Fate of compost nutrients as affected by co-composting of chicken and swine manures

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1 Int. Agrophys., 214, 28, doi: /intg INTERNATIONAL Agrophysics Fte of compost nutrients s ffected y co-composting of chicken nd swine mnures Golo A. Ogunwnde*, Lwrence A.O. Ogunjimi, nd Jmes A. Osunde Deprtment of Agriculturl nd Environmentl Engineering, Ofemi Awolowo University, Ile-Ife, Nigeri Received July 7, 213; ccepted Jnury 3, 214 A s t r c t. Pssive ertion co-composting using four mixtures of chicken mnure nd swine mnure t 1:, 1:1, 3:7 nd :1 with swdust nd rice husk ws crried out to study the effects of co-composting on the physicochemicl properties of the orgnic mterils. The experiment, which lsted 66 dys, ws crried out in ins equipped with inverted T ertion pipes. The results showed tht nutrient losses decresed s the proportion of chicken mnure in the mixtures decresed for sw dust nd rice husk tretments. This indictes etter nutrientst conservtion during composting in swine thn chicken mnure. Mnure mixtures with rice husk hd higher pile tempertures (> 55 C), totl cron nd totl nitrogen losses, while mnure mixtures with sw dust hd higher totl phosphorus loss nd cron to nitrogen rtio. Composts with rice husk demonstrted the ility to rech mturity fster y the rte of drop of the cron to nitrogen rtio. K e y w o r d s: co-composting, chicken mnure, swine mnure, ulking gent, nutrient loss INTRODUCTION Co-composting is the controlled eroic degrdtion of orgnics using more thn one mteril. The ojective of co-composting is to integrte the vrious micro-orgnisms from the different orgnic mterils with view to optimizing the composting process nd producing useful nd sfe end product. Generlly, co-composting of high nitrogenous orgnic mterils (niml mnure, kitchen wste) with low nitrogenous orgnic mterils (dry leves, newsprint, swdust, strw, rice husk) otherwise known s ulking gents (BAs) to djust the moisture content (MC), nitrogen content, cron to nitrogen (C:N) rtio nd void spces etween prticles hs een the trend. Poultry nd swine mnures, which hve ecome environmentl concern in Nigeri due to incresed poultry nd swine frming, hve een difficult to pply in limited nery lnd nd re limited in griculturl use due to pthogens, weed seeds nd unstle nutrients. Severl uthors hve reported the composting of these mnures with different BAs: poultry mnure (Ogunwnde, 211; Ogunwnde nd Osunde, 211; Ogunwnde et l., 28; Predes et l., 1996; Silv et l., 29; Tiqui nd Tm, 22) nd swine mnure (Chng et l., 23; Hung et l., 24; Zhu, 27). It ws oserved tht vrying degrees of nutrient losses, depending on composting methods used nd prmeters controlled, were reported. The cocomposting of poultry mnure nd municipl solid wstes hs lso een reported (Adewumi et l., 25; Lhdi et l., 26). However, informtion on the co-composting of chicken mnure (CM) nd swine mnure (SM) which re oth rich in nitrogen, t different rtios (w w -1 dry sis), with BAs is still sketchy. In the study, CM nd SM were co-composted with swdust ( commonly used BA), nd rice husk (n uncommonly used BA) with view to determining the effects of mnure mixture (MM) on losses of compost nutrients for ech of the BA. MATERIALS AND METHODS The co-composting study ws conducted under shed t the Deprtment of Agriculturl nd Environmentl Engineering, Ofemi Awolowo University, Ile-Ife, Nigeri. The rw chicken nd swine mnures used for the experiments were collected from the Teching nd Reserch Frm of the University, while the BAs swdust nd rice husk were collected from swmill nd rice mill plnts, respectively, in Ile-Ife. Plstic uckets nd polyvinyl chloride (PVC) pipes used for the construction of the composting ins nd ertion pipes were purchsed from pluming mterils deler in Ile-Ife. The initil chrcteristics of the mnures nd BAs re presented in Tle 1. *Corresponding uthor e-mil: golwnde@gmil.com 214 Institute of Agrophysics, Polish Acdemy of Sciences

2 178 G.A. OGUNWANDE et l. Tle 1.Initil properties of composting mterils Property Chicken mnure Swine mnure Swdust Rice husk ph 6.95 (.34) 6.46 (.23) 7.3 (.48) 7.32 (.18) EC (ms cm -1 ) 6.77 (.83) 4.39 (.3).61 (.6).33 (.1) MC (%, w) 8.9 (.73) 74.2 (1.2) 15. (1.12) 11.3 (.94) Ash (%, d) 27.2 (2.19) 41. (1.94) 2.64 (.98) 21.1 (1.66) C T (%, d) 4.4 (.27) 32.8 (1.39) 54.1 (1.3) 43.8 (.29) N T (%, d) 2.4 (.26) 1.83 (.21).48 (.8).81 (.43) P T (mg l -1, d) 22. (2.11) 25.8 (.92) 2.23 (.1) 36.4 (.38) C:N rtio 19.9:1 17.9: :1 54.1:1 Men nd stndrd devition re shown in prenthesis (n = 3). EC electricl conductivity, MC moisture content, C T totl cron, N T totl nitrogen, P T totl phosphorus, w wet weight sis, d dry weight sis. An inverted T pipe ws improvised ccording to Ogunwnde et l. (212) using 5 mm inner dimeter PVC pipes. Eight holes of 15 mm dimeters (four ech on the horizontl nd verticl rms) were drilled on the pipe for pssive ertion. The perfortions were covered with plstic mesh while the top of the verticl rm ws locked with cp to prevent mnures from dropping into the pipe. The composting in ws plstic ucket with ottom nd top dimensions of 34 nd 45 mm dimeters, respectively, nd height of 6 mm. Three holes of 15 mm dimeters were drilled t the se of the in for lechte drin. A 5 mm dimeter hole ws drilled t the centre of the in cover for the escpe of het, wter vpour nd cron dioxide. The inverted T pipe ws fixed inside the in, on top of 5 mm BA lyer, with the open ends of the horizontl rm extending outside the in for ir supply. The ins were equipped with thermometer proes t heights of 265 nd 45 mm from the se. Two experiments of MMs of CM:SM (1:, 1:1, 3:7 nd :1) denoted y M1, M2, M3 nd M4, respectively, were set up with the ddition of BAs to djust the mixtures C:N rtio: first, with swdust (SD) nd second, with rice husk (RH) (Tle 2). The CM nd SM were first mixed to the desired rtios, fter which the C:N rtio of ech mixture ws rised to 25:1 (Wortmnn et l., 26) through the ddition of SD nd RH. The mixture quntities were clculted on dry weight sis. Moisture ddition ws unnecessry s the initil MC of ll the mixtures ws not elow the resonle rnge (4-65%) for composting (Rynk et l., 1992). The mterils were mixed to uniformity using hnd shovel nd stcked to height of 55 mm in the composting ins. Ech tretment ws replicted three times. The mient temperture nd tempertures within ech pile were mesured etween 6: nd 8:.m. when the mient temperture ws firly stle. Smples were collected fortnightly for the first four weeks nd weekly therefter t three loctions (2, 35, 475 mm from the top of the se mteril) in ech in. The collected smples were homogenized nd nlyzed Tle 2.Mnure mixtures with ulking gents Nme of mnure mixture t 15 C dry weight sis for the following prmeters using stndrd methods: MC (15 C for 24 h), sh (expressed s percentge of residues fter comustion t 55 C for 5 h), totl nitrogen (N T ) using regulr-kjeldhl method, totl phosphorus (P T ) (fter cid digestion) using ultr-violet visile, scnning spectrophotometer of wvelength 19-9 nm (Model Unicm Pye UV4-1 from LABEQUIP Limited, Cnd), ph nd electricl conductivity (EC) (1:1 w/v smple : wter extrct) using digitl ph meter (Model 8 from VWR Scientific Products, USA) nd Conductivity/TDS meter (Model YK-22CT from Lutron Electronic Enterprise Compny Limited, Tiwn). The totl cron (C T ) ws estimted from the sh content ccording to the formul used y Ogunwnde et l. (212): C (%) [ 1 Ash (%)]/ 1.8. (1) T Mnure mixture rtio CM:SM M1SD 1: M2SD 1:1 M3SD 3:7 M4SD :1 M1RH 1: M2RH 1:1 M3RH 3:7 M4RH :1 CM chicken mnure, SM swine mnure. Bulking gent swdust rice husk

3 FATE OF COMPOST NUTRIENTS AS AFFECTED BY CO-COMPOSTING OF CHICKEN AND SWINE MANURES 179 Tle 3. Effects of ulking gent on pooled mens of mnure mixture tretments during composting (Duncn multiple rnge test) Bulking gent Temperture ( C) MC (%) ph EC (ms cm -1 ) Prmeter C T N T P T C:N rtio (%) Swdust Rice husk p-vlue <.1 <.1 <.1 <.1 <.1 <.1 <.1 <.1 The sme letter re not sttisticlly different t p.5. Explntion s in Tle 1. Tle 4.Effects of mnure mixture on compost prmeters for swdust nd rice husk tretments during co-composting (Duncn multiple rnge test) Prmeter Mnure mixture M1 M2 M3 M4 p-vlue Swdust Temperture c 3.8d <.1 ( C) MC (%) ph EC (ms cm -1 ) 3.2c <.1 C T (%) N T (%) 27.1c 24.5c <.1 P T (%) C:N rtio c 27.7d 24.8 <.1 Rice husk Temperture c <.1 ( C) MC (%) <.1 ph c <.1 EC (ms cm -1 ) 3.54c 3.43d <.1 C T (%) <.1 N T (%) 53.2c 43.1c <.1 P T (%) <.1 C:N rtio M1, M2, M3 nd M4 chicken mnure to swine mnure mixture of 1:, 1:1, 3:7, nd :1, respectively. Other explntions s in Tle 1. Loss of nutrients from the piles ws clculted s mss lnce, tking into ccount the dry weight reduction of the pile. Hence, the initil (X 1 ) nd finl (X 2 ) sh concentrtions were used to estimte the loss, ccording to the formul used y Ogunwnde nd Osunde (211): X1Y2 Y loss (%) =1-1, (2) Y Y 2 1 where: Y represents nutrient, nd Y 1 nd Y 2 represent the initil nd finl concentrtions of Y. The dt collected were sujected to sttisticl nlyses. One-wy nlysis of vrince (ANOVA) ws performed to compre vritions in compost properties for ech BA nd for pooled mens of MMs. Where differences mong tretments were significnt t p.5, mens were seprted using the Duncn multiple rnge test (DMRT). Correltion nlysis ws used to estlish the reltionships etween compost properties. All nlyses were performed using the Sttisticl Anlysis Systems (SAS, 22) softwre. RESULTS AND DISCUSSION Tle 3 shows tht BA hd significnt (p.5) effect on the pooled mens of MM tretments in ll the compost properties monitored. It is reveled in Tle 4 tht MM hd significnt (p.5) effect on the compost properties for ech BA except for ph in SD tretments. Pile temperture ws used to ssess the stility of the composts, which occurred within 66 dys. This durtion fell within the rnge of 15 nd 18 dys for converting mnure into stilised compost (Rynk et l., 1992). The men vlues showed tht the tempertures of RH tretments were higher thn those of SD tretments (Tle 3). The temperture trend exhiited sinusoidl curve s the proportion of CM decresed in the mixtures, for oth BAs. The highest vlue ws recorded in M2, while the lest in M3. The verge of the upper nd lower tempertures within the piles ws used to plot the temperture profiles shown in Fig. 1. The temperture evolution followed the idel composting ehviour nd it ws the sme pttern in ll the piles: it strted from mesophilic tempertures ( nd CinSD nd RH tretments, respectively), within 24 h to thermophilic tempertures (>42 C) within 6-16 nd 2-8 dys in SD nd RH tretments, respectively, nd dropped to mesophilic tempertures (<4 C) efore stilising t vlues close to mient tempertures. Tretments mnure mixture with: swdust (M4SD) nd rice husk (M4RH) of CM:SM :1, were, however, distinct s they strted with slightly higher tempertures (38.6 nd 38.5 C). Oservtions from the temperture chrcteristics of ech pile (Fig. 1) showed tht the pek

4 18 G.A. OGUNWANDE et l. Temperture ( o C) Amient M1SD M2SD M3SD M4SD ph M1SD M2SD M3SD M4SD Composting time (dys) Temperture ( o C) Amient M1RH M2RH M3RH M4RH Composting time (dys) Fig. 1. Chnges in ir nd pile tempertures during co-composting of chicken nd swine mnures with: swdust, rice husk. M1SD, M2SD, M3SD, M4SD with swdust; M1RH, M2RH, M3RH, M4RH with rice husk; chicken mnure to swine mnure mixture of 1:, 1:1, 3:7 nd :1, respectively. tempertures, which were ttined t different dys during composting, nd the durtion of thermophilic tempertures were much lower in SD tretments. None of the SD tretments met the snittion requirement (tempertures >55 C for three consecutive dys) for weed seeds nd pthogens tement (Zhu et l., 24). Similrly, mnure mixture with rice husk (M1RH, M3RH) of CM:SM 1: nd 3:7, respectively, lso filed to meet this requirement. The high temperture oserved in RH tretments compred to SD tretments ws ttriuted to low ulk density of rice husk (11-12 kg m -3 ) compred to swdust (19-21 kg m -3 ) (Chng nd Chen, 21), which reflected high porosity (or free ir spce) nd resulted in high ir circultion within the RH tretments for efficient performnce of the decomposing microorgnisms. Generlly, the low thermophilic tempertures nd short thermophilic phse oserved in ll the tretments were proly result of the high initil MC of the mnures ( %) which my hve impeded ir supply to the piles for effective microil ctivities. It ws reported tht excessive moisture cn reduce free ir spce to the point where oxygen storge nd trnsport through the void spces ph M1RH M2RH M3RH M4RH Fig. 2. Chnges in ph during co-composting of chicken nd swine mnures with: swdust, rice husk. Error rs show stndrd errors of mens (n = 3). is reduced (Petric et l., 29). In spite of this shortcoming, the ttinment of thermophilic tempertures y mnure mixture with: swdust (M2SD, M3SD) nd rice husk (M2RH, M3RH) of CM:SM 1:1 nd 3:7, respectively; showed tht co-composting of CM nd SM hd no negtive effect on the temperture of the piles. Temperture dt collected t the two levels within the piles showed no sttisticl difference (p vlues rnged from.33 to.964), implying tht composting rtes nd compost qulity within the levels were the sme. Uniform composting rtes re chrcteristic of n inverted T pipe (Ogunwnde et l., 212). The initil MC of the mixtures rnged from % (SD tretments) nd % (RH tretments). The higher vlues for SD tretments were result of the slightly higher initil MC of the SD (Tle 1). Lechte from the piles ws sored y the se mteril. The MC of the piles decresed y evportion grdully s orgnic mtter (OM) degrdtion occurred in the piles. The rte of moisture loss ws higher in RH tretments (verge of 2.4% week -1, R 2 =.96) thn in SD tretments (verge of 1.23% week -1, R 2 =.977) ecuse SD hs higher wter sorption cpcity (43-45%) thn RH (33-34%) (Chng nd Chen, 21). The men vlues (Tle 3) showed tht MC of the piles decresed s the proportion of CM in the mixtures

5 FATE OF COMPOST NUTRIENTS AS AFFECTED BY CO-COMPOSTING OF CHICKEN AND SWINE MANURES 181 decresed for SD tretments while slight increse ws oserved in M3RH. The MC of the piles ws not replenished throughout the experiment s no pile hd elow 45%. The initil ph of SD tretments ( ) ws lower thn tht of RH tretments ( ). This order ws reflected during the composting (Tle 2) nd it ws ttriuted to the high initil ph of RH (Tle 1). The strting ph of the mixtures ws within the resonle rnge of for rpid composting (Rynk et l., 1992). The highest ph ws oserved in mnure mixture with swdust of CM:SM 1: (M1SD), nd M3RH. The chnges in ph of composting piles re shown in Fig. 2. The ph of SD tretments followed the sme trend. It showed slight vritions from the initil vlues etween week nd week 5 (Fig. 2) efore steep increse to y week 6 nd grdul drop to y week 9. In RH tretments (Fig. 2), the ph of M3RH nd mnure mixture with rice husk (M4RH) of CM:SM :1, incresed grdully from 6.84 nd 6.93 to 7.29 nd 7.22 y week 8 efore decresing to 6.91 nd 6.94, respectively, y week 9. Conversely, M1RH nd M2RH hd their ph decresed from 7.21 nd 7.1 to 6.83 nd 6.77 y week 5 nd incresed to 7.1 nd 7.15 y week 8 nd gin decresed to 6.98 nd 6.97, respectively, y week 9. The ph rise ws linked to the iodegrdtion of the orgnic cids, minerlistion of orgnic compounds, nd the consequent relese of voltile NH 3 (Predes et l., 2). The temporry drops in ph noticed during composting were ttriuted to the production of orgnic cids during decomposition of OM contined in the mixtures (Chrest nd Beuchmp, 22). The decrese in ph t the lter stge of composting my e linked to the voltilistion of mmoni nitrogen nd H + relesed s result of microil nitrifiction process y nitrifying cteri (Eklind nd Kirchmnn, 2). The finl ph vlues of the compost rnged etween 6.59 nd These vlues were within the limit of 7.2 recommended for the improvement of griculturl soils (Rynk et l., 1992), for optimum plnt growth (Perry, 23), nd for comptiility with most plnts (Lsridi et l., 26). Electricl conductivity reflects the degree of slinity in the composting product, which indictes its possile phytotoxicity/phyto-inhiitory effects on the growth of plnts (Lin, 28). The EC of SD tretment ws lower thn tht of RH tretment (Tle 2). EC vrition followed the sme trend in oth BA tretments (Tle 3). The highest vlues were oserved in M3. The chnges in EC of composting piles re shown in Fig. 3. The EC vrition followed the sme pttern in SD tretments. It decresed grdully from initil vlues of to ms cm -1 y week 7, nd incresed fterwrd to finl vlues of ms cm -1. M1RH nd M3RH hd their EC incresed grdully from initil vlues of 3.16 nd 3.24 ms cm -1 to pek vlues of 3.84 (y week 4) nd 4.1 ms cm -1 (y week 2), nd decresed to finl vlues of 3.18 nd 3.8 ms cm -1, respectively. In M2RH, the EC decresed from 3.51 ms cm -1 to the lowest vlue of 2.77 ms cm -1 nd incresed EC (ms cm -1 ) EC (ms cm -1 ) Fig. 3. Chnges in electricl conductivity during co-composting of chicken nd swine mnures with: swdust, rice husk. Error rs show stndrd errors of mens (n = 3). Explntions s in Fig. 2. grdully to the finl vlue of 3.71 ms cm -1. The EC of M4RH hd repeted fluctutions throughout the experiment. It strted with n initil vlue of 3.7 ms cm -1 nd hd finl vlue of 2.26 ms cm -1. The increse in EC during composting could e due to the relese of minerl slts through decomposition of OM, nd the concentrtion effect due to net loss of dry mss (Silv et l., 29), wheres, the voltiliztion of mmoni nd the precipittion of minerl slts could e the possile resons for the decrese (Wong et l., 1995). The finl EC vlues ( ms cm -1 ) were elow the upper limit of 4. ms cm -1 considered tolerle y plnts of medium sensitivity (Lsridi et l., 26). The C T contents showed n increse in the finl vlues in SD tretments nd decrese in RH tretments. The C T loss in RH tretments ws greter thn in SD tretments (Tle 2). The C T loss ws ttriuted to io-oxidtion of OM resulting in the evolution of cron dioxide nd het (Brrington et l., 22). It ws oserved tht M1SD nd M2SD hd the sme (p >.5) nd higher losses thn M3SD nd M4SD which hd the sme (p >.5) nd lower losses (Tle 4). The high losses recorded in M1 tretments compred to those in M4 tretments showed tht higher level of OM iodegrdtion occurred in CM thn in SM. The vrition in losses showed high fluctutions in SD tretments (Fig. 4). All tretments hd gins in C T y week 2.

6 182 G.A. OGUNWANDE et l. Totl C loss (%) Totl C loss (%) Tle 5.Finl losses in compost nutrients Nutrients Prmeter C T N T P T (%) Swdust M1 18.5*,, M2 15.8*, M3 28.8*, 32.*, 55. M4 28.8*, 35.5*, 51.1 p-vlue Rice husk M c 65.d M c 57.9 M3 4.4c *,c M4 37.6d 7.51*, 2.8*, p-vlue <.1 <.1 <.1 Explntions s in Tle 1. Fig. 4. Chnges in totl C losses during co-composting of chicken nd swine mnures with: swdust, rice husk. Error rs show stndrd errors of mens (n = 3). Explntions s in Fig. 2. However, M1SD nd M2SD lost vrying proportions (-59%) of C T y week 4 to week 8 nd hd finl gins of 18.5% nd 15.8%, respectively (Tle 5). M3SD nd M4SD gined C T throughout the composting experiment, with finl vlues of 28.6 nd 21.%, respectively (Tle 5). These gins corresponded to increse in C T content of the piles. All the mixtures in RH tretments recorded C T losses during composting (Fig. 4). The losses were significntly (p.5) correlted with MC (R 2 =.943), N T (R 2 =.865) nd C:N rtio (R 2 =.935). In RH tretments, M1 nd M2 hd consistently close nd higher losses thn M3 nd M4 which hd consistently close nd lower losses. The losses incresed grdully to finl vlues etween 37.7 nd 89.9% (Tle 4). The N T contents of RH tretments incresed significntly during composting, from initil vlues of % to finl vlues of %. The SD tretments recorded decrese in N T contents of M1SD nd M2SD from 1.73 nd 1.61% to finl vlues of 1.49 nd 1.3%, respectively, nd n increse in M3SD nd M4SD from 1.58 nd 1.52% to finl vlues of 1.72 nd 1.71%, respectively. The N T content increse ws due to the net loss of dry mss in terms of cron dioxide, s well s wter loss y evportion cused y het evolved during oxidtion of OM (Hung et l., 24). During composting, the verge vlues showed tht N T losses from M1 nd M2 were sttisticlly the sme Totl N loss (%) Totl N loss (%) Fig. 5. Chnges in totl N losses during co-composting of chicken nd swine mnures with: swdust, rice husk. Error rs show stndrd errors of mens (n = 3). Explntions s in Fig. 2.

7 FATE OF COMPOST NUTRIENTS AS AFFECTED BY CO-COMPOSTING OF CHICKEN AND SWINE MANURES 183 C:N rtio C:N rtio Fig. 6. Chnges in C:N rtio during co-composting of chicken nd swine mnures with: swdust, rice husk. Error rs show stndrd errors of mens (n = 3). Explntions s in Fig. 2. (p >.5) for oth RH nd SD tretments (Tle 4). The vrition of N T loss during composting showed tht SD tretments hd fluctuting ptterns (Fig. 5), while M3SD nd M4SD experienced gins throughout the experiment, nd M1SD nd M2SD recorded losses. The losses in M1SD nd M2SD peked t week 5 nd week 6, respectively. All the RH tretments hd reltively grdul vritions (Fig. 5). M1RH nd M2RH recorded higher losses, M3RH recorded lower losses nd M4RH recorded gins. At the end of composting, M3SD, M4SD nd M4RH hd gins in N T (Tle 5). Becuse of the low thermophilic tempertures nd short thermophilic phse oserved in this study compred to other pssive ertion composting studies (Ogunwnde, 211; Ogunwnde nd Osunde, 211), significnt prt of the N T losses oserved during the erly dys of composting could therefore not e ttriuted to mmoni voltiliztion which hs een found to occur t high tempertures (Brrington et l., 22; Ling et l., 26), ut to denitrifiction (Ling et l., 26). The gin in N T recorded in some piles my hve een result of the rise in N T levels due to iologicl-n fixtion (formtion of NO 3 -N) through microil ctivities which cn esily develop t moderte tempertures (Predes et l., 1996). The C:N rtio of SD tretments decresed s the proportion of CM in the mixtures decresed (Tle 4). However, for RH tretments, n increse in C:N rtio from M2RH, M1RH, M4RH to M3RH ws oserved. During composting, the C:N rtio of SD tretments hd n initil increse during week 2 nd fluctuted therefter (Fig. 6). The C:N rtio of RH tretments (Fig. 6) hd grdul decrese, with the highest rte of decrese in M2RH nd the lest in M3RH. Decrese in C:N rtio with composting time hs een reported in previous studies (Chrest nd Beuchmp, 22; Hung et l., 24; Ogunwnde, 211; Ogunwnde nd Osunde, 211), nd ttriuted to either the minerlistion of the sustrtes present in the initil composting mterils or n increse in totl N concentrtion resulting from the concentrtion effect s C is iodegrded. The finl C:N rtios of M3SD nd M4SD were less thn the initil (24.4:1 nd 23.4:1, respectively), while those of M1SD nd M2SD were ove (3.1:1 nd 32.4:1, respectively). The composts with finl C:N rtio less thn 25:1 showed n indiction of mturity (Bernl et l., 29). The RH composts demonstrted the ility to rech mturity fster y the rte of drop of the C:N rtio of the piles. The losses of C T,N T nd P T followed the sme trend, with losses decresing s the proportion of CM in the mixtures decresed for oth BAs (Tle 4). From the men vlues otined during composting (Tle 4) nd the finl vlues (Tle 5), it ws oserved tht for the individul mnure tretments, M4 conserved nutrients etter thn M1, while M3 ws etter for nutrients conservtion thn M2 when co-composting. Generlly, the finl losses oserved (Tle 4) differ from vlues reported in previous composting studies (Chng et l., 23; Ogunwnde et l., 28; Ogunwnde et l., 212; Silv et l., 29; Tiqui nd Tm, 22), proly ecuse of the: different composting method, BAs used, MM, or non-exposure of the piles to direct sunlight which my hve ccelerted the decomposition nd loss of vlule nutrients (Kwkye, 1977). CONCLUSIONS 1. Rice husk tretments hd higher pile tempertures, totl cron nd totl nitrogen losses, while swdust tretments hd higher totl phosphorus loss nd C:N rtio. 2. Rice husk composts demonstrted the ility to rech mturity fster y the rte of drop of the C:N rtio of the piles. 3. Nutrient losses decresed s the proportion of chicken mnure in the mixtures decresed. Hence, swine mnure ws etter thn chicken mnure t nutrients conservtion during composting while chicken mnure to swine mnure 3:7 ws etter thn 1:1. 4. The composts hd the potentil to dequtely ttin optimum tempertures for pthogen nd weed seeds tement t reduced moisture content.

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