Population growth and growing demand for livestock products produce large amounts of manure,which can be harnessed to maintain soil sustainability and crop productivity.However,the impacts of excessive manure applicat...Population growth and growing demand for livestock products produce large amounts of manure,which can be harnessed to maintain soil sustainability and crop productivity.However,the impacts of excessive manure application on crop yields,nitrogen(N)-cycling processes and microorganisms remain unknown.Here,we explored the effects of 20-year of excessive rates(18 and 27 Mg ha^(–1)yr^(–1))of pig manure application on peanut crop yields,soil nutrient contents,N-cycling processes and the abundance of N-cycling microorganisms in an acidic Ultisol in summer and winter,compared with none and a regular rate(9 Mg ha^(–1)yr^(–1))of pig manure application.Long-term excessive pig manure application,especially at the high-rate,significantly increased soil nutrient contents,the abundance of N-cycling functional genes,potential nitrification and denitrification activity,while it had a weaker effect on peanut yield and plant biomass.Compared with manure application,seasonality had a much weaker effect on N-cycling gene abundance.Random forest analysis showed that available phosphorus(AP)content was the primary predictor for N-cycling gene abundance,with significant and positive associations with all tested N-cycling genes.Our study clearly illustrated that excessive manure application would increase N-cycling gene abundance and potential N loss with relatively weak promotion of crop yields,providing significant implications for sustainable agriculture in the acidic Ultisols.展开更多
Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the ...Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system.展开更多
Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimul...Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimulate this degradation by different means. Thus, this study aimed to improve the bio-degradation of diesel and crude oil in a Ghanaian soil by biostimulation. For this, the sampled soil was characterized by standard methods and contaminated with diesel and crude oil at a proportion of 1% (w/w). Then, contaminated soil samples were supplemented with biochar-compost, poultry manure or cow dung at the proportion of 10% (w/w). Periodically, fractions of these samples were taken to evaluate the density of hydrocarbon utilizing bacteria (HUB) and the residual quantities of diesel or crude oil. The characteristics of the soil used show the need for supplementation for better degradation of hydrocarbons. The results of the study show that supplementing the soil with organic substrates increases HUB loads in soils contaminated by diesel and crude oil. They also show that the residual quantities of diesel and crude oil are generally significantly lower in supplemented soils (p = 0.048 and p < 0.0001 respectively). In addition, the study shows that degradation was generally greater in soils contaminated by diesel compared to those contaminated by crude oil, especially at the end of the study.展开更多
A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received se...A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received several treatments with various amendments for different periods ranging from 9 to 17 months. The amendments included annual ryegrass or Festulolium residues, powder limestone and various humate compounds alone or in combination with the grass residues. The results suggested a significant effect of ryegrass and Festulolium in reducing penetration resistance into the top 10 cm of the fragipan within 9 - 17 months, particularly when used in combination with certain humate materials such as Leonardite. Apparently, this is the result of the release of certain soluble organic compounds from the plant residues or the humate amendments that increase the solubility of Si and Al associated with the fragipan brittleness, thus decreasing the density of the compacted fragipan material.展开更多
Inversion tillage with straw amendment is widely applied in northeastern China, and it can substantially increase the storage of carbon and improve multiple subsoil functions. Soil microorganisms are believed to be th...Inversion tillage with straw amendment is widely applied in northeastern China, and it can substantially increase the storage of carbon and improve multiple subsoil functions. Soil microorganisms are believed to be the key to this process,but research into their role in subsoil amelioration is limited. Therefore, a field experiment was conducted in 2018 in a region in northeastern China with Hapli-Udic Cambisol using four treatments: conventional tillage(CT, tillage to a depth of 15 cm with no straw incorporation), straw incorporation with conventional tillage(SCT, tillage to a depth of 15 cm),inversion tillage(IT, tillage to a depth of 35 cm) and straw incorporation with inversion tillage(SIT, tillage to a depth of 35 cm). The soils were managed by inversion to a depth of 15 or 35 cm every year after harvest. The results indicated that SIT improved soil multi-nutrient cycling variables and increased the availability of key nutrients such as soil organic carbon, total nitrogen, available nitrogen, available phosphorus and available potassium in both the topsoil and subsoil.In contrast to CT and SCT, SIT created a looser microbial network structure but with highly centralized clusters by reducing the topological properties of average connectivity and node number, and by increasing the average path length and the modularity. A Random Forest analysis found that the average path length and the clustering coefficient were the main determinants of soil multi-nutrient cycling. These findings suggested that SIT can be an effective option for improving soil multi-nutrient cycling and the structure of microbial networks, and they provide crucial information about the microbial strategies that drive the decomposition of straw in Hapli-Udic Cambisol.展开更多
Restoration of mining soils is important to the vegetation and environment.This study aimed to explore the variations in soil nutrient contents,microbial abundance,and biomass under different gradients of substrate am...Restoration of mining soils is important to the vegetation and environment.This study aimed to explore the variations in soil nutrient contents,microbial abundance,and biomass under different gradients of substrate amendments in mining soils to select effective measures.Soil samples were collected from the Bayan Obo mining region in Inner Mongolia Autonomous Region,China.Contents of soil organic matter(SOM),available nitrogen(AN),available phosphorus(AP),available potassium(AK),microbial biomass carbon/microbial biomass nitrogen(MBC/MBN)ratio,biomass,and bacteria,fungi,and actinomycetes abundance were assessed in Agropyron cristatum L.Gaertn.,Elymus dahuricus Turcz.,and Medicago sativa L.soils with artificial zeolite(AZ)and microbial fertilizer(MF)applied at T0(0 g/kg),T1(5 g/kg),T2(10 g/kg),and T3(20 g/kg).Redundancy analysis(RDA)and technique for order preference by similarity to ideal solution(TOPSIS)were used to identify the main factors controlling the variation of biomass.Results showed that chemical indices and microbial content of restored soils were far greater than those of control.The application of AZ significantly increases SOM,AN,and AP by 20.27%,23.61%,and 40.43%,respectively.AZ significantly increased bacteria,fungi,and actinomycetes abundance by 0.63,3.12,and 1.93 times of control,respectively.RDA indicated that AN,MBC/MBN ratio,and SOM were dominant predictors for biomass across samples with AZ application,explaining 87.6%of the biomass variance.SOM,MBC/MBN ratio,and AK were dominant predictors with MF application,explaining 82.9%of the biomass variance.TOPSIS indicated that T2 was the best dosage and the three plant species could all be used to repair mining soils.AZ and MF application at T2 concentration in the mining soils with M.sativa was found to be the most appropriate measure.展开更多
Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial a...Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial and fungal communities,we established a field experiment in a region in Northeast China with Haplic Chernozems using four treatments:conventional tillage(CT,tillage to a depth of 15 cm with no straw incorporation),straw incorporation with conventional tillage(SCT,tillage to a depth of 15 cm),inversion tillage(IT,tillage to a depth of 35 cm)and straw incorporation with inversion tillage(SIT,tillage to a depth of 35 cm).The soils were managed by inversion to a depth of 15 or 35 cm after harvest.The results show that soil organic carbon content was significantly higher and pH and bulk density were significantly lower in the 15–35 cm layer in IT and SIT than CT and SCT.Fungal abundance was higher with straw incorporation,but fungal diversity was lower in the 0–15 cm layer in SCT and SIT than in CT and IT.Path length in the bacterial network was shorter and connectivity was higher in CT+SCT than in IT+SIT,leading to a more complex ecosystem,and the fungal network had opposite patterns.The key taxa in the phylum Actinobacteriota and Ascomycota in the microbial networks changed dramatically at the genus level following inversion tillage with straw amendment,which may increase bacterial network resistance to environmental disturbances and unstable fungal networks,resulting in large changes in the fungal community involved in the decomposition of recalcitrant straw-derived C and the more efficient acquisition of limiting resources.展开更多
Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core prio...Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).展开更多
The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural productio...The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural production systems as alternative to synthetic elemental fertilizers has potential application to improve crop yield and fruit quality. A randomized complete block design (RCBD) was established to investigate the impact of nine soil treatments on yield and quality of bell pepper, Capsicum annuum and eggplant, Solanum melongena. The nine soil treatments included: chitin CH, biochar Bio, sewage sludge SS, chicken manure CM, SS mixed with biochar (SSBio), SS mixed with CH (SSCH), CM mixed with biochar (CMBio), CM mixed with CH (CMCH), and unamended (UN) native soil used as control treatment. At maturity, fruits from each treatment, were counted, weighed, and classified according to the USDA grades to U.S. Fancy, U.S. No.1, U.S. No.2, and culls. Overall number and weight of green pepper fruits collected from plants grown in SSCH were significantly greater (26.2 and 3.14 kg 5 plants<sup>-1</sup>) compared to fruits of plants grown in unamended control treatment (17.1 and 1.98 kg 5 Plants<sup>-1</sup>, respectively). Whereas CH alone was superior in increasing the number and weight of eggplant fruits compared to the control treatment. Average weight and number of eggplant fruits of plants grown in soil amended with chitin (4.46 kg and 11.5, respectively) were significantly (P ≤ 0.05) greater than weight and number of fruits obtained from plants grown in other soil treatments. Results also revealed a positive correlation coefficient (r) and high probability of significance (P) between number of fruits and weight of fruits among the nine soil treatments. Utilization of animal manures in agricultural systems is an inexpensive means for limited-resource farmers looking for improvements in crop yield and quality at affordable costs.展开更多
Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil...Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil is not clear.In this project,the soil of newly built peach orchard in the Longquan Mountain of Chengdu was applied with 45 t/hm 2 of organic fertilizer.After 9 months of planting 6 varieties of honey peach(Wanhujing,Baifeng,Zhongtao 13,Huangjinmitao 1,Zhongpan 101,Zhongpan 104),the locally well developed peach orchard was taken as the control.The physical and chemical properties of soil from four topography(top slope,middle slope,lower slope and flat land)of newly built peach orchard were analyzed,and the effect of organic fertilizer on soil was evaluated.The results showed that combined application of organic fertilizer had different effects on soils from orchards with different varieties of peach and from different terrain parts of the same peach variety.Specifically,it had the best effect on soil improvement in Baifeng(local variety),Zhongpan 101 and Zhongpan 104(introduced varieties).Meanwhile,the best effect of soil improvement was found on top slope.Cluster analysis divided newly built peach orchards,uncultivated soil,and locally well developed peach orchard into four groups,indicating that the selected amount of organic fertilizer application in this study has improved the soil of peach orchards to some extent,but it was still necessary to increase the application amount.It was better for 54 t/hm 2 amount of organic fertilization on the part of top and middle slope,and 60 t/hm 2 on the lower slope and flat land.The comprehensive ecological benefit assessment of organic fertilizer should be conducted based on long-term monitoring of peach orchard ecological environment,fruit tree growth,fruit yield and quality,which would provide scientific basis for peach orchard production and management.展开更多
The objective of this work was to determine the suitability of poultry methacompost from the 2nd methanizer of the BRIN FOUNDATION in Yaokokoroko (Bondoukou, Côte d’Ivoire), to be used in the improvement of soil...The objective of this work was to determine the suitability of poultry methacompost from the 2nd methanizer of the BRIN FOUNDATION in Yaokokoroko (Bondoukou, Côte d’Ivoire), to be used in the improvement of soil fertility. The methacompost studied has a C/N ratio = 17.26, which could characterize a stable methacompost with high amending power. It also contains mineral elements Nitrogen (N) = 0.68% DM;Phosphorus (P) = 0.084% DM;Potassium (K) = 0.67% DM;Calcium (Ca) = 0.65% DM;Magnesium (Mg) = 0.15% DM. red in the standard relating to the organic amendments (NFU 44-051). The methacompost has fertilizing and amending properties and could not present any risk for vegetation and soils.展开更多
Definitions and features of eco-park and theme park were introduced as well as their differences, it was proposed that by applying cultural themes suited to regional ecological resources in the construction of eco-par...Definitions and features of eco-park and theme park were introduced as well as their differences, it was proposed that by applying cultural themes suited to regional ecological resources in the construction of eco-park, the eco-park could achieve not only desired ecological benefits, but also social and economic benefits, and the optimal comprehensive benefits. Design of Baiyunzhai Demonstration Eco-park was taken for an example, integration of eco-park and farming culture was confirmed as the nature, principles of "adaptation to actual conditions, amended protection and construction of plant system" proposed, three functional areas of "Colorful Forest Belt, Yiyun Health Maintenance Zone, Lakefront Meditation Zone" are given on the basis of actual terrains, planning highlights and desired landscape effects expounded to promote the value of regional cultures in Chongqing by building Baiyunzhai Eco-park.展开更多
Heavy metals in variable charge soil are highly bioavailable and easy to transfer into plants. Since it is impossible to completely eliminate rice planting on contaminated soils, some remediation and mitigation techni...Heavy metals in variable charge soil are highly bioavailable and easy to transfer into plants. Since it is impossible to completely eliminate rice planting on contaminated soils, some remediation and mitigation techniques are necessary to reduce metal bioavailability and uptake by rice. This pot experiment investigated the effects of seven amendments on the growth of rice and uptake of heavy metals from a paddy soil that was contaminated by copper and cadmium. The best results were from the application of limestone that increased grain yield by 12.5-16.5 fold, and decreased Cu and Cd concentrations in grain by 23.0%--50.4%. Application of calcium magnesium phosphate, calcium silicate, pig manure, and peat also increased the grain yield by 0.3-15.3 fold, and effectively decreased the Cu and Cd concentrations in grain. Cd concentration in grain was slightly reduced in the treatments of Chinese milk vetch and zinc sulfate. Concentrations of Cu and Cd in grain and straw were dependent on the available Cu and Cd in the soils, and soil available Cu and Cd were significantly affected by the soil pH.展开更多
Excessive use of agro-chemicals (such as mineral fertilizers) poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible and environmenta...Excessive use of agro-chemicals (such as mineral fertilizers) poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible and environmentally sound approaches to de- velop sustainable agriculture. This study investigated and evaluated the effects of mineral fertilizer reduction and partial substitution of organic amendment on soil fertility and heavy metal content in a 10-season continually planted vegetable field during 2009-2012. The experiment included four treatments: 100% chemical fertilizer (CF100), 80% chemical fertilizer (CF80), 60% chemical fertilizer and 20% organic fertilizer (CF60+OM20), and 40% chemical fertilizer and 40% organic fertilizer (CF40+OM40). Soil nutrients, enzyme activity and heavy metal content were determined. The results showed that single chemical fertilizer reduction (CF80) had no significant effect on soil organic matter content, soil catalase activity and soil heavy metal content, but slightly reduced soil available N, P, K, and soil urease activity, and significantly reduced soil acid phosphatase activity. Compared with CF100, 40 or 60% reduction of chemical fertilizer supplemented with organic fertilizer (CF60+OM20, CF40+OM40) significantly increased soil organic matter, soil catalase activity and urease activity especially in last several seasons, but reduced soil available P, K, and soil acid phosphatase activity. In addition, continu- ous application of organic fertilizer resulted in higher accumulation of Zn, Cd, and Cr in soil in the late stage of experiment, which may induce adverse effects on soil health and food safety.展开更多
The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with ...The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with residues of Posidonia oceanica (PoR), collected from Tunis beaches. The accumulation in beaches (as well as their removal) constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion: (a) C/N ratio 〈 15; (b) NH4^+-N 〈 400 mg/kg; (c) CO2-C 〈 2000 mg CO2-C/kg; (d) dehydrogenase activity 〈 1 mg TPF/g dry matter; (e) germination index (GI) 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N (13.0 g/kg), P (4.74 g/kg) and MgO (15.80 g/kg). Thus composting definitively constitutes the most optimal option to exploit these wastes.展开更多
Greenhouse vegetable production has been characterized by high agricultural inputs, high temperatures, and high cropping indexes. As an intensive form of agriculture, nutrient cycling induced by microbial activities i...Greenhouse vegetable production has been characterized by high agricultural inputs, high temperatures, and high cropping indexes. As an intensive form of agriculture, nutrient cycling induced by microbial activities in the greenhouses is relatively different from open fields in the same region. However, the responses of soil microbial biomass carbon (MBC) and nitrogen (MBN), enzyme activities, microbial community composition, and yield to organic amendment are not well understood. Therefore, a 5-year greenhouse tomato (Solanum lycopersicum Mill.)-cucumber (Cucumis sativus L.) rotation experiment was conducted. The field experiment comprised 5 treatments: 4/4CN (CN, nitrogen in chemical fertilizer), 3/4CN+1/4MN (MN, nitrogen in pig manure), 2/4CN+2/4MN, 2/4CN+1/4 MN+1/4 SN (SN, nitrogen in corn straw) and 2/4CN+2/4SN. The amounts of nitrogen (N), phosphorus (P2O5), and potassium (K2O) were equal in the five treatments. Starting with the fourth growing season, the optimal yield was obtained from soil treated with straw. MBC, MBN, phospholipid fatty acid (PLFA) profiles, and enzyme activities were significantly changed by 5 years of substitution with organic amendments. Redundancy analysis showed that MBC accounts for 89.5 and 52.3% of the total enzyme activity and total community variability, respectively. The activities of phosphomonoesterase, N-acetyl-glucosaminidase, and urease, and the relative abundances of fungi, actinomycetes, and Gram-negative bacteria were significantly and positively related to vegetable yields. Considering the effects of organic amendments on soil microbial characteristics and vegetable yield, 2/4CN+1/4MN+1/4SN can improve soil quality and maintain sustainable high yield in greenhouse vegetable production.展开更多
The application of straw and biochar is widely practiced for the improvement of soil fertility.However,its impact on microbial functional profiles,particularly with regard to paddy soils,is not well understood.The aim...The application of straw and biochar is widely practiced for the improvement of soil fertility.However,its impact on microbial functional profiles,particularly with regard to paddy soils,is not well understood.The aim of this study was to investigate the diversity of microbial carbon use patterns in paddy soils amended with straw or straw-derived biochar in a 3-year field experiment in fallow soil and at various development stages of a rice crop(i.e.,tillering and blooming).We applied the community level physiological profiling approach,with 15 substrates(sugars,carboxylic and amino acids,and phenolic acid).In general,straw application resulted in the greatest microbial functional diversity owing to the greater number of available C sources than in control or biochar plots.Biochar amendment promoted the use of α-ketoglutaric acid,the mineralization of which was higher than that of any other substrate.Principal component analyses indicated that microbial functional diversity in the biochar-amended soil was separated from those of the straw-amended and control soils.Redundancy analyses revealed that soil organic carbon content was the most important factor regulating the pattern of microbial carbon utilization.Rhizodeposition and nutrient uptake by rice plants modulated microbial functions in paddy soils and stimulated the microbial use of N-rich substances,such as amino acids.Thus,our results demonstrated that the functional diversity of microorganisms in organic amended paddy soils is affected by both physicochemical properties of amendment and plant growth stage.展开更多
An increase in atmospheric nitrogen (N) deposition can promote soil acidification, which may increase the release of ethylene (C2H4) under forest floors. Unfortunately, knowledge of whether increasing N deposition...An increase in atmospheric nitrogen (N) deposition can promote soil acidification, which may increase the release of ethylene (C2H4) under forest floors. Unfortunately, knowledge of whether increasing N deposition and C2H4 releases have synergistic effects on soil methane (CH4) uptake is limited and certainly deserves to be examined. We conducted some field measurements and laboratory experiments to examine this issue. The addition of (NH4)2SO4 or NH4Cl at a rate of 45 kg N ha-1 yr-1 reduced the soil CH4 uptake under a temperate old-growth forest in northeast China, and there were synergistic effects of N amendments in the presence of C2H4 concentrations equal to atmospheric CH4 concentration on the soil CH4 uptake, particularly in the NH4Cl-treated plots. Effective concentrations of added C2H4 on the soil CH4 uptake were smaller in NH+4 -treated plots than in KNO3-treated plots. The concentration of ca 0.3 μl C2H4 L-1 in the headspace gases reduced by 20% soil atmospheric CH4 uptake in the NH4Cl-treated plots, and this concentration was easily produced in temperate forest topsoils under short-term anoxic conditions. Together with short-term stimulating effects of N amendments and soil acidification on C2H4 production from forest soils, our observations suggest that knowledge of synergistic effects of NH+4 , rather than NO3- , amendments and C2H4 on the in situ soil CH4 uptake is critical for understanding the role of atmospheric N deposition and cycling of C2H4 under forest floors in reducing global atmospheric CH4 uptake by forests. Synergistic functions of NH4+ -N deposition and C2H4 release due to soil acidification in reducing atmospheric CH4 uptake by forests are discussed.展开更多
The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar,straw,and chemical fertilizers compared with chemical fertilization alone.Five soi...The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar,straw,and chemical fertilizers compared with chemical fertilization alone.Five soil fertilization treatments were evaluated:regular chemical fertilizers(RF),straw+regular chemical fertilizers(SRF),straw biochar+regular chemical fertilizers(SCRF),bamboo biochar(BC)+regular chemical fertilizers(BCRF),and straw biochar+70%regular chemical fertilizers(SC+70%RF).Their effects were investigated after approximately 1.5 years.The soil p H and cation exchange capacity(CEC)were significantly higher in biochar-treated soils.The soil phosphorous(P)and potassium(K)contents increased with biochar application.The soil Colwell P content was significantly increased with the addition of straw biochar in the treatments of SCRF and SC+70%RF.The oxygen(O):carbon(C)ratio doubled in BC picked from the soil.This indicated that BC underwent a significant oxidation process in the soil.The denaturing gradient gel electrophoresis(DGGE)fingerprints of microbial communities differed among the treatments.Soils with added biochar had higher Shannon diversity and species richness indices than soils without biochars.The results suggest that biochar can improve soil fertility.展开更多
基金supported by the National Natural Science Foundation of China(41930756 and 42077041)。
文摘Population growth and growing demand for livestock products produce large amounts of manure,which can be harnessed to maintain soil sustainability and crop productivity.However,the impacts of excessive manure application on crop yields,nitrogen(N)-cycling processes and microorganisms remain unknown.Here,we explored the effects of 20-year of excessive rates(18 and 27 Mg ha^(–1)yr^(–1))of pig manure application on peanut crop yields,soil nutrient contents,N-cycling processes and the abundance of N-cycling microorganisms in an acidic Ultisol in summer and winter,compared with none and a regular rate(9 Mg ha^(–1)yr^(–1))of pig manure application.Long-term excessive pig manure application,especially at the high-rate,significantly increased soil nutrient contents,the abundance of N-cycling functional genes,potential nitrification and denitrification activity,while it had a weaker effect on peanut yield and plant biomass.Compared with manure application,seasonality had a much weaker effect on N-cycling gene abundance.Random forest analysis showed that available phosphorus(AP)content was the primary predictor for N-cycling gene abundance,with significant and positive associations with all tested N-cycling genes.Our study clearly illustrated that excessive manure application would increase N-cycling gene abundance and potential N loss with relatively weak promotion of crop yields,providing significant implications for sustainable agriculture in the acidic Ultisols.
文摘Ploughing and fertilization practices in rice-wheat system have deteriorated the soil carbon (C) pools. Conservation agriculture (CA) based management approaches have proven to enhance C sequestration and reverse the loss of soil-organic-carbon (SOC), which further enhances soil fertility. Different fractions of SOC pools react to the alterations in management practices and indicate changes in SOC dynamics as compared to total C in the soil. Higher SOC levels in soil have been observed in case of reduced/no-till (NT) practices than conventional tillage (CT). However, between CT and zero tillage/NT, total SOC stocks diminished with an increase in soil depth, which demonstrated that the benefits of SOC are more pronounced in the topsoil under NT. Soil aggregation provides physical protection to C associated with different-sized particles, thus, the improvement in soil aggregation through CA is an effective way to mitigate soil C loss. Along with less soil disturbance, residual management, suitable crop rotation, rational application of manures and fertilizers, and integrated nutrient management have been found to be effective in not only improving soil C stock but also enhancing the soil health and productivity. Thus, CA can be considered as a potential method in the build-up of SOC of soil in rice-wheat system.
文摘Soil contamination by hydrocarbons poses numerous environmental, health and agricultural problems. The degradation of these pollutants can occur naturally but very slowly. It is therefore generally necessary to stimulate this degradation by different means. Thus, this study aimed to improve the bio-degradation of diesel and crude oil in a Ghanaian soil by biostimulation. For this, the sampled soil was characterized by standard methods and contaminated with diesel and crude oil at a proportion of 1% (w/w). Then, contaminated soil samples were supplemented with biochar-compost, poultry manure or cow dung at the proportion of 10% (w/w). Periodically, fractions of these samples were taken to evaluate the density of hydrocarbon utilizing bacteria (HUB) and the residual quantities of diesel or crude oil. The characteristics of the soil used show the need for supplementation for better degradation of hydrocarbons. The results of the study show that supplementing the soil with organic substrates increases HUB loads in soils contaminated by diesel and crude oil. They also show that the residual quantities of diesel and crude oil are generally significantly lower in supplemented soils (p = 0.048 and p < 0.0001 respectively). In addition, the study shows that degradation was generally greater in soils contaminated by diesel compared to those contaminated by crude oil, especially at the end of the study.
文摘A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received several treatments with various amendments for different periods ranging from 9 to 17 months. The amendments included annual ryegrass or Festulolium residues, powder limestone and various humate compounds alone or in combination with the grass residues. The results suggested a significant effect of ryegrass and Festulolium in reducing penetration resistance into the top 10 cm of the fragipan within 9 - 17 months, particularly when used in combination with certain humate materials such as Leonardite. Apparently, this is the result of the release of certain soluble organic compounds from the plant residues or the humate amendments that increase the solubility of Si and Al associated with the fragipan brittleness, thus decreasing the density of the compacted fragipan material.
基金funded by the National Key Research and Development Program of China (2022YFD1500100)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA28070100)+1 种基金the National Natural Science Foundation of China (41807085)the earmarked fund for China Agriculture Research System (CARS04)。
文摘Inversion tillage with straw amendment is widely applied in northeastern China, and it can substantially increase the storage of carbon and improve multiple subsoil functions. Soil microorganisms are believed to be the key to this process,but research into their role in subsoil amelioration is limited. Therefore, a field experiment was conducted in 2018 in a region in northeastern China with Hapli-Udic Cambisol using four treatments: conventional tillage(CT, tillage to a depth of 15 cm with no straw incorporation), straw incorporation with conventional tillage(SCT, tillage to a depth of 15 cm),inversion tillage(IT, tillage to a depth of 35 cm) and straw incorporation with inversion tillage(SIT, tillage to a depth of 35 cm). The soils were managed by inversion to a depth of 15 or 35 cm every year after harvest. The results indicated that SIT improved soil multi-nutrient cycling variables and increased the availability of key nutrients such as soil organic carbon, total nitrogen, available nitrogen, available phosphorus and available potassium in both the topsoil and subsoil.In contrast to CT and SCT, SIT created a looser microbial network structure but with highly centralized clusters by reducing the topological properties of average connectivity and node number, and by increasing the average path length and the modularity. A Random Forest analysis found that the average path length and the clustering coefficient were the main determinants of soil multi-nutrient cycling. These findings suggested that SIT can be an effective option for improving soil multi-nutrient cycling and the structure of microbial networks, and they provide crucial information about the microbial strategies that drive the decomposition of straw in Hapli-Udic Cambisol.
基金supported by the Beijing Forestry University(BJFU),China。
文摘Restoration of mining soils is important to the vegetation and environment.This study aimed to explore the variations in soil nutrient contents,microbial abundance,and biomass under different gradients of substrate amendments in mining soils to select effective measures.Soil samples were collected from the Bayan Obo mining region in Inner Mongolia Autonomous Region,China.Contents of soil organic matter(SOM),available nitrogen(AN),available phosphorus(AP),available potassium(AK),microbial biomass carbon/microbial biomass nitrogen(MBC/MBN)ratio,biomass,and bacteria,fungi,and actinomycetes abundance were assessed in Agropyron cristatum L.Gaertn.,Elymus dahuricus Turcz.,and Medicago sativa L.soils with artificial zeolite(AZ)and microbial fertilizer(MF)applied at T0(0 g/kg),T1(5 g/kg),T2(10 g/kg),and T3(20 g/kg).Redundancy analysis(RDA)and technique for order preference by similarity to ideal solution(TOPSIS)were used to identify the main factors controlling the variation of biomass.Results showed that chemical indices and microbial content of restored soils were far greater than those of control.The application of AZ significantly increases SOM,AN,and AP by 20.27%,23.61%,and 40.43%,respectively.AZ significantly increased bacteria,fungi,and actinomycetes abundance by 0.63,3.12,and 1.93 times of control,respectively.RDA indicated that AN,MBC/MBN ratio,and SOM were dominant predictors for biomass across samples with AZ application,explaining 87.6%of the biomass variance.SOM,MBC/MBN ratio,and AK were dominant predictors with MF application,explaining 82.9%of the biomass variance.TOPSIS indicated that T2 was the best dosage and the three plant species could all be used to repair mining soils.AZ and MF application at T2 concentration in the mining soils with M.sativa was found to be the most appropriate measure.
基金Under the auspices of Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28070100)the National Key Research and Development Program of China(No.2022YFD1500100)+1 种基金the National Natural Science Foundation of China(No.41807085)the Earmarked Fund for China Agriculture Research System(No.CARS04)。
文摘Straw is widely incorporated into soil worldwide,but most studies have concentrated on the effects of straw mulching or incorporation with topsoil.To determine the effect of depth of straw incorporation on bacterial and fungal communities,we established a field experiment in a region in Northeast China with Haplic Chernozems using four treatments:conventional tillage(CT,tillage to a depth of 15 cm with no straw incorporation),straw incorporation with conventional tillage(SCT,tillage to a depth of 15 cm),inversion tillage(IT,tillage to a depth of 35 cm)and straw incorporation with inversion tillage(SIT,tillage to a depth of 35 cm).The soils were managed by inversion to a depth of 15 or 35 cm after harvest.The results show that soil organic carbon content was significantly higher and pH and bulk density were significantly lower in the 15–35 cm layer in IT and SIT than CT and SCT.Fungal abundance was higher with straw incorporation,but fungal diversity was lower in the 0–15 cm layer in SCT and SIT than in CT and IT.Path length in the bacterial network was shorter and connectivity was higher in CT+SCT than in IT+SIT,leading to a more complex ecosystem,and the fungal network had opposite patterns.The key taxa in the phylum Actinobacteriota and Ascomycota in the microbial networks changed dramatically at the genus level following inversion tillage with straw amendment,which may increase bacterial network resistance to environmental disturbances and unstable fungal networks,resulting in large changes in the fungal community involved in the decomposition of recalcitrant straw-derived C and the more efficient acquisition of limiting resources.
基金funded by Abdulaziz City for Science and Technology,Saudi Arabia(Grant Research No.1-17-04-001-0021).
文摘Water insufficiency is the hampering feature of crop sustainability,especially in arid and semi-arid regions.So,the effectual usage of all water resources especially underground brackish water represents the core priority in Saudi Arabia.The present study aimed to recognize the influence of different types of water irrigation(tap water as a control,salinized well water,and magnetized salinized well water)with or without soil amendments(soil without any amendment as a control,peat-moss,ferrous sulfate,and peat-moss plus ferrous sulfate)on petunia plant growth and flowering as well as ion content.Irrigating Petunia plants with saline well water adversely affected growth and flowering as compared to tap water and magnetized saline well water.Additionally,plants irrigated with magnetized water showed a significant enhancement in all the studied vegetative and flowering growth parameters as compared to those irrigated with salinized well water.Furthermore,mineral contents and survival of Petunia plants irrigated with magnetized well water were higher than those irrigated with tap water.Irrigation with magnetized well water significantly reduced levels of Na+and Cl−ions in leaves of Petunia plants indicating the role of magnetization in alleviating harmful effects of salinity.In conclusion,we recommend the utilization of magnetized saline well water for irrigating Petunia plants either alone or in combination with soil amendments(peat moss plus ferrous sulfate).
文摘The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural production systems as alternative to synthetic elemental fertilizers has potential application to improve crop yield and fruit quality. A randomized complete block design (RCBD) was established to investigate the impact of nine soil treatments on yield and quality of bell pepper, Capsicum annuum and eggplant, Solanum melongena. The nine soil treatments included: chitin CH, biochar Bio, sewage sludge SS, chicken manure CM, SS mixed with biochar (SSBio), SS mixed with CH (SSCH), CM mixed with biochar (CMBio), CM mixed with CH (CMCH), and unamended (UN) native soil used as control treatment. At maturity, fruits from each treatment, were counted, weighed, and classified according to the USDA grades to U.S. Fancy, U.S. No.1, U.S. No.2, and culls. Overall number and weight of green pepper fruits collected from plants grown in SSCH were significantly greater (26.2 and 3.14 kg 5 plants<sup>-1</sup>) compared to fruits of plants grown in unamended control treatment (17.1 and 1.98 kg 5 Plants<sup>-1</sup>, respectively). Whereas CH alone was superior in increasing the number and weight of eggplant fruits compared to the control treatment. Average weight and number of eggplant fruits of plants grown in soil amended with chitin (4.46 kg and 11.5, respectively) were significantly (P ≤ 0.05) greater than weight and number of fruits obtained from plants grown in other soil treatments. Results also revealed a positive correlation coefficient (r) and high probability of significance (P) between number of fruits and weight of fruits among the nine soil treatments. Utilization of animal manures in agricultural systems is an inexpensive means for limited-resource farmers looking for improvements in crop yield and quality at affordable costs.
基金Supported by the Research Project of China Railway 23 rd Bureau Group Co.,Ltd.(LQST-03-GCB-2022-02)the National Natural Science Foundation of China(42277245).
文摘Combined application of organic fertilizer is an effective measure to improve the productivity and ecological effect of newly added soil.However,the effect of organic fertilizer application in newly added orchard soil is not clear.In this project,the soil of newly built peach orchard in the Longquan Mountain of Chengdu was applied with 45 t/hm 2 of organic fertilizer.After 9 months of planting 6 varieties of honey peach(Wanhujing,Baifeng,Zhongtao 13,Huangjinmitao 1,Zhongpan 101,Zhongpan 104),the locally well developed peach orchard was taken as the control.The physical and chemical properties of soil from four topography(top slope,middle slope,lower slope and flat land)of newly built peach orchard were analyzed,and the effect of organic fertilizer on soil was evaluated.The results showed that combined application of organic fertilizer had different effects on soils from orchards with different varieties of peach and from different terrain parts of the same peach variety.Specifically,it had the best effect on soil improvement in Baifeng(local variety),Zhongpan 101 and Zhongpan 104(introduced varieties).Meanwhile,the best effect of soil improvement was found on top slope.Cluster analysis divided newly built peach orchards,uncultivated soil,and locally well developed peach orchard into four groups,indicating that the selected amount of organic fertilizer application in this study has improved the soil of peach orchards to some extent,but it was still necessary to increase the application amount.It was better for 54 t/hm 2 amount of organic fertilization on the part of top and middle slope,and 60 t/hm 2 on the lower slope and flat land.The comprehensive ecological benefit assessment of organic fertilizer should be conducted based on long-term monitoring of peach orchard ecological environment,fruit tree growth,fruit yield and quality,which would provide scientific basis for peach orchard production and management.
文摘The objective of this work was to determine the suitability of poultry methacompost from the 2nd methanizer of the BRIN FOUNDATION in Yaokokoroko (Bondoukou, Côte d’Ivoire), to be used in the improvement of soil fertility. The methacompost studied has a C/N ratio = 17.26, which could characterize a stable methacompost with high amending power. It also contains mineral elements Nitrogen (N) = 0.68% DM;Phosphorus (P) = 0.084% DM;Potassium (K) = 0.67% DM;Calcium (Ca) = 0.65% DM;Magnesium (Mg) = 0.15% DM. red in the standard relating to the organic amendments (NFU 44-051). The methacompost has fertilizing and amending properties and could not present any risk for vegetation and soils.
文摘Definitions and features of eco-park and theme park were introduced as well as their differences, it was proposed that by applying cultural themes suited to regional ecological resources in the construction of eco-park, the eco-park could achieve not only desired ecological benefits, but also social and economic benefits, and the optimal comprehensive benefits. Design of Baiyunzhai Demonstration Eco-park was taken for an example, integration of eco-park and farming culture was confirmed as the nature, principles of "adaptation to actual conditions, amended protection and construction of plant system" proposed, three functional areas of "Colorful Forest Belt, Yiyun Health Maintenance Zone, Lakefront Meditation Zone" are given on the basis of actual terrains, planning highlights and desired landscape effects expounded to promote the value of regional cultures in Chongqing by building Baiyunzhai Eco-park.
文摘Heavy metals in variable charge soil are highly bioavailable and easy to transfer into plants. Since it is impossible to completely eliminate rice planting on contaminated soils, some remediation and mitigation techniques are necessary to reduce metal bioavailability and uptake by rice. This pot experiment investigated the effects of seven amendments on the growth of rice and uptake of heavy metals from a paddy soil that was contaminated by copper and cadmium. The best results were from the application of limestone that increased grain yield by 12.5-16.5 fold, and decreased Cu and Cd concentrations in grain by 23.0%--50.4%. Application of calcium magnesium phosphate, calcium silicate, pig manure, and peat also increased the grain yield by 0.3-15.3 fold, and effectively decreased the Cu and Cd concentrations in grain. Cd concentration in grain was slightly reduced in the treatments of Chinese milk vetch and zinc sulfate. Concentrations of Cu and Cd in grain and straw were dependent on the available Cu and Cd in the soils, and soil available Cu and Cd were significantly affected by the soil pH.
基金financially supported by grants of the Key Projects in the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD14B00)the Guangdong Provincial Science and Technology Plan Key Project,China(2012A020100003,2015A050502043)
文摘Excessive use of agro-chemicals (such as mineral fertilizers) poses potential risks to soil quality. Application of organic amendments and reduction of inorganic fertilizer are economically feasible and environmentally sound approaches to de- velop sustainable agriculture. This study investigated and evaluated the effects of mineral fertilizer reduction and partial substitution of organic amendment on soil fertility and heavy metal content in a 10-season continually planted vegetable field during 2009-2012. The experiment included four treatments: 100% chemical fertilizer (CF100), 80% chemical fertilizer (CF80), 60% chemical fertilizer and 20% organic fertilizer (CF60+OM20), and 40% chemical fertilizer and 40% organic fertilizer (CF40+OM40). Soil nutrients, enzyme activity and heavy metal content were determined. The results showed that single chemical fertilizer reduction (CF80) had no significant effect on soil organic matter content, soil catalase activity and soil heavy metal content, but slightly reduced soil available N, P, K, and soil urease activity, and significantly reduced soil acid phosphatase activity. Compared with CF100, 40 or 60% reduction of chemical fertilizer supplemented with organic fertilizer (CF60+OM20, CF40+OM40) significantly increased soil organic matter, soil catalase activity and urease activity especially in last several seasons, but reduced soil available P, K, and soil acid phosphatase activity. In addition, continu- ous application of organic fertilizer resulted in higher accumulation of Zn, Cd, and Cr in soil in the late stage of experiment, which may induce adverse effects on soil health and food safety.
基金The study is part of the 1999–2002 research program "Municipal solid waste treatment and compost agriculture application" which is supported jointly by the Tunisian Secretariat of Scientific Research and Technology
文摘The aim of this study was to characterize the biological stability and maturity degree of compost during a controlled pile-composting trial of mixed vegetable residues (VR) collected from markets of Tunis City with residues of Posidonia oceanica (PoR), collected from Tunis beaches. The accumulation in beaches (as well as their removal) constitutes a serious environmental problem in all Mediterranean countries particularly in Tunisia. Aerobic-thermophilic composting is the most reasonable way to profit highly-valuable content of organic matter in these wastes for agricultural purposes. The physical, chemical, and biological parameters were monitored during composting over 150 d. The most appropriate parameters were selected to establish the maturity degree. The main result of this research was the deduction of the following maturity criterion: (a) C/N ratio 〈 15; (b) NH4^+-N 〈 400 mg/kg; (c) CO2-C 〈 2000 mg CO2-C/kg; (d) dehydrogenase activity 〈 1 mg TPF/g dry matter; (e) germination index (GI) 〉 80%. These five parameters, considered jointly are indicative of a high maturity degree and thus of a high-quality organic amendment which employed in a rational way, may improve soil fertility and soil quality. The mature compost was relatively rich in N (13.0 g/kg), P (4.74 g/kg) and MgO (15.80 g/kg). Thus composting definitively constitutes the most optimal option to exploit these wastes.
基金supported by the National Key Research and Development Program of China (2016YFD0201001)the earmarked fund for China Agriculture Research System (CARS-23-B02)the Key Research and Development Program of Shandong Province,China (2017CXGC0206)
文摘Greenhouse vegetable production has been characterized by high agricultural inputs, high temperatures, and high cropping indexes. As an intensive form of agriculture, nutrient cycling induced by microbial activities in the greenhouses is relatively different from open fields in the same region. However, the responses of soil microbial biomass carbon (MBC) and nitrogen (MBN), enzyme activities, microbial community composition, and yield to organic amendment are not well understood. Therefore, a 5-year greenhouse tomato (Solanum lycopersicum Mill.)-cucumber (Cucumis sativus L.) rotation experiment was conducted. The field experiment comprised 5 treatments: 4/4CN (CN, nitrogen in chemical fertilizer), 3/4CN+1/4MN (MN, nitrogen in pig manure), 2/4CN+2/4MN, 2/4CN+1/4 MN+1/4 SN (SN, nitrogen in corn straw) and 2/4CN+2/4SN. The amounts of nitrogen (N), phosphorus (P2O5), and potassium (K2O) were equal in the five treatments. Starting with the fourth growing season, the optimal yield was obtained from soil treated with straw. MBC, MBN, phospholipid fatty acid (PLFA) profiles, and enzyme activities were significantly changed by 5 years of substitution with organic amendments. Redundancy analysis showed that MBC accounts for 89.5 and 52.3% of the total enzyme activity and total community variability, respectively. The activities of phosphomonoesterase, N-acetyl-glucosaminidase, and urease, and the relative abundances of fungi, actinomycetes, and Gram-negative bacteria were significantly and positively related to vegetable yields. Considering the effects of organic amendments on soil microbial characteristics and vegetable yield, 2/4CN+1/4MN+1/4SN can improve soil quality and maintain sustainable high yield in greenhouse vegetable production.
基金financially supported by the National Key Research and Development Program of China(2016YFE0101100)the National Natural Science Foundation of China(41771334,41771337 and 31470629)+2 种基金the Youth Innovation Team Project of the Institute of Subtropical Agriculture,Chinese Academy of Sciences(2017QNCXTD_GTD)the Chinese Academy of Sciences Instrument Function Development Project,the Government Program of Competitive Growth of Kazan Federal University and by the “RUDN University program5–100”
文摘The application of straw and biochar is widely practiced for the improvement of soil fertility.However,its impact on microbial functional profiles,particularly with regard to paddy soils,is not well understood.The aim of this study was to investigate the diversity of microbial carbon use patterns in paddy soils amended with straw or straw-derived biochar in a 3-year field experiment in fallow soil and at various development stages of a rice crop(i.e.,tillering and blooming).We applied the community level physiological profiling approach,with 15 substrates(sugars,carboxylic and amino acids,and phenolic acid).In general,straw application resulted in the greatest microbial functional diversity owing to the greater number of available C sources than in control or biochar plots.Biochar amendment promoted the use of α-ketoglutaric acid,the mineralization of which was higher than that of any other substrate.Principal component analyses indicated that microbial functional diversity in the biochar-amended soil was separated from those of the straw-amended and control soils.Redundancy analyses revealed that soil organic carbon content was the most important factor regulating the pattern of microbial carbon utilization.Rhizodeposition and nutrient uptake by rice plants modulated microbial functions in paddy soils and stimulated the microbial use of N-rich substances,such as amino acids.Thus,our results demonstrated that the functional diversity of microorganisms in organic amended paddy soils is affected by both physicochemical properties of amendment and plant growth stage.
基金funded jointly by the National Natural Science Foundation of China (Grant Nos. 41021004, 20777071 and 20477044)the Key Project of Knowledge Innovation Program from the Chinese Academy of Sciences (KZCX2-YW-432)the Hundred Talents Project from the Chinese Academy of Sciences
文摘An increase in atmospheric nitrogen (N) deposition can promote soil acidification, which may increase the release of ethylene (C2H4) under forest floors. Unfortunately, knowledge of whether increasing N deposition and C2H4 releases have synergistic effects on soil methane (CH4) uptake is limited and certainly deserves to be examined. We conducted some field measurements and laboratory experiments to examine this issue. The addition of (NH4)2SO4 or NH4Cl at a rate of 45 kg N ha-1 yr-1 reduced the soil CH4 uptake under a temperate old-growth forest in northeast China, and there were synergistic effects of N amendments in the presence of C2H4 concentrations equal to atmospheric CH4 concentration on the soil CH4 uptake, particularly in the NH4Cl-treated plots. Effective concentrations of added C2H4 on the soil CH4 uptake were smaller in NH+4 -treated plots than in KNO3-treated plots. The concentration of ca 0.3 μl C2H4 L-1 in the headspace gases reduced by 20% soil atmospheric CH4 uptake in the NH4Cl-treated plots, and this concentration was easily produced in temperate forest topsoils under short-term anoxic conditions. Together with short-term stimulating effects of N amendments and soil acidification on C2H4 production from forest soils, our observations suggest that knowledge of synergistic effects of NH+4 , rather than NO3- , amendments and C2H4 on the in situ soil CH4 uptake is critical for understanding the role of atmospheric N deposition and cycling of C2H4 under forest floors in reducing global atmospheric CH4 uptake by forests. Synergistic functions of NH4+ -N deposition and C2H4 release due to soil acidification in reducing atmospheric CH4 uptake by forests are discussed.
基金financially supported by the National Key Technologies R&D Program of China during the 12th Fiveyear Plan period (2012BAD22B01)
文摘The objective of this study was to evaluate the effects on chemical and microbiological properties of paddy soil of short-term biochar,straw,and chemical fertilizers compared with chemical fertilization alone.Five soil fertilization treatments were evaluated:regular chemical fertilizers(RF),straw+regular chemical fertilizers(SRF),straw biochar+regular chemical fertilizers(SCRF),bamboo biochar(BC)+regular chemical fertilizers(BCRF),and straw biochar+70%regular chemical fertilizers(SC+70%RF).Their effects were investigated after approximately 1.5 years.The soil p H and cation exchange capacity(CEC)were significantly higher in biochar-treated soils.The soil phosphorous(P)and potassium(K)contents increased with biochar application.The soil Colwell P content was significantly increased with the addition of straw biochar in the treatments of SCRF and SC+70%RF.The oxygen(O):carbon(C)ratio doubled in BC picked from the soil.This indicated that BC underwent a significant oxidation process in the soil.The denaturing gradient gel electrophoresis(DGGE)fingerprints of microbial communities differed among the treatments.Soils with added biochar had higher Shannon diversity and species richness indices than soils without biochars.The results suggest that biochar can improve soil fertility.