Pig Deep-litter Research Articles

Chemical and spectroscopic composition of humic substances in soil subjected to pig manure applications for ten years

ABSTRACT Application of pig manure (PM) in agriculture can influence the amount and composition of soil organic matter (SOM). This study evaluated the changes in contents and stock of C in chemical fractions of SOM and the chemical and spectroscopic composition of humic substances (HS) in a Typic Hapludult (Argissolo Vermelho-Amarelo) after ten years of PM application. Experimental area received 90 and 180 kg ha -1 of N in the form of pig slurry (PS90 and PS180) and pig deep litter (DL90 and DL180), in addition to the control, without application (SA). Soil samples were prepared, and the chemical fractioning of SOM, elemental analysis, and Fourier Transform Infrared Spectroscopy of HS were performed. Applications of PM favored the accumulation of C in soil (up to 53 %), and PS180 increased humic acids (HA) (up to 185 %), while applications of DL favored the increase of hydrophilic substances extracted with HCl and humin (HU) (up to 10 times and 60 %, respectively). Applications of PS180 and DL180 promoted an increase in the aromatic and carboxylic character of the HS, increasing cationic exchange capacity. Therefore, PM applications, especially with DL, contribute positively to C fixation in the soil and the chemical composition of organic material.

Nitrogen and carbon stocks in sandy soil cultivated with corn subjected to 17 years of animal manure and mineral fertilizer application

Animal manure can be used as a source of nutrients in cropping systems throughout the world. However, in subtropical climates, the impacts of animal manure application over multiple years on crop productivity and on the total organic carbon (TOC) and total nitrogen (TN) stocks in the soil profile are not well understood. In this study, we aimed to evaluate how animal manure application carried out over more than 17 years can impact corn productivity and TOC and TN stocks in different soil layers. This long-term study was conducted from 2004 to 2021 under no-till conditions in southern Brazil. The treatments included pig slurry (PS), cattle slurry (CS), pig deep litter (PDL), mineral fertilizer (NPK) and a control (no fertilizer application). To determine soil TOC and TN stocks, soil samples were collected from the 0.00–0.10, 0.10–0.20, 0.20–0.30, 0.30–0.40 and 0.40–0.50 m layers in December 2008, 2012, 2016 and 2020. Corn productivity was evaluated for the 2008/09, 2012/13, 2016/17, and 2020/21 crops. The highest yields and TOC and TN stocks were observed in soils with pig deep litter and cattle slurry application. In the sandy soil under a no-till system after 26 animal manure applications over 17 years, the highest TOC and TN stocks were observed in the 0.00–0.10 m layer. On average, the TOC stocks obtained for the 0.00–0.10 m layer were 11.21, 14.88, 15.82, 22.59 and 15.16 Mg ha−1 for the control, PS, CS, PDL and NPK treatments, respectively. The soil TN stocks in the 0.00–0.10 m layer were 1.06, 1.40, 1.65, 2.03 and 1.43 Mg ha−1 for the control, PS, CS, PDL and NPK treatments, respectively. The application of pig deep litter to the soil over 17 years resulted in a notable increase in TOC and TN levels, playing a crucial role in increasing the productivity of maize crops.

Long‐term application of different organic and inorganic fertilizers in no‐tillage crops changes the soil microstructural viscoelasticity and shear resistance to transient stresses

AbstractThe processes involved in deformation, internal strength and stability of soils with long‐term application of fertilizers (organic and inorganic sources) remain poorly investigated and hence understood, particularly in agricultural systems under subtropical climatic conditions. We investigated how long‐term fertilizer management with organic and inorganic amendments in no‐till crops affects the microstructural stability of a sandy Alfisol under oscillatory shear. The study was conducted in southern Brazil on a 17‐year completely randomized block experiment with five fertilizer treatments: pig slurry (PS), cattle slurry (CS), pig deep litter (PDL), mineral fertilizer (MF) and control, i.e. unfertilized (CL). Soil samples were collected from two layers (0–5 and 5–15 cm) for physical and chemical analyses and evaluation of soil rheological properties under oscillatory shear at two matric potentials (0 and −10 kPa). Organic matter accumulation in soil provided by the PDL and CS fertilizers resulted in higher soil stability and elasticity under oscillatory shear, especially in the 0–5 cm layer. Conversely, MF and PS enhanced the soil susceptibility towards deformation under transient stresses, mainly in the 0–5 cm layer under saturated conditions. The PDL significantly increased soil shear resistance under low‐shear strain conditions. Significant differences ceased under high‐shear strain conditions, though PS and MF yielded at significantly lower strains. Hence, under subtropical conditions, long‐term application of organic fertilizers with fibrous components promoted soil microstructure strengthening, reducing soil susceptibility to erosive processes and compaction.

Phosphorus Balance in Sandy Soil Subjected to 12 Years of Successive Applications of Animal Manure and Mineral Phosphate Fertilizer in Subtropical Climate

Assessing the phosphorus (P) balance in agricultural soils is crucial for optimizing its use and reducing contamination risks. The objective of this study was to evaluate the impact of different animal wastes on the distribution of P in soil profiles subjected to 12 years of successive applications of animal wastes and mineral phosphate fertilizer, within a crop rotation system under no-till system. The study was conducted from 2004 to 2016 in the southern region of Brazil. The treatments were the applications of pig slurry (PS), cattle slurry (CS), pig deep-litter (PD), mineral fertilizer (MF), and a control treatment without application. The highest accumulation of P and its movement was observed in the 0–40 cm layer, in the soil submitted to applications of all P sources. The inputs of P via MF, CS, PS, and PD promoted the accumulation of 18, 42, 48, and 100 kg P ha−1 year−1. The P mass balance showed that between 77 and 98% of the P added by animal manure and MF was accounted for in grain exports (17–34%), soil storage (41–72%), and post-harvest residues (<1%), with the remaining 2–33%, unaccounted for, which was attributed, especially, to P transfer at the soil surface.

Long-Term Effects of Animal Manures on Nutrient Recovery and Soil Quality in Acid Typic Hapludalf under No-Till Conditions

No-till farming and manure application are means of storing carbon in soil and increasing soil quality. However, the organic fertilization of no-till soils may sustain subtropical agroecosystems for only a limited period until the soil quality declines. The C, N, P, and other nutrient cycles are perturbed due to the nutrient imbalance in manures and their application on the soil surface, which poses a risk for nutrient dispersion into the environment. Long-term N-based manure application also impacts the apparent nutrient recovery (ANR) by crops and, hence, the crop quality. Our objective was to monitor changes in soil quality and to measure nutrient recovery from N-based organic fertilization in a Brazilian agroecosystem. A long-term experiment was established in May 2004 on Typic Hapludalf soil in Southern Brazil. The experiment comprised two periods: 2004–2009 and 2009–2020. The treatments were unfertilized (control), pig slurry, pig deep litter (swine manure and rice husk), cattle slurry, and mineral fertilizer (urea, triple superphosphate, and K chloride). Grain and cover crops were grown. The maize grain yield and oat biomass were used as indicators of productivity. The application of cattle slurry, pig deep litter, and pig slurry increased the grain production by 20% on average compared to mineral fertilization. Organic manuring increased the soil pH by up to one unit, while urea acidified the soil. The highest crop yields were obtained with pig deep litter, which increased the levels of P, K, Ca, Mg, and C in the soil test. Pig deep litter showed the highest N-ANR for the aboveground part of the plants. The ANRs for P, K, Ca, and Mg were also highest when pig slurry had been applied. The ANR values for the micronutrients varied widely among the organic sources but indicated large marginal offtake gains compared to mineral fertilization. The N-based fertilization with animal manures increased the rate of nutrient uptake by plants but led to an accumulation of nutrients in the soil, threatening the sustainability of the system. Manure applications must be monitored regularly to avoid the accumulation of nutrients that could impair the soil quality and become an environmental problem in the future.

Repeated Manure Application for Eleven Years Stimulates Enzymatic Activities and Improves Soil Attributes in a Typic Hapludalf

Animal manure may be a valuable resource for the development of agricultural sustainability. We proposed to verify the feasibility of applications of three types of animal manures to improve soil attributes and to sustain crop yields under intensive cropping and no-tillage systems. The field experiment was established in 2004 on Typic Hapludalf soil with pig slurry (PS), cattle slurry (CS), pig deep-litter (PL), mineral fertilizer (MF) and a non-fertilized treatment. From 2004 to 2015, were grown black oat, maize, forage turnip, black beans, and wheat. Soil samples were taken after winter 2014 and summer 2015, and submitted to chemical, physical, microbiological and biochemical analyses. Animal manures increased soil pH, but MF caused acidification of soil. The PL and CS applications reduced soil density, and increased total pore volume and hydraulic conductivity. Animal manures increased soil P fractions, total organic carbon, total nitrogen, stimulated soil respiration, and had higher activities of glucosidase and acid phosphatase. Wheat had its biggest dry matter and grain yields with MF, but maize grain yields with CS were higher than MF. All indicators pointed that application of animal manure converges to an interesting strategy to recycle nutrients at farmyard level and to contribute to global sustainability.

Forms of nitrogen and phosphorus transfer by runoff in soil under no-tillage with successive organic waste and mineral fertilizers applications

The use of organic wastes in southern Brazil is a common practice in the farms and in many of these, the criterion for defining the doses of organic wastes is to meet the N demand by crops. This may mean the accumulation of chemical elements in the soil, especially in soils managed under no-tillage systems, and enhance the transfer of these elements by surface runoff. The aim was evaluated how successive applications of organic and mineral sources of nutrients in a long-term experiment, managed under no-tillage system in a subtropical environment, influence the transfer of quantities and forms of N and P by surface runoff. The experiment was carried out in southern Brazil, in a Typic Hapludalf soil. The treatments consisted of the application of pig slurry, pig deep litter, cattle slurry, mineral fertilizer and a control, without nutrients. The doses of organic wastes were to meet the N demand by crops. Were evaluated the surface runoff and the transfers of mineral N and forms of P (soluble, particulate, and total) from 2009 to 2013 period. The amount of solution transferred by surface runoff decreased with fertilization and present a negative relationship with the soil organic matter (SOM). The transfers of mineral N increased with the increase in the contents of SOM, but decreased with the runoff. The transfers of P forms present a great relationship with the amounts of P applied and the contents of soil P extracted by Mehlich-1, and more than 55% of total P transferred by surface runoff, in the treatments that received nutrients application, is on soluble form. In addition, the transfer of soluble, particulate and total P was lower with mineral fertilizer application, when compared with organic wastes. This suggest that the use of N demand by crops as a criterium to meet the doses of organic wastes is not adequate in subtropical environment.

Short- and long-term effects of animal manures and mineral fertilizer on carbon stocks in subtropical soil under no-tillage

Establishing the long-term effects of different types of animal manures on soil organic carbon (SOC) stocks has both agronomic and environmental implications. However, only a few studies have analyzed the effects of the types of animal manure on SOC storage in subsurface soil layers. Furthermore, the effect of animal manure on labile and stable soil organic matter (SOM) fractions has been scarcely reported for subtropical no-till soils. We evaluated the effect of animal manure application in the short and long term (4 and 12 years) on SOC storage at different depths throughout a 0–70 cm soil profile and on the physical fractions of SOM in the 0–20 cm layer of a sandy Alfisol cropped under no-tillage. The study involved five treatments: pig deep-litter (PDL), cattle slurry (CS), pig slurry (PS), mineral fertilizer (MF) and a control without fertilization (CL). The SOC stock in the soil profile (0–70 cm) was influenced by manure application in only the long term, which was due to high SOC accumulation in the surface (0–20 cm) in the short-and long-term. The PDL and CS applications resulted in 16% (8.6 Mg ha−1) and 10% (5.2 Mg ha−1) increases in the SOC stock, respectively, compared with those in the CL, but only PDL resulted in greater SOC stocks than MF. These results are related to the greater C addition and higher SOC retention coefficient with the PDL application (17%) than with the CS (15%) and PS (7%) applications. Most of the manure-induced changes were observed in the silt plus clay-sized heavy fraction (SCHF), with PDL and CS being more efficient at increasing SOC storage as organic-mineral complexes than PS or MF in the 0–20 cm soil layer. However, in the subsurface layer (20–70 cm), manure caused a decrease in SOC compared with that in the CL, resulting in negative SOC storage rates in this layer, which partially or completely neutralized the SOC storage rates observed in the surface layer (0–20 cm). In the long term, this condition resulted in SOC storage rates in the 0–70 cm soil profile of 0.48 Mg ha−1 year−1 for PDL, 0.21 Mg ha−1 year−1 for CS, −0.03 Mg ha−1 year−1 for PS and 0.01 Mg ha−1 year−1 for MF. These results indicate that PDL and CS are suitable alternatives to MF for increasing the SOC stock and that the SOC retention is greater with solid manure than with liquid manure (PDL vs CS and PS) and with CS than with PS. Moreover, the results reveal the importance of monitoring SOC changes in the long term and within deep soil layers to better quantify the effects of successive applications of animal manure on SOC storage potential in subtropical sandy soils under no-tillage.

Carbon, nitrogen, and aggregation index in Ultisol with 11 years of application of animal manures and mineral fertilizer

Soil erosion in Brazil is very high, and there is need to promote aggregate stability technics to increase the soil organic matter and the soil water infiltration, with a consequent decrease in erosion processes. Applications of animal manure on sandy loam soil may increase carbon (C) and nitrogen (N) contents in soil aggregates, causing increased aggregate stability. This study aimed to evaluate the contents of total organic carbon (TOC) and total nitrogen (TN) as well as the physical properties of a sandy loam soil subjected to 11 years of application animal manure and mineral fertilizer. The experiment was conducted under no-tillage (NT) system with corn (<i>Zea mays</i> L.)/black oat (<i>Avena strigose</i> Schreb.), bean (<i>Phaseolus vulgaris</i> L.)/black oat, and corn/wheat (<i>Triticum</i> spp.) crops. The following treatments were used: control (no fertilization), pig slurry (PS), pig deep litter (DL), cattle slurry (CS), and mineral fertilizer (NPK). Soil aggregates were obtained from undisturbed soil samples collected at soil depths of 0 to 5, 5 to 10, and 10 to 20 cm. Applications of PS, DL, and CS on soil increased TOC and TN contents, and increasing weighted mean diameter (WMD) and geometric mean diameter (GMD) in the topsoil. Use of DL and CS increased TOC at 0 to 5 cm in comparison to PS, NPK, and control. The use of animal manure also resulted in higher TN contents at 0 to 5 and 10 to 20 cm compared to control. The use of animal manure for 11 years under NT reduced the amount of mesoaggregates (2.0 &gt; Ø ≥ 0.25 mm) and microaggregates (Ø &lt; 0.25 mm) and increased GMD in the topsoil in comparison to the NPK and control. The animal manure promoted the dispersion of clays at 5 to 10 and 10 to 20 cm, resulting in lower soil aggregation in depth. Principal component analysis confirmed that animal manure reduced the degree of flocculation, with a consequent decrease in aggregation indexes, as it grouped the manure treatments in opposition to the NPK and control treatments.

Productivity and quality of Mombasa grass under fertilization with pig deep-litter and NPK

ABSTRACT The use of pig deep-litter (PDL) in pasture fertilization can be an important alternative from an environmental and economic point of view. This study was conducted to evaluate the fertilization with PDL exclusively or in association with mineral fertilizers on the quality and productivity of Panicum maximum cv. Mombasa. The experiment was carried out in Ipameri, GO, Brazil. The design was a randomized block design in a 2 x 5 factorial scheme with four repetitions, in plots of 24 m². The doses of PDL (0; 5; 10; 15 and 20 Mg ha-1) were tested, with or without fertilization with NPK (50 kg ha-1 of P2O5, 10 kg ha-1 of K2O and 10 kg ha-1 of N). The organic fertilizer was applied broadcast at the planting of the pasture, and the mineral fertilizers were split and applied at planting and as topdressing. Dry mass, crude protein, acid detergent fiber and neutral detergent fiber were evaluated. PDL doses associated with mineral fertilization led to linear increases from 52 to 282% in the analyzed variables and better bromatological composition. PDL application is beneficial to the production of pastures, and increasing applications up to the PDL dose of 20 Mg ha-1 associated with mineral fertilization promoted better quantitative and qualitative results. With exclusive fertilization with PDL, the gains in quality and productivity were more modest.

Copper and Zn distribution in humic substances of soil after 10 years of pig manure application in south of Santa Catarina, Brazil.

This study aims to evaluate available Cu and Zn levels in soil and related in soil organic matter (SOM) fractions (fulvic acids-FA, humic acids-HA, and humins-HU) after 10years of application of pig slurry (PS) and pig deep litter (PL). Soil samples were collected from an experiment with black oat/corn succession under no-tillage in southern Brazil. The treatments consisted of fertilization of 90 and 180kgNha-1 applied as PS and PL from 2002 to 2012 and a control treatment without any fertilization. SOM chemical fractionation was performed in air-dried samples. Copper and Zn concentrations were analyzed in soil (total, EDTA- and CaCl2-extracted) and in SOM fractions. The amount of Cu and Zn (in mol) related to each fraction of SOM (Cu/C and Zn/C molar ratios) was established. The applications of PS and PL promoted the accumulation of total and available Cu and Zn, especially in the PL180 treatment. The highest amount of Zn was found with HU, while for Cu both HA and HU were important retention compartments. The highest Cu/CFA, Cu/CHA and Cu/CHU ratios were found with the addition of PL. Increases in Zn/C ratio were found mainly in FA fraction. The high levels of Cu and Zn obtained in the HCl-extracted SOM fraction suggest that a considerable part is bound to SOM and clay minerals with low energy. However, the SOM is an important source of metal adsorption in soils with swine manure application.

Greenhouse gas emissions and global warming potential from biofuel cropping systems fertilized with mineral and organic nitrogen sources

Non-legume bioenergy crops can be fertilized with animal manures instead of mineral fertilizers, but the simultaneous application of carbon (C) and nitrogen (N) with manures can increase nitrous oxide (N2O) emissions. On the other hand, manure could increase soil organic C stocks and partly offset greenhouse gas (GHG) emissions and global warming potential (GWP) of crop systems. We performed a two-year study in a biofuel cropping system with sunflower and canola to examine the effects of manure fertilization on grain yields and N use efficiency of crops, and on GWP and GHG intensity (GHGI) in no-till soils under subtropical conditions. The GWP and GHGI were calculated from measured methane (CH4) and N2O emissions and soil organic C stock change, and from estimated carbon dioxide emissions associated with agricultural inputs and farm operations. The following treatments were tested: (i) mineral fertilizer (MF); (ii) poultry manure (PM); (iii) pig deep-litter (PDL); and (iv) no-N control. The application rate of each treatment was adjusted to provide 60 kg available N ha−1 to crops. Grain yield and N accumulated by sunflower and canola were greater in fertilized treatments than in the control, and did not differ among N sources. However, crop N use efficiency was on average 50% lower with manures than MF. CH4 emissions were not affected by N sources, but N2O emissions increased as follows: control (1.37) < MF (2.04) < PDL (4.12) < PM (4.95 kg N ha−1). On the other hand, soil organic C stocks increased more rapidly with manures than MF, resulting in significantly lower GWP and GHGI with manures than MF after two years. These results indicate that animal manures can replace MF as the main source of N to non-legume oil crops and reduce net GHG emissions in biofuel cropping systems under subtropical conditions.

Nitrogen Availability and Physiological Response of Corn After 12 Years with Organic and Mineral Fertilization

The study aimed to evaluate the effects of long-term organic and mineral fertilization on soil solution dynamics of nitrogen (N), as well as to understand its relationship with corn plant growth, plant N uptake, and grain yield. The study was conducted in Santa Maria, State of Rio Grande do Sul, Brazil, for 12 years. The treatments consisted of pig slurry (PS); cattle slurry (CS); pig deep-litter (PL); mineral fertilizer (NPK); and no fertilization (control). We determined concentrations of dissolved inorganic N (DIN) and dissolved organic N (DON) in soil solution in situ, prior to sowing and during the growing cycle of corn. In plants, we determined the gaseous exchange, shoot N content, grain yield, and indices of recovery and efficiency of N. DIN in soil solution was the predominant N form in all treatments, ranging from 53 to 80% of total dissolved nitrogen (TDN). NPK was the only treatment that maintained high NO3-concentration in the soil solution up to 35 days after plant emergence (DAE) and this resulted in higher grain yield. The plants fertilized with CS obtained a recovery of 80% of the N, and promoted improvements in crop growth. The results of this study showed the importance of combining the application of organic fertilizers (before sowing) with mineral sources of N (topdressing), allowing the maintenance of N availability in the soil solution during periods of demand of organic fertilizer.

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.

Health risk assessment and soil and plant heavy metal and bromine contents in field plots after ten years of organic and mineral fertilization

Heavy metals and bromine (Br) derived from organic and industrialized fertilizers can be absorbed, transported and accumulated into parts of plants ingested by humans. This study aimed to evaluate in an experiment conducted under no-tillage for 10 years, totaling 14 applications of pig slurry manure (PS), pig deep-litter (PL), dairy slurry (DS) and mineral fertilizer (MF), the heavy metal and Br contents in soil and in whether the grains produced by corn (Zea mays L.) and wheat (Triticum aestivum L.) under these conditions could result in risk to human health. The total contents of As, Cd, Pb, Cr, Ni, Cu, Zn and Br were analyzed in samples of fertilizers, waste, soil, shoots and grains of corn and wheat. Afterwards, enrichment factor (EF), accumulation factor (AF), health risk index (HRI), target hazard quotient (THQ) and target cancer risk (TCR) were determined. Mineral fertilizer exhibited the highest As and Cr content, while the highest levels of Cu and Zn were found in animal waste. The contents of As, Cd, Cr, Cu, Ni, Pb and Zn in soil were below the limits established by environmental regulatory agencies. However, a significant enrichment factor was found for Cu in soil with a history of PL application. Furthermore, high Zn contents were found in shoots and grains of corn and wheat, especially when the plants were grown in soil with organic waste application. Applications of organic waste and mineral fertilizer provided high HRI and THQ for Br and Zn, posing risks to human health. The intake of corn and wheat fertilized with pig slurry manure, swine deep bed, liquid cattle manure and industrialized mineral fertilizer did not present TCR.

Physical attributes of Humic Cambisol subjected to nitrogen sources in an apple orchard

The application of nitrogen sources in soil under apple orchards can change the soil physical attributes and soil-plant relationship. The objective was to evaluate the physical attributes of Humic Cambisol (Inceptisol) in an apple orchard, under nitrogen sources in Urubici county, Santa Carina State, Brazil. The treatments were: control (without fertilization), common urea, pelleted urea and organic fertilizer (pig deep-litter), at rates of 33 kg N ha-1 yr-1. After two years of implementation of the N sources, soil undisturbed samples were collected at layers of 0.0-0.05, 0.05-0.10, 0.10-0.15 and 0.15-0.20 m depth, and these were evaluated the bulk density (BD); penetration resistance (PR); total porosity, macro, meso, and micropores; the geometric mean diameter of air-dried aggregates (GMDad) and water-stable aggregates (GMDws) and water content. The organic fertilizer increased the total porosity, microporosity, the water content and decreased BD, compared to other treatments, at the layer of 0.0-0.05 m depth. The organic fertilization and the common urea did not change the macroporosity and PR, but provided lower macroporosity, compared to the control, and RP in relation to pelleted urea. The N sources increased GMDws compared with the control in the topsoil.

Physiological Changes in Maize Grown in Soil with Copper and Zinc Accumulation Resulting from the Addition of Pig Slurry and Deep Litter over 10 Years

The aim of the present study was to evaluate if increased Cu and Zn concentrations in soils, as a consequence of distribution at the field level for 10 consecutive years of pig slurry (PS) and pig deep litter (DL), would cause toxicity to maize plants affecting, in turn, the biomass production and grain yield. With this aim, maize was grown in two cycles in undisturbed samples from soil that had been fertilized with annual applications of 90 or 180 kg N ha−1, either as PS or DL, in a field experiment carried out for 10 years in southern Brazil. The PS180 and DL180 treatments resulted in Cu and Zn accumulation in soil, and PS180 resulted in Zn accumulation in the tissue of maize plants. The increased availability of Cu and Zn was associated to slight changes in stomatal density, chlorophyll content, and catalase and ascorbate peroxidase activities. Nevertheless, soluble carbohydrate and protein contents and plant dry matter accumulation were not significantly affected by exposure of plants to those high levels of either metal. The results here presented indicate that, although successive applications of PS and DL resulted in a really considerable increase of Cu and Zn in the soils, they do not cause toxic effects in maize plants as to impair their ability to produce biomass and grain.

Produção e nitrogênio no solo e na solução em pomar demacieira submetido à aplicação de fontes de nutrientes

A aplicação de fontes de nitrogênio (N) em pomar de macieira pode incrementar o teor do nutriente no solo ao longo do ciclo, afetar o estado nutricional e a produção, mas parte do N pode ser perdido por lixiviação. O trabalho objetivou avaliar o teor de N total em folhas, a produção e o fluxo de N no solo e na solução, em um pomar de macieira com a aplicação de distintas fontes de N, em um experimento em Urubici (SC). Plantas foram selecionadas, receberam a aplicação de ureia (U), ureia peletizada (UP) e cama sobreposta de suínos (CS); além de um tratamento sem adubação (SA). Nas safras 2011/2012 e 2012/2013 foram analisados teores de N em folhas completas e mensurados o crescimento das plantas e a produção de frutos. Foram coletadas amostras de solo e de solução, e analisados os teores de N-NH4 + e N-NO3 - ao longo da segunda safra. Aplicações de U, UP e CS aumentaram o rendimento da macieira no segundo ano, mas o teor de N em folhas não foi afetado nas duas safras. A aplicação de N afetou o fluxo de formas do nutriente no solo e na solução ao longo do ciclo da cultura, com pequenos incrementos nos teores do solo e da solução em períodos próximos à aplicação das diferentes fontes de N

Available content, surface runoff and leaching of phosphorus forms in a typic hapludalf treated with organic and mineral nutrient sources

The application of animal manure to soil can increase phosphorus availability to plants and enhance transfer of the nutrient solution drained from the soil surface or leached into the soil profile. The aim of this study was to evaluate the effect of successive applications of organic and mineral nutrient sources on the available content, surface runoff and leaching of P forms in a Typic Hapludalf in no-tillage systems. Experiment 1 was set up in 2004 in the experimental area of UFSM, in Santa Maria (RS, Brazil). The treatments consisted of: control (without nutrient application) and application of pig slurry (PS), pig deep-litter (PL), cattle slurry (CS), and mineral fertilizers (NPK). The rates were determined to meet the N crop requirements of no-tillage black oat and maize, grown in the 2010/2011 growing season. The soil solution was collected after each event (rain + runoff or leaching) and the soluble, particulate and total P contents were measured. In November 2008, soil was collected in 2 cm intervals to a depth of 20 cm, in 5 cm intervals to a depth of 40 cm, and in 10 cm intervals to a depth of 70 cm. The soil was dried and ground, and P determined after extraction by anion exchange resin (AER). In experiment 2, samples collected from the Typic Hapludalf near experiment 1 were incubated for 20, 35, 58, 73 and 123 days after applying the following treatments: soil, soil + PS, soil + PL, soil + CS and soil + NPK. Thereafter, the soil was sampled and P was analyzed by AER. The applications of nutrient sources over the years led to an increase in available P and its migration in the soil profile. This led to P transfer via surface runoff and leaching, with the largest transfer being observed in PS and PL treatments, in which most P was applied. The soil available P and P transfer via surface runoff were correlated with the amounts applied, regardless of the P source. However, P transfer by leaching was not correlated with the applied nutrient amount, but rather with the solution amount leached in the soil profile.

Forms and accumulation of copper and zinc in a sandy typic hapludalf soil after long-term application of pig slurry and deep litter

Successive applications of pig slurry and pig deep litter may lead to an accumulation of copper (Cu) and zinc (Zn) fractions in the soil profile. The objective of this study was to evaluate the Cu and Zn forms and accumulation in a Sandy Typic Hapludalf soil after long-term application of pig slurry and deep litter. In March 2010, eight years after initiating an experiment in Braço do Norte, Santa Catarina (SC), Brazil, on a Sandy Typic Hapludalf soil, soil samples were collected from the 0-2.5, 2.5-5.0, 5-10 and 10-15 cm layers in treatments consisting of no manure application (control) and with applications of pig slurry and deep litter at two levels: the single and double rate of N requirement for maize and black oat succession. The soil was dried, ground in an agate mortar and analyzed for Cu and Zn contents by 0.01 mol L-1 EDTA and chemically fractionated to determine Cu and Zn. The applications of Pig deep litter and slurry at doses equivalent to 90 kg ha-1 N increased the contents of available Cu and Zn in the surface soil layer, if the double of this dose was applied in pig deep litter or double this dose in pig slurry, Cu and Zn migrated to a depth of 15 cm. Copper is accumulated mainly in the organic and residual fractions, and zinc preferentially in the fraction linked to clay minerals, especially in the surface soil layers.