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1 PAT December, 212; 8 (2): 37-5 ISSN: Online copy available at Publication of Nasarawa State University, Keffi Measurement of the amount of a selected Greenhouse gas (Carbon dioxide) emitted during a short term decomposition of applied animal manure on an acidic Typic Kandiudult Onwuka, M. I. and Idiong N. Department of Soil Science and Meteorology, Michael Okpara University of Agriculture Umudike, PMB 7267, Umuahia, Abia State, Nigeria. ifyonwuka2@yahoo.com Abstract Increased amount of CO 2 released from soils which came from agricultural practices such as animal manure application has stimulated a great worry especially in the area of its input to global warming. In this incubation investigation, conducted at Michael Okpara University of Agriculture Umudike we aimed at measuring the amount of emitted carbon dioxide from applied animal manure in the soil and subsequent effect of these manure on some selected soil properties. Treatment comprised of a control and five animal manures (poultry manure, cow dung, goat dung, rabbit manure and swine manure) applied at 5t/ha (the kilogram equivalent of the rate that was.71kg) to 2g of soil. In other to achieve the stated objectives, the treatments were added to the soil and the amounts of emitted from the soil were measured, at weekly intervals for ten weeks during a laboratory incubation study. Other soil parameters like ph, exchangeable acidity, and organic carbon, among others were determined at the end of the incubation study. Poultry manure emitted the highest cumulative CO 2 of mg kg 1 with cow dung and control emitting the lowest amount of CO 2 of mg kg 1 and 944 mg kg 1 respectively. The carbon sink was increased with the application of cow dung from.89% to 1.47% while poultry manure significantly (p<.5) increased the soil ph from 4.4 to 7.2 and the calcium aluminum ratio from 6.87 to 435. Total nitrogen and available phosphorus were significantly (p<.5) increased by the application of goat dung and swine waste respectively. This study showed that poultry manure has the ability to release more CO 2 while cow dung has the potential to sequester carbon in form of organic carbon in an acidic typic kandiudlt. A field investigation should be conducted to further prove the result. Key words: Carbon dioxide, incubation, emission, organic carbon and animal manure Introduction In the world today the major contributors of greenhouse gases have been identified to include industries, energy supply, transport, residential and commercial building, waste and waste water use, forestry, agriculture among others (Paramasivam, et al., 26). Agricultural practices like fertilizer application, animal housing and manure management, cultivation of wetland rice, manure handling, biomass burning, tillage practices, mineralization of organic matter and soil degradation has contributed up to 13.5% of global greenhouse gases (Barker et al., 27). Due to the shift towards organic farming, more attention is now been given to the use of animal manure as soil amendment. Animal manure, has been found to improve soil health by decreasing soil bulk density for proper root penetration, improving water

2 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 38 infiltration rate and hydraulic conductivity, improving soil aggregate stability, increasing the soil organic matter and plant nutrients (Adeniyan, et al,. 211) of agricultural soils for enhanced crop yield. Although animal manure has all these great potentials in stabilizing the health of the soil, it has also been found to be one of the major culprits in greenhouse gases increase in the world (Paramasivam, et al., 26). The marginal increase in the concentration of various greenhouse gases and their possible contributions to the supposed global warming are becoming a serious concern to the world. Increase in global warming has some remarkable effect on the world and these include crop failure due to drought and flood in some parts of the world, rise in temperature of the ocean that has led to frequent and strong hurricanes, wide spread of infectious diseases, polar ice caps melting which has led to some of the species of animals being endangered, increase in wildfire and food shortage which is causing starvation and death (Khasnis and Nettleman 25, Gore 26). Animal manure from different animal types has diverse chemical compositions (Ano and Agwu 25) and this depends on the animal feeding habits and the type of feed they take in. Reasonable progress has been made in knowing the chemical composition of the animal manure, however many gap still exist in the amount of emitted greenhouse gases from various types of animal manure especially in the tropics, therefore the objective of this work were to ascertain the amount of carbon dioxide emitted from some animal manures and to determine the effect of the applied manures on some soil properties. Materials and Methods The experiment was an incubation study, carried out on the Laboratory benches of the Department of Soil Science and Meteorology, Michael Okpara University of Agriculture Umudike. Umudike is located between latitude 5 29` N and longitude 7 33` E, with an elevation of 122m above sea level and is situated within the Tropical rainfall zone with a mean rainfall of 2117mm, distributed over nine to ten months in a bimodal rainfall pattern. The soil is a Sandy loam soil with a ph of 4.4 (Table 1) and is a well-drained soil and belongs to the coastal plain sand which is classified as Typic Kandiudult (Lekwa and Whiteside 1986). The soil for the experiment was collected from the Eastern farm of the University from a depth of -15cm using a soil auger. The samples were air dried and passed through 2mm sieve. The chemical composition of the soil used for the research is shown on Table 1. The treatment comprised of five animal manures applied at 5t/ha (the kilogram equivalent of the rate.71kg was applied). The treatments were: poultry manure (PM), cow dung (CD), goat dung (GD), rabbit manure (RM); swine manure (SM) and a control. The treatments were laid out in a completely randomized design replicated three times. All the manure was sourced from the livestock farm of Michael Okpara

3 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 39 University of Agriculture Umudike. Two hundred gramme of the air dried soil were weighed in triplicate and the treatment added. The treatments were thoroughly mixed with the soil and the amended soil placed in 2ml incubation flask and moistened to maintain the soil moisture to the field capacity. About 5ml of 1N NaOH solution was put in a small jar and placed inside the soil in the container, lay out on the laboratory benches and were tightly screwed. At weekly intervals, the small jars with the NaOH were taken out and titrated with 1N HCI to determine the amount of CO 2 released into the NaOH solution. About.1% of phenolphthalein was used as the indicator and the CO 2 produced from the manures were calculated with the following formular as stated by Stotzky (1965): CO 2 (mg/kg) = (B-V) NE Where B= Volume (ml) of blank (alkali that was not placed on the amendment) V= Volume (ml.) of acid to titrate the alkali in the small jar placed on top of the amended soils N= Normality of the acid E= Equivalent weight The soil temperature was monitored and measured from the treatment on weekly basis. The experiment lasted for 1 weeks after which it was terminated. At the end of the incubation study the following soil parameters were determined; soil ph at 1:2.5 soil to water suspension using the glass- electrode ph meter (Mclean,1982) ;exchangeable acidity by the method of Peech (1965) using 1N KCI and titrating with.5 NaOH. Organic carbon was by wet oxidation method of Walkley and Black as modified by Nelson and Sommer (1982). Available phosphorus in the soil was gotten by Bray 1 method (Bray and Kurtz 1945). Exchangeable bases were extracted with IN NH 4 OAc buffered at ph 7. (Lanyob, and Heald 1982); potassium and sodium were read with flame photometer while calcium and magnesium were determined by EDTA titration. Total nitrogen was determined by macro Kjeldahl method as described by Bremmer (1982). Dispersion ratio was determined by the following formular [% silt + clay (H 2 )] / [% silt + clay (dispersed)] while the aggregated silt and clay were determined using the formular [% clay + silt (dispersed)] [% clay + silt (H 2 )]. Aggregate size distribution and mean weight diameter were determined according to Kemper and Chepil (1965). The data generated were subjected to analysis of variance (ANOVA) for completely randomized design using the SPSS software package while the means were separated using the Fisher s Least Significant difference (LSD) and linear correlation analysis was done using GENSTAT package.

4 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 4 Table 1: Some of the properties of the soil used for the experiment. Properties Value Sand (%) 8.8 Silt (%) 6.4 Clay (%) 12.8 Textural Class Sandy loam Soil ph (H 2 O) 4.4 Exchangeable Acidity (cmol kg -1 ) 1.28 Exchangeable Aluminum (cmol kg -1 ) 1.9 Exchangeable Hydrogen (cmol kg -1 ).19 Organic Carbon (%).89 Total Nitrogen (%).4 Available Phosphorus (mg kg -1 ) 9.12 Exchangeable Calcium (cmol kg -1 ) 2.56 Exchangeable Potassium (cmol kg -1 ).9 Exchangeable Magnesium (cmol kg -1 ).94 Exchangeable Sodium (cmol kg -1 ).24 ECEC (cmol kg -1 ) 4.92 Result and Discussion The results of the quantities of the carbon dioxide emitted from the applied treatment from first week of the incubation to the tenth week were presented from Figs 1 to 1. The result showed that all the applied animal manure significantly (p<.5) emitted certain amount of carbon dioxide over the control. The results on the Figures showed that there were no significant differences observed at the temperature during the period incubation. During the first week of incubation (Fig 1), swine manure released 228 mg kg -1 of carbon dioxide which was significantly (p<.5) higher than the other treatments. In Figure 2 the production of carbon dioxide was significantly (p<.5) increased in pots that received poultry manure with the value of 266 mg kg 1. This value was the highest amount of carbon dioxide emitted during the incubation period. This highest value recorded at two weeks of incubation may be one the reasons why some researcher like Mbagwu (1989), Obi and Ebo (1995), Ayeni and Adetunji (21) and a lot others recommended that crops should be planted at any time after two weeks of incorporating poultry manure into the soil. At 4, 5, 6 and 7 weeks of incubation (Figures 4, 5, 6 and 7), Goat dung significantly (p<.5) increased the amount of the carbon dioxide released from the soil. At the 8 th week of incubation (Fig 8) the increase in the amount of carbon dioxide liberated was brought about by poultry manure. The increase was in this order PM >GD > RD > SW >CD >C. At 9 and 1 weeks of the

5 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 41 incubation (Figs 9 and 1) the amount of carbon dioxide emitted started reducing and there was no significant difference recorded = = 5.61 Values of emited CO 2 and Temperature Fig 1: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 1 week of incubation. Vertical bar represents lsd at.5 Values of emited CO 2 and Temperature C2 Fig 2: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 2 week of incubation. Vertical bar represents lsd at = Values of emited CO 2 and Temperature C PM GD RD CD SW Fig 3: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 3 weeks of incubation. Vertical bar represents lsd at.5.

6 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 42 Values of emited and Temperature = 4.35 Fig 4: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 4 weeks of incubation. Vertical bar represents lsd at.5 Values of emited CO 2 and Temperature = 4.14 C PM GD RD CD Fig 5: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 5 weeks of incubation. Vertical bar represents lsd at.5 C T Values of emited CO 2 and Temperature Fig 6: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 6 weeks of incubation. Vertical bar represents lsd at.5 Values of emited CO 2 and Temperature Fig 7: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 7 weeks of incubation. Vertical bar represents lsd at.5

7 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of Values of emited and Temperature Values of emitted CO 2 and temperature Fig 8: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 8 weeks of incubation. Vertical bar represents lsd at.5 Fig 9: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 9 weeks of incubation. Values of emitted CO 2 and temperature Fig 1: Quantities of Carbondioxide (mg/kg) emitted and the values of temperature o C at 1 weeks of incubation.

8 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 44 The emitted soil CO 2 flux increased from the first week of the incubation to the eight week and reached its maximum at the second week, although there were substantial fluctuation overall (Fig 11). The flux declined gradually and reached a minimum at the tenth week of incubation. The soil CO 2 flux differed among the treatment tested going from the highest to the lowest in the following order PM>SW>RD>GD>CD>C. Cow dung which gave the least emitted carbon dioxide from the experiment may imply that cow dung stored more of its carbon in the soil 3 25 Amount of CO 2 emitted Weeks of incubation Fig 11: Effect of treatments on the Carbondioxide flux at weeks of incubation. Vertical bars represents Lsd at.5 C PM GD RD CD SW The result of the applied treatment on the soil acidity indices (Table 2) showed that the soils that received poultry manure significantly (p<.5) increased the soil ph and the calcium aluminum ratio over the other treatments applied. Rabbit manure significantly (p<.5) reduced the exchangeable acidity while poultry manure and swine manure significantly (p<.5) reduced the percentage aluminum saturation. The result on the increase of soil ph and the reduction of exchangeable acidity by the application of poultry manure agrees with the findings of Ano and Ubochi (27) and Adeniyan et al,

9 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 45 (211) who reported in their various works with animal manure that the application of animal manure significantly increased the soil ph. The reason for this increase in the soil ph and the reduction in exchangeable acidity and aluminum saturation could be attributed to the release of Ca ions by the process of mineralization of calcium from the organic materials. The released Ca ions move into the soil solution and are hydrolyzed given rise to calcium hydroxide which reacts with soluble aluminum ions in the soil solution to give insoluble Al (OH) 3 and the hydroxide of calcium reacts with hydrogen ions of form water and thus an increase in soil ph due to the formation of calcium hydroxide. Table 2: Effect of treatment on soil acidity indices at the end of the experiment Treatment ph (H 2 O) Exchangeable Acidity Exchangeable Aluminum Exchangeable Hydrogen %Al Saturation Control PM GD RM CD SW Lsd (.5) (cmol/kg) (cmol/kg) Ns (cmol/kg) ns PM= Poultry Manure, GD = Goat Dung, RM= Rabbit Manure, CD= Cow Dung, SW= Swine manure Ca: Al Table 3: Effect of treatment on other soil chemical parameters at the end of the incubation study Treatment N 2 (%) AvP OC (%) Exchangeable bases (mg/kg) Ca Mg K Na Control PM GD RM CD SW Lsd (.5) cmol/kg The effect of the treatments on other soil chemical parameters is domicile in Table 3. The result pointed out that the application of the treatments significantly (p<.5) increased the chemical properties tested over the control. The application of cow dung significantly (p<.5) increased the soil total nitrogen, organic carbon and exchangeable potassium at the end of the incubation study. Available phosphorus and exchangeable calcium were increased significantly (p<.5) by the addition of swine manure. The result also showed that the application of rabbit manure and poultry manure,

10 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 46 significantly (p<.5) increased exchangeable magnesium and exchangeable sodium respectively. The increased by the treatment could be attributed to the presence of organic matter and this result confirms the result of Adeniyan and Ojeniyi (25) who reported that the application of animal manure increased some soil properties. The applied treatment significantly (p<.5) increased the total exchangeable bases and effective cation exchange capacity (Fig 12) over the control. The result further showed that the swine wastes, gave the highest significant (p<.5) values for the total exchangeable bases and effective cation exchange capacity. The lowest emitted carbon dioxide recorded for cow dung as compare to the other tested animal manures could be the reason while more organic carbon was found in the soil amended with cow dung at the end of the study; this may implies that cow dung may have the ability to sequester carbon in a short team Lsd at.5 = 1.68 Lsd at.5=.5 Values for TEB and ECEC (cmolkg-1) TEB Soil proerties ECEC Fig 12: Effect of treatments on Total Exchangeable Bases and Effective Cation Exchange Capacity (comlkg -1 ). Vertical bars represent Lsd at.5 C CD GD PM RM SW Pots that received cow dung significantly (p<.5) reduced the dispersion ratio over the treatment (Table 4) over the control, although no significantly differences existed among the manures. The result also showed that there were no significant differences recorded for the mean weight diameter.

11 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 47 Table 4: Effect of treatment on dispersion ratio and aggregate size distribution Treatment Dispersion Aggregate size distribution (mm) ratio <.6 Control PM GD RM CD SW Lsd (.5) MWD = Mean weight diameter MWD Ns Table 5: Correlation matrix of the cumulated carbon dioxide and some soil chemical properties Soil Properties Cumulated CO 2 ph (Water) Exchangeable Acidity Organic Carbon - 2 ph (water).65 ns - Exchangeable -.66 ns -.83** - Acidity Organic Carbon.28 ns.84** -.55 ns - Total Nitrogen.43 ns.58 ns.9 ns.6 ns - Total Nitrogen *** = Significant at P <.1 ** = Significant at P <.1 * = Significant at P <.5 ns = Not significant The correlation matrix of the cumulated carbon dioxide and some chemical properties at the end of the incubation is shown on Table 5. The result showed that ph correlated positively but not significantly (p<.5) with cumulated carbon dioxide. Exchangeable acidity correlated negatively and none significantly (p<.5) with cumulated carbon dioxide while it correlated negatively and significantly (p<.1) with soil ph. Organic carbon correlated positively but not significantly (p<.5) with cumulated carbon dioxide, it correlated positively and significantly (p<.1) with ph and negatively correlated and not significant (p<.5) with exchangeable acidity. Total

12 PAT 212; 8 (2):37 5: ISSN: ; Onwuka, and Idiong: Measurement of the amount of. 48 nitrogen correlated positively but not significantly (p<.5) with cumulated CO 2, ph, exchangeable acidity and organic carbon. Soil ph correlating positively with cumulated CO 2, organic carbon and total nitrogen implies that as ph is increasing the availability of these parameters are also increasing. It could be deduced that ph favours the micro organisms that undertake the decomposition and mineralization of the animal manure to produce organic carbon and nitrogen. The negative correlation displayed by exchangeable acidity with ph, cumulated carbon and organic carbon indicated that as exchangeable acidity is increasing, the values of ph, cumulated carbon and organic carbon are decreasing and the reason for this could be because animal manure that decomposed to form organic matter and organic carbon contain humic substance, which increases the soil ph. When the ph is increased, exchangeable hydrogen and aluminum which are the main constitute of exchangeable acidity according to Hern et al., (1988) and Gurung et al., (1996) form an Al-organic matter complex, which will in turn make the phyto-toxic Al of the exchangeable acidity to become non- toxic and non available. Conclusion An incubation study was undertaken to ascertain the amount of carbon dioxide emitted from five animal manure namely: poultry manure, cow dung, goat dung, rabbit manure and swine manure applied at 5t/ha the kilogram (equivalent of.71kg) to 2g of an acidic typic kandiudult. Other objective set out was to determine the effect of the applied manures on some selected soil properties. All the animal manure applied showed significant values over the control in relation to the soil parameters tested. Poultry manure emitted the highest cumulative CO 2 and also increased the soil ph, calcium aluminum ration and reduced exchangeable acidity while cow dung and control emitting the lowest CO 2. Consequently soil treated with cow dung increased the exchangeable potassium and retained more organic carbon and as such had the highest value of organic carbon recorded. Therefore it may be imperative to use more of cow dung in farming as this could store more organic carbon in the soil. Further work on field verification of this should be done References Adeniyan O. N., Ojo A. O., Akinbode, O. A. and Adediran J. A. (211) Comparative study of different organic manures and NPK fertilizer for improvement of soil chemical properties and dry matter yield of maize in two different soils. Journal of Soil Science and Environmental Management Vol. 2(1), pp Adeniyan, O.N, Ojeniyi S.O (25). Effect of poultry manure and NPK and combination of their reduced levels on maize growth and soil chemical properties. Nig. J. Soil Sci., 15:

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