Long-term Application Of Farmyard Manure Research Articles

Long-term farmyard manure application affects soil organic phosphorus cycling: A combined metagenomic and 33P/14C labelling study

Maintaining an adequate phosphorus (P) supply for plants and microorganisms is central to agricultural production; however, the long-term effects of organic manure and inorganic fertilizer application on soil P cycling remain unclear. Organic P cycling in a sandy loam soil receiving medium and high rates of farmyard manure (FYM) with and without mineral fertilisers was studied in a long-term field experiment with 14C/33P isotope labelling and metagenomic shotgun sequencing. FYM application alone negatively affected soil total P and organic P (Po) accumulation by enhancing crop offtake, enhancing Po mineralisation and stimulating P loss from the topsoil by reducing its P sorption potential. The P mineralisation/immobilisation rates detected by the 33P pool dilution method were significantly correlated with the abundance of microbial P cycling genes. Soil available C and N concentrations were related to gross P mineralisation/immobilisation rates and the abundance of P uptake/scavenging genes. Microbial genes related to P uptake and metabolism were more abundant than P scavenging genes, while P scavenging genes may work efficiently as both of them can sustain similar P mineralisation and immobilisation rates. The addition of FYM also promoted phosphatase activity reflecting the increased supply of Po in these soils. Our study demonstrates that long-term FYM application alters soil Po stocks and cycling, and that microbial functional gene abundance was coupled with P cycling rates.

Farmyard manure applications stimulate soil carbon and nitrogen cycling by boosting microbial biomass rather than changing its community composition

Land application of farmyard manure (FYM) is a widespread agronomic practice used to enhance soil fertility, but its long-term effects on soil microbial carbon (C) and nitrogen (N) cycling have not been investigated in detail. Topsoils (0–23 cm) and subsoils (23–38 cm) were collected from a field trial on a sandy-textured soil where FYM had been applied at high (50–25 t ha−1 yr−1, 28 yr) and low rates (10 t ha−1 yr−1, 16 yr), and compared to soil treated only with synthetic NPK fertilisers. The turnover rate of key components of soil organic matter (SOM; proteins, peptides, amino acids, cellulose, and glucose) were evaluated by 14C labelling and measuring cellobiohydrolase, β-glucosidase, β-1,4-N-acetylglucosaminidase, L-leucine aminopeptidase, protease, and deaminase activities, whereas gross NH4+ and NO3− production and consumption were determined by 15N-isotope pool dilution. Microbial communities were determined using phospholipid fatty acid (PLFA) profiling. Our results indicate that long-term FYM addition significantly enhanced the accumulation of soil C and N, soil organic N (SON) turnover, exoenzyme activity, and gross NO3− production and assimilation. Rates of protein, peptide, and amino acid processing rate were 169–248, 87–147, and 85–305 mg N kgDWsoil−1 d−1, respectively, gross NH4+ and NO3− production and consumption were 1.8–5.8 mg N kgDWsoil−1 d−1, and the highest rates were shown under the high FYM treatment in topsoil and subsoil. The half-life of cellulose and glucose decomposition under the high FYM treatment were 16.4% and 31.0% lower than them in the synthetic NPK fertiliser treatment, respectively, indicating higher rates of C cycling under high manure application as also evidenced by the higher rate of CO2 production. This was ascribed to an increase in microbial biomass rather than a change in microbial community structure. Based on the high pool sizes and high turnover rate, this suggests that peptides may represent one of the dominant forms of N taken up by soil microorganisms. We conclude that long-term FYM application builds SOM reserves and induces faster rates of nutrient cycling by boosting microbial biomass rather than by changing its community composition.

Effect of long-term fertilization in maize-wheat cropping system on carbon mineralization in soil

Quantitative information on mineralization of soil organic carbon (SOC) under different long-term nutrient management practices is essential for better assessment of carbon (C) loss from soil. With an aim to evaluate long-term nutrient management effects on C mineralization kinetics in soils, a laboratory incubation study was conducted with soils collected from different depths (0–15, 15–30, 30–60, and 60–100 cm) of a 46-year old maize-wheat experiment. The treatments in the field involved long-term application of 100% N, 100% NP, 100% NPK, 150% NPK, 100% NPK + FYM (farmyard manure), and an unfertilized control. Long-term application of fertilizers significantly (p < 0.05) influenced organic C concentration and C mineralization kinetics in soil. Integrated application of inorganic fertilizers and organic manure (100% NPK + FYM) resulted in greater SOC accumulation and higher potentially mineralizable C in soil compared to other treatments. The microbial biomass carbon (MBC), basal soil respiration (BSR), carbon mineralization (Cmin), and microbial quotient (qMic) values were significantly higher under integrated application of NPK and FYM in maize-wheat system. The results showed that long-term application of FYM along with inorganic fertilizer enhanced SOC pool compared to solitary application of mineral fertilizers.

Distribution of N-mineralizing Enzymes in Soil Aggregate Fractions over 46 Years Application of Inorganic and Organic Fertilizers in a Tropical Rice-Rice System

The stability of enzymes in soil has been attributed to enzyme association with organic matter and the protection provided within soil aggregates. Enzymes namely urease, amidase and protease significantly affects nitrogen (N) mineralization and their assessment is crucial to study the nutrient cycling. Therefore, the objective of this study was to evaluate the hypothesis that the long-term application of farmyard manure (FYM) and inorganic fertilizers (N-nitrogen; P-phosphorus; K-potassium) impact the distribution pattern of enzymes namely, urease, amidase and protease in different fractions of water stable soil aggregates, and whole soil at 0–15 cm and 15–30 cm soil depth. The treatments comprised of unfertilized control and different combinations of inorganic fertilizers and FYM viz. control, N, NP, NK, NPK, FYM, FYM+N, FYM+NP, FYM+NK and FYM+NPK. A significant difference in soil aggregate size distribution was observed at two sampling depths. Total water stable aggregates (WSA) ranged between 69.8–91.2% in which 0.1–0.053 mm aggregate fraction contributed (2.11–3.87%), whereas 0.25–0.5 mm aggregate fraction was having the highest (27.3–32.6%) contribution. The activities of three enzymes in whole soil as well in aggregate fractions were lowest in control and highest in FYM+NPK except for amidase, which was having highest activity in FYM alone treatment. Activities of all the three enzymes were highest in aggregate fraction of 5–2 mm. Activities of three enzymes in whole soil as well as in aggregate fractions were lower at 15–30 cm compared to 0–15 cm soil depth. It may be concluded from this study that long-term addition of FYM alone or in combination with inorganic fertilizer increases the macroaggregate (5–2 mm) and hence the overall activities of N mineralization enzymes.

Nutrient status of soil and winter wheat (Triticum aestivum L.) in response to long-term farmyard manure application under different climatic and soil physicochemical conditions in the Czech Republic

ABSTRACTLong-term field experiments with annual crop rotation were established in 1955 and 1956 at three locations (Lukavec, Čáslav, Ivanovice) in the Czech Republic, which differ in their climate and soil physicochemical properties. The effect of cattle farmyard manure (FM) and a combination of FM and mineral (NPK) fertilizer application (FMNPK) on nutrient status of soil and the response of winter wheat, and nutrient content of wheat grain and straw were evaluated after ~60 years since the establishment. The results showed higher pseudototal (aqua regia soluble) contents of phosphorus and sulfur from FM and FMNPK application compared with control, whereas the labile and moderatory labile content of individual nutrients (except calcium) varied between treatments. The nutrient content of wheat grain and straw was more significantly (p < 0.05) affected by the location and growing season than by the fertilizers. The substantial changes in wheat nutrient uptake occurred for the weakly acidic loamy Gleyic Phaeozem, whereas the lowest response due to fertilizer application was observed for the acidic Cambisol (sandy loam texture). Even after six decades of FM and FMNPK application, the effectiveness of these treatments was predominantly influenced by the soil and climatic conditions at the individual locations.

Microbial biomass and activity down the soil profile after long-term addition of farmyard manure to a sandy soil

Long-term application effects of cattle farmyard manure (CM) without and with biodynamic preparations (CMBD) on basal respiration, 0.5 M K2SO4 extractable C and the relationships of microbial biomass C (MBC) estimates by chloroform fumigation extraction (CFE) and substrate-induced respiration (SIR) were evaluated down to 1 m depth. The contents of total N, K2SO4 extractable C and MBC-CFE declined with depth from 0–25 to 90–100 cm by −82, −47 and 86%, respectively. The contents of these three soil properties were always 17% lower in the mineral fertilization (MIN) treatment than in the CM and CMBD treatments. However, these differences were not always significant. The MBC-SIR/CFE ratio varied around 1 and did not show a significant depth gradient, due to the strong layer-to-layer variation within each treatment, although this ratio was generally 25% lower in the subsoil than in the topsoil. The metabolic quotient qCO2, i.e. the ratio of basal respiration to MBC, was positively affected by the MBC-SIR/CFE ratio, soil pH and K2SO4 extractable C and negatively by total N. Long-term application of farmyard manure, especially in the CMBD treatment, resulted in a subsoil microbial community with a more efficient use of SOC and glucose.

Mobility and plant availability of risk elements in soil after long-term application of farmyard manure.

Crop rotation long-term field experiments were established in 1955 and 1956 at three locations in the Czech Republic (Čáslav, Ivanovice, and Lukavec) differing in their climatic and soil physicochemical properties. The effect of long-term application of farmyard manure and farmyard manure+NPK treatments on plant-available, easily mobilizable, potentially mobilizable, and pseudo-total contents of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) contents in soils (in 2013) as well as the uptake of these elements by winter wheat (Triticum aestivum L.) grain and straw were analyzed in the two following seasons: 2012 and 2013. The treatments resulted in increasing the soil pH level when compared to the control, but the cation exchange capacity remained unchanged. Although all fertilizers were applied for six decades, the pseudo-total concentration elements in both the soil and wheat plants stayed far below those of the Czech and European threshold limits for agricultural soils and cereals for human nutrition and feedstuff. Although the mobile pools of As, Cu, and Zn were slightly changed at the treated soils, these changes were not related to the element uptake by the wheat plants. Moreover, the effect of the location and growing season was more decisive for the differences in soil and plant element contents than for the individual treatments. Thus, the long-term application of farmyard manure did not result in any substantial change in risk element contents in both soils and winter wheat plants.

Soil porosity in physically separated fractions and its role in SOC protection

Processes that lead to soil organic carbon (SOC) protection depend on both soil porosity and structure organization, as well as chemical and biological properties. In particular, the soil micro-nano porosity (<30 μm) regulates microorganism accessibility to the soil pore system and offers surfaces for organic carbon adsorption and intercalation into soil minerals. The aim of this work was to investigate how pore size distribution can selectively protect specific carbon pools in different aggregate size fractions, by considering the effects of long-term application of farmyard manure (FYM) and mineral (Min) fertilization. Macroaggregates (250–2000 μm), microaggregates (53–250 μm), and silt–clay (<53 μm) fractions of three different soils (clayey, peaty, and sandy) were separated by wet sieving technique and then subjected to chemical and physical analysis. Sample porosity and pore size distribution were analyzed using mercury intrusion porosimetry (MIP), while SOC chemical structure was characterized by means of nuclear magnetic resonance (13C cross-polarization–magic angle spinning nuclear magnetic resonance (CP MAS 13C NMR)) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopies. Results showed that FYM increased organic (OC) and humic carbon (HC) content compared to the Min fertilization and unfertilized soils. However, it caused a gradual decrease in O,N-alkyl C, and alkyl C of humic C from macroaggregate to silt–clay fractions, suggesting an advanced state of humic component degradation as revealed by CP MAS 13C NMR, DRIFT analyses. MIP analysis showed a clear increase of micropores (5–30 μm) and cryptopores (0.0035–0.1 μm) from macroaggregate to silt–clay fractions, while minor differences were observed among the treatments. The application of principal component analysis to mineral soil fractions identified the formation of three main clusters, where (i) macroaggregates of clayey soil were mainly associated to cryptopores and OC and (ii) microaggregates and silt–clay fraction were mainly isolated by carbonyl C, ultramicropores, and total porosity. The third cluster was associated with medium and fine sand of the sand soil fraction as coupled with O,N-alkyl C, anomeric C, mesopores, and HC/OC ratio. Overall, this study indicates that pore size distribution may be a valuable indicator of soil capacity to sequester carbon, due to its direct influence on SOC linkages with soil aggregates and the positive effects against SOC decomposition phenomena. In this context, micropore- to nanopore-dominated structures (e.g., clayey soil) were able to protect OC compounds by interacting with mineral surfaces and intercalation with phyllosilicates, while meso/macropore-dominated structures (i.e., sandy soil) exhibited their low ability to protect the organic components.

Soil aggregation and distribution of carbon and nitrogen in different fractions after 41 years long-term fertilizer experiment in tropical rice–rice system

Inorganic fertilizers and manure application can alter the aggregate distribution as well as aggregate associated organic carbon and nitrogen. It is not fully understood how long term addition of carbon (C) and nitrogen (N) through biomass, farm yard manure (FYM) and inorganic fertilizers are distributed in soil aggregates in a tropical rice–rice system. Therefore, the objectives of this study were to investigate the long-term effects of FYM and inorganic fertilizer in a rice–rice system on (i) distribution of water stable aggregates in the soil, and (ii) amount of total soil organic carbon (TOC), total N and C/N ratio in different aggregate fractions. The total water stable aggregates (WSA) ranged from 71.6% under control to 91.1% under NPK+FYM in the surface soil (0–15cm). The incorporation of FYM increased the macroaggregates (5–2mm) by 165.3% and mesoaggregates by 130.7% (2–1mm) and 282.8% (1–0.5mm) over control in 0–15cm soil layer. Mean weight diameter (MWD), varied from 0.43 to 0.78 in 0–15cm and from 0.40 to 0.72 in 15–30cm soil layer. MWD was higher under FYM treated plots than inorganic fertilizer alone and unfertilized control plots. Irrespective of treatment, macroaggregates (5–2mm) had the highest (4.13–14.03gkg−1) and microaggregate fraction (0.25–0.1mm) had the least (3.70–8.89gkg−1) TOC content in the 0–15cm soil layer. The application of FYM either alone or in combination with inorganic fertilizers significantly increased the accumulation of TOC in all aggregate fractions over control, however, the effect was more pronounced in macroaggregates fraction 5–2mm and microaggregate fraction 0.1–0.053mm. The combined application of inorganic fertilizers and FYM resulted in an increase in total N content which ranged from 0.43 to 1.0gkg−1 in 5–2mm and from 0.09 to 0.44gkg−1 in 0.25–0.1mm aggregate fractions. The highest C:N ratio was recorded in aggregate fraction of 0.1–0.053mm irrespective of treatment, whereas aggregate fraction of 0.5–0.25mm had the least C:N ratio. A higher C:N ratio was observed in 15–30cm than 0–15cm soil layer. Hence it was concluded that the long-term application of FYM resulted in C and N accumulation in bulk soil and aggregates, but the accumulation pattern was dependent on aggregate size.

Influence of long-term fertilisation and crop rotation on changes in fungal and bacterial residues in a tropical rice-field soil

Amino sugars, as a microbial residue biomarker, are highly involved in microbial-mediated soil organic matter formation. However, accumulation of microbial biomass and responses of bacterial and fungal residues to the management practices are different and poorly characterized in rice soils. The objectives of this study were to evaluate the effects of mineral fertiliser (MIN), farmyard manure (FYM) and groundnut oil cake (GOC) on crop yield and co-accumulation of microbial residues and microbial biomass under rice-monoculture (RRR) and rice–legume–rice (RLR) systems. In the organic fertiliser treatments and RLR, rice grain yield and stocks of soil and microbial nutrients were significantly higher than those of the MIN treatment and RRR, respectively. The increased presence of saprotrophic fungi in the organic fertiliser treatments and RRR was indicated by significantly increased ergosterol/Cmic ratio and extractable sulphur. In both crop rotation systems, the long-term application of FYM and GOC led to increased bacterial residues as indicated by greater accumulation of muramic acid. In contrast, the higher fungal C/bacterial C ratio and lower ergosterol/Cmic ratio in the MIN treatment, is likely caused by a shift within the fungal community structure towards ergosterol-free arbuscular mycorrhizal fungi (AMF). The organic fertiliser treatments contributed 22 % more microbial residual C to soil organic C compared to the MIN treatment. Our results suggest that the negative relationship between the ratios ergosterol/Cmic and fungal C/bacterial C encourages studying responses of both saprotrophic fungi and AMF when assessing management effects on the soil microbial community.

Sulfur specification in bulk soil as influenced by long-term application of mineral and organic fertilizers

A field experiment established in 1962 on a luvisol derived from loess was chosen to investigate the effect of long-term application of farmyard manure, compost and sewage sludge, respectively, in two increments on inorganic and organic S fractions in bulk soil. Compared with mineral fertilizer, the high application rates of the different organic fertilizers (10 t farmyard manure (FYM2), 29 t compost (COM2), 7.44 t sewage sludge (SS2)/ha/year, respectively), resulted in an increase of the total S content in the bulk soil: 220 mg/kg (FYM2), 298 mg/kg (COM2), 277 mg/kg soil (SS2) as compared to the control (MIN) with 158 mg/kg soil. The sum of water soluble plus adsorbed S was significantly higher in the treatments with the high amount of compost (17.9 mg/kg soil) and sewage sludge (16.4 mg/kg) soil as compared to all the other treatments (10.0 to 13.1 mg/kg soil). The treatments with the high amounts of organic manures contained lower contents of ester sulfate and higher contents of C-bonded S as compared to the treatments with the low amounts, and vice versa. &amp;nbsp; &amp;nbsp;

Sulfur fractions in particle-size separates as influenced by long-term application of mineral and organic fertilizers

A field experiment established in 1962 was chosen to investigate the effect of long-term application of farmyard manure (FYM), compost (COM) and sewage sludge (SS), respectively, in two increments as compared to mineral fertilizer on inorganic and organic S fractions in particle-size separates (&amp;lt; 0.002 mm, 0.002&amp;ndash;0.02 mm, 0.02&amp;ndash;2 mm). Independent of the particle-size the application of the high amounts of COM and SS resulted in the highest total S contents. It is evident that the particle-size fractions &amp;lt; 0.002 mm contained the majority of total soil sulfur (S). The content of plant available S (water-soluble and adsorbed SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2&amp;ndash;&lt;/sup&gt;) decreased with increasing particle-size, while the influence of the kind and amount of organic fertilizers was negligible. As compared to C-bonded S sulfate esters were the dominant organic S fraction in size separates. The content of both organic S fractions was highest in the particle-size fraction &amp;lt; 0.002 mm and lowest in the particle-size fraction 0.02&amp;ndash;2 mm. The influence of the application of organic fertilizers was less pronounced. Only high application rates of COM and SS, respectively, resulted in the highest contents of both organic S fractions in the particle-size fractions 0.002&amp;ndash;0.02 mm and 0.02&amp;ndash;2 mm. &amp;nbsp; &amp;nbsp;

Quantification of chemical sulphur species in bulk soil and organic sulphur fractions by S K-edge XANES spectroscopy

A new data treatment method for fitting spectra obtained by sulphur (S) K-edge X-ray absorption near-edge structure (XANES) spectroscopy was used to quantify the chemical S speciation at three experimental sites with arable soils receiving the same long-term field treatments. Two treatments, crop residue (CR) incorporation and farmyard manure (FYM) application, with equal applications of mineral nutrients were included in the study. In the new data treatment method, internally calibrated spectra of dilute solutions (30 mm) of model compounds were used to fit the sample spectra. This greatly enhanced the reliability of quantitative determination of contributing S species in soil samples and soil extracts. The results indicated that long-term FYM application shifted S species composition from highly oxidized towards intermediate oxidization in two of the soils, but in the third soil the opposite trend was observed. Sulphur XANES spectroscopy of acetylacetone extracts of physically protected and unprotected organic S in two of the soils revealed that physical protection was not related to S speciation; however, intermediate forms of oxidized S species appeared to accumulate in the residual S pool (not extractable by acetylacetone).

Emission rates of N2O and CO2 from soils with different organic matter content from three long-term fertilization experiments—a laboratory study

Increasing organic matter stocks in soils reduce atmospheric carbon dioxide (CO2), but they may also promote emissions of nitrous oxide (N2O) by providing substrates for nitrification and denitrification and by increasing microbial O2 consumption. The objectives of this study were to determine the effects of fertilization history, which had resulted in different soil organic matter stocks on (1) the emission rates of N2O and CO2 at a constant soil moisture content of 60% water-holding capacity, (2) the short-term fluxes of N2O and CO2 following the application of different fertilizers (KNO3 vs. farmyard manure from cattle) and (3) the response to a simulated heavy rainfall event, which increased soil moisture to field capacity. Soil samples from different treatments of three long-term fertilization experiments in Germany (Methau, Sproda and Bad Lauchstadt) were incubated in a laboratory experiment with continuous determination of N2O and CO2 emissions and a monitoring of soil mineral N. The long-term fertilization treatments included application of mineral N (Methau and Sproda), farmyard manure + mineral N (Methau and Sproda), farmyard manure deposition in excess (Bad Lauchstadt) and nil fertilization (Bad Lauchstadt). Long-term addition of farmyard manure increased the soil organic C (SOC) content by 55% at Methau (silt loam), by 17% at Sproda (sandy loam) and by 88% at Bad Lauchstadt (silt loam; extreme treatment which does not represent common agricultural management). Increased soil organic matter stocks induced by long-term application of farmyard manure at Methau and Sproda resulted in slightly increased N2O emissions at a soil moisture content of 60% water-holding capacity. However, the effect of fertilization history and SOC content on N2O emissions was small compared to the short-term effects induced by the current fertilizer application. At Bad Lauchstadt, high N2O emissions from the treatment without fertilization for 25 years indicate the importance of a sustainable soil organic matter management to maintain soil structure and soil aeration. Emissions of N2O following the application of nitrate and farmyard manure differed because of their specific effects on soil nitrate availability and microbial oxygen consumption. At a soil moisture content of 60% water-holding capacity, fertilizer-induced emissions were higher for farmyard manure than for nitrate. At field capacity, nitrate application induced the highest emissions. Our results indicate that feedback mechanisms of soil C sequestration on N2O emissions have to be considered when discussing options to increase soil C stocks.

Root Growth and Soil Water Dynamics in Relation to Inorganic and Organic Fertilization in Maize–Wheat

Agricultural productivity is increasingly becoming dependent upon soil fertility, which is generally thought to be supplemented through the application of nutrients mainly through inorganic fertilizers. The present study aims to characterize the soil physical environment in relation to long-term application of farmyard manure (FYM) and inorganic fertilizers in a maize–wheat cropping system. The treatments in both the maize and wheat systems included a control (without any fertilizer or FYM), FYM (farmyard manure at 20 t ha−1), N100 (nitrogen at 100 kg ha−1), N100P50 (nitrogen and phosphorus at 100 and 50 kg ha−1), and N100P50K50 (nitrogen, phosphorus, and potash at 100, 50, and 50 kg ha−1). The treatments were replicated four times in a randomized complete block design in sandy loam soil. The root mass density in surface layers of both the crops was lower in FYM and higher in inorganic fertilizer plots. The root length density was found to be highest in FYM-treated plots and lowest in control plots. The periodic soil matric suction during wheat following maize remained highest in FYM plots followed by that in N100 plots in all the layers. The soil water storage of wheat at harvest (rice–wheat) was highest (21.1 cm) in control and lowest (17.8 cm) in FYM-treated plots. The soil water status, root growth, and crop performance improved with balanced fertilization.

Long-term effects of organic farming on fungal and bacterial residues in relation to microbial energy metabolism

Samples from the bio-dynamic, bio-organic, and conventional trial, Therwil, Switzerland, were analyzed with the aim of determining the effects of organic land use management on the energy metabolism of the soil microbial biomass and on the fraction of microbial residues. The contents of adenylates, adenosine triphosphate (ATP), glucosamine, muramic acid, and galactosamine were significantly largest in the biodynamic organic farming (BYODIN) treatment and significantly lowest in the conventional farming treatment with inorganic fertilization (CONMIN). In contrast, the ergosterol-to-ATP ratio and fungal C-to-bacterial C ratios were significantly lowest in the BYODIN treatment and significantly largest in the CONMIN treatment. No clear treatment effects were observed for the ergosterol content and the adenylate energy charge (AEC), the ATP-to-microbial biomass C ratio and the ergosterol-to-fungal C ratio. Ergosterol, an indicator for saprotrophic fungal biomass, and fungal residues were significantly correlated. The microbial biomass carbon-to-nitrogen ratio showed a negative relationship with the AEC and strong positive relationships with the ratios ergosterol-to-microbial biomass C, ergosterol-to-ATP and fungal C-to-bacterial C. In conclusion, the long-term application of farmyard manure in combination with organic farming practices led to an increased accumulation of bacterial residues.

Net sulfur mineralization potential in Swedish arable soils in relation to long-term treatment history and soil properties

The long-term treatment effect (since 1957–1966) of farmyard manure (FYM) application compared with crop residue incorporation was investigated in five soils (sandy loam to silty clay) with regards to the net sulfur (S) mineralization potential. An open incubation technique was used to determine accumulated net S mineralization (SAccMin) and a number of soil physical and chemical properties were determined. Treatments and soil differences in SAccMin, as well as correlations with soil variables, were tested with single and multivariate analyses. Long-term FYM application resulted in a significantly (p = 0.012) higher net S mineralization potential, although total amounts of C, N, and S were not significantly (p < 0.05) increased. The accumulated S mineralization differed significantly (p < 0.05) between soils within this treatment. The measured soil variables were not significantly correlated to SAccMin. Conclusively, different treatment histories influenced the quality (e.g., chemical composition) and cycling rate of the organic S pool, rather than its size.

Effects of organic and inorganic amendments on soil organic matter properties

The aim of this work was to investigate the effects of long-term application of different organic fertilizers (sewage sludge, farmyard manure, compost) as compared to mineral fertilizer on the structure of the soil organic matter. Capillary electrophoresis was employed for the quantification of monosaccharides and phenolic compounds, whereas NMR and FT-IR were used for the overall characterization of the soils organic matter. Application of farmyard manure results in a higher content of organic matter derived from angiosperms, suggested by the higher levels of syringic and vanillic phenols. Spectroscopic studies show an increase of lignin and lignin-like products in the organic matter of the soil, which may be derived from the cereal straw supplied with farmyard manure. According to spectroscopic analysis, 13C CPMAS-NMR and FT-IR spectra, higher contents of methylene groups (– CH 2) from proteins and protein-like compounds, as well as higher levels of carbohydrates, were found in the soil supplied with compost. The monosaccharide (rhamnose, xylose, glucose, mannose, arabinose, fucose and galactose) content was not significantly influenced by the different organic fertilizers, suggesting that the type of amendment used does not affect any of these six studied monomers. Comparing the three organic amendments the most significant differences were observed after long-term application of farmyard manure, with an increase in lignin and lignin-like products in the soil organic matter, and compost, which appears to contribute to an increase of protein and protein-like, as well as carbohydrates content on soil organic matter. The knowledge of such changes can be essential to understand the sorption and bioavailability of pollutants, as well as establish/unestablish ways to recycling organic residues as organic fertilizers.

Soil organic carbon and physical properties as affected by long-term application of FYM and inorganic fertilizers in maize–wheat system

The physical quality of the soil, which creates suitable environment for the availability and uptake of the plant nutrients, is generally ignored. Though the effect of organic manures on soil physical quality has been widely appreciated but that of inorganic fertilizers is studied to a lesser extent. The present study carried out during 2004–2005 aims to characterize the soil physical quality in relation to the long-term (32 years) application of farmyard manure (FYM) and inorganic fertilizers in maize ( Zea mays L.) wheat ( Triticum aestivum L.) cropping system. The treatments during both maize and wheat crops were (i) farm yard manure at 20 Mg ha −1 (FYM), (ii) nitrogen at 100 kg ha −1 (N 100), (iii) nitrogen and phosphorus at 100 and 50 kg ha −1 (N 100P 50) and (iv) nitrogen, phosphorus and potassium at 100, 50 and 50 kg ha −1 (N 100P 50K 50) in addition to (v) control treatment, i.e. without any fertilizer and/or FYM addition. The treatments were replicated four times in randomized block design in a sandy loam (Typic Ustipsament, non-saline, slightly alkaline). Bulk density, organic carbon content, structural stability of soil aggregates and water holding capacity of 0–60 cm soil layer were measured. The application of FYM to maize increased the organic carbon by 16% whereas N 100P 50K 50 increased it by 21%. The increased organic matter with both FYM and N 100P 50K 50 increased the total soil porosity and decreased soil bulk density from that in control plots. The mean weight diameter (MWD) was highest in FYM plots of both maize (0.160 mm) and wheat (0.172 mm) closely followed by that in N 100P 50K 50 plots. The effect of FYM in increasing the MWD decreased with soil depth. The average water holding capacity (WHC) was higher with FYM and N 100P 50K 50 application than that in control plots. The MWD, total porosity, OC content and WHC improved with the application of balanced application of fertilizers. The grain yield and uptake of N, P and K by both maize and wheat were higher with the application of FYM and inorganic fertilizers than in control plots. The uptake of N, P and K increased with the application of FYM and N 100P 50K 50.

Soil physical fertility and crop performance as affected by long term application of FYM and inorganic fertilizers in rice–wheat system

Soil fertility, one of the important determinants of agricultural productivity, is generally thought to be supplemented through the application of nutrients mainly through inorganic fertilizers. The physical fertility of the soil, which creates suitable environment for the availability and uptake of these nutrients, is generally ignored. The present study aims to characterize the soil physical environment in relation to the long term application of farm yard manure (FYM) and inorganic fertilizers in rice–wheat. The treatments during both rice and wheat crops were (i) farm yard manure @ 20 t ha −1 (FYM); (ii) nitrogen @ 120 kg ha −1 (N 120); (iii) nitrogen and phosphorus @ 120 and 30 kg ha −1 (N 120P 30) and (iv) nitrogen, phosphorus and potassium @ 120, 30 and 30 kg ha −1 (N 120P 30K 30) in addition to (iv) control treatment, i.e. without any fertilizer and/or FYM addition. The treatments were replicated four times in randomized block design in a sandy loam (typic Ustipsament, non-saline, slightly alkaline). Bulk density, structural stability of soil aggregates and water holding capacity of 0–60 cm soil layer were measured. The average mean weight diameter (MWD) was highest in FYM-plots both in rice (0.237 mm) and wheat (0.249 mm) closely followed by that in N 120P 30K 30 plots. The effect of FYM in increasing the MWD decreased with soil depth. The addition of both FYM and N 120P 30K 30 increased the organic carbon by 44 and 37%, respectively in rice. The total porosity of soil increased with the application of both FYM and N 120P 30K 30 from that in control plots. In 0–15 cm soil layer, the total porosity increased by 25% with FYM from that in control plots. This difference decreased to 13% in 15–30 cm soil layer. The average water holding capacity (WHC) was 16 and 11% higher with FYM and N 120P 30K 30 application from that in control plots. The MWD, total porosity and WHC improved with the application of balanced application of fertilizers. The grain yield and uptake of N, P and K by both rice and wheat were higher with the application of FYM and inorganic fertilizers than in control plots. The carbon sequestration rate after 32 years was maximum (0.31 t ha −1 year −1) in FYM-plots, followed by 0.26 t ha −1 year −1 in N 120P 30K 30-plots, 0.19 t ha −1 year −1 in N 120P 30 and minimum (0.13 t ha −1 year −1) in N 120-plots.