Long-term Application Of Pig Manure Research Articles

Long-Term Application of Pig Manure to Ameliorate Soil Acidity in Red Upland

While the application of manure to improve soil quality has attracted attention, the effect of pig manure application rates on soil acidity remains poorly understood. In this study, we analyzed the changes and correlations between soil acidity, pH buffer capacity (pHBC), soil chemical properties, and crop yields after 8 years of pig manure application at different rates (i.e., 0, 7.5, 15, 30, and 45 Mg ha−1) in a red upland soil (Ultisol). With an increase in the application rates, the crop yields were 0.77–8.85 times higher; the pH was enhanced by 0.4–0.8 units; and the soil organic matter (SOM), pHBC, iron activation (Feo), exchangeable calcium (ExCa), and exchangeable magnesium (ExMg) contents increased by up to 74.1%, 92.7%, 36.7%, 62.2%, and 48.7%, respectively, whereas that of total exchangeable acid (ExAcid) decreased by 17.2–52.9%. The crop yields were positively related to the soil pH but negatively correlated with ExAcid. Redundancy analysis revealed ExAcid and pHBC were more sensitive than pH was to the other chemical indicators. ExAcid was negatively correlated with SOM and ExCa; pHBC was positively correlated with ExMg, TN, SOM, and Feo. In conclusion, the crop yield could be improved by adjusting the soil acidity characteristics, and the application of pig manure reduced the soil acidity, with an optimal application rate of 15 Mg·ha−1.

Effects of Application of Pig Manure on the Accumulation of Heavy Metals in Rice.

Pig manure (PM) is often highly enriched in heavy metals, such as Cu and Zn, due to the wide use of feed additives. To study the potential risks of heavy metal accumulation in the soil and rice grains by the application of PM and other organic manure, a four-year field experiment was conducted in the suburb of Shanghai, southeast China. The contents of Cu, Zn, Pb, and Cd in the soils and rice plants by the treatments of PM and fungal culturing residues (FCR) show a trend of annual increase. Those in the soils and rice by the PM treatment are raised even more significantly. Cu and Zn contents in the soil and rice roots by the PM are significantly higher than those by the non-fertilizer control (CK) during the four years, and Pb and Cd also significantly higher than CK in the latter two years. Heavy metals taken up by the rice plants are mostly retained in the roots. Cu and Zn contents in the rice plants are in the decreasing order of roots > grains > stems > leaves, and Pb and Cd in the order of roots > stems > leaves > grains. Cu, Zn, Pb, and Cd contents in the soils by the PM treatment increase by 73%, 32%, 106%, and 127% on annual average, and those in the brown rice by 104%, 98%, 275%, and 199%, respectively. The contents of Cu, Zn, Pb, and Cd in the brown rice of the treatments are significantly correlated with those in the soils and rice roots (p < 0.05), suggesting the heavy metals accumulated in the rice grains come from the application of PM and FCR. Though the contents of heavy metals in the brown rice during the four experimental years are still within the safe levels, the risks of their accumulative increments, especially by long-term application of PM, can never be neglected.

Assembly of functional microbial communities in paddy soil with long-term application of pig manure under rice-rape cropping system

Organic farming is considered an efficient approach to improve soil fertility for sustainable agriculture. However, its soil micro-ecological effects and functions in intensive rice cropping systems are still obscure. Twelve soil samples were collected from a field experiment with four treatments such as M0 (no pig manure), M1 (1.6 t ha−1 pig manure), M2 (3.2 t ha−1 pig manure) and M3 (4.8 t ha−1 pig manure) after eight rice-oilseed rape rotation. Soil chemical property, enzyme activity and abundant/rare bacterial or fungal communities were analyzed to investigate the effect of conversion to organic farming with continuous pig manure application on soil microbiota. Stochastic processes controlled the assembly of abundant taxa, and deterministic processes dominated rare taxa. The composition and network construction of bacterial and fungal communities were significantly affected by pig manure, with changes in soil property and enzyme activity. Based on partial least squares path modeling (PLS-PM), pig manure application affected bacteria construction and enzyme activities by increasing soil carbon (C) and nitrogen (N). In summary, long-term pig manure application promotes specific microbial associations known to be involved in degrading complex organic compounds, and improving soil fertility such as soil enzyme activities. This research provides insight into understanding the processes behind changes in bacterial and fungal communities in paddy soil after conversion to organic farming.

Copper and Zinc fractions and adsorption in sandy soil with long-term pig manure application

ABSTRACT Copper (Cu) and zinc (Zn) fraction accumulation and adsorption capacity were evaluated in sandy-soil after 16 pig slurry (PS) and deep-litter (DL) applications under subtropical climate. Sixteen PS and DL applications to a Typic Hapludalf increased soil Cu and Zn soluble, exchangeable, mineral, organic, and total fractions. Cu mostly accumulated in organic and residual fractions (1.03, 4.39, 9.81, and 9.68, 12.9, 13.98 mg Cu kg−1 in the control, PS, and DL, respectively), whereas Zn presented a greater increase in mineral and exchangeable fractions (0.42, 6.39, 15.46 and 1.67, 8.96, 14.83 mg Zn kg−1 in the control, PS, and DL, respectively). Manure applications changed Cu and Zn adsorption behavior, with the greatest (895.8 mg Cu kg−1 and 945.9 mg Zn kg−1) adsorption occurring in DL, which is related to the 1.5- and 1.6-times organic matter increase compared to PS and control. Cu showed a preference for soil exchangeable sites under the competitive adsorption system, reducing Zn absorption about 11 and 6 times in the PS and DL, respectively. Application of pig manure rates based solely on crop N demand is unwise as it potentiates Cu and Zn accumulation, Zn bioavailability, increasing the risk of Zn toxicity and transference to aquatic environments.

Abundance and morphology of microplastics in an agricultural soil following long-term repeated application of pig manure.

Microplastics occur widely in the terrestrial environment and they currently occur in organic fertilizers applied to agricultural land. However, there is little information available on the accumulation of microplastics in soils fertilized over the long term. Here, we investigate the characteristics of microplastics in both pig manure and soil following long-term manure application in an attempt to assess their accumulation and the potential risk to agricultural soils of repeated application of pig manure. Microplastics were separated from soil and pig manure samples using a sequential flow separation and flotation method. The abundances of microplastics were 16.4±2.7 and 43.8±16.2 particles kg-1 in control plots (CK, no manure applied) and plots amended annually with pig manure for 22 years (PM), respectively. The microplastics (especially fragments) were significantly enriched in PM-amended soil compared with the control plots. The average annual abundance of microplastics was 1250±640 particles kg-1 in manure. Interestingly, the type and polymer composition of microplastics were very similar in the soil and manure. Differences in color and particle size indicate that microplastics sourced from pig manure may be gradually weathered and degraded after incorporation into the soil. The average accumulation rate of microplastics in the agricultural soil with long-term application of pig manure was estimated to be 3.50±1.71 million particles ha-1 a-1. The microplastics in the manured soil displayed complicated weathered surfaces. The presence of carbonyl groups suggests that the weathered microplastics in soil may have the potential to adsorb contaminants.

Unexpected bulk density and microstructures response to long-term pig manure application in a Ferralic Cambisol Soil: Implications for rebuilding a healthy soil

Excessive applications of chemical fertilizers (e.g., nitrogen fertilizers) result in soil degradation, while organic manure application can alleviate soil degradation and rebuild a healthy soil. However, the effect of organic manure application on alleviating soil degradation over long-term fertilization remains poorly understood. Using soils (Ferralic Cambisol) that had been collected from a long-term fertilization experiment for 23 years (1990 − 2013) in subtropic South China, we showed that soil organic carbon (SOC) stocks increased by 2.5 times following 23 years of manure fertilizations (pig manure or a combination of manure and chemical fertilizers) or by 1.4 − 1.8 times following non-manure fertilizations, compared to the initial SOC stock in 1990. Strikingly, soil bulk density after 23 years fertilizations decreased in the order: 1.41 g cm−3 (manure) > 1.26 g cm−3 (no fertilizer) > 1.12 g cm−3 (chemical fertilizer), suggesting that long-term manure fertilization increased soil bulk density when compared to the non-manure treatments. The X-ray micro-computed tomography further demonstrated that compared to the non-manure treatments, manure fertilizations decreased the number of pores, throats and paths as well as porosity. In addition, the stock of oxalate-extractable Al and Fe increased by 2 times following 23 years of manure fertilizations, relative to the initial soil. In summary, this study for the first time showed that changes in mineral reactivity impact soil physical properties and the potential of soils to stabilize C, strengthening the possibility in alleviating soil degradation and rebuilding a healthy soil.

Copper and Zinc in Rhizosphere Soil and Toxicity Potential in White Oats (Avena sativa) Grown in Soil with Long-Term Pig Manure Application

Successive applications of pig manure increase Cu and Zn contents in soils and may cause toxicity to plants. However, plants may have defense strategies that reduce Cu and Zn availability in rhizosphere soil. The study aimed to evaluate growth of white oats (Avena sativa) and Cu and Zn availability in rhizosphere soil subjected to long-term applications of pig slurry (PS) and pig deep litter (PL). The study was carried out with samples of a Typic Hapludalf soil from an 11-year experiment with annual fertilization of 180 kg N ha−1 as pig slurry (PS180) and pig deep litter (PL180) and a control (C) treatment. White oats were grown in pots with soil collected at 0.0–0.10 m depth. Thirty-five and 70 days after emergence (DAE), rhizosphere (RS) and bulk soil (BS) were analyzed to determine Cu and Zn availability. Plant growth, tissue Cu and Zn concentration, and content (concentration X dry weight) were measured. The application of pig manure for 11 years increased available soil Cu and Zn, as well as tissue concentration and content. Dry matter yield and plant height in PL180 were similar to those found in plants grown in the control treatment, while plants grown in PS180 had higher dry matter than in C. We found few differences in soil chemical characteristics and Cu and Zn contents between RS and BS. The high Cu concentrations in roots, especially in soil treated with PL180, show that Cu retention in the roots prevents excess Cu transport to white oat shoots.

Effects of long-term pig manure application on antibiotics, abundance of antibiotic resistance genes (ARGs), anammox and denitrification rates in paddy soils

Previous studies of long-term manure applications in paddy soil mostly focused on the effects on denitrification, occurrence of antibiotics and antibiotic resistance genes (ARGs) without considering the effects on anaerobic ammonium oxidation (anammox). Here, we investigated the potential rates of anammox and denitrification, occurrence of antibiotics and AGRs in response to three fertilization regimes (C, no fertilizer; N, mineral fertilizer; and NM, N plus pig manure) in six long-term paddy experiment sites across China. The potential rates of anammox (0.11–3.64 nmol N g−1 h−1) and denitrification (1.5–29.05 nmol N g−1 h−1) were correlated with the abundance of anammox genes (hzsB) and denitrification functional genes (narG, nirK, nirS and nosZ), respectively. The anammox and denitrification rates were affected by soil organic carbon (SOC) and significantly (p < 0.05) increased in NM treatments relative to those in N treatments. Although pig manure application increased antibiotic concentrations and abundance of ARGs compared with N treatments, the increased antibiotics did not directly affect the anammox and denitrification rates. Our results suggested that long-term pig manure application significantly increased antibiotic concentrations, abundance of ARGs, and rates of anammox and denitrification, and that the effects of pig manure-derived antibiotics on anammox and denitrification were marginal. This is the first report that investigates the effects of long-term pig manure application on anammox in paddy soils. More attention should be paid to the potential ecological risk of increased ARGs caused by pig manure application in paddy soils.

Increased occurrence of heavy metals, antibiotics and resistance genes in surface soil after long-term application of manure

The purpose of this study was to investigate the impact of long-term application of pig manure on the accumulation of heavy metals, antibiotics and ARGs in surface soil sampled from the Jiaxing long-term field experimental site with three manure treatments, N-PM (0 kg/ha/y, dw), L-PM (7720 kg/ha/y, dw), and H-PM (11,580 kg/ha/y, dw), in 2013 and 2014. The results showed that most serious metal pollution of Zn and Cu was recorded in all manured samples in both years, and their contents exceeded the soil quality standards. Among the three tetracyclines, chlortetracycline was the predominant antibiotic detected with a range of 3.04–98.03 μg·kg−1 in 2013 and 28.67–344.74 μg·kg−1 in 2014 after long-term pig manure application. Q-PCR results showed that the average accumulation of ribosomal protection protein genes (tetM, tetO, tetQ and tetW) was lower than most of the efflux pump genes (tetA and tetG). The abundance of tet and sul genes of those sites with manure application was significantly higher than that of sites without manure application in both years. Metagenomics analysis of ARGs revealed that the abundance of multidrug resistance genes was the most abundant subtype, followed by fluoroquinolone, bacitracin, sulfonamide and tetracycline. There was a positive correlation between the levels of ARGs; soil organic matter, antibiotics, Cu, As, and Zn levels in both years. These results may shed light on the mechanism underlining the effects of long-term manure application on the occurrence and dissemination of ARGs in surface soil.

Effects of long-term fertilizer applications on peanut yield and quality and plant and soil heavy metal accumulation

The status of essential and potentially toxic trace elements in soils and crops can be affected by long-term fertilization practices. This study aimed to investigate changes in peanut (Arachis hypogaea L.) yield and kernel quality, and changes in copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) concentrations in soil and peanut kernels after 16 years of continuous cropping with different fertilization treatments. Five fertilization treatments were applied at a red soil site in Southeast China: chemical fertilizer (F) containing nitrogen, phosphorus, and potassium, F + trace elements (FT), pig manure (M), M + effective microorganisms (MB), and MB + trace elements (MBT). Properties of soil and pig manure, heavy metal contents in soil and peanut kernels, and the compositions of amino and fatty acids in kernels were determined. Application of pig manure significantly increased peanut biomass, kernel yield, and crude protein and total amino acid contents in kernels, but led to higher amounts of Cu, Zn, and Cd in soil and higher amounts of Zn and Cd in peanut kernels compared with that of chemical fertilizer. There should be greater concern about potential kernel Cd and Zn contaminations resulting from long-term application of pig manure contaminated with potentially toxic metals as an organic fertilizer.

Metaproteome of the microbial community in paddy soil after long-term treatment with mineral and organic fertilizers

The soil microbial community research conducted in the field has focused on the genetic diversity of these organisms. In this study, we assessed the proteins expressed in soil microbial communities following the long-term application of mineral fertilizer (NPK) and organic manure (M) to paddy soil, indirect extraction method and separated via two-dimensional (2D) gel electrophoresis and identified using a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) approach. We found that the number of cells in the primary soil in the M treatment was significantly greater than in the NPK and CK treatments. The numbers of cells extracted were consistent with the total cell numbers and the concentration of extracted proteins (CK &lt; NPK &lt; M). 303 and 306 protein spots being detected in the CK map and NPK map, respectively. Eleven spots of interest were identified in the 2D gels, including 8 different protein spots and 3 unique protein spots. Three common proteins involved in protein hydrolysis and glutamate synthesis and metabolism. Eight differentially expressed proteins involved in DNA replication, transcription, protein folding and energy metabolism, the processes of cofactor and vitamin metabolism, transcriptional regulation, recombination and xenobiotic compound biodegradation and metabolism. The long-term application of fertilization resulted in significant changes in the microbial community structure and function, and the long-term application of pig manure significantly increased the microbial biomass and the functional and structural diversity in the soil. It is very interesting to address the MS identification of intracellular proteins from microbial communities under different fertilizer treatments in a paddy soil.

长期施用猪粪红壤稻田土壤Cu、Zn累积规律

长期施用猪粪红壤稻田土壤Cu、Zn累积规律

Effect of long-term fertilization on free-living nematode community structure in Mollisols

The influence of long-term application of pig manure combined with chemical fertilizer (MCF) or chemical fertilizer (CF) on free-living nematodes was evaluated in this study. The application model of fertilizers lasted 14 years in Mollisols, and treatments included MCF, CF and no fertilizer (NF). A total of 26 free-living nematode genera belonging to seven functional guilds were found in maize fields, and the community structure of free-living nematodes was different in MCF, CF and NF. Pig manure increased the abundance of bacterivores, especially those belonging to c-p1 (Ba1) and c-p2 (Ba2) guilds. Channel index (CI) was higher in NF than in MCF and CF, but enrichment index (EI) was higher in MCF and CF compared to NF. The structure index (SI) was highest in NF among three treatments. Total bacterivores, Ba1 and Ba2 guilds were positively correlated to organic C, total N, available N, total P and available P, but fungivores only had correlation with organic C and soil moisture. The SI index was negatively related to organic C, total N, available N, total P and available P. Collectively, these results indicate that the pig manure or chemical fertilizer normally applied to increase soil nutrition also induce negative influence on soil food web structure as reflected from biological aspect, and that soil nematodes can enhance agroecological assessments of changes induced by long-term fertilizer application in maize field in Mollisols.

Phosphorus Composition and Phosphatase Activities in Soils Affected by Long-Term Application of Pig Manure and Inorganic Fertilizers

The long-term (25 years) effect of using chemical fertilizers and animal manure on soil phosphorus (P) composition and phosphatase activities was investigated in this study. Results showed that pig manure applications significantly increased soil total P, Olsen P, and phosphatase activities, whereas chemical fertilizers had no significant effects on soil chemical properties and phosphatase activities. Manure applications doubled or tripled the orthophosphate concentrations as compared to chemical fertilizers. Analysis of solution 31P nuclear magnetic resonance (NMR) spectroscopy showed that P composition in sodium hydroxide (NaOH)–ethylenediamenetetraacetic acid (EDTA) extracts was dominated by orthophosphate (59–84%), followed by phosphomonoesters (15–40%). More organic P (Po), especially myo-inositol hexakisphosphate, was observed in soil treated with manure as compared with soil treated with chemical fertilizer.

Accumulation of copper and zinc in soil and plant within ten-year application of different pig manure rates

Fertilization of crops with pig manure is a common practice throughout the world. Nevertheless, due to the relatively high copper (Cu) and zinc (Zn) contents in pig manure, continuous application of pig manure could have negative effects on soil and plant. The study aimed at the impacts of long-term applying different pig manure rates (equivalently 0, 100, 250 and 500 kg total N/ha/year from 2002 to 2008 and 0, 10, 25 and 50 t fresh weight/ha/year from 2009 to 2011, respectively) on Cu and Zn accumulation in soil and plant. During the 10 years of the experiment, a total of 2.04 to 10.20 kg/ha/year for Cu, 3.15 to 15.73 kg/ha/year for Zn were applied to the soil. Results from this study showed that long-term pig manure application resulted in serious accumulation of Cu and Zn in soil, total Cu and Zn concentrations increased by 204% and 107% at high application rates, respectively. Although topsoil Cu and Zn concentrations were below concentrations considered phytotoxic to crops, according to current Chinese legislation, it would take only less time than 16 and 27 years of high application rates to reach the allowable limits. Our result also suggested that Cu and Zn leaching occurred in the tested soil. The Cu and Zn concentrations in stalks and grains were not affected by the application of pig manure, and these values were lower than the threshold values for animal and human ingestion.

Nitrogen leaching under corn cultivation stabilized after four years application of pig manure to red soil in subtropical China

The impact of long-term pig manure application to a red soil in subtropical China on nitrate leaching was investigated in a field lysimeter experiment from 2002 to 2009. Simultaneously, nitrate leaching was simulated by water and nitrogen management model (WNMM) basing on these observed data to determine the environmental threshold of manure application. Nitrate concentrations in the drainage and nitrate leaching under low manure application (150 kg N ha −1 y −1) did not increase during the study period. Interestingly, the nitrate concentrations in drainage water following high manure application (600 kg N ha −1 y −1) increased exponentially in the first four years and then remained at 13 mg l −1 for the next four years. Addition of lime based on high manure application had no significant effect on nitrate concentrations or total nitrate leaching. WNMM simulated the variation in corn yields and nitrate leaching well. The environmentally safe threshold for long-term application of pig manure was 360 kg N ha −1.

Long‐term pig manure application reduces the requirement of chemical phosphorus and potassium in two rice–wheat sites in subtropical China

AbstractProducing optimal grain yields while reducing adverse environmental impacts of over‐fertilization is essential in intensive, but sustainable, farming systems. We investigated the effects of long‐term (1982–2005) application of chemical nitrogen (N), N + chemical phosphorus (P) and N + P + chemical potassium (K) on grain yield, nitrogen recovery efficiency (NRE) and N losses in two rice–wheat sites in subtropical China where pig manure was applied (Suining and Wuchang). Four (Suining) or five (Wuchang) treatments were examined: no‐fertilizer, chemical N plus manure (NM), chemical NP plus manure (NPM), chemical NPK plus manure (NPKM) or chemical NPK plus 1.6 times manure (NPKhM, Wuchang only). Fertilizers resulted in 1.5–2.5 times higher grain yields than no‐fertilizer, which led to a NRE in the range from 21.0 to 58.3%. Grain yields of rice and wheat were significantly increased by 22.6–25.9 and 34.4–37.5%, respectively, under NPM and NPKM (similar to each other) compared to NM at Suining. Yields were similar for NM, NPK, NPKM and NPKhM at Wuchang. The N accumulation and NRE among fertilizers were in the order NM &lt; NPM = NPKM at the low amount of manure‐applied site (Suining), but NM = NPM = NPKM at the high amount of manure‐applied site (Wuchang). The ratio of N losses to total N input was 21.4–49.1% at the studied sites. Soil total N accumulated at a rate of 0.01–0.04 g/kg/yr during 1982–2005 with fertilizers and decreased or was constant in soil without fertilizer. Application of chemical P and K fertilizers could be reduced or eliminated after long‐term manure application at these two sites, while maintaining optimal grain yields and enhancing soil N accumulation.

Changes in diversity, protein content, and amino acid composition of earthworms from a paddy soil under different long-term fertilizations in the Tai Lake Region, China

Abstract Influence of the agricultural management practices on soil quality and the ecosystem functioning has been an increasing concern in soil science and ecology with sustainable agriculture. This study deals with the changes of soil earthworm communityfrom a paddy soil under different long-term fertilizations. The soil earthworms were collected and counted from different fertilizer treated plots in the field after the rape harvest in May 2004, and their taxonomic groups were determined under a binocular stereoscope at the laboratory. The body of the earthworm ( Metaphire californica) was crushed by a cell crusher to collect protein, and the protein molecules with different sizes were analyzed by electrophoresis. Furthermore, the Metaphire californica collected was hydrolyzed and the aliquots were subject to an amino acid auto-analyzer. The results showed that totally seven species of earthworms were recognized in the paddy field with the number varying with different fertilization treatments. The structure of earthworm communities was dramatically affected by the fertilization practice. Under chemical fertilization only, both the number of earthworm species and the quantity of individuals were significantly smaller than those under other treatments, or even than those under no fertilization. Furthermore, there was an obvious decrease in the total amino acid and the contents of most individual amino acids of Metaphire californica under chemical fertilization only, compared with those under the combined fertilization of chemical and organic fertilizers. Although chemical fertilizers in combination with rice straw return increased earthworm amino acid content, long-term pig manure application tended to increase earthworm protein content. As a molecular footprint, long-term chemical fertilization caused a reduction in the content of protein with MW less than 25 kd, but a significant increase in that of protein with molecule size around 33 kd. Our study demonstrated that different fertilizations affected not only earthworm population but also diversity and richness in the paddy soil after 16 years of treatment, and that long-term chemical fertilization may impact the soil animal community and, thus, influence the paddy ecosystem functioning for yield stability. This study implicated that not only the community structure but also the amino acid metabolism for life functioning of earthworms in cropland soils may pose significant responses to the agricultural management practices.