In organic farming, where nutrient management is constrained and sustainability is claimed, bio-e... more In organic farming, where nutrient management is constrained and sustainability is claimed, bio-effectors pave their way. Considering selected bio-effectors, this study integrates metabolomics to agronomy in depicting induced relevant phenomena. Extracts of three agro-industrial wastes (Lemon processing residues, Fennel processing residues and Brewer’s spent grain) are being investigated as sources of bio-effectors for the third trial consequently. Corresponding individual and mixture aqueous extracts are assessed for their synergistic and/or single agronomic and qualitative performances on soil-grown tomato, compared to both a control and humic acid treatments. A metabolomic profiling of tomato fruits via the Proton Nuclear Magnetic Resonance (NMR) spectroscopy, as holistic indicator of fruit quality and extract-induced responses, complements crop productivity and organoleptic/nutritional qualitative analyses. Results are expected to show mainly an enhancement of the fruit qualitat...
In this research, rocket (Eruca vesicaria L. Cavalieri), a common edible plant species in the Med... more In this research, rocket (Eruca vesicaria L. Cavalieri), a common edible plant species in the Mediterranean regions, was used as bio-indicator to evaluate the effect of different organic amendments on Zn toxicity, absorption, and translocation. The main objectives of this study were to investigate the bioavailability of Zn in an artificially contaminated soil after the addition of compost, manure and chemical fertilizers at agronomically recommended doses and to evaluate their ability to reduce Zn concentration in the edible plant part. A greenhouse pots experiment was carried out using rocket plant grown on an artificially contaminated soil. In this study, the effect of compost, manure and chemical fertilizers on Zn fate in a soil-plant system was evaluated. At the end of the experiment main growth parameters and Zn content in plants were determined. In addition, Zn speciation in the soil was assessed using the original BCR sequential extraction and the DTPA extraction. The overall...
ABSTRACT Organic farming systems rely on soil fertility management to enhance the soil chemical p... more ABSTRACT Organic farming systems rely on soil fertility management to enhance the soil chemical properties for the optimization of crop production and increase food quality. Soil fertility-building crops have been reported as a way to reduce inputs of fertilizers, improve soil fertility and increase the subsequent crop yield. A four-year rotation programme was launched by the Mediterranean Agronomic Institute of Bari that aims at identifying the most suitable fertilization strategy in organic farming for Mediterranean countries under the prevailing conditions. The present study was conducted in southern Italy and it consists in evaluating the effects of pre-crops (faba bean, vetch and broccoli) in comparison to a fallow test on the subsequent crop (zucchini, tomato, lettuce and radish) in four consecutive years. Vetch and faba bean were able to satisfy the nutrient requirement of the main crop without any compost application; while commercial compost was applied to broccoli and fallow treatments prior to transplanting the main crop. The main soil chemical parameters: organic carbon, total nitrogen, available phosphorus, and exchangeable potassium were improved over four years experiment. The trend was consistent; all main chemical parameters displayed a significant increase in all treatments, while no significant differences were obtained between treatments. Based on the results obtained in the first two years, the effect of different pre-crops and fertilizers on zucchini and organic tomato qualitative and quantitative parameters were not significant. While the results obtained in the third and forth years showed that pre-crops and fertilizers had significant effects on lettuce and radish yield and quality. Low nitrate contents were found in fallow and broccoli treatments (70 to 80% lower) in comparison to Vetch and Faba bean treatments and the ascorbic acid contents were (20 to 40% higher) after broccoli and fallow treatments. The low nitrate content in broccoli and fallow treatment can be due to the compost application rich in humified organic matter. Humified organic matter breaks down very slowly in the soil releasing gradually nutrients. Whereas, the high amount of fresh organic matter incorporated with vetch and faba bean may break down quickly in comparison to compost, releasing a flush of nutrients for plant growth. Additionally, nutrient accumulation such as nitrate can lead in a decrease in the vitamin C content. These suggest that the pre-crops, especially vetch and faba bean, can improve main crop yields; while compost improves the quality parameters.
The main goal of organic farming is the “production of high quality products”. Integrity and vita... more The main goal of organic farming is the “production of high quality products”. Integrity and vital quality of products should be preserved along the entire production chain. In order to evaluate the effect of organic vs. conventional production systems on durum wheat phenolic acids and antioxidant activity open field experiment has been carried out. During the whole process chain from field to fork, there are various factors influencing the quality of the end product. Organic production should rely on genotypes with high nitrogen use efficiency, disease and pest resistance, weed competitiveness and tolerance especially under Mediterranean conditions. In this study, production systems differed according to the practices and inputs applied to manage the soil fertility and plant protection. In conventional system, synthetic fertilizers and pesticides were used. Whereas, in the two organic systems, cow manure with fertilizers and temporary intercropping with fava bean (Vicia faba) and f...
Journal of the science of food and agriculture, Jan 3, 2017
Biostimulants have gained recently an increased attention due to their multiple benefits for sust... more Biostimulants have gained recently an increased attention due to their multiple benefits for sustainable agriculture. In this study, three food processing by-products - fennel processing residues (FPR), lemon processing residues (LPR) and brewers' spent grain (BSG) - were investigated as potential sources of biostimulants. Their aqueous extracts as individual and associated applications were assessed for their effects on agronomic, quality and metabolic performances of organic tomato in comparison to humic substances extract (HS) and untreated control (CTRL). Only FPR extracts stimulated shoot growth and tomato dry matter content while all candidates improved tomato yield. FPR and BSG increased fruit mineral contents and BSG-FPR-LPR in combination enhanced the titratable acidity. FPR-treated fruits had also 20% more vitamin C than CTRL and higher phenols content was obtained in those of BSG-LPR. Fruit metabolomic profile showed the tendency of all extracts, except BSG-LPR, to in...
ABSTRACT Among several methods used to assess maturity of compost, determina-tion of diethyl ethe... more ABSTRACT Among several methods used to assess maturity of compost, determina-tion of diethyl ether and choloroform extractable lipids seems to be a promising tech-nique as lipids are an important portion of all organic wastes. The aim of this paper was to monitor maturity parameters of compost piles made from different organic sources (cow manure, poultry slaughterhouse, and dairy industry) using different methods. Di-ethyl ether (DEE) and chloroform (CHCl 3) extractable lipids have been measured during composting and compared to other parameters commonly utilized to study compost sta-bility and maturity (organic carbon, total and inorganic N, CO 2 evolution rate, microbial biomass C, and phytotoxicity test). Results suggested none of these parameters may exhaustively describe maturity of composts studied.
ABSTRACT Nickel is an ubiquitous trace element and occurs in soil, water, air and in the biospher... more ABSTRACT Nickel is an ubiquitous trace element and occurs in soil, water, air and in the biosphere. Ni is an essential element for several plants, microorganisms and vertebrates. Human requirement for Ni has not been conclusively demonstrated. Nickel is normally present in human tissues at low concentration and, under conditions of high exposure, these levels may increase significantly. Food is the major source of Ni exposure. Nickel is present in many food products, especially vegetables. The amount of Ni present in vegetables is increasing because of environmental contamination and cultural practices. It has been demonstrated that the consumption of a Ni-rich diet can cause an increase of immunological disorders including Systemic Ni Allergy Syndrome (SNAS). The SNAS patients are currently treated with a diet that is closely Ni-free. Therefore, there is a need to produce certified and guaranteed vegetables with a low Ni concentration in the market. The proposed research aims to develop new methods for vegetable production and innovative cultural practices through a suitable choice of agricultural soil, cultivar, amendments and fertilizers as well as good agricultural practices in order to reduce Ni plant uptake and its translocation to the edible plant parts and therefore to produce Ni-free food products for SNAS patients.
Regulation of organic farming allows the use of a limited range of fertilisers and soil amendment... more Regulation of organic farming allows the use of a limited range of fertilisers and soil amendments to meet nutritional needs of the plants. Before advocating alternative strategies for fertility management, performance should be evaluated. An open field experiment was conducted to study the effects of different fertilisation scenarios on tomato (Solanum lycopersicum Mill, cv. San Marzano) production and soil chemical properties. Fertilisation scenarios were based on combinations of amendments (composts and biochar) with organic and/or mineral fertilisers to balance plant nutrient requirements. Amendments were produced from agricultural and food-industry wastes available in the region. Most of the soil parameters did not vary by the end of experiment; only available phosphorus slightly increased in the treatments where organic fertilisers were applied. All treatments significantly increased yields over control and biochar alone. Different compost types showed promising results for to...
ABSTRACT The success of phytoremediation depends upon the identification of suitable plants speci... more ABSTRACT The success of phytoremediation depends upon the identification of suitable plants species that hyperaccumulate/tolerate heavy metals and produce large amounts of biomass. In this study, three endemic Mediterranean plant species Atriplex halimus, Medicago lupulina and Portulaca oleracea, were grown hydroponically to assess their potential use in phytoremediation of Ni, Pb and Zn and biomass production. The objective of this research is to improve phytoremediation procedures by searching for a new endemic Mediterranean plant species which can be used for phytoremediation of low/moderate contamination in the Mediterranean arid and semiarid conditions and bioenergy production. The hydroponics experiment was carried out in a growth chamber using half strength Hoagland's solution as control (CTR) and 5 concentrations for Pb and Zn (5, 10, 25, 50 and 100 mg L-1) and 3 concentrations for Ni (1, 2, and 5 mg L-1). Complete randomized design with five replications was adopted. Main growth parameters (shoot and root dry weight, shoot and root length and chlorophyll content) were determined. Shoots and roots were analyzed for their metals contents. Some interesting contributions of this research are: (i) plant metal uptake efficiency ranked as follows: A. halimus > M. lupulina > P. oleracea, whereas heavy metal toxicity ranked as follows: Ni > Zn > Pb, (ii) none of the plant species was identified as hyperaccumulator, (iii) Atriplex halimus and Medicago lupulina can accumulate Ni, Pb and Zn in their roots, (iv) translocate small fraction to their above ground biomass, and (v) indicate moderate pollution levels of the environment. In addition, as they are a good biomass producer, they can be used in phytostabilisation of marginal lands and their above ground biomass can be used for livestock feeding as well for bioenergy production.
Among several methods used to assess maturity of compost, determination of diethyl ether and chol... more Among several methods used to assess maturity of compost, determination of diethyl ether and choloroform extractable lipids seems to be a promising technique as lipids are an important portion of all organic wastes. The aim of this paper was to monitor maturity parameters of compost piles made from different organic sources (cow manure, poultry slaughterhouse, and dairy industry) using different methods. Diethyl ether (DEE) and chloroform (CHCl3) extractable lipids have been measured during composting and compared to other parameters commonly utilized to study compost stability and maturity (organic carbon, total and inorganic N, CO2 evolution rate, microbial biomass C, and phytotoxicity test). Results suggested none of these parameters may exhaustively describe maturity of composts studied.
Organic amendments, green manure and plant residues incorporation are the main sources of nutrien... more Organic amendments, green manure and plant residues incorporation are the main sources of nutrients in organic farming, their decomposition rate is crucial for the accumulation and long-term storage of organic matter in soils. In this study the decomposition of compost from olive mill waste (N: 29.3 g kg-1; total dissolved nitrogen or TDN: 3.82 g kg-1), goat manure (N: 31.5 g kg-1; TDN: 0.94 g kg-1), the shoots (N: 33.6 g kg-1; TDN: 17.57 g kg-1) and roots (N: 22.12 g kg-1; TDN: 8.87 g kg-1) of Medicago sativa was followed in three Lebanese soils. The nitrogen, phosphorus and potassium released were followed over one year, starting in early winter (December-January). The mild sub-humid Mediterranean conditions allowed a rapid mass loss in alfalfa shoots 30 days after incorporation. Manure and compost were more persistent. Between 80 and 90% of TDN were released, after 30 days of in-situ incubation for compost, the release was over 90% for alfalfa shoots. The movement of P was slower...
ABSTRACT Laser-induced breakdown spectroscopy (LIBS) is a fast and reliable technique suitable fo... more ABSTRACT Laser-induced breakdown spectroscopy (LIBS) is a fast and reliable technique suitable for the simultaneous qualitative and quantitative analysis of major and trace elements in samples of various nature and origin. In last decades, the use of metal accumulator plants, in combination with compost, has become a cheap and sustainable alternative technique to lower soil contamination by toxic heavy metals. In the present work, the LIBS technique has been applied to measure the concentrations of selected elements, including Al, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, Sr, and Zn, in two composts of different origin and nature and four accumulator plant species (Atriplex halimus, Brassica alba, Brassica napus, and Eruca vesicaria). The plant samples were analyzed either as bulk plant material or as specific organs (i.e. shoots and roots). The concentrations measured by LIBS were assessed by complementary induced coupled plasma-optical emission spectroscopy. The significant correlation found between the data obtained by the two techniques (R = 0.732–0.999) supports the feasibility of LIBS for fast screening of major, trace and toxic elements in plant and compost samples. In conclusion, the LIBS technique shows promising for further applications in soil remediation as well as in agriculture.
Agricultural practices, particularly land use, inputs and soil management, have a significant imp... more Agricultural practices, particularly land use, inputs and soil management, have a significant impact on the carbon cycle. Good management of agricultural practices may reduce carbon emissions and increase soil carbon sequestration. In this context, organic agricultural practices may have a positive role in mitigating environmental burden. Organic olive cultivation is increasing globally, particularly in Italy, which is ranked first worldwide for both organic olive production and cultivated area. The aim of the present study was to assess the effects of agricultural practices in organic and conventional olive systems on global warming potential (GWP) from a life cycle perspective and to identify the hot spots in each system. The impacts assessed were associated with the efficiency of both systems at sequestering soil in order to calculate the net carbon flux. There was a higher environmental impact on GWP in the organic system because of higher global greenhouse gas (GHG) emissions resulting from manure fertilisation rather than the synthetic foliar fertilisers used in the conventional system. However, manure was the main reason behind the higher soil organic carbon (SOC) content and soil carbon sequestration in the organic system. Fertilisation activity was the main contributor to carbon emissions, accounting for approximately 80% of total emissions in the organic system and 45% in the conventional system. Conversely, given the similarity of other factors (land use, residues management, soil cover) that may affect soil carbon content, manure was the primary contributor to increased SOC in the organic system, resulting in a higher efficiency of carbon sequestration in the soil following the addition of soil organic matter. The contribution of the manure to increased SOC compensated for the higher carbon emission from the organic system, resulting in higher negative net carbon flux in the organic versus the conventional system (–1.7 vs –0.52 t C ha –1 year –1 , respectively) and higher efficiency of CO 2 mitigation in the organic system.
In organic farming, where nutrient management is constrained and sustainability is claimed, bio-e... more In organic farming, where nutrient management is constrained and sustainability is claimed, bio-effectors pave their way. Considering selected bio-effectors, this study integrates metabolomics to agronomy in depicting induced relevant phenomena. Extracts of three agro-industrial wastes (Lemon processing residues, Fennel processing residues and Brewer’s spent grain) are being investigated as sources of bio-effectors for the third trial consequently. Corresponding individual and mixture aqueous extracts are assessed for their synergistic and/or single agronomic and qualitative performances on soil-grown tomato, compared to both a control and humic acid treatments. A metabolomic profiling of tomato fruits via the Proton Nuclear Magnetic Resonance (NMR) spectroscopy, as holistic indicator of fruit quality and extract-induced responses, complements crop productivity and organoleptic/nutritional qualitative analyses. Results are expected to show mainly an enhancement of the fruit qualitat...
In this research, rocket (Eruca vesicaria L. Cavalieri), a common edible plant species in the Med... more In this research, rocket (Eruca vesicaria L. Cavalieri), a common edible plant species in the Mediterranean regions, was used as bio-indicator to evaluate the effect of different organic amendments on Zn toxicity, absorption, and translocation. The main objectives of this study were to investigate the bioavailability of Zn in an artificially contaminated soil after the addition of compost, manure and chemical fertilizers at agronomically recommended doses and to evaluate their ability to reduce Zn concentration in the edible plant part. A greenhouse pots experiment was carried out using rocket plant grown on an artificially contaminated soil. In this study, the effect of compost, manure and chemical fertilizers on Zn fate in a soil-plant system was evaluated. At the end of the experiment main growth parameters and Zn content in plants were determined. In addition, Zn speciation in the soil was assessed using the original BCR sequential extraction and the DTPA extraction. The overall...
ABSTRACT Organic farming systems rely on soil fertility management to enhance the soil chemical p... more ABSTRACT Organic farming systems rely on soil fertility management to enhance the soil chemical properties for the optimization of crop production and increase food quality. Soil fertility-building crops have been reported as a way to reduce inputs of fertilizers, improve soil fertility and increase the subsequent crop yield. A four-year rotation programme was launched by the Mediterranean Agronomic Institute of Bari that aims at identifying the most suitable fertilization strategy in organic farming for Mediterranean countries under the prevailing conditions. The present study was conducted in southern Italy and it consists in evaluating the effects of pre-crops (faba bean, vetch and broccoli) in comparison to a fallow test on the subsequent crop (zucchini, tomato, lettuce and radish) in four consecutive years. Vetch and faba bean were able to satisfy the nutrient requirement of the main crop without any compost application; while commercial compost was applied to broccoli and fallow treatments prior to transplanting the main crop. The main soil chemical parameters: organic carbon, total nitrogen, available phosphorus, and exchangeable potassium were improved over four years experiment. The trend was consistent; all main chemical parameters displayed a significant increase in all treatments, while no significant differences were obtained between treatments. Based on the results obtained in the first two years, the effect of different pre-crops and fertilizers on zucchini and organic tomato qualitative and quantitative parameters were not significant. While the results obtained in the third and forth years showed that pre-crops and fertilizers had significant effects on lettuce and radish yield and quality. Low nitrate contents were found in fallow and broccoli treatments (70 to 80% lower) in comparison to Vetch and Faba bean treatments and the ascorbic acid contents were (20 to 40% higher) after broccoli and fallow treatments. The low nitrate content in broccoli and fallow treatment can be due to the compost application rich in humified organic matter. Humified organic matter breaks down very slowly in the soil releasing gradually nutrients. Whereas, the high amount of fresh organic matter incorporated with vetch and faba bean may break down quickly in comparison to compost, releasing a flush of nutrients for plant growth. Additionally, nutrient accumulation such as nitrate can lead in a decrease in the vitamin C content. These suggest that the pre-crops, especially vetch and faba bean, can improve main crop yields; while compost improves the quality parameters.
The main goal of organic farming is the “production of high quality products”. Integrity and vita... more The main goal of organic farming is the “production of high quality products”. Integrity and vital quality of products should be preserved along the entire production chain. In order to evaluate the effect of organic vs. conventional production systems on durum wheat phenolic acids and antioxidant activity open field experiment has been carried out. During the whole process chain from field to fork, there are various factors influencing the quality of the end product. Organic production should rely on genotypes with high nitrogen use efficiency, disease and pest resistance, weed competitiveness and tolerance especially under Mediterranean conditions. In this study, production systems differed according to the practices and inputs applied to manage the soil fertility and plant protection. In conventional system, synthetic fertilizers and pesticides were used. Whereas, in the two organic systems, cow manure with fertilizers and temporary intercropping with fava bean (Vicia faba) and f...
Journal of the science of food and agriculture, Jan 3, 2017
Biostimulants have gained recently an increased attention due to their multiple benefits for sust... more Biostimulants have gained recently an increased attention due to their multiple benefits for sustainable agriculture. In this study, three food processing by-products - fennel processing residues (FPR), lemon processing residues (LPR) and brewers' spent grain (BSG) - were investigated as potential sources of biostimulants. Their aqueous extracts as individual and associated applications were assessed for their effects on agronomic, quality and metabolic performances of organic tomato in comparison to humic substances extract (HS) and untreated control (CTRL). Only FPR extracts stimulated shoot growth and tomato dry matter content while all candidates improved tomato yield. FPR and BSG increased fruit mineral contents and BSG-FPR-LPR in combination enhanced the titratable acidity. FPR-treated fruits had also 20% more vitamin C than CTRL and higher phenols content was obtained in those of BSG-LPR. Fruit metabolomic profile showed the tendency of all extracts, except BSG-LPR, to in...
ABSTRACT Among several methods used to assess maturity of compost, determina-tion of diethyl ethe... more ABSTRACT Among several methods used to assess maturity of compost, determina-tion of diethyl ether and choloroform extractable lipids seems to be a promising tech-nique as lipids are an important portion of all organic wastes. The aim of this paper was to monitor maturity parameters of compost piles made from different organic sources (cow manure, poultry slaughterhouse, and dairy industry) using different methods. Di-ethyl ether (DEE) and chloroform (CHCl 3) extractable lipids have been measured during composting and compared to other parameters commonly utilized to study compost sta-bility and maturity (organic carbon, total and inorganic N, CO 2 evolution rate, microbial biomass C, and phytotoxicity test). Results suggested none of these parameters may exhaustively describe maturity of composts studied.
ABSTRACT Nickel is an ubiquitous trace element and occurs in soil, water, air and in the biospher... more ABSTRACT Nickel is an ubiquitous trace element and occurs in soil, water, air and in the biosphere. Ni is an essential element for several plants, microorganisms and vertebrates. Human requirement for Ni has not been conclusively demonstrated. Nickel is normally present in human tissues at low concentration and, under conditions of high exposure, these levels may increase significantly. Food is the major source of Ni exposure. Nickel is present in many food products, especially vegetables. The amount of Ni present in vegetables is increasing because of environmental contamination and cultural practices. It has been demonstrated that the consumption of a Ni-rich diet can cause an increase of immunological disorders including Systemic Ni Allergy Syndrome (SNAS). The SNAS patients are currently treated with a diet that is closely Ni-free. Therefore, there is a need to produce certified and guaranteed vegetables with a low Ni concentration in the market. The proposed research aims to develop new methods for vegetable production and innovative cultural practices through a suitable choice of agricultural soil, cultivar, amendments and fertilizers as well as good agricultural practices in order to reduce Ni plant uptake and its translocation to the edible plant parts and therefore to produce Ni-free food products for SNAS patients.
Regulation of organic farming allows the use of a limited range of fertilisers and soil amendment... more Regulation of organic farming allows the use of a limited range of fertilisers and soil amendments to meet nutritional needs of the plants. Before advocating alternative strategies for fertility management, performance should be evaluated. An open field experiment was conducted to study the effects of different fertilisation scenarios on tomato (Solanum lycopersicum Mill, cv. San Marzano) production and soil chemical properties. Fertilisation scenarios were based on combinations of amendments (composts and biochar) with organic and/or mineral fertilisers to balance plant nutrient requirements. Amendments were produced from agricultural and food-industry wastes available in the region. Most of the soil parameters did not vary by the end of experiment; only available phosphorus slightly increased in the treatments where organic fertilisers were applied. All treatments significantly increased yields over control and biochar alone. Different compost types showed promising results for to...
ABSTRACT The success of phytoremediation depends upon the identification of suitable plants speci... more ABSTRACT The success of phytoremediation depends upon the identification of suitable plants species that hyperaccumulate/tolerate heavy metals and produce large amounts of biomass. In this study, three endemic Mediterranean plant species Atriplex halimus, Medicago lupulina and Portulaca oleracea, were grown hydroponically to assess their potential use in phytoremediation of Ni, Pb and Zn and biomass production. The objective of this research is to improve phytoremediation procedures by searching for a new endemic Mediterranean plant species which can be used for phytoremediation of low/moderate contamination in the Mediterranean arid and semiarid conditions and bioenergy production. The hydroponics experiment was carried out in a growth chamber using half strength Hoagland's solution as control (CTR) and 5 concentrations for Pb and Zn (5, 10, 25, 50 and 100 mg L-1) and 3 concentrations for Ni (1, 2, and 5 mg L-1). Complete randomized design with five replications was adopted. Main growth parameters (shoot and root dry weight, shoot and root length and chlorophyll content) were determined. Shoots and roots were analyzed for their metals contents. Some interesting contributions of this research are: (i) plant metal uptake efficiency ranked as follows: A. halimus > M. lupulina > P. oleracea, whereas heavy metal toxicity ranked as follows: Ni > Zn > Pb, (ii) none of the plant species was identified as hyperaccumulator, (iii) Atriplex halimus and Medicago lupulina can accumulate Ni, Pb and Zn in their roots, (iv) translocate small fraction to their above ground biomass, and (v) indicate moderate pollution levels of the environment. In addition, as they are a good biomass producer, they can be used in phytostabilisation of marginal lands and their above ground biomass can be used for livestock feeding as well for bioenergy production.
Among several methods used to assess maturity of compost, determination of diethyl ether and chol... more Among several methods used to assess maturity of compost, determination of diethyl ether and choloroform extractable lipids seems to be a promising technique as lipids are an important portion of all organic wastes. The aim of this paper was to monitor maturity parameters of compost piles made from different organic sources (cow manure, poultry slaughterhouse, and dairy industry) using different methods. Diethyl ether (DEE) and chloroform (CHCl3) extractable lipids have been measured during composting and compared to other parameters commonly utilized to study compost stability and maturity (organic carbon, total and inorganic N, CO2 evolution rate, microbial biomass C, and phytotoxicity test). Results suggested none of these parameters may exhaustively describe maturity of composts studied.
Organic amendments, green manure and plant residues incorporation are the main sources of nutrien... more Organic amendments, green manure and plant residues incorporation are the main sources of nutrients in organic farming, their decomposition rate is crucial for the accumulation and long-term storage of organic matter in soils. In this study the decomposition of compost from olive mill waste (N: 29.3 g kg-1; total dissolved nitrogen or TDN: 3.82 g kg-1), goat manure (N: 31.5 g kg-1; TDN: 0.94 g kg-1), the shoots (N: 33.6 g kg-1; TDN: 17.57 g kg-1) and roots (N: 22.12 g kg-1; TDN: 8.87 g kg-1) of Medicago sativa was followed in three Lebanese soils. The nitrogen, phosphorus and potassium released were followed over one year, starting in early winter (December-January). The mild sub-humid Mediterranean conditions allowed a rapid mass loss in alfalfa shoots 30 days after incorporation. Manure and compost were more persistent. Between 80 and 90% of TDN were released, after 30 days of in-situ incubation for compost, the release was over 90% for alfalfa shoots. The movement of P was slower...
ABSTRACT Laser-induced breakdown spectroscopy (LIBS) is a fast and reliable technique suitable fo... more ABSTRACT Laser-induced breakdown spectroscopy (LIBS) is a fast and reliable technique suitable for the simultaneous qualitative and quantitative analysis of major and trace elements in samples of various nature and origin. In last decades, the use of metal accumulator plants, in combination with compost, has become a cheap and sustainable alternative technique to lower soil contamination by toxic heavy metals. In the present work, the LIBS technique has been applied to measure the concentrations of selected elements, including Al, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, Sr, and Zn, in two composts of different origin and nature and four accumulator plant species (Atriplex halimus, Brassica alba, Brassica napus, and Eruca vesicaria). The plant samples were analyzed either as bulk plant material or as specific organs (i.e. shoots and roots). The concentrations measured by LIBS were assessed by complementary induced coupled plasma-optical emission spectroscopy. The significant correlation found between the data obtained by the two techniques (R = 0.732–0.999) supports the feasibility of LIBS for fast screening of major, trace and toxic elements in plant and compost samples. In conclusion, the LIBS technique shows promising for further applications in soil remediation as well as in agriculture.
Agricultural practices, particularly land use, inputs and soil management, have a significant imp... more Agricultural practices, particularly land use, inputs and soil management, have a significant impact on the carbon cycle. Good management of agricultural practices may reduce carbon emissions and increase soil carbon sequestration. In this context, organic agricultural practices may have a positive role in mitigating environmental burden. Organic olive cultivation is increasing globally, particularly in Italy, which is ranked first worldwide for both organic olive production and cultivated area. The aim of the present study was to assess the effects of agricultural practices in organic and conventional olive systems on global warming potential (GWP) from a life cycle perspective and to identify the hot spots in each system. The impacts assessed were associated with the efficiency of both systems at sequestering soil in order to calculate the net carbon flux. There was a higher environmental impact on GWP in the organic system because of higher global greenhouse gas (GHG) emissions resulting from manure fertilisation rather than the synthetic foliar fertilisers used in the conventional system. However, manure was the main reason behind the higher soil organic carbon (SOC) content and soil carbon sequestration in the organic system. Fertilisation activity was the main contributor to carbon emissions, accounting for approximately 80% of total emissions in the organic system and 45% in the conventional system. Conversely, given the similarity of other factors (land use, residues management, soil cover) that may affect soil carbon content, manure was the primary contributor to increased SOC in the organic system, resulting in a higher efficiency of carbon sequestration in the soil following the addition of soil organic matter. The contribution of the manure to increased SOC compensated for the higher carbon emission from the organic system, resulting in higher negative net carbon flux in the organic versus the conventional system (–1.7 vs –0.52 t C ha –1 year –1 , respectively) and higher efficiency of CO 2 mitigation in the organic system.
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