil particles. Therefore, nitrate can readily leach downward with percolating water and contaminate
groundwater supplies. Surface water can also be contaminated, trough surface runoff that can transport soil,
vegetation and even the fertilizer applied.
• Plant pollution is mainly caused by a luxury consumption of N by the plants. If an excessive amount of fertilizer is
applied, the plant, being able to support high levels of NO3-, will absorb it in excess, and accumulate it in their
tissues. Therefore, some vegetable products can present levels of N that can cause toxicity to the consumers.
Simultaneously, the intensification of agriculture, as well as the development of industry, has been leading to the
increasing production of organic residues such as manure, municipal solid waste, crop and forest waste, food industry
waste, among others (Sims, 1995).
These organic materials need to be recycled in order to prevent, or at least to minimize environmental damage. Their
application to agricultural land can be a good solution to organic residues recycling. They can be added to soils, not
only to increase organic matter content, thus improving the physical nature of the soil, but also to provide several plant
nutrients such as nitrogen. These materials are therefore, a good alternative to commercial fertilizers, but they must be
applied in high quantities, because their nutrients concentration is relatively low. This might become a problem, if the
residues are not produced in the same place where they’ll be applied, because it involves high transportation costs.
Another cost associated, is the need to treat the materials in order to remove all pathogens (Cordovil, 2004).
Despite these disadvantages, there are many environmental benefits in using these materials. The most obvious one,
after the cutback in the use of mineral fertilizers, is the enrichment of the soil in organic matter. Not less important, is
the increase of microbial activity, the decrease of erosion losses, because the residues will protect the soil, and they will
also improve soil physical characteristics (Costa 1999; Varennes, 2003).
The application of organic residues to agricultural soils as a source of nitrogen needs a better understanding of the
processes involving N organic compounds mineralization. A good prediction of the amounts of N mineralized from the
residues is an interesting issue, and also a valuable tool for the sustainable and rational use of these sources of nutrients
to plants growth, while preserving the environment. More than 90% of the nitrogen (N) in soils is bond in the form of
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 2
3. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
organic N compounds. Within the organic N in soils, the available N is considered to be a fraction of easily
mineralizable organic N that can be estimated based on the mineral N released during incubation of soil at an
appropriate temperature. However, incubation procedures are time consuming, and several chemical methods have been
developed as substitutes for incubations by several authors. Thus, the development of a rapid accurate and cost-effective
method for the prediction of N supply both from soil organic matter and the application of organic waste materials is of
great interest.
1.1 Research objectives
The nitrogen mineralization is not yet fully understood. Having in mind that N is one of the most important elements for
crops, it becomes of major importance to study its behaviour.
The growth of the population in the last century, and the acknowledgment that the growth will continue, lead to various
problems. One of the problems is the need to produce enough food to the entire population, witch will lead to a
excessive use of the land, and to its impoverishment in nutrients and organic matter, soil physical conditions
degradation, increasing problems with plagues and diseases, and environmental pollution due to fertilizers applications,
among others (Cordovil, 2004).
Other problem is the increasing amount of residues produced by the population. If we look at these residues as litter, the
problem increases along with the quantities, and the question becomes “what to do with them?”.
But we know that the organic residues are rich in organic matter and elements considered nutrients for plants, so they
may be faced as a products that might help increase the soil value in organic matter, nutrients, water holding and
erosion resistance, and at the same time solving the problem of these organic materials disposal.
The objective of the present work is therefore to know more about nitrogen mineralization, and finding if it’s possible to
predict by the use of a quick and easy method, its availability from organic residues applied to soil.
1.2 Organic Residues
The organic residues chosen for this experiment were:
• Secondary pulp mill sludge (S) – this material is very rich in biodegradable organic matter, an as there are little
alternatives for its improvement, the utilization as fertilizer, is an effective alternative that might resolve
several issues, both environmental and economical (Vasconcelos and Cabral, 1993). This material is mostly
water, biosolids and fibres. Presenting a high content in organic matter, they are rich in N, P and Mg (Cordovil,
2003; Costa, 1993). They have almost all the totality of the elements considered nutrients. The potentially toxic
elements, as metals, are present in these materials in quantities so low that problems are not to be expected as
long as the applications are not excessive (Costa, 1993).
• Poultry manure (PM) – this material is considered one of the best organic fertilizers, due to its low humidity
levels (Moore et al., 1998). Poultry manure contains large amounts of N, P, and K as well as secondary and
trace elements. In addition to providing nutrients for crop production, poultry manure applications build soil
organic reserves. The organic matter benefits crop production as it increases soil water-holding capacity, water
infiltration rates, cation exchange capacity, structural stability, and soil tilt (Moore et al. 1998).
2 METHODOLOGY
A quick and easy to perform waterlogged incubation experiment was developed by Kokkonen et al. (2006), to
investigate the evolution of mineralization of nitrogen compounds in several different soils. In this experiment, this
methodology was used in soils with and without application of two different organic residues (poultry manure and
secondary pulp mill sludge). Soils tested, differed in texture, organic matter content as well as in pH. A mild
solubilising agent (H2O) was used to extract easily mineralizable N.
2.1 Soil and residues
Fifteen different soils and two different residues were used in this experiment. Both soils and residues are representative
of the Portuguese soils and of Mediterranean climates, and of the animal and industrial activities related to the
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 3
4. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
agricultural practices in such region. The soils were collected in regions between the latitudes 37º05’N and 40º71’ N
and respective longitudes 8º06’ W and 7º89’ W. After the gathering of soil samples from 15 different locations in
Portugal with Mediterranean like climate, as referred above, these samples where dried and ground to pass through a 2
mm mesh. Soils were then submitted to a mechanical analysis, to determine the sand, loam and clay fractions, according
to Póvoas and Barral (1992) methodology. Some characteristics were also analysed, namely the pH and the organic
matter content. In table 1 we can see the results of the analysis.
TABLE 1 Characteristics of the soils used in the experiment, including particle size distribution.
Coarse Fine sand Silt Clay Organic
Soil Location pH
sand (%) (%) (%) (%) Matter (%)
1 Pegões 70 17.2 9.9 2.90 0.59 6.1
2 Viseu 9.10 14.9 56.4 19.60 1.65 8.5
3 Vila Viçosa 14.98 42.08 20.51 22.42 1.8 8.2
4 Mira Sintra 21.36 54.76 10.95 12.93 4.16 4.9
5 Bencatel 8.46 38.97 27.14 25.43 0.9 7.9
6 Escoural 1 18.29 49.43 20.25 12.03 3.42 5.8
7 Escoural 2 17.19 56.78 13.29 12.74 2.43 5.9
8 Albufeira 61.24 28.06 4.04 6.66 0.76 8.1
9 Alcácer 80.25 17.66 1.46 0.62 1.19 5.9
10 Pegões 2 56.65 29.45 8.15 5.75 2.25 7.3
11 Montemor 1 35.20 39.46 13.73 11.60 1.63 6.2
12 Reguengos 32.19 42.49 13.55 11.77 3.13 6.5
13 Montemor 2 37.09 41.88 12.78 8.26 1.89 5.5
14 Montemor 3 17.78 50.53 15.47 16.22 2.02 6.0
15 Montemor 4 31.07 40.04 13.65 14.73 1.95 5.0
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 4
5. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
The organic residues studied were also analysed, for some chemical characteristics as can be seen in Table 2.
TABLE 2 Characteristics of the residues used in the experiment.
Poultry Manure Secondary Pulp Mill Sludge
pH (H2O) 8.35 6.75
-1
Dry Matter (g kg ) 856.50 893.20
-1
Organic Matter (g kg ) 765.80 874.80
-1
Total organic C (g kg ) 444.20 507.40
-1
N Kjeldahl (g kg ) 40.13 33.59
-1
N-NH4 (g kg ) 10.48 1.03
N-NO3 (g kg-1) 0.36 0.41
C/N ratio 12.51 12.65
2.2 Development of incubation method
Samples of each one of the dry soils weighing 5 g were placed into 36 bottles, 12 were left with soil alone, 12 were
mixed with 0.085 g of poultry manure and the other 12 were mixed with 0.101g of secondary pulp mill sludge. The
amounts of organic residues added to each one of the soils, corresponded to applications of 170 kg N ha-1. To each one
of the bottles, an amount of 50 mL of distilled water was then added and the air inside was removed. All the bottles
were placed in a shaker for 1 hour, and immediately after the shaking, each suspension was incubated at 37 ºC. After,
the extraction suspensions were further incubated at 37ºC for 10 days and sampled over this period, for mineral N
content.
2.3 Determination of mineral nitrogen
Mineral N (NH4-N and NO3-N) was determined in all the soils tested. Both soils and soil – residues mixtures were
analysed. After 0 (T0), 2 (T1), 5 (T2) and 10 (T3) days, 3 bottles from each soil preparation were analyzed, by adding
3.72 g of KCl(s) to each one and taking them to shake for 1 hour. After shaking, the suspension was centrifuged for 10
minutes at a speed of 3500 rpm, and the supernatant was taken to N determination by segmented flow
spectrophotometry.
3 RESULTS AND DISCUSSION
Figure 1 shows the different amounts of N extracted from the 15 soils alone, in the different sampling times. During the
anaerobic incubation, the mineral N contents of soils raised by an average amount of 40%. Only soil 4, which had a
higher content of organic matter (Table 1), showed a decrease in mineral N present. This was probably the result of an
intense initial mineralization of the soil organic matter (SOM) that could have given raise to immobilization or to
denitrification, due to anaerobic conditions. Soil 6 and soil 8 showed a similar tendency. While in soil 6 this fact can be
hypothised by the presence of a high SOM content, in soil 8, no logical explanation is found for this result. Unless,
denitrification occurred, no immobilization phenomenon was expected, taking into consideration that the SOM content
of the soil was low and no exogenous organic matter was added to this soil treatment. This increases in soil mineral N,
represent variable mineralization of organic N from the SOM of each one of the soils tested. The percentage of N
mineralized from SOM of the soils ranged between 0.5 and 49.5% (data not shown). The highest mineralization
percentages were observed in soils with the highest OM contents, showing the presence of significant amounts of easily
mineralizable compounds. Soils that were poorer in OM, had a low mineralization potential during the time of the
experiment, as expected, due to the more recalcitrant nature of the organic matter itself. In figure 1, it’s clear that the
amounts of N mineralized from SOM, were more related to OM content of soils than to the texture itself. Sand and clay
contents were poorly correlated to the N mineralization potential in all the soils tested.
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 5
6. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
120 soil 1
soil 2
soil 3
100
soil 4
soil 5
80 soil 6
soil 7
mg Nmin/kg soil
soil 8
60
soil 9
soil 10
40 soil 11
soil 12
soil 13
20 soil 14
soil 15
0
0 2 4 6 8 10
-20
Time (days)
FIGURE 1 Amount of Nmin present in each soil at each sampling time (mg N min kg-1 soil).
350
300
soil 1
soil 2
250 soil 3
soil 4
soil 5
mg Nmin/kg soil
soil 6
200
soil 7
soil 8
soil 9
150
soil 10
soil 11
soil 12
100 soil 13
soil 14
soil 15
50
0
0 2 4 6 8 10
Time (days)
FIGURE 2 Amount of Nmin in the mixtures of each soil with poultry manure at each sampling time (mg N min kg-1
mixture).
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 6
7. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
The addition of organic residues to the soil enhanced the N mineralization potential as expected (Figures 2 and 3). In
general, for all the soils tested, between day 5 and day 10, there was an immobilization effect of the N released by
mineralization (Figure 2). In fact, the addition of poultry manure generally leads to high amounts of N mineralized in a
short period of time (Cordovil et al., 2005), due to the high contents in easily mineralizable organic compounds. On the
contrary, when the organic residue tested was pulp mill sludge, almost all the mixtures showed a lower potential for
mineralization (Figure 3). In fact, at the end of the incubation, the amounts of mineral N present in the mixtures was
approximately half the amounts presents when the residues tested was poultry manure. While the poultry manure
mineralized an average of 3.35 kg N ha-1, the pulp mill sludge mineralized only 1.74 kg N ha-1. This represented
respectively 1.97 and 1.02 % of the total Kjeldahl N applied as organic amendment.
200
150 soil 1
soil 2
soil 3
soil 4
soil 5
mg Nmin/kg soil
100 soil 6
soil 7
soil 8
soil 9
50 soil 10
soil 11
soil 12
soil 13
soil 14
0 soil 15
0 2 4 6 8 10
-50
Time (days)
FIGURE 3 Amount of Nmin in the mixtures of each soil with pulp mill sludge at each sampling time (mg N min kg-1
mixture).
Moreover, except on soil 4, all the mixtures of soil and pulp mill sludge, led to an increasing N mineralization
during the time of the incubation (Figure 3). Soil 4 showed a clear immobilization of N during the period of the
experiment.
In table 3 it is possible to see the R-squared values of the polynomial trend lines fitted to the results of the
experiment and showed good r-squared values. The presence of organic residues clearly weakens the fitting of
the data collected for N mineralization during the incubation period to polynomial trend lines. When only soil
was considered, there was no general trend line in SOM mineralization behaviour (Figure 1). On the other hand,
the presence of poultry manure revealed the potential for an initial flush in N mineralization, contrary to the pulp
mill sludge applied (Figures 2 and 3).
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 7
8. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
TABLE 3 Polynomial trend lines R-squared values
2
r
Soil Soil alone Soil + PM Soil + S
1 0,99 0,68 0,98
2 0,68 0,75 1,00
3 0,96 0,64 0,99
4 0,90 0,72 0,69
5 0,90 0,90 0,99
6 0,98 0,73 0,98
7 0,99 0,50 0,99
8 0,71 0,71 0,96
9 0,61 0,74 0,99
10 0,70 0,75 0,92
11 0,93 0,63 0,95
12 0,87 0,86 0,97
13 0,99 0,68 0,99
14 0,99 0,84 0,99
15 1,00 0,80 0,98
The less favourable results were obtained for soil with poultry manure, and this effect was particularly visible in soils
with lower sand content. When secondary pulp mill sludge was added to the soils, all r-squared values were excellent,
all above 0,9, with only one exception for soil 4. Also for soil alone the results were good, being once again the less
favourable ones for the less sandy soils. The best fitting of mineralization curves to the results obtained in incubation
experiments, was already reported to be applicable to soils with high contents of sand (Cordovil et al., 2005, 2007).
Heavier textures tend to give rise to different mineralization patterns.
The correlation between the N mineralization evolution and the initial amount of N (Nkj) reveals mild results for the
soil with poultry manure mixture (-0,33) and soil alone (0,31) and a better result for soil with secondary pulp mill
sludge mixture (-0,61). The correlation between the initial amount of N (Nkj) and the r-squared, reveals good results for
soil alone (0,49) and S (-0,56) and not so favourable for PM (-0,13). Correlating the r-squared and the final amount of
N, obtained after 10 days, only in the soil with secondary pulp mill sludge the result was very good (0,69), while the
other two mixtures revealed the worse results of all correlations (0,00 for soil and -0,04 for S).
4 CONCLUSIONS
N mineralization behaviour of the soils and mixtures was well adjusted to polynomial equations and was better fitted for
soil and secondary pulp mill sludge mixture. Initial N content of soils was also correlated to N mineralization patern.
This simple incubation procedure was efficient, on the simulation of the release of the easily mineralizable organic N,
both from soil and residues. However, a greater potential for N mineralization exists from both residues tested.
5 ACKNOWLEDGEMENTS (IF ANY)
The authors acknowledge Mrs Isabel Carvalho, and Mrs Madalena Simão for technical assistance.
REFERENCES
Cordovil CMdS 2004. Dinâmica do azoto na reciclagem de resíduos orgânicos aplicados ao solo. Instituto do Ambiente.
Lisboa. 56 p.
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 8
9. An easy incubation method for measuring nitrogen mineralization from soils and organic residues
Teixeira T. et al.
Cordovil CMdS 2003. Previsão da disponibilidade de azoto para as plantas a partir da mineralização de resíduos
orgânicos aplicados ao solo. Doutoramento em Engenharia Agronómica. Instituto Superior de Agronomia –
Universidade Técnica de Lisboa. Lisboa. 188 p.
Cordovil, CMdS, Coutinho J, Goss M, Cabral F 2005. Potentially mineralizable nitrogen from organic materials applied
to a sandy soil: fitting the one-pool exponential model. Soil Use Manage. 21, 65-72.
Cordovil C M d S, Coutinho J, Goss M J, Cabral F 2007. Comparison of chemical methods of assessing potentially
available organic nitrogen, from organic residues applied to a sandy soil. Commun. Soil Sci. Plant Anal. 38, 989-
1006
Kokkonen A, Esala M, Aura E 2006. Acceleration of N mineralization by release of enzymes and substrates from soil
mineral particles with phosphates. Soil Biol. Biochem. 38: 504-508.
Moore P A Jr, Daniel T C, Sharpley A N e Wood C W, 1998. Puoltry manure management. In: Agricultural uses of
municipal animal and industrial byproducts. USDA, Agriculture Research Service, Conservation Research
Report 44, pp 60-77.
Póvoas I e Barral M F 1992. Métodos de análise de solos. Comun. IICT Sér. Ciênc. Agrárias n10. 61 p.
Santos J Q 1995 Fertilização e poluição: Reciclagem agro-florestal de resíduos orgânicos. Author’s edition. Pp 70-83
Varennes A 2003. Macronutrientes no solo. In: Produtividade dos solos e ambiente. Escolar Editora. Lisboa. Cap 5. Pp.
157-177.
ORBIT2008 - 13 - 15th of Oct. 2008, Wageningen, The Netherlands. 9