10 Environmental Implications of Inositol Phosphates in Animal Manures

Transcription

1 10 Environmentl Implictions of Inositol Phosphtes in Animl Mnures April B. Leytem l nd Rory 0. Mguire 2 'United Sttes Deprtment of Agriculture Agriculturl Reserch Service, Northwest Irrigtion nd Soils Reserch Lbortory, 3793 N E., Kimberly, ID 83341, USA; 2 Crop nd Soil Environmentl Sciences, Virgini Tech, Box 0404, Blcksburg, VA 24061, USA Animl production in the USA is vlued t more thn $100 billion nd hs consolidted significntly during the lst 20 yers, with lrger number of nimls being produced on n incresingly smller lnd bse (Kellogg et l., 2000). Mnure generted from niml production is currently estimted to exceed 335 million t of dry mtter per yer in the USA, while globl mnure production is estimted t 13 billion t of dry mtter per yer (Mullins et l., 2005). Mnures contin significnt mounts of phosphorus, with vlues between 6.7 nd 29.1 g P/kg on dry weight bsis reported for severl species of nimls (Brnett, 1994). This phosphorus includes inorgnic nd orgnic forms, with the ltter constituting between 10 / nd 80% of the totl (Peperzk et l., 1959; Gerritse nd Zugec, 1977). Inositol phosphtes re one of the primry orgnic phosphorus species found in mnures, with rrtyo-inositol hexkisphosphte typiclly being the most bundnt (Peperzk el l., 1959; Brnett, 1994; Turner nd Leytem, 2004). The environmentl fte of phosphorus in niml mnures is determined in prt by the chemicl composition of the phosphorus, yet few studies hve fully chrcterized mnure phosphorus nd determined the effect of the vrious phosphorus compounds on phosphorus behviour in soil. The vrious forms of orgnic phosphorus differ in the extent of their sorption when pplied to soils, with triyo-inositol hexkisphosphte being strongly hound while other orgnic phosphorus compounds such s nucleotides, DNA nd glucose phosphtes re more mobile (Celi nd Brberis, 2005), Phosphorus pplied to soil s mnure my lso behve differently from minerl phosphte fertilizer, due to other chemicl chrcteristics of the mnure. Orgnic mtter in mnure cn complex iron nd luminium vi orgnic lignds, which decreses the precipittion of Inositol phosphtes with these metls. It lso competes for sorption sites in soil, incresing the concentrtion of phosphte in solution (Iymuremye et l., 1996). Inositol phosphtes in mnure cn lso disperse soil colloids nd therefore increse the potentil for prticulte phosphorus trnsport in runoff (see Celi nd Brberis, Chpter 13, this volume). Bsed on this evidence, more detiled informtion on the lorms of phosphorus in mnures, s well s those mnure chrcteristics tht influence phosphorus sorption, my shed light on the potentil for off-site losses of phosphorus from lnd ppliction of mnure. This chpter ddresses environmentl issues concerning phosphorus nd inositifl phosphtes in niml production. We summrize studies on the phosphorus composition of mnures, including those using trditionl extrction procedures nd the more recent ppliction of nucler mgnetic resonnce (NMR) spectroscopy. Finlly, we review how dietry modifiction nd storge lters the phosphorus composition of mnures, nd explore the impct of such ltertions on CAB Interntionl Inositol Phosphtes: Linking Agriculture nd the Environment 150 (eds B.L. Turner, A.E. Richrdson nd E.J. Mullney) phosphorus soluf for phosphorus tn Why is M Enviror Consolidtion of te regionl nd where nutrient in tilizer exceed nuts ml products (Sh 1998). These nu increse the risk ment nd polluth 1996; Sims et t mnures cn he ri lnd, which reduce tilizers. Unfortim produced in loc. high cost of effect gies in n unbl disposl vi lnd nutrient needs, r res with nutrier 1998). Phosphorus is it cn ccumulte i thn those needed This is due in p phosphorus rtios uptke of these nt results in overpp mnures re p t requirement of the result, long-term n turl lnd leds to nd greter potent runoff to wter be eutrophiction in numerous exmple ssocited with ph in l opertions r Glsgow, 1997; L Boesch et l., 2001) need to understnd ml mnures on d This demnds n the behviour of m. its potentil for pl Importnt spects i

2 Environmentl Implictions in Animl Mnures 151 phosphorus solubility in soils nd the potentil istics tht determine phosphorus hehviour for phosphorus trnsfer in runoff. following lnd ppliction nd the potentil chnges induced by dietry modifiction. Why is Mnure Phosphorus n Environmentl Concern? Consolidtion of niml production cn generte regionl nd frm-scle nutrient surpluses where nutrient imports in feed nd minerl fertilizer exceed nutrient exports in crops nd niml products (Shrpley el l., 1994; Sims et l., 1998). These nutrient surpluses cn in turn increse the risk of nutrient loss to the environment nd pollution of wter bodies (Shrpley, 1996; Sims et l., 1998, 2000). Nutrients in mnures cn be recycled by ppliction to croplnd, which reduces the need for commercil fertilizers. Unfortuntely, lrge mounts of mnure produced in loclized res, coupled with the high cost of effective nutrient utiliztion strtegies in n unblnced system, fvour mnure disposl vi lnd ppliction in excess of crop nutrient needs, rther thn utilizing mnure in res with nutrient deficiencies (Shrpley et l., 1998). Phosphorus is prticulr concern, becuse it cn ccumulte in soil to concentrtions greter thn those needed for optimum crop production. This is due in prt to unfvourble nitrogen/ phosphorus rtios in mnures reltive to the uptke of these nutrients by most crops, which results in overppliction of phosphorus when mnures re pplied to meet the nitrogen requirement of the crop (Mikkelsen, 2000). As result, long-term mnure ppliction to griculturl lnd leds to soil phosphorus ccumultion nd greter potentil for phosphorus trnsfer in runoff to wter bodies. This cn contribute to eutrophiction in freshwter ecosystems, nd numerous exmples of wter qulity impirment ssocited with phosphorus pollution from niml opertions now exist (Burkholder nd Glsgow, 1997; US Geologicl Survey, 1999; Boesch it l., 2001). There is therefore n urgent need to understnd nd reduce the impct of niml mnures on the pollution of wter bodies. This demnds mechnistic mulerstnding of the behviour of mnure phosphorus in soils nd its potentil lbr phosphorus trnsfer in runoff. Importnt spects include the mnure chrcter- Phosphorus Composition of Animl Mnures Investigtion of the dynmics of mnure phosphorus following ppliction to soils requires informtion on the phosphorus composition of the mnure, One of the erliest studies of mnure chrcteriztion ws performed by Funtsu (1908), who used sequentil extrction techniques to frctionte the phosphorus in guno. The procedure involved dilute cid to extrct inorgnic phosphte, inositol phosphtes nd other orgnic forms, followed by ether nd lcohol to extrct phospholipids, with the residue (unextrcted frction) being lbelled s nucleic cid. Vritions of this procedure were subsequently used by others to chrcterize mnures from pigs fed vriety of feed rtions (Rther, 1918), poultry nd mixed frmyrd mnure (Ghni, 1941), sheep mnure (McAuliffe nd Peech, 1949) nd fresh mnure from horses, cttle, sheep, pigs nd hens (Kil, 194-8). Orgnic phosphorus in these studies rnged between 18% nd 50% of the totl phosphorus, with the cidsoluble orgnic phosphorus (which typiclly included inositol phosphtes) constituting between 0% nd 86% of the totl orgnic frction. Peperzk et l. (1959) used similr sequentil extrction procedure to determine the phosphorus composition of vriety of mnures. Totl phosphorus concentrtions rnged between 4 nd 30 g P/kg dry weight, with the inorgnic frction constituting % of totl phosphorus (Tble 10.1). In this procedure, tffyo-inositol hexkisphosphte ws isolted from the cid extrct nd ws found to represent between 1% nd 22' of totl phosphorus, with other cid-soluble orgnic phosphorus lorms constituting between 3% nd 4V/. The lcohol-soluble frctions were smll ( %) while residul phosphorus vlues rnged between 2% nd 27% of totl phosphorus. When mnures of different ges were exmined from stockyrd, the generl trend ws decrese in orgnic phosphorus from 49% to 320/6 of totl phosphorus over 20 yers, with

3 152 A.B. Leytem nd R.O. Mguire Tble Concentrtions of phosphorus compounds in sequentil extrcts of niml mnures. (From Peperzk et l., 1959.) Animl Totl P (g P/kg) Phosphte myo-lnositol hexkisphosphte Other cidsoluble P of totl P Alcoholsoluble P Residul P Chick ND Hen Sheep Sow Horse Steer Bull Cow Clf ND = not detected. concomitnt decrese in myo-inositol hexkisphosphte from 3.9% to 1.5 0/0 of totl phosphorus. Brnett (1994) published the most recent comprehensive study on orgnic phosphorus compounds in niml mnures using conventionl sequentil frctiontion techniques. Orgnic phosphorus in vriety of mnures ws frctionted into phospholipids, nucleic cids, cid-soluble orgnic phosphorus, inorgnic phosphte nd residul phosphorus. Inorgnic phosphte constituted the gretest proportion of the totl phosphorus, followed in descending order of mgnitude by residul phosphorus, cid-soluble orgnic phosphorus nd smll mounts of phospholipids. In this study the myo-inositol hexkisphosphte content ws not directly mesured, but the cid-soluble orgnic phosphorus frction, which typiclly includes the inositol phosphtes, rnged between 7.8% nd 53.4% of the totl phosphorus. Interest in the environmentl fte of mnure phosphorus prompted recent studies to dopt the Hedley frctiontion (Dou et l., 2000; Shrpley nd Moyer, 2000; Weinhold nd Miller, 2004). This procedure ws originlly developed to ssess phosphorus solubility in soil (Hedley et l., 1982) nd involves sequentil extrction with wter, sodium bicrbonte, sodium hydroxide nd hydrochloric cid. Phosphorus extrcted in wter nd bicrbonte is considered redily soluble, while tht extrcted in sodium hydroxide (ssumed to be ssocited with morphous iron/luminium nd orgnic mtter) nd hydrochloric cid (ssumed to be clcium phosphtes) is considered poorly soluble. However, severl problems compromise the suitbility of the Hedley frctiontion for mnures. In prticulr, phosphorus chemistry differs mrkedly between soils nd mnures, being controlled commonly by iron nd luminium oxides nd clcium crbonte in soils (Henley et l., 1982), nd by ssocition with clcium nd mgnesium in mnures (Cooperbnd nd Wrd Good, 2002). Turner nd Leytem (2004) used solution NMR spectroscopy to unequivoclly identify phosphorus compounds in the vrious frctions of the Hedley extrction scheme s pplied to poultry, swine nd cttle mnures. Two min groups of phosphorus compounds were determined with this procedure: redily soluble frction extrcted with wter nd sodium bicrbonte nd stble frction extrcted with sodium hydroxide nd hydrochloric cid. Orgnic phosphorus in the redily soluble frction included DNA, phospholipids nd simple phosphte monoesters. Orgnic phosphorus in the stble frction consisted minly of myo-inositol hexkisphosphte. Since there ws considerble overlp between the extrcts, the uthors recommended simpler procedure consisting of extrction with sodium bicrbonte to remove the redily soluble frction (which would be most susceptible to trnsport in runoff), followed by extrction with solution contining sodium hydroxide nd ethylenedimine tetrcette (EDT A) to recover the more stble frction. This ir recovery of phos1 mnure (Turner, 2004). Solution 31 P used to quntify ti wide vriety of m Leytem et l., 200, 2004; Turner nd 2005). These stud phorus is predomii lowed in descei monoesters, phosp phospholipid), pyre phosphontes. C. hexkisphosphte 80% of the totl vriety of ruminn gstric nimls (poi stte 31 P NMR spe. to mnures (e.g. H ccurtely ssess th demonstrt tion nd solution myo-inositol hexkis cn vry widely, b. (Tble 10.2). Theo between ruminnt cn ccount for ti monogstric nim of cerel grins, in I occurs s slts of 1, (phytte); for exm of the phosphorus it form (see Rboy, monogstric nirm phytse (McCuig poultry nd pigs c; undigested phytte 2004). In contrst, cpcity to hydrolyt diet, nd mnures lucerne-bsed die However, there is e\ grin-bsed diet, vent extensive hydi isphosphte nd / niml intct (see D. Dietry effects given species. For c hens fed mize with

4 Environmentl Implictions in Animl Mnures 153 frction. This method gve ner-quntittive recovery of phosphorus from swine nd poultry mnure (Turner, 2004; Turner nd Leytem, 2004). Solution 31 P NMR spectroscopy hs been used to quntify the phosphorus composition of wide vriety of mnures (Leinweber et l., 1997; 1,eytem et l., 2004; Mguire et l., 2004; Turner, 2004; Turner nd Leytem, 2004; McGrth et l., 2005). These studies indicte tht mnure phosphorus is predomintely inorgnic phosphte, followed in descending order by phosphte monoesters, phosphte diesters (nucleic cids nd phospholipid), pyrophosphtes nd, in some cses, phosphontes. Concentrtions of myo-inositol hexkisphosphte rnged from non-detectble to 80% of the totl phosphorus in mnures from vriety of ruminnt (cttle nd sheep) nd monogstric nimls (poultry, swine; Tble 10.2). Solidstte 31 P NMR spectroscopy hs lso been pplied to mnures (e.g. Hunger et l., 2004), but cnnot ccurtely ssess the orgnic phosphorus frction. As demonstrted by both sequentil frctiontion nd solution 31 P NMR spectroscopy, the go-inositol hexkisphosphte content of mnures cn vry widely, both mong nd within species (Tble 10.2). There rc physiologicl differences between ruminnt nd monogstric nimls tht cn ccount for these differences. The diets of monogstrie nimls often include lrge mounts of cerel grins, in which much of the phosphorus occurs s slts of myo-inositol hexkisphosphte (phytte); for exmple, pproximtely two-thirds of the phosphorus in mize nd soybens is in this firm (see Rboy, Chpter 8, this volume). As nnmogstric nimls do not possess mple gut phytse (McCuig et l., 1972), mnures from poultry nd pigs cn contin lrge mounts of undigested phytte (lthough see Leytem et l., 2004). In contrst, ruminnt nimls hve the cpcity to hydrolyse inositol phosphtes in their diet, nd mnures from nnuls fed grss or lucerne-bsed diets contin little phytte. However, there is evidence tht for ruminnts grin-bsed diet, metl complextion cn prevent extensive hydrolysis of niyo-inositol hexkisphosphte nd llow it to pss through the niml intct (see Do, Chpter I I, this volume). Dietry effects re lso evident within given species. For exmple, mnure from lying hens fed mize with vrying levels of non-phytte phosphorus, with nd without phytse dditions, cn contin wide rnge of now-inositol hexkisphosphte concentrtions (35-80% of totl phosphorus, wheres mnure from broilers fed diet consisting minly of brley contins closer to 10% of totl phosphorus in this form (Tble 10.2). This indictes the importnce of determining dietry impcts on the composition of mnure phosphorus excreted from the niml to ssess the potentil behviour of mnure phosphorus once pplied on lnd. Since it hs been demonstrted tht inositol phosphtes cn sorb strongly to soils (see Celi nd Brberis, Chpter 13, this volume), chnges in the concentrtion of nryo-inositol hexkisphosphte in mnure could be of concern from n environmentl stndpoint (discussed lter). Impct of Dietry Mnipultion on myo-inositol Hexkisphosphte in Mnure As monogstrie nimls cnnot fully utilize phytte in cerel grins, minerl phosphte supplements re commonly dded to their diets to prevent phosphorus deficiency. As described bove, this increses phosphorus concentrtions in mnure nd cn led to phosphorus ccumultion in soils when mnure phosphorus is pplied in excess of crop phosphorus removl (Sims et l., 2000). To ddress concerns regrding surplus phosphorus in mnure, strtegies involving dietry mnipultion re being widely dopted to reduce mnure phosphorus concentrtions (see Lei nd Porres, Chpter 9, this volume). By reducing phosphorus excretion, mnures with nitrogen/ phosphorus rtios more closely mtching the nutrient needs of crops cn be generted, thereby reducing overppliction of phosphorus nd build-up of soil phosphorus. For monogstric nimls tht hve limited bility to digest phytte, dietry strtegies include the isoltion of mutnt grins tht store most of the ultr phosphorus in the grin s inorgnic phosphte nd less s phytte (Rboy et l., 2000; Dorsch et t., 2003, see Rboy, Chpter 8, this volume), thereby enhncing phosphorus uptke by the niml nd reducing the excreted phosphorus (Spencer et l., 2000; Veum el l., 2002; fng et l., 2003; Klunzinger et l., 2005). Supplementtion of niml feeds with microbil phytse is

5 154 A.B. Leytem nd R.O. Mguire Tble Concentrtions of phosphorus compounds in extrcts of mnures from selection of nimls determined by solution 3'P NMR spectroscopy. (From Leytem t l., 2004, 2005, 2006 nd unpublished dt; Mguire et l., 2004.) Mnure Swine mnure, fresh (brley feed) Swine lgoon liquid Broiler mnure (brley feed) Broiler mnure (stndrd mize diet) Broiler mnure (mize, low NPP0) Broiler mnure (mize, low NPP + phytse) Broiler litter (mize, high NPP) Broiler litter (mize, high NPP + phytse) Turkey litter (mize, high NPP) Turkey litter (mize, high NPP + phytse) Diry lgoon liquid Diry compost Beef mnure (mize-fed) Beef mnure (psture-fed) Sheep (brley-fed) Totl Phosphte Pyrophosphorus Phosphtebmonoesters bphosphte b g P/kg dry wt (97) (94) 0.67 (5) 0.13 (1) Tr (99) (97) 0.75 (3) 0.09 (<1) ND myo-lnositol hexkisphosphte b 6.36 (99) 4.46 (70) 1.92 (30) ND 0.74 (12) (96) 7.21 (46) 8.19 (53) 0.21 (1) 7.61 (49) 9.49 (99) 1.22 (28) 8.17 (86) 0.10(1) 7.62 (80) 9.61 (98) 5.33 (56) 4.04 (42) 0.13(1) 3.39 (35) (98) 5.71 (41) 8.38 (60) 0.06 (<1) 7.83 (56) (96) 5.05 (49) 5.74 (55) ND 4.88 (47) (87) (71) 6.74 (44) 0.14 (1) 5.09 (33) (94) 8.56 (67) 4.82 (38) 0.14 (1) 3.45 (26) 8.80 (93) 7.93 (90) 0.82 (9) 0.06 (<1) 0.37 (4.2) 2.50 (98) 2.28 (91) 0.22 (9) (<1) 0.03 (1) 4.20 (99) 2.51 (60) 1.60 (38) 0.09 (2) 0.34 (8) 4.10 (83) 2.65 (65) 1.0 (25) 0.25 (6) ND 8.45 (91) 5.52 (65) 1.68 (20) 0.41 (5) 0.47 (6) 'Vlues re totl phosphorus extrcted by sodium hydroxide nd ethylenediminetetrcette (EDTA), nd vlues in prentheses re the proportion (%) of the totl mnure phosphorus determined by microwve digestion. 'Vlues in prentheses re the proportion (%) of the extrcted phosphorus. NPP = non-phytte phosphorus. Tr = trce; ND = not detected. position, which environmentl (Turner et l., impct of diet n mls on phosphc be chnges in tl with correspor, of the mnure p extrctble phosr reduces the prop rus occurring s the proportion of the mnure incre phorus, even the centrtion my evident for poulti be importnt wh. on the bsis of common in sever Feedinc Mutnt grins thz tte thn the wild tionlly been fed Dorsch et l., 20 volume) hve rec, ent there re lowley nd soyben formultions. Lo mutnt grins hv future improveme ii Tor lso used to increse phytte hydrolysis in the gut, thereby enhncing phosphorus utiliztion by the niml (Cromwell et l., 1993; Coelho nd Koniegy, 1996; see Lei nd Porres, Chpter 9, this volume). The combintion of low-phytte grins with phytse dditions is lso utilized to further reduce phosphorus excretion. In ddition to reducing the concentrtions of phosphorus in mnure, dietry modifiction is expected to influence mnure phosphorus com Mi Fig The effec wter-extrctble pl modified poultry die Toor et l., 2005; Le

6 Environmentl Implictions in Animl Mnures 155 position, which my hve implictions for the environmentl fte of mnure phosphorus (Turner el l., 2002). Potentilly the gretest impct of diet modifiction in monogstric nimls on phosphorus forms in mnure is likely to be chnges in the mount of phytte excreted, with corresponding increse in the proportion of the mnure phosphorus tht occurs s wterextrctble phosphte. 'Elms, s diet modifiction reduces the proportion of the mnure phosphorus occurring s myo-inositol hexkisphosphte, the proportion of wter-extrctble phosphte in the mnure increses s frction of totl phosphorus, even though the totl phosphorus concentrtion my be reduced. This is prticulrly evident fin- poultry mnures (Fig. 10.1) nd my be importnt when mnures re pplied to lnd on the bsis of phosphorus content, s is now cominon in severl sttes in the USA. Feeding low-phytte grins Mutnt grins tht contin substntilly less phytte thn the wild-type equivlent tht hs trditionlly been led to nimls (Rboy et l., 201)0; 1)orsch el l., 2(1)13; see Rboy, Chpter 8, this volume ) hve recently been developed. Ai present there re low-phytte vrieties of mize, brley nd soyben mel tht cn be used in feed formultions. Low gronomic yields of these mutnt grins hve prevented wide doption, Inn future improvements re likely, nd these grins E ro m 0 Toor et l. (2005) Mguire et l. (2004) Leytem et l. (2006) Mnure phytte (9 70 totl P) 100 Fig The effect of phytte concentrtion on wter-extrctble phosphorus in mnures from modified poultry diets. (From Mguire et l., 2004; Toor et l., 2005; Leytem et l., 2006.) will be useful for developing strtegies to reduce phosphorus excretion by monogstric nimls. Lrge reductions in totl phosphorus excretion cn be chieved using these grins (Spencer et l., 2000; Li et l., 2001; Venn et l., 2002; Jng et l., 2003; see Lei nd Porres, Chpter 9, this volume), lthough only few studies hve determined their impct on phosphorus composition in mnure. Toor et l. (2005) reported decrese of only 10 9/0 in excreted totl phosphorus from broilers fed diets contining norml mize vs. low-phytte mize, lthough there ws 47./0 reduction in the m ount of mho-inositol hexkisphosphte excreted by the birds. Bxter et l. (20(13) sw the sme trend for swine fed low-phytte mize; totl phosphorus excretion ws only slightly reduced, but myo-inositol hexkisphosphte excretion ws reduced by lmost 50 /0. When low-phytte brleys were included in broiler diets, mnure totl phosphorus concentrtions were reduced by 14 24% (Leytem el l., 2006b; Tble 1(1.3). However, myo-inositol hexkisphosphte concentrtions in mnures from ll dietry tretments constituted only 3 I2% of the totl phosphorus in the mnure, even when s much s 91% of totl phosphorus in the feed ws phytte. This sme trend ws lso reported for swine in ;t similr study; totl phosphorus excretio n ws reduced by 33% when nimls were fed lowphytte diets, yet myo-inositol hexkisphosphte ws excreted only in trce mounts (Leytem it l., 21)04; Tble 10.3). This indictes tht even though monogstric nimls do not possess sufficient phytse to hydp tlyse phytte in the prt of the digestive trct where phosphorus sorption tkes plce, the phytte is not necessrily excreted by the ;mitnl. A possible explntion is tht brley diets contin high intrinsic phytse ctivity (see [xi nd Porn's, Chpter 9, this volume), which might led to phytte hydrolysis in the niml. However, in study of swine mnure from nimls led diets contining wild-type nd low-phytte mize, which contins little intrinsic phytse, most of the excreted phosphorus (-80% of totl phosphorus) ws inorgnic phosphte nd there ws little difference in the mnure frctions cross dietry tretments (Weinhold nd Miller, 2004). A more likely explntion, therefore, is iht phytte is hydrolysed in the hindgut by intestinl mierollor, even though the nimls derive little nutritionl benefit from this process in the lower intestine.

7 156 A.B. Leytem nd R.O. Mguire Tble Phosphorus concentrtions in poultry nd swine mnure fed either wild-type brley (Copelnd nd CDC Bold) or mutnt brley with reduced mounts of grin phytic cid content (M 422, M 635, M 955). Phosphorus concentrtions were determined by extrction in sodium hydroxide nd ethylenediminetetrcette (EDTA) nd solution 31 P NMR spectroscopy. Mens in the sme column (for ech niml type) followed by the sme letter do not differ significntly (P> 0.05). (From Leytem et l., 2004; Leytem, A.B., Thcher, RA. nd Turner, B.L., 2006, unpublished dt.) Feed phytte myo-lnositol Phosphte (% totl hexkis- Grin type phosphorus) Totl P Phosphtebmonoesters phosphte Copelnd M 422 M 635 M 955 CDC Bold M 422 M 635 M 955 NOH-EDTA extrctble P (g P/kg dry wt) Poultry (broiler chicks) (99) 4.46 (70) 1.92 (30) 0.74 (12) (93)c 3.42 (69)c 1.53 (31)b 0.34 (7)b (92)bc 3.20 (72)c 1.29 (29)b 0.34 (8)b < (92)b 3.88 (75)b 1.24 (24)b 0.14 (3)b Swine (brrows) (97) (94) 0.67 (5) Tr (95)b 7.77 (86)b 1.08 (12) Tr (91)b 7.59 (86)b 1.08 (12) Tr (95)b 7.78 (88)b 0.91 (11) ND 'Vlues in prentheses re the proportion (%) of the totl mnure phosphorus determined by microwve digestion. bvlues in prentheses re the proportion (%) of the NOH-EDTA extrcted phosphorus. 'Vlues for phosphte monoesters Include myo-inositol hexkisphosphte nd other monoesters. Tr, trce; ND, not detected. 9 - (5 c ct E 2 c 0 ""c13 S 2 Lo. 0.z Feeding microbil phytse s supplement There re severl different types of phytse enzymes (see Mullney nd Ullh, Chpter 7, this volume), lthough they ll ctlyse the relese of phosphte residues from myo-inositol hexkisphosphte. Phytse supplements re now common component of niml diets nd hve been successful in reducing phosphorus concentrtions in mnures (see Lei nd Porres, Chpter 9, this volume). However, the effects on mnure phosphorus composition nd therefore mnure phosphorus behviour in soils re poorly understood. It would be expected tht mnures from diets tht included phytse would hve less myoinositol hexkisphosphte thn equivlent diets without phytse. This ws the cse in study of mnures from swine fed diets with nd without phytse (Bxter et l., 2003). Concentrtions of myo-inositol hexkisphosphte in fresh swine mnure were decresed by g P/kg by dding phytse to the feed. However, during storge of mnure from the norml diet for 150 dys, myo-inositol hexkisphosphte s percentge of totl phosphorus decresed from 15.5 /0 to 8.5%, which ws ttributed to microbil degrdtion. For the phytse-mended diet the decrese in myo-inositol hexkisphosphte during storge ws only between 9.1% nd 9.8%, indicting hydrolysis by the dded phytse prior to excretion (Bxter et l., 2003). Therefore, fter 150 dys of storge, there ws no significnt difference in myo-inositol hexkisphosphte concentrtions in swine mnures from the two diets. Mguire et l. (2004) grew three flocks of broilers nd two flocks of turkeys on the sme bed of litter using diets tht were 'high' nd 'low' in non-phytte phosphorus with nd without phytse dditions. Concentrtions of myo-inositol hexkisphosphte in both broiler nd turkey litters from diets tht included phytse were consistently lower thn in litters from equivlent non-phytse diets (Tble 10.4). Inorgnic phosphte levels in the broiler nd turkey litters To O.c tt, U S 0..c to 2.^.0 ;.

8 Environmentl Implictions in Animl Mnures 157 ) C ) cc CO 2 4) O to o n to co In ' C') ) 0) N.. C') co co co O o o ci ) ILO ) Lo o -4- co co Lc) oi 1 oi ES 2 4 C".4 N. I!) n cl- d s co.0.0, o y 1.6 l (.0-0 c i 4 4 c\i c0 crl CO l c? 0) to 12 CO -8 tq Q -0 V i 2.0 co cy co oi C1) O fjj 0, - Z Z )- Z)- Z >- 2 RI cji) 0000 ci ci c5 co co ) co E C CT) 'C m CT).6: :(1'. co co co z-d- :o= O c: COCCICOCO

9 158 A.B. Leytem nd R.O. Mguire were lrgely unffected by dietry phytse. This ws most likely due to the benefit of decresed dietry inorgnic phosphte supplements being cncelled out by the incresed phytte hydrolysis by dietry phytse. McGrth et l. (2005) determined myo-inositol hexkisphosphte in litters from broilers fed vriety of diets with nd without phytse ddition, nd found tht concentrtions were lower in litter from diets contining phytse thn from diets without phytse (Tble 10.4). Toor et l. (2005) nlysed turkey mnure nd broiler litter smples from diets with nd without phytse using X-ry bsorption ner-edge structure spectroscopy. Although detection of orgnic phosphtes ws difficult using this technique, the uthors concluded tht dietry phytse ddition decresed myo-inositol hexkisphosphte concentrtions in mnures nd litters, nd tht diclcium phosphte ws the most bundnt form of phosphorus present. There hs been some discussion in the literture s to whether residul dietry phytse will continue to hydrolyse myo-inositol hexkisphosphte in mnures following excretion, hence mking phosphorus more wter-soluble. Angel et l. (2005) used combintions of boiling poultry nd swine mnures, or dded ntibiotics, to show tht dietry phytse supplementtion hd no effect on phytte hydrolysis following excretion. These uthors concluded tht the 'increse in wter-soluble phosphorus s percent of totl phosphorus post excretion is function of excret microbil ctivity nd not dietry phytse ddition' (Angel el l., 2005). McGrth et l. (2005) stored broiler litters generted from diets 'high' nd 'low' in phosphorus, with nd without phytse, t two diffi)rent moisture contents for 440 clys. By compring the interctions of storge time nd moisture, they showed tht nyo-inositol hexkisphosphte concentrtions decresed through time only in litter tht ws stored 'wet'. This ws unrelted to dietry phytse nd ws insted ttributed to enhnced microbil ctivity in the wet litter (McGrth et l., 2005). Mguire et l. (2006) fed broiler breeders diets 'high' nd 'low' in dietry non-phytte phosphorus, with nd without phytse. Soluble phosphorus ws similr in mnure from under the feeder s in clen re, indicting no effect of spilled feed whether or not it included phytse. However, under the drinker, mnure moisture nd soluble phosphorus were higher irrespective of the diet, presumbly due to incresed microbil ctivity breking down myo-inositol hexkisphosphte into more soluble forms. The effects of mnurederived phytse in soils re unknown, lthough discussion of the interctions of phytse with soil constituents cn be found elsewhere in this volume (see George et l., Chpter 14). Combining low-phytte grins nd phytse In ddition to reserch on low-phytte grins or phytse lone, few studies hve investigted combintion of low-phytte grins nd phytse. Bxter et l. (2003) reported tht such combintion decresed myo-inositol hexkisphosphte fresh swine mnures more thn either pproch individully (Tble 10.5). This trend ws lso seen in broiler litters, in which myo-inositol hexkisphosphte decresed front 20% of totl phosphorus h in norml mize diet to 12% nd 10 % in diets contining low-phytte mize nd lowphytte mize plus phytse, respectively (Toor et l., 2005; Tble 10.5). Other studies combined phytse nd low-phytte grins in poultry diets nd reported reductions of 27 45% of totl phosphorus nd /0 of wter-extrctble phosphte in the litter, lthough none determined tryo-inositol hexkisphosphte directly (Applegte et l., 2003; Miles et l., 2003; Penn et l., 2004). Mnure phosphorus composition nd phosphorus solubility in soil Mnipulting the diets of monogstric nimls cn hve lrge impct on the mount of nqoinositol hexkisphosphte excreted from swine, poultry nd fish. In ddition, storge of mnure prior to lnd ppliction cn lso influence inositol phosphte concentrtions by promoting microbil degrdtion. This rises n importnt question: Do differences in inoshol phosphte concentrtions influence the solubility nd potentil trnsport of mnure phosphorus to wter bodies following ppliction to soil? Relese of soluble phosphorus from mnuremended soil vries considerbly depending on the source of the mnure pplied (i.e. niml Tble Dietz effect on mnure not significntly d Animl Diet Broiler Norml Broiler Low-phy miz( Broiler Low-phy mize Swine Norml Swine Low-phy mize Swine Low-phy mize 0WSP wter-solubt species, diets fed, This is primrily c trtions of totl mnure (Shrply) et l., 2002:0); Vt clue in prt to v chemicl propert phosphte is relt to myo-inositol hex; retined nd unlit. phorus in runoff el l., 2002). "There rus composition of ences in species, is through dietry phosphorus trnsp, to wter bodies (V: When vriet beef cttle mnure: ferently) were incur ous soils, there IA between myo-inosi (rnging between rus) nd soil phos 1 Westermnn, 9005 die smll mount:, phte in the mono to influence phosi Insted, phosphort

10 Environmentl Implictions in Animl Mnures 159 Tble Dietry studies utilizing low-phytte grins with nd without the ddition of phytse nd the effect on mnure phytte content. Mens followed by the sme letter (within column for ech study) re not significntly different t P= Totl P WSP WSP/totl P rtio Phytte/totl P rtio Animl Diet Phytse g P/kg dry weight Reference Broiler Norml mize No Toor et l. (2005) Broiler Low-phytte No 20.1b mize Broiler Low-phytte mize Yes 15.7c Swine Norml mize No Bxter et l. (2003) Swine Low-phytte No 20.7b mize Swine Low-phytte mize Yes 15.2c 7.9b WSP = wter-soluble phosphte in mnure. species, diets led, mnure hndling nd storge). This is primrily due to differences in the concentrtions of totl nd soluble phosphorus in the mnure (Shrpley nd Moyer, 2000; Kleinmn et l., 20(12,b; Vds et /., 2004), but my lso be due in prt to vribility in other physicl nd chemicl properties of the mnure. Inorgnic phosphte is reltively soluble in soils compred to riyo-inositol hexkisphosphte, which is strongly retined nd unlikely to be lost s soluble phosphorus in runoff (Anderson el l., 1974; Leytem el l., 2002). Therefore, vribility of the phosphorus composition of mnures, either due to differences in species, mnure-hndling techniques or through dietry mnipultion, could increse phosphorus trnsport from lnd-pplied mnures to wter bodies (Vds et /., 2004). When vriety of mnures (swine, diry nd beef cttle mnures tht were hndled/stored differently) were incorported into semirid clcreous soils, there ws no significnt correltion between myo-inositol hexkisphosphte content (rnging between 0% nd 8 o of totl phosphorus) nd soil phosphorus solubility (Leytem nd Westermnn, 2005; Fig. 10.2). In this instnce, the smll mounts of myo-inositol hexkisphosphte in the mnures were probbly insufficient to influence phosphorus solubility in the soil. Insted, phosphorus solubility ws clerly influenced by the mount of crbon dded to the soil (Fig. 10.2h). When poultry mnures were dded to similr clcreous soil, the mount of myo-inositol hexkisphosphte in the mnures, which rnged between 35% nd 80')/o of totl phosphorus, ws strongly nd negtively correlted with bicrbonte-extrctble soil phosphte, following mnure ppliction (Fig. 10.3). Mnures were pplied t the sme totl phosphorus rte, so this correltion ws lmost certinly due to the greter proportion of wter-soluble phosphte dded in mnure with lower myo-inositol hexkisphosphte concentrtions. However, the reltionship ws trnsient, becoming insignificnt fter 9 weeks of incubtion (Fig )). This demonstrtes clerly tht when mnures re pplied on the bsis of phosphorus content, the proportion of nfro-inositol hexkisphosphte, nd therefore of wter-soluble phosphte, hs strong influence on the solubility of the mnure phosphorus soon fter ppliction. Extrctble phi isph le concentrtions incresed between the second nd ninth week of incubtion nd were correlted with the mount of mro-inositol hexkisphosphte in the mnures. In other words, mn tires with more myo-inositol hexkisphosphte cused greter increses in extrctble soil phosphte over time. Anlysis of

11 160 A.B. Leytem nd R.O. Mguire () r2 = 0.16; P = 0.43 (b) r2 = 0.81; P = 0.01 () 400"441, (b) the mnure-mended soils immeditely following incorportion (Fig. 10.4) nd fter 9 weeks of incubtion (Fig. 10.4b) using solution 31 P NMR spectroscopy demonstrted the hydrolysis of myoinositol hexkisphosphte in the soil, strongly () Mnure phytte (% totl P) Mnure crbon/phosphorus rtio Fig Reltionship between bicrbonte-extrctble phosphte nd () mnure phytte concentrtion nd (b) mnure crbon/phosphorus rtio for six mnures of vrying origin dded to clcreous rble soil (Portneuf silt lom) from Idho, USA, contining 0.75% orgnic crbon, ph 7.6 nd 18% cly. (From Leytem nd Westermnn, 2005.) suggesting tht this ws responsible for the increse in extrctble phosphte. Although rnyo-inositol hexkisphosphte is strongly bound in soils, microbes in the semirid clcreous soil were ble to brek it down into (b) 1 6 Fig Solution (NMR) spectr of e poultry mnure () Lion nd (b) fter 9 t 6.3 ppm is inorgi four lbelled signl: hexkisphosphte.. reltively rpid hydr inositol hexkispho: et l., 2006.) weeks 9 weeks r2 = 0.99; P r2 = 0.48; P = Mnure phytte (% totl P) Fig Reltionship between the phytte concentrtion in poultry mnure nd the bicrbonteextrctble phosphte in mnure-mended soil following () 2 weeks of incubtion nd (b) 9 weeks of incubtion. The soil ws clcreous rble soil (Portneuf silt lom) from Idho, USA, contining 0.75% orgnic crbon, ph 7.6 nd 18% cly. (From Leytem et l., 2006.) inorgnic phosph therefore not be e^ soils following sue This confirms th biovilbility of i ous soils (Turner why some contii Turner, Chpter the sme mnure showed no correl myo-inositol hexk soil phosphte (M( the smpling dte: bon/phosphorus r extrctble phospl t 2 weeks of incub The solubility mended soils see chrcteristics of

12 Environmentl Implictions in Animl Mnures 161 () (b) -t Chemicl shift (ppm) Flg Solution 31 P nucler mgnetic resonnce (NMR) spectr of extrcts of soil mended with poultry mnure () immeditely following incorportion nd (b) fter 9 weeks of incubtion. The pek t 6.3 ppm is inorgnic phosphte, while the other four lbelled signls re from myo-inositol hexkisphosphte. The spectr demonstrte the reltively rpid hydrolysis of mnure-derived myoinositol hexkisphosphte in soil. (From Leytem et l., 2006.) inorgnic phosphte within few weeks. It would therefore not be expected to ccumulte in these soils following successive mnure pplictions. This confirms the evidence for the reltive biovilbility of inositol phosphtes in clcreous soils (Turner et l., 2003) nd my explin why some contin no detectble phytte (see Turner, Chpter 12, this volume). In contrst, the sme mnures pplied to n cidic soil showed no correltion between dded mnure myo-inositol hexkisphosphte nd extrctble soil phosphte (Mehlich-3 extrction) on ny of the smpling dtes, with only the mnure crbon/phosphorus rtio being correlted to the extrctble phosphte concentrtions (12 = 0.84 t 2 weeks of incubtion; dt not shown). The solubility of phosphorus in mnuremended soils seems to be influenced by the chrcteristics of the mnure pplied. In the short term, mnures with lrge concentrtions of myo-inositol hexkisphosphte cn demonstrte lower phosphorus solubility on clcreous soils, lthough this trend does not seem to hold true for cidic soils. However, due to microbil brekdown of myo-inositol hexkisphosphte in pplied mnures nd concurrent relese of soluble phosphte, these differences re likely to become insignificnt over time. Other mnure properties, prticulrly the crbon content, seem to exert lrge influence on phosphorus solubility following ppliction to both clcreous nd cidic soils (Leytem et l., 2005), presumbly due to stimultion of the microbil biomss nd fixtion of phosphorus in microbil tissue. This mens tht the ddition of mnure results in lower soluble phosphorus concentrtion thn would be expected from minerl phosphte fertilizer ppliction. It therefore follows tht in the long term the most importnt fctor to consider for lnd ppliction of mnures is totl phosphorus, rther thn the form of the phosphorus pplied. An importnt impct of mnure inositol phosphtes on the loss of phosphorus to wter bodies involves erosion nd trnsport of prticulte phosphorus. Erosion cn be severe on griculturl lnd nd is potentilly responsible for the movement of lrge mounts of inositol phosphtes to wter bodies (see McKelvie, Chpter 16, this volume). Erosion cn be promoted by inositol phosphtes in mnures due to the dispersion of soil colloids following sorption to soil components (see Ccli nd Brberis, Chpter 13, this volume). There is lmost no informtion on inositol phosphte trnsport in prticulte mteril from griculturl lnd, nd it is not discussed further here. However, severl stereoisomeric forms of inositol hexkisphosphte hve been reported from riverine-suspended solids (Suzumur nd Krntni, 1995). More infbrmtion cn he found in detiled review of orgnic phosphorus trnsfer from soils to wter bodies (Turner, 2005). Dietry Mnipultion nd the Environmentl Fte of Mnure Phosphorus Mnures from low-phytte feed Although the totl phosphorus excreted from monogstric nimls ied vriety of low-phytte

13 162 A.B. Leytem nd R.O. Mguire grins hs been shown to be significntly reduced, the impcts of these mnures on potentil phosphorus losses following long-term ppliction to griculturl lnd hve not been studied. One of the primry resons for this is the lck of sufficient quntities of mnure needed for fieldscle ssessments, prticulrly multi-yer projects. Investigtion is therefore limited to lbortoryscle studies. Gollny et l. (2003) showed 10 / reduction in mnure phosphorus vilbility when mnure from swine fed low-phytte mize-bsed diets vs. norml mize diets ws incorported into silt lom soil. Leytem et l. (2005) incorported mnure from swine fed vriety of lowphytte brley-bsed diets nd found no significnt reltionship between the mount of nuto-inositol hcxkisphosphte dded in the mnures nd bicrbonte-extrctble phosphte in soil (Fig. 10.5). However, s with previous studies, there ws strong reltionship between the mounts of crbon dded with the mnures nd the bicrbonte-extrctble phosphte (Fig. 10.5b). As the mount of phosphorus excreted by nimls fed low-phytte grins is reduced, there is corresponding increse in the mnure crbon/ phosphorus rtio, which cn enhnce the stbiliztion of phosphorus in mnure-mended soils compred with soils mended with mnures from norml grin-bsed diets. Therefore, even when ti i) 100 E 80 - m cis 60 ( () (b) r2 < 0.01; P= 0.51 r2 =0.80; P< pplied on the sme totl phosphorus bsis, there is potentil environmentl benefit to feeding low-phytte grins when the subsequent mnures re lnd-pplied, t lest in the short term. Mnures from phytse-mended feed Studies hve consistently shown reductions in mnure totl phosphorus nd noto-inositol hexkisphosphte from swine nd poultry tht hve been ( led diets with phytse, but only when, s recommended, inorgnic phosphte supplementtion is reduced to ccount fbr enhnced phosphorus vilbility due to phytse ddition. However, there hs been some disgreement over the effect of dded phytse on mnure wter-extrctble phosphte, which is importnt becuse it is linked directly to phosphorus losses in runoff (Mguire et l., 2005). Dietry phytse ddition cn decrese totl mnure phosphorus concentrtions by s much s 45% for poultry nd 40"/o for swine (see Lei nd Porres, Chpter 9, this volume). These reductions re importnt, s totl phosphorus determines build-up or decline in soil test phosphorus following lnd ppliction of mnures. This is prticulrly true where mnure is pplied on the bsis of introgen content the effects of chnges in mnure Mnure phytte (% totl P) Mnure crbon/phosphorus rtio Fig The reltionship between bicrbonte-extrctble phosphte nd () mnure phytte concentrtion or (b) mnure crbon/phosphorus rtio for mnures from swine fed low-phytte grin diets pplied to clcreous rble soil (Portneuf silt lom) from Idho, USA, contining 0.75% orgnic crbon, ph 7.6 nd 18% cly. (From Leytem et l., 2005.) phosphorus compc to become relevr the bsis of phospb. Severl studio nd litters derived nd mesured pho (2004) reported t dditions decrese phte in swine mt effect on soluble mnured soils, rel; phytse-mended becuse equivlen pplied, so mnure of wter-soluble p mended diets) wer phosphte in runof soluble phosphte c ditely following th from phytse-rr (Com soils tht rece (Smith et l., 2004b on weight bsis becme insignificn fll events were incl in both studies th minium sulphte) reduced soluble phi Ibllowing litter ppli which dietry ptn mnure wter-extr (2004) reported no hle phosphte cone soils mended with I nd non-phytse- mnures were pplii rus rte. Using turkey t lent phytse- nd Mguire ci l. (200 2 phytse decresed u in litters, but generl inorgnic phosphn in runoff when mr soil prior to rinfill. ws pplied on I he 1 rus content. Where ws conducted, decresed s the incresed, nd the chrcteristics becrr highlight the point

14 Environmentl Implictions in Animl Mnures 163 phosphorus composition re therefore only likely to become relevnt when mnure is pplied on the bsis of phosphorus content. Severl studies hve surfce-pplied mnures nd litters derived from phytse-mended diets nd mesured phosphorus in runoff Smith el l. (2004) reported tht lthough dietry phytse dditions decresed the wter-extrctble phosphte in swine mnure, this hd no significnt effect on soluble phosphorus losses in runoff from mnured soils, reltive to mnure from nonphytse-mended diet. This ws surprising becuse equivlent weights of mnures were pplied, so mnures with smller concentrtions of wter-soluble phosphte (i.e. from phytsemended diets) were expected to yield less soluble phosphte in runoff In similr study, however, soluble phosphte concentrtions in runoff immeditely following the ppliction of poultry litter from phytse-mended diet were lower thn from soils tht received litter from norml diet (Smith et l., 2004h). Agin, mnure ws pplied on weight bsis nd, importntly, the effect becme insignificnt when three consecutive rinfll events were included. It should be noted tht in both studies the ppliction of lum (luminium sulphte) to the litters considerbly reduced soluble phosphte in litter nd in runoff fidlowing litter ppliction to MA In one study in which dietry phytse significntly incresed mnure wter-extrctble phosphte, Vds et l. (2004) reported no significnt differences in soluble phosphte concentrtions in runoff between soils mended with poultry mnures from phytse nd non-phytse-mended diets, even when mnures were pplied t the sme totl phosphorus rte. Using turkey nd broiler litters from equivlent phytse- nd non-phytse-mended diets, Mguire et l. (2004, 20051)) found tht dietry phytse decresed nfro-inositol hexkisphosphte in litters, but generlly hd little effect on mnure inorgnic phosphte or soluble phosphte losses in runoff when mnures were incorported into soil prior to rinfll. This occurred whether litter ws pplied on the bsis of nitrogen or phosphorus content. Where more thn one runoff event ws conducted, soluble phosphte losses decresed s the number of runoff events incresed, nd the elli.cts of diet nd mnure chrcteristics becme less significnt. These dt highlight the point tht the soluble phosphorus in mnure hs greter impct on runoff soluble phosphte concentrtions in the short term thn in the long term (Penn et l., 2004; Smith et l., 2004b; Mguire et l., 2005h). However, we still must consider the fct tht long-term lnd ppliction of mnures results in the ccumultion of lrge pool of phosphorus, which my he vilble for relese to runoff wter over time. The reduction in totl mnure phosphorus with phytse dditions hs the long-term benefit of reducing totl phosphorus dditions to fields receiving continul nitrogen-bsed mnure pplictions tht overpply phosphorus compred to crop needs. Mnures from low-phytte grins nd phytse-mended feeds As lredy discussed, combining low-phytte grins nd phytse ws shown to result in greter reductions in mnure totl phosphorus thn either strtegy on its own. It hs lso been shown to reduce wter-extrctble phosphte by 27-49% )Mguire et l., 2005). Smith et l. (2004b) reported tht dding phytse to poultry diets contining low-phytte mize led to less soluble phosphte in runoff compred to tht from nonnl diet, but ws not difli'ent to solulde phosphte in runoff from diets contining phytse or low-phytte mize on their own when mnures were surfce-pplied t the sme totl phosphorus rte. Penn et l. (2004) observed similr concentrtions of soluble phosphte in runoff from soils receiving surfce ppliction of turkey mnure (sme totl phosphorus pplied) from norml or low-phytte mize plus phytse diets. As there re only limited number if studies mesuring runoff from soils mended with these mnures, it is too erly to drw firm conclusions. However, the consistent reduction in totl phosphorus nd wterextrctble phosphte in the mnures suggests cler benefit in terms of wter qulity. Summry Reserch to dte hs shown mnure composition to he hevily dependent on both niml species nd diet. In prticulr, differences in feed composition nd phytse supplementtion men tht

15 164 A.B. Leytem nd R.O. Mguire mnures from monogstric nimls contin wide rnge of myo-inositol hexkisphosphte concentrtions. However, mnure tends to be stored for long periods of time prior to lnd ppliction, which llows microbil ctivity to brek down lrge frction of the myo-inositol hexkisphosphte. This cretes mnures tht hve low myoinositol hexkisphosphte concentrtions when they re eventully lnd-pplied. An importnt consequence is tht other mnure chrcteristics, such s the crbon/phosphorus rtio, my hve greter influence on subsequent phosphorus solubility in the short term thn the phosphorus composition of the mnure upon excretion from the niml. This must be considered when ssessing the effects of dietry mnipultion on the environmentl impct of mnure phosphorus. When mnure is pplied to soil, vriety of fctors cn influence the phosphorus solubility nd the potentil for phosphorus trnsport to wter bodies. In the cse of surfce-pplied mnure, the wter-extrctble phosphte concentrtion hs the gretest influence on soluble phosphte losses when rinfll immeditely follows mnure ppliction. When mnures re incorported into soils, other fctors control phosphorus solubility nd the potentil for phosphorus losses to wter bodies. In clcreous soils with low orgnic mtter contents, phosphorus sorption cn be influenced in the short term by the myo-inositol hexkisphosphte content of the mnure, becuse mnure with lrge concentrtions of myo-inositol hexkisphosphte led to smll increses in soil phosphte solubility compred with mnures dominted by inorgnic phosphte. However, this effect is reduced s myo-inositol hexkisphosphte undergoes hydrolysis nd contributes to the extrctble phosphte pool, t which point other fctors, such s the mnure crbon/phosphorus rtio, determine differences in phosphte solubility. In contrst, when mnures re pplied to cidic soils, there seems to be no influence of rigsinositol hexkisphosphte content on extrctble soil phosphte, nd other mnure chrcteristics my hve greter influence on phosphorus solubility. In situtions where phosphorus losses re dominted by soil erosion nd prticulte phosphorus losses, the phosphorus concentrtion in the soil will overwhelm ny influence of the pplied mnure phosphorus forms. Concern hs been expressed bout the potentil negtive environmentl implictions of diet ltertion on phosphorus losses from mnuremended soils, but given the urgent requirement to reduce totl phosphorus concentrtions in mnures in res of high livestock density, dietry mnipultion is overwhelmingly beneficil. Such mnipultion my increse the proportion of the mnure phosphorus tht is soluble in wter, but this is likely to hve negtive environmentl consequences only when mnure is pplied on phosphorus bsis nd without prolonged storge prior to lnd ppliction. If mnures re pplied on n equivlent weight or nitrogen bsis, diet modifiction will result in less totl phosphorus being dded to soils nd therefore reduction in soil test phosphorus build-up over time. This in turn decreses the risk of phosphorus trnsfer to wter bodies. In ddition, most reserch indictes reduction or no increse in phosphorus losses in runoff from soils mended with mnures from modified diets compred with norml diets, when these re pplied on n equivlent phosphorus bsis (surfce ppliction or incorportion of mnures). It therefore seems likely tht in most cses there is no enhnced environmentl risk from dietry modifiction nd ssocited chnges in mnure phosphorus composition. Future Reserch Needs There is n incresing body of reserch imed t understnding the influence of mnure phosphorus composition on the potentil environmentl impcts relted to lnd ppliction of mnure. At present, few studies hve determined mnure phosphorus composition using techniques such s solution NMR spectroscopy, yet this informtion provides vluble insight into the behviour of phosphorus in mnure fter lnd ppliction nd cn help identify the potentil risks of modifying mnures through diet mnipultion. The study of dietry impcts on mnure phosphorus composition nd subsequent environmentl risk is becoming more importnt. There re few studies tht hve detiled the impcts of ltering niml diets on mnure phosphorus composition, nd these hve focused primrily on phosphorus in feeds (i.e. non-phytte phosphorus levels nd the use of phytse). Dietry components, such s the clcium/phosphorus rtio in feeds, micronutrient dditions nd crbon composition of fe phosphorus compc extrctble phosph gted in detil (see volume). There is other divlent ctio ent supplements cr kisphosphte, mid] digestion (Menz should therefore lot phorus in order tr which we cn lter in mnures nd m mnipultion. The use of lo feeding opertions interest (see Rboy, further reserch wil become vilble, economiclly vible. dvntge over phy Anderson, G., Willims inositol hexphosi Angel, C.R., Powers, wter-soluble pho Applegte, T. J.,.Joern. broiler litter is de Poultry Science 82, 1 Brnett, G.M. (1994) P1 Bxter, C.A.Joern, B.( nd storge effece Boesch, D.F., Brinsfield ecosystem restort Burkholder, J.A. nd G for dinoflgellte., Celi, L. nd Brberis, F Frossrd, E. nd 13 pp Coelho, M.B. nd Kon Olive, New Jersey. Cooperbnd, L.R. nd 1 loss to surfce wn Cromwell, G.L.T., Stl improving hiovi Science 71, Dorsch, J.A., Gook, A. Rboy, V. (2003) Phviochemistry 62, 61 Don, Z., Toth,.J.D., G cterizing mnure

16 Environmentl Implictions in Animl Mnures 165 composition of feeds, cn lter the mnure phosphorus composition nd influence wterextrctble phosphte, but hve not been investigted in detil (see lso D, Chpter 11, this volume). There is evidence tht clcium nd other divlent ctions often found in micronutrient supplements cn bind with myo-inositol hexkisphosphte, mking both less vilble during digestion (Menz et l., 1999). Future studies should therefore look beyond just dietry phosphorus in order to understnd the extent to which we cn lter the phosphorus composition in mnures nd mximize the benefits of dietry mnipultion. The use of low-phytte grins in niml feeding opertions hs received considerble interest (see Rboy, Chpter 8, this volume) nd further reserch will be necessry s new grins become vilble, especilly s these become economiclly vible. Low-phytte grins hve n dvntge over phytse ddition, becuse they minimize the interference tht dietry inputs (such s clcium nd other micronutrients) my hve on phytte digestion nd phytse efficcy. An importnt drwbck t this point to using low-phytte grins is the issue of identity preservtion (bility to keep low-phytte grins seprte from other grins during processing), which will hopefully be overcome in the future. Now tht modified diets (phytse dditions, low-phytte grins nd lower phosphorus) re widely implemented, there is need for long-term studies to determine the environmentl effects of mnure ppliction resulting from these diets nd the effects on soil phosphonis forms. There re no long-term trils studying the effect of lnd-pplied mnures from low-phytte diets on soil orgnic mtter, soil phosphorus vilbility nd forms, or phosphorus losses in runoff Given the importnce of understnding the impct of intensive niml opertions on the phosphorus pollution of wter bodies, such studies re urgently required. References Anderson, G., Willims, E.G. nd Moir, J.O. (1974) A comprison of the sorption of inorgnic orthophosphte nd inositol hexphosphte by six cid soils. Journl of Soil Science 25, Angel, C.R., Powers, W. J., Applegte, T. J., Tmitn, N.M. nd Christmn, M.G. (2005) Influence of phytse on wter-soluble phosphorus in poultry nd swine mnure. Journl of Environmentl Qulity 34, Applegte, T. J., Joern, B.C., Nussbum-Wgler, D.E. nd Angel, R. (2003) Wter-soluble phosphorus in fresh broiler litter is dependent upon phosphorus concentrtion fed but not on fungl phytse supplementtion. Poultry Scieme 82, Brnett, G.M. (1994) Phosphorus forms in niml mnures. ltiortsource Technology 49, Bxter, C.A., Joern, B.C., Rglnd, D., Snds,,J.S. nd Adeol, 0. (2003) Phytse, high-vilble-phosphorus corn, nd storge effects on phosphorus levels in pig excret. Journl of Environmentl (bit> 32, Boesch, DT., Brinsfield, R.B. nd Mgnien, R.E. (2001) Chespeke By eutrophiction: scientific understnding, ecosystem restortion nd chllenges for griculture. Journl of Environmentl Qulity 30, Burkholder, J.A. nd Glsgow, H.B. Jr (1997) Trophic controls on stge trnsformtions of toxic mbush-predtor dinuflgellte. Journl of Etilurtyotit Afierobiolv 44, Ceti, L. nd Brberis, E. (2005) Ahiotic stbiliztion of orgnic phosphorus in the environment. In: Turner, B.L., Frossrd, E, nd Bldwin, D.S. (eds) Orgnic Plwsphorus in the Environment. CAB Interntionl, Wllingford, UK, pp Coelho, M.B. nd Komegy, E.T. (1996) Phytse in Animl Nutrition nd Wste Mngement. BASF Corportion, Mt Olive, New Jersey. Cooperbnd, L.R. nd Wrd Good, I.. (2002) Biogettic phosphte minerls in mnure: implictions for phosphorus loss to surfce wters. Environmentl Science nd Teclumlogy 36, Cromwell, G.L.T., Sthly, T.S., Coffey, RD., Monegue, HJ. nd Rndolph, J.H. (1993) Efficcy of phytse in improving biovilbility of phosphorus in soyben nd corn -soyben mel diets for pigs. Journl of Aninzl Since 7 I, Dorsch, IA., Cook, A., Young, K.A., Anderson, J.M., Btunn, A.T., Volkmnn, C. J., Murthy, P.P.N. nd Rboy, V. (2003) Seed phosphorus nd inositol phosphte phenotype of brley low phytil: cid genotypes. Phytocheini.dry 62, Dou, Z., Toth, JD., Gillign, D.T., Rmberg, C.F. J. nd Ferguson, J.D. (2000) Lbortory procedures for chrcterizing mnure phosphorus. Journl q I. Environmentl Qtlity 29,

17 166 A.B. Leytem nd R.O. Mguire Funtsu, T. (1908) On different forms of phosphoric cid in press ckes. Imperil University College Agriculturl Bulletin 7, Gerritse, R.G. nd Zugec, I. (1977) The phosphorus cycle in pig slurry mesured from 12PO4 distribution rtes. Journl ifagriculturl Science, Cmbridge 88, Ghni, M.O. (1941) Frctiontion of phosphoric cid in orgnic mnures. Indin Journl of Agriculturl Science 11, Gollny, H.T., Schmitt, MA., Bloom, P.R., Rndll, G.W. nd Crter, P.R. (2003) Extrctble phosphorus following soil mendment with mnure from swine fed low-phytte corn. Soil Science 168, Hedley, M. J., Stewrt,,J.W.B. nd Chuhn, B.S. (1982) Chnges in inorgnic nd orgnic soil phosphorus frctions induced by cultivtion prctices nd by lbortory incubtions. Soil Science Society of Americ Journl 46, Hunger, S., Cho, H., Sims,.J.T. nd Sprks, D.L. (2004) Direct specition of phosphorus in lum-mended poultry litter: solid-stte 3I P NMR investigtion. Environmentl Science nd Technology 38, Iymuremye, F., Dick, R.P. nd Bhm, J. (1996) Orgnic mendments nd phosphorus dynmics. I. Phosphorus chemistry nd sorption. Soil Science 161, Jng, D.A., Dde!, Klsing, K.C., Mireles, A. J. Jr, Ernst, R.A., Young, K.A., Cook, A. nd Rboy, V. (2003) Evlution of low-phytte corn nd brley on broiler chick perffirmnce. Poultry Science 82, Kil, A. (1948) Viljelysmn orgniset fosforist. Vltion Mrnlouskomiminnn Julkistij No, 129, Helsinki, Finlnd. Kellogg, R.L., Lnder, C.H., Moffitt, D.C. nd Goellehon, N. (2000) Mnure nutrients reltive to the cpcity of croplnd nd psturelnd to ssimilte nutrients: sptil nd temporl trends for the United Sttes. USDA- NRCS Publ. NpsOO Avilble t: United Sttes Deprtment of Agriculture, Wshington, DC. Kleinmn, P. J.A., Shrpley, A.N., Moyer, B.G. nd Elwinger, G.F. (2002) Effect of minerl nd mnure phosphorus sources on runoff phosphorus. Journl of Environmentl Qulity 31, Kleinmn, P. J.A., Shrpley, A.N., Wulf, AM., Bee*, D.B. nd Moore, P.A. (2002h) Mesuring wter-extrctble phosphorus in mnure s n indictor of phosphorus in runoff. Soil Science Society of Americ Journl 66, Klunzinger, M.W., Roberson, K.D. nd Chrheneu, R.A. (2005) Confirmtion of phosphorus vilbility in lowphytte nd high-protein corn to growing-finishing lrge white toms. Journ/ if.1pplied Poultry Reserch 14, Leinweber, P., Humier, L. nd Zech, W. (1997) Sequentil extrctions nd "'P-NMR spectroscopy of phosphorus ffirms in niml mnures, whole soils nd prticle-size seprtes from densely populted livestock re in northwest Germny. Biology nd Fertility of Soils 25, Leytem, A.B. nd NVestermnn, D.T. (2005) Phosphorus vilbility to brley from mnures nd fertilizers on clcreous soil. Soil Science 170, Leytem, A.B., Mikkelsen, R.L. nd Gillim, J.W. (2002) Adsorption of orgnic phosphorus compounds in Atlntic Costl Plin soils. Soil Science 167, Leytem, A.B., Turner, B.L. nd Thcker, P.A. (2004) Phosphorus composition of mnure from swine fed low-phytte grins: evidence for hydrolysis in the niml. Journl of Environmentl Quility 33, Leytem, A.B., Turner, B.L., Rboy, V. nd Peterson, K. (2005) Linking mnure properties to phosphorus solubility in clcreous soils. Soil Science Society of Americ Journl 69, 1516-'1524. Leytem, A.B., Smith, DR., Applegte, T. J. nd Thcker, P.A. (2006) The influence of mnure phytic cid on phosphorus solubility in clcreous soils. Sil Science Society of Ameiic journl 70, 1629-'1638. Li, Y.C., Ledoux, DR., Veum, Rboy, V. nd Zyl, K. (2001) Low phytic cid brley improves performnce, bone minerliztion, nd phosphorus retention in turkey poults. Journl of Applied Poultry Reserch 10, Menz, D.D., Engele-Schn, C.M., Newkirk, R.W. nd Clssen, H.I.. (1999) The effect of minerl dicttors on the formtion of phytse-resistnt nd phytse-susceptible limns ul phytic cid in solution nd in slurry of cnol mel. Animl Feed Science nd Technology 81, Mguire, R.O., Sims, J.T., Sylor, W.W., Turner, B.L., Angel, R. nd Applegte, T. J. (2004) Influence of phytse ddition to poultry diets on phosphorus forms nd solubility in litters mid mended soils. Journl of Environmentl Qulity 33, Mguire, R.O., 1)ou, Z.. Sims, J.T., Brke, J. nd Joern, B.C. (2005) Dietry strtegies for reduced phosphorus excretion nd improved wter qulity. Journl of Environmentl (hility 34, Mguire, R.O., Sims, J.T, nd Applegte, T. J. (2005b) Phytse supplementtion nd reduced phosphorus turkey diets reduce phosphorus loss in runoff following litter ppliction..7mmud of Environmentl Qulity Mguire, R.O., Plum phosphorus in b McAuliffe, C. nd Pee McCuig, LW., Dvi dietry mgnesi McGrth, J.M., Sims, ction nd litter Mikkelsen, R.L. (2000 W.A. (eds) Lnd Mdison, Wise, Miles, D.M., Moore, Simmons, J.D. (l tretment nd di 82, Mullins, G., Joern, B. Sims, J.T. nd S Americn Societt Penn, Cj., Mullins, C phorus from Vir t diets.,journl of F Peperzk, P., Cldwell 87, Rboy, V., Gerbsi, P W.F. nd Ertl, D Physiology 124, 35 Rther, J.B. (1918) 77o Agriculture, Agri, Shrpley, A.N. (1996) Shrpley, A.N. nd Mt rinfll. Journl of Shrpley, Chpr phosphorus for pr Shrpley, A., Gburek, nd mngement Sims, J.T., Simrd, R.1 current reserch., Sims, J. T., Edwrds, A. ronmenilly bse( Smith, D.R., Moore, P. from swine mn Smith, D.R., Moore. P from lnd pplies 33, Spencer, J.D., Alice, (". geneticlly modifi, Stztnnur. NI. nd Ki sediments. firrinolo Toot-, G.S., Pek,.J.D. from mot Idled die Turner, B.L. (2004) 0 1 netic resonnce sp Turner. BI Frossrd, E. nd PP

18 Environmentl Implictions in Animl Mnures 167 Mguire, R.O., Plumsted, P.W. nd Brke, J. (2006) Impct of diet, moisture, loction nd storge on soluble phosphorus in broiler breeder mnure. journl of Environmentl Qulity 35, McAuliffe, C. nd Peech, M. (1949) Utiliztion by plnts of phosphorus in frm mnure: I. Soil Science 68, McCuig, L.W., Dvies, M.I. nd Motzok, I. (1972) Intestinl lkline phosphtse nd phytse of chicks: effects of dietry mgnesium, clcium, phosphorus nd thyroctive csein. Poultry Science 51, McGrth, J.M., Sims, J.T., Mguire, R.O., Sylor, W.W., Angel, R. nd Turner, B.L. (2005) Broiler diet modifiction nd litter storge: impcts on phosphorus in litters, soils, nd runoff.7ournl of Environmentl Qulity 34, Mikkclsen, R.L. (2000) Beneficil use of swine by-products: opportunities for the future. In: Powers, J.F. nd Dick, W.A. ieds) Lnd Appliction of Agriculturl, Industril, nd.1,iunicipl By-products. Soil Science Society of Americ, Mdison, Wisconsin, pp Miles. D.M., Moore, P.A., Smith, D.R., Rice, D.W., Stilborn, HI., Rowe, D.R., Lott, B.D., Brnton, SI. nd Simmons, J.D. (2003) Totl nd wter-soluble phosphorus in broiler litter over three flocks with lum litter tretment nd dietry inclusion of high vilble phosphorus corn nd phytse supplementtion. Poultg Science G.,,Joern. B. nd Moore, P. (2005) By-product phosphorus: sources, chrcteristics nd mngement. In: Sims, J.T. nd Shrpley, A.N. ids) Phosphonm Agriculture nd the Enprionment. Agronomy Monogrph No. 46. Americn Society of Agronomy, Mdison, Wisconsin, pp Penn. C,J., Mullins, G.L., Zelzny, LW., Wrren, J.G. nd McGrth,.J.M. (.2004) Surfce runoff losses of phosphorus from Virgini soils mended with turkey mnure using phytse nd high vilble phosphorus corn diets..7ouml of Environmentl Qulity 33, 143 I Peperzk, P., Cldwell, A.G., Hunziker, R.R. nd Blck, C.A. (1959) Phosphorus frctions in mnures. Soil Science 87, Rboy, V., Gerbsi, P.F., Young, K.A., Stoneberg, S.D., Pickett, S.G., Bumn, A.T., Murthy, P.P.N., Sheridn, W.F. nd Ertl, D.S. (2000) Origin nd seed phenotype of mize btu! phylic cid 1 1 nd low phylic cid 2 I. Plnt Physiology 124, Rther, J.B.,1918) The UtilL:tion of Pl!vlin Phosphorus b y the Pig. Bulletin No University of Arknss College of Agriculture, Agriculture Experiment Sttion, Fyetteville, Arknss. Shrpley. A.N. (1996) Avilbility of residul phosphorus in mmml soils. Soil Science Society of Americ journl 60, Shrpley, A.N. nd Moyer, B. (2000) Phosphorus firms in mnure nd compost nd their relese during simulted,journl cf Environmentl Qulity 19, Shrpley, A.N., Chpr, S.(:.. Wedephol, R., Sims, J.T., Dniel, T.C. nd Reddy, K.R. (. 1994) Mnging griculturl phosphorus thr per pet ecti m or surfce wters: issues nd options. journl q. Emironnitntl Qulity 23, , Shrpley, A., (;bunk, W. nd Hcthwite, L. (1998) Agriculturl phosphorus nd wter qulity: sources, trnsport nd mngement...1,05-ullure nd h'od Science qf Finlnd Sims, J.T.. Simrd, R.R. nd,jotirn, B.C. (1998) Phosphorus loss in griculturl dringe: historicl perspective nd current reserch. journl q Enuironmenll (dulit y 27, Sims, IT.. Edwrds, A.C., Schotimns, O.F. nd Simrd, R.R. (2000) Integrting soil phosphorus testing into rnin tnmentlly bsed griculturl mngement prctices. journl y' Environmentl Qulity 29, Smith. D.R., Moore, P.A. Jr, Mxwell, C.V., Hggrd, B.E. nd Dniel. T.C. 201)-1) Reducing phosphorus runoff from swine mnure with dietry phytse nd luminum chloride. Journl of Environmentl Qulity Smith, D.R., Moore, P.A. Jr, Miles, D.M., Hggrd, B.E. nd Dniel, (2004I1 Decresing phosphorus runoff Irluir lud pplied poultry liner with dietry modifictions nd lum ddition..7ournl of Environmentl Qulity Spencer, J.1).,.Allier, G.L. nd Suber, T.E. (200(1) Phosphorus biovilbility nd digestibility of norml nd geneticlly modified low-phytse torn 11w pigs. journl of Animl Science 78, Suzinttr. M. nd Kmtni, A. (1995) Origin nd distribution of inositol hexphosphte in esturine nd costl sediments. Lintoolv nd Oreonwphy 40, I 25I 'loon, G.S., Pek, J.D. nd Sims, J.T. (2005) Phosphorus specition in broiler litter nd turkey mnure produced from modified diets., 7ourn/ uf Environmentl Qulity 34, Turner, HI,.,2(101 1 Optimizing phosphorus chrcteriztion in niml mnures by phosphorus-31 nucler mgnetic resonnce spectroscopy. journl (?)(Emiirontnetl Qulity 33, Turner, 8.1,.,,2005) Orgnic phosphorus trnsfer from terrestril to qutic environments. In: Turner, BA._ Frossrl, L. nd Bldwin, D.S. (eds) Orgnic Phosphornv in the Enoironnunt. (:AB Interntionl, Wllingffrd, UK, pp

19 168 A.B. Leytem nd R.O. Mguire Turner, B.L. nd Leytem, A.B. (2004) Phosphorus compounds in sequentil extrcts of niml mnures: chemicl specition nd novel frctiontion procedure. Environmentl Science nd Technology 38, Turner, B.L., Pph.zy, M.. Hygrth, P.M. nd McKelvie, I.D. (2002) Inositol phosphtes in the environment. Philosophicl Trnsctions of the Royl Sociepi, London, Series B 357, Turner, B.L., Cde-Menun, B. J. nd Westermnn, D.T. (2003) Orgnic phosphorus composition nd potentil biovilbffity in semi-rid rble soils of the western United Sttes. Soil Science Society of Americ Journl 67, US Geologicl Survey (1999). The qulity of our ntion's wters: nutrients nd pesticides. USGS Informtion Services, Denver, Colordo. Vds, P.A., Meisinger, J. J., Sikor, L.J., McMurtry, J.P. nd Sefton, A.E. (2004) Effect of poultry diet on phosphorus in runoff from soils mended with poultry mnure nd compost. Journl of Environmentl Qulio 33, Veum, T.L., Ledoux, D.R., Bollinger, D.W., Rboy, V. nd Cook, A. (2002) Low-phytic cid brley improves clcium nd phosphorus utiliztion nd growth performnce in growing pigs. Journl if Animl Science 80, Weinhold, B. J. nd Miller, P.S. (2004) Phosphorus frctions in mnure from swine fed trditionl nd low-phytte corn diets. Journl of Environmentl Qu4 33, Lic Solubi United Sttes Agriculturl Re In regions with high ml production op( ppliction over mn turl soils tht corns (Simrd et l., 1995; nd Sims, 2000; Zh 2005). The build-ui phosphorus leching nerby wter bodiet wter qulity impir 1978; Chrdon el, A lrge proportion mnures cn be in which occur minly isphosphte (phyt Gerritse nd Ekstee el l., 2005). As is res est in the identificti phosphtes in mnur Other chpters tol phosphtes in r mnures nd the f: the environment (se( nd Leytem nd Ms ume). This chpter influence the soluhil lion of these inositol is of prticulr imp( context, becuse th relese nd biovilt in soils nd wter be CAB Interntionl 2 (eds B.L. Turner, A.E.

20 Inositoi Phosphtes Linking Agriculture nd the Environment