Concentration and vertical distribution of total soil phosphorus in relation to time of abandonment of arable fields

Transcription

1 Nutr Cyl Agroeosyst (2007) 79:73 79 DOI /s ORIGINAL PAPER Conentrtion nd vertil distriution of totl soil phosphorus in reltion to time of ndonment of rle fields A. vn der Wl Æ W. de Boer Æ I. M. Luers Æ J. A. vn Veen Reeived: 6 Otoer 2006 / Aepted: 13 Ferury 2007 / Pulished online: 15 Mrh 2007 Ó Springer Siene+Business Medi B.V Astrt Andonment of griulturl soils is ommon prtie in Western Europe to inrese the re of nture nd to ountert griulturl overprodution. However, it hs een suggested tht rupt hnges in mngement of lnd, suh s ndonment of hevily fertilized griulturl fields, ould trigger lehing of phosphorus into deeper soil lyers nd groundwter. In previous study we oserved tht totl phosphorus (P) in the upper 10 m of ex-rle soils in the Netherlnds ws negtively relted to the time of ndonment. In susequent study in the region reported here, we mesured totl P onentrtions t different soil depths in four ex-griulturl fields tht differed in time sine ndonment to exmine if the derese in totl P with inresing time of ndonment ould e due to lehing of P into deeper soil lyers. At eh site totl P onentrtion deresed with inresing depth, nd for eh soil profile depth, totl P lso deresed with inresing yers sine ndonment. We lulted, sed on estimted P fertilizer gifts over the lst dedes nd the regression oeffiient of the reltion etween A. vn der Wl (&) W. de Boer I. M. Luers J. A. vn Veen Netherlnds Institute of Eology (NIOO-KNAW), Centre for Terrestril Eology, Boterhoeksestrt 48, Heteren 6666 GA, The Netherlnds e-mil:.vnderwl@nioo.knw.nl totl P in ore of 95 m nd time of ndonment, the mount of net totl P tht should hve umulted in the oldest ex-rle field to reh the P level of the most reently ndoned field. The ontinution of umultion of P for longer period of time in reently ndoned fields ppered to e the most resonle explntion for the derese of P with yers of ndonment. Therefore, ndonment of griulturl lnd does not seem to trigger hemil time om to explode s no lrge mounts of P seem to leh into deeper soil lyers. Keywords Phosphorus Lnd ndonment Lehing Vertil distriution Aumultion of P Soil restortion Introdution In previous study we oserved tht totl phosphorus (P) onentrtions in the top 10 m of ex-rle sndy soils in the Netherlnds ws inversely relted to time sine ndonment from griulture. Fields tht hd een ndoned for 34 yers hd lower totl P in the topsoil thn fields tht were reently ndoned (Vn der Wl et l. 2006). There re numer of possile explntions for the inverse reltionship etween period of ndonment nd totl P in the topsoil, i.e., (1) lrger umultive P enrihment of the

2 74 Nutr Cyl Agroeosyst (2007) 79:73 79 topsoil, vi inorgni fertilizer nd mnure, of fields tht hve een ndoned only reently, (2) vritions etween sites in initil P ontent, (3) uptke of P from the topsoil y the oveground plnt iomss fter ndonment, nd (4) lehing of P from the topsoil to the susoil. Phosphorus is n essentil nutrient for plnt growth nd most rle sndy soils nnot supply suffiient mounts of this element to the rops. Therefore, pplition of P-fertilizers is needed to overome this defiieny. From the erly 20th entury reltively hep P fertilizers eme ville nd the mounts of P in niml mnure inresed rpidly during the seond hlf of the 20th entury. The use of huge mounts of oth these inorgni nd orgni fertilizers hs led to P enrihment of the topsoil of griulturl lnd in the Netherlnds nd elsewhere in Europe. The enrihment gretly depended on the intensity of frming, with lrgest umultions in res with intensive niml prodution on sndy soil in the entrl, estern nd southern hlf of the Netherlnds (Breeuwsm et l. 1990; Reijerink nd Breeuwsm 1992). Phosphorus enrihment ws most severe in the period 1950 nd From 1985, P fertiliztion deresed following the implementtion of series of governmentl poliies nd mesures restriting the pplition of niml mnure (RIVM 2002). However, the sorption pity of sndy soils for P is in generl limited nd P enrihment in the pst my hve inresed the risk for P lehing into deeper soil lyers or even into the groundwter, espeilly in flt res with high groundwter levels (Sims et l. 1998; Shoumns nd Groenendijk 2000). This phenomenon is speulted to e triggered y rupt hnges in mngement of the lnd, suh s ndonment of hevily fertilized griulturl lnd, nd hs een referred to s the signl for hemil time om to explode (Vn Ltesteijn 1998). Soil P n exist in inorgni nd orgni forms. Phosphte is the min inorgni form of P tht is ville to plnts nd n e divided into two forms: lile nd oluded P (Brdgett 2005). The mount of lile P is very low reltive to the totl P pool nd n rpidly e fixed in oluded forms unville to plnts: Al- nd Fe-phosphtes in id soils nd C-phosphtes in lkline soils. A lrge proportion, 29 65%, of totl soil P is present in orgni form (Hrrison 1987). Orgni P ompounds rnge from redily ville plnt residues nd miroes within the soil to stle ompounds tht hve eome prt of the soil orgni mtter. Biologil proesses in the soil ontrol the minerliztion nd immoiliztion of orgni P. The moility of soil P depends on the hemil form nd nture of the element, the hemil nd minerlogil nture of the soil nd the physil nd iologil environment of the soil, e.g. sorption y plnt roots or lehing y dringe (Stewrt nd Tiessen 1987; MBride 1994). Myorrhizl fungi ply n importnt role in the uptke nd trnsport of soil P to the host plnts. They n ess nd enhne the vilility of soil P tht is eyond the reh of roots, therey inresing the upwrds trnsport of P (Brdgett 2005). The tul downwrd movement of P in the soil n e desried y the tipping uket model (MBride 1994). In this model, the soil profile is visulized s stk of empty ukets, eh uket symolizing the sorption pity of one soil horizon. As phosphte is dded to the surfe lyer, the top uket must e ompletely filled efore ny phosphte n flow into the uket elow. In this study, we ddress the question whether or not the derese in totl P in the root zone with inresing time of ndonment of former rle lnd is due to lehing of P into deeper soil horizons. To study this, we mesured the totl onentrtion of phosphorus t different depths in soils of four ex-griulturl fields tht differed in time sine ndonment. Clultions, using dt on pst fertiliztion regimes, were mde to interpret the results. The dt were ompred with tht of hethlnd soil tht hd not een fertilized s griulturl fields re ndoned to hopefully eventully return to hethlnd. Hethlnds re highly vlued euse of their historil ulturl ssoitions nd their importnt role in preservtion of flor nd fun (Aerts nd Heil 1993). Hene, the restortion of hethlnds is reeiving muh ttention, espeilly in ountries with very intensive frming systems, whih frgment the lndspe.

3 Nutr Cyl Agroeosyst (2007) 79: Mteril nd methods Soils nd smpling For this study, 5 sites in the entrl prt of the Netherlnds were seleted from the hronosequene study tht hs een desried previously (Vn der Wl et l. 2006). The sites onsisted of 4 ndoned rle fields, whih differed in the time sine ndonment nd 1 referene hethlnd, whih is the restortion trget of the ex-rle fields. All soils were well drined with groundwter levels elow (>2 m) the smpling depth (Gehrels et l. 1994). A summry of the soil hrteristis of these sites is given in Tle 1. In Novemer 2004, five soil ores (3.5 m dimeter) were olleted in m plot in eh of the seleted sites. Soil ws smpled from 0 10 m, m, m, m, m nd m deep nd eh lyer ws olleted. Smples were ir-dried nd ground efore nlysis. Chemil nlyses Totl P ws determined olorimetrilly fter digestion of smples with mixture of H 2 SO 4 -Se, H 2 O 2 nd sliyli id (Novozmsky et l. 1984). Although this wet oxidtion of soil orgni mtter is proly not omplete (Novozmsky et l. 1995), P ontents of the otined extrts orrelte well with P otined fter pplying dry shing tehnique nd is suggested s useful method for nlyzing totl P (Akinremi et l. 2003). Sttistil nlyses All dt were nlyzed in SPSS for Windows (Relese ; stndrd version). Differenes etween the distriution nd the solute mount of totl P in different soil lyers (depths) within fields were lulted y one-wy ANOVA with soil depth s ftor t p < Differenes etween totl P in ore of 95 m nd fields were lso tested with one-wy ANOVA. The ssumption for normlity ws tested with Shpiro-Wilk sttistis nd homogeneity of vrines with Levene s test. Differenes etween groups were tested y Tukey s honestly signifint differene test or, when vrines were unequl, y Tmhne s T2 test t p < When only one replite ws ville (whih ws sometimes the se with the deepest lyer euse of the hrdness of the soil), one-smple t test ws performed in order to ompre mens of different depths. The reltion etween totl P in the deepest horizon nd time sine ndonment ws lulted y the oeffiient of the liner eqution t p = Estimtion of P umultion nd uptke of P y plnts The following prmeters nd ssumptions were used to estimte the mount of net totl P tht should hve umulted in the oldest ex-rle field to reh the P level of the most reently ndoned field: (1) the regression oeffiient of the reltion etween totl P in ore of 95 m nd time of ndonment, (2) the ulk density of snds nd sndy loms is on verge 1.43 g/m 3 (Hrtge 1978), (3) the mount of kg soil in soil ore of 95 m is 1.3 kg, (4) the uptke nd removl of P vi hrvest of rops remins the sme every yer. To estimte the possiility tht P is tken up from the top soil vi the plnt iomss fter ndonment we ssumed tht (1) the ontent of P in plnt dry weight is out 0.2% Tle 1 Soil hrteristis (0 10 m) of the fields under study (Vn der Wl et l. 2006) Field nme Yers sine ndonment Former rop or vegettion t smpling % Lom (2 50 lm) ph C (g/kg) P totl (mg/kg) Assel 2 Mize Krtellenerg 9 Whet Dennenkmp 22 Rye, pottoes, sprgus Boershos 35 Whet Mossel Referene Hethlnd

4 76 Nutr Cyl Agroeosyst (2007) 79:73 79 (Shhtmn et l. 1998), (2) the ove nd elowground iomss in 10 yer old ex-rle lnd is round 9780 kg/h (Bezemer et l. 2006) nd (3) no P is removed from the system vi plnt iomss sine the ex-rle field ws not mown. Results nd disussion The mount of totl phosphorus in ore of 95 m deresed with time sine ndonment (Fig. 1). In ddition, the portion of totl P per lyer ompred to the totl mount of P present in 95 m generlly deresed with depth (Fig. 2). P ontent of the deeper soil horizons ws lwys totl P mg/kg yers ndoned d referene Fig. 1 Totl phosphorus in the 0 95 m soil lyer of 4 ex-rle fields nd hethlnd lower thn the P ontent of the upper 30 m (Fig. 3). The P levels mesured in soil got loser to the levels mesured in hethlnd referene soil s the yers sine ndonment form griulture inresed (Fig. 3). Differenes in phosphorus ontent in the upper lyer (0 30 m) nd the lowest lyer (70 95 m) were deresing with time sine ndonment (p < 0.01). There ws no signifint hnge in P with time of ndonment in the lowest depth lyer (p > 0.17). These results indite tht the previous oserved derese of totl P in the upper soil (10 m) with yers of ndonment is proly not due to lehing of lrge mounts of P in the top soil to lower lyers of the soil. It my e tht prt of the P derese in the top lyer is pprent nd due to limittions of the wet oxidtion to relese ll P from soil orgni mtter. On the other hnd, fertiliztion histories of the fields my hve een different. Soils tht were longer in prodution hve reeived fertiliztion for longer period thn the oldest ndoned fields. In this wy, P ould umulte in the youngest ex-rle soils. We n estimte the mount of net P tht hs to umulte per yer to remin t onstnt level of totl P. The regression oeffiient of the reltion etween totl P in ore of 95 m nd time of ndonment ws 14.8 mg P/kg soil/yer (p < 0.10). This numer times the mount of kg soil in soil ore Fig. 2 Vertil distriution of totl phosphorus in the 0 95 m lyer of 4 ex-rle fields (Assel ndoned sine 2 yers, Krtellenerg sine 9 yers, Dennenkmp sine 22 yers nd Boershos sine 35 yers) nd hethlnd. Given re the perentges of totl P, on sis of dry weight soil, per depth Assel, Boershos,, Krtellenerg d d Mossel Dennenkmp ,,,

5 Nutr Cyl Agroeosyst (2007) 79: Fig. 3 Vertil distriution of totl phosphorus in the 0 95 m lyer of 4 ex-rle fields. Given re the totl mounts of phosphorus, on sis of dry weight soil, per depth totl P mg/kg , 2 d d ,,,,, 35 referene yers ndoned (1.3 kg) results in the mount of net P tht hs to umulte per yer (19.3 mg). The re of the soil ore ws m 2, so 19.3/9.621 = 2.00 mg/ m 2 = 200 kg/h/yer should hd een pplied to the oldest ndoned field to reh the level of totl P tht ws found in the most reent ndoned field. In 33 yers, 33 * 200 = 6600 kg P/h must hve umulted in the soil during the totl period of ndonment. Bsed on the ssumptions given in the Mteril & methods setion, the estimted mount of P fixed in plnt iomss (9780 kg/h in 10 yers) fter ndonment, 0.2% * 9780 = 196 kg P/h, is negligile ompred to 6600 kg P/h. Thus, 200 kg P/h is the estimted mount tht must hve umulted nnully in order to keep the P level equl over period of 33 yers. However, it should e kept in mind tht this mount n e higher or lower due to vrition etween (e.g. historil differenes) nd within (e.g. heterogeneity of soil) lotions. The mount of 200 kg dded P/h/yer is more thn twie s high s the verge net surplus (dded fertilizer minus output vi hrvest) of 84 kg P/h/yer on griulturl mize fields in the Netherlnds in the period (Shoumns et l. 2004). The differene ould e due to the removl of P in plnt iomss y herivores. The lrgest mximum uptke of P under optiml onditions vi plnt iomss is lulted s 50 kg P/h/yer (Sivl nd Chrdon 2004). This is strong overestimtion for the fields in this study, sine the systems re more or less losed nd the onditions re likely not optiml for plnt growth, ut even under optiml growth nd removl of plnt iomss this numer n not ompenste for the differene etween 200 nd 84 kg p/h/ yer. The estimted surplus of P s mentioned y Shoumns et l. (2004) is, however, n verge of rle sndy fields in the Netherlnds nd n e n underestimtion of the P tht hs tully een pplied in the pst. Frmers were only restrited in the gift of P vi niml mnure nd the introdution of rtifiil fertilizer ws unlimited (RIVM 2002). It is likely tht in the pst the gift of P ws muh higher thn offiilly doumented. Therefore, umultion of P for longer periods of time in reently ndoned fields is the most resonle explntion for the inverse reltion etween P nd yers of ndonment, lthough some unertinty remins s the initil onditions nd former mngement of the soil ould e different etween lotions. The fields showed differenes in soil profile development; the ex-rle sites showed some fetures of podzols (Assel, Boersosh) nd renosols (Krtellenerg, Dennenkmp). However, ll soils of the ex-rle fields were homogenous in the upper 30 m nd hd distured profiles due to tilling in the pst. The referene hethlnd hd n undeveloped podzol profile s it lked n E horizon (AE/Bs/C), possily due to sod-utting in the pst. Some depth lyers ontined different soil horizons (Tle 2). The upper 30 m ontined the highest mount of phosphorus in every field, lthough the perentge of totl P in the upper 30 m in the podzols (Assel, Boershos nd the hethlnd) ws lower ( %) thn in the renosols (Krtellenerg,

6 78 Nutr Cyl Agroeosyst (2007) 79:73 79 Tle 2 Soil horizons present in eh depth lyer per field Depth Assel Krtellenerg Dennenkmp Boershos Mossel Horizon Horizon Horizon Horizon Horizon 0 10 A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE A/AE E/Bs C C A/AE/E Bs Bs C C Bs C C C C C C A nd AE stnds for humi nd trnsitionl horizon; E stnds for eluvition horizon; Bs stnds for illuvition horizon nd C stnds for prent mteril. The suffix s stnds for umultion of sesquioxides (Fe, Al) in the B-horizon (Bs) (FAO 1990) Dennenkmp) (76.6% nd 87.2%, respetively). In ddition, the distriution of totl P in the different depth lyers differed etween the fields, espeilly Boershos showed higher mounts of totl P in the m depth lyer, whih ws identified s Bs horizon (Tle 2). Phosphte sorption in different soil horizons is espeilly likely to depend on the degree of eluvtion nd illuvition of Al nd Fe oxides from one lyer into nother. The possiility of storge lyer of phosphte my e pplile for soils, whih ontin Bs soil horizon tht is hrterized y the illuvil umultion of luminum nd iron, sine inorgni P n ret with these irons to form solid ompounds (Brrow 1983; Vn der Zee et l. 1987). Therefore, the Bs lyer in this podzol my eome storge lyer in future when possily more phosphte lehes out of the surfe lyers. Conlusions The previous oserved inverse reltion etween totl P in the upper soil (10 m) nd yers of ndonment n not e explined y lehing of lrge mounts of P to lower lyers of the soil sine totl phosphorus vlues were deresing with soil depth in every field. We estimted tht 200 kg P/ h/yer must hve een pplied to the ndoned fields to keep the level of totl P of tht of the most reent ndoned field. This mount my e resonle onsidering the high mounts of P pplition in the pst entury nd therefore, umultion of P for longer periods of time is the most likely explntion for the lower mount of P in longer ndoned fields. Bsed on these results, ndonment of griulturl lnd does not seem to trigger hemil time om to explode nd no lrge mounts of P pper to leh into deeper soil lyers. However, inresing mounts of totl P in the Bs horizon my indite tht in future, when more P lehes out of the upper lyers, this horizon is likely to eome storge lyer for P. Aknowledgment We thnk Prof. Oene Oenem nd Wim H. vn der Putten for helpful omments on the mnusript nd Wieher Smnt for tehnil ssistne. The study ws funded y TRIAS-SKB. This is pulition numer 4017 of the NIOO-KNAW Netherlnds Institute of Eology. Referenes Aerts R, Heil GW (1993) Hethlnds, ptterns nd proesses in hnging environment. Kluwer, Dordreht Akinremi OO, Armisen N, Kshem MA, Jnzen HH (2003) Evlution of nlytil methods for totl phosphorus in orgni mendments. Commun Soil Si Plnt Anl 34: Brdgett RD (2005) The iology of soil: ommunity nd eosystem pproh. Oxford University Press, New York Brrow NJ (1983) A mehnisti model for desriing the sorption nd desorption of phosphte y soil. J Soil Si 34: Bezemer TM, Hrvey JA, Kowlhuk GA, Korpershoek H, Vn der Putten WH (2006) Interply etween Seneio joe nd plnt, soil, nd oveground inset ommunity omposition. Eology 87: Breeuwsm A, Reijerink JGA, Shoumns OF (1990) Fosftverzdigde gronden in het Oostelijk, Centrl en Zuidelijk Zndgeied. String Centrum Wgeningen, Rpport no. 68 FAO (1990) FAO-Uneso soil mp of the world. Revised legend. Soils Bulletin 60. FAO, Rome, p 119 Gehrels JC, vn Geer FC, de Vries JJ (1994) Deomposition of groundwter level flututions using trnsfer modeling in n re with shllow to deep unsturted zones. J Hydrol 157:

7 Nutr Cyl Agroeosyst (2007) 79: Hrrison AF (1987) Soil orgni phosphorus. A review of world literture. CAB Interntionl, Oxford Hrtge KH (1978). Einfurhrung in die Bodenphysik. Ferdinnd Enke Verlg, Stuttgrd, p 364 MBride MB (1994) Environmentl hemistry of soils. Oxford University Press, In., New York, United Sttes of Ameri, p 406 Novozmsky I, Hou VJG, Temminghoff E, Vn der Lee JJ (1984) Determintion of totl N nd totl P in single soil digest. Neth J Agr Si 32: Novozmsky I, Vn der Lee HJ, Hou VJG (1995) Smple digestion proedures for tre-element determintion. Mikrohim At 119: Reijerink JGA, Breeuwsm A (1992) Ruimtelijk eeld vn de fosftverzdiging in mestovershotgeieden. String Centrum-rpport 222 RIVM (2002) MINAS nd the environmnet. Blne nd explortion. (In Duth). RIVM-rpportnr , ISBN The ntionl institute of puli helth nd the environment, Bilthoven, The Netherlnds Shhtmn DP, Reid RJ, Ayling SM (1998) Phosphorus uptke y plnts: from soil to ell. Plnt Physiol 116: Shoumns OF, Groenendijk P (2000) Modeling soil phosphorus levels nd phosphorus lehing from griulturl lnd in the Netherlnds. J Environ Qul 29: Shoumns OF, Renud R, Oosterom HP, Groenendijk P (2004) Lot vn het fosftovershot. Wgeningen, Alterr, Alterr-rpport Sims JT, Simrd RR, Joern BC (1998) Phosphorus loss in griulturl dringe: historil perspetive nd urrent reserh. J Environ Qul 27: Sivl FP, Chrdon WJ (2004) Ntuurontwikkeling op fosftverzdigde gronden: fosftontrekking door een gews. Wgeningen, Alterr, Alterrrpport 1090 Stewrt JWB, Tiessen H (1987) Dynmis of soil orgni phosphorus. Biogeohemistry 4:41 60 Vn der Wl A, vn Veen JA, Smnt W, Boshker HTS, Bloem J, Krdol P, vn der Putten WH, de Boer W (2006) Fungl iomss development in hronosequene of lnd ndonment. Soil Biol Biohem 38:51 60 Vn der Zee SEATM, Fokkink LGJ, Vn Riemsdijk WH (1987) A new tehnique for ssessment of reversiility dsored phosphte. Soil Si So Am J 51: Vn Ltesteijn HC (1998) A poliy perspetive on lnd use hnges nd risk ssessment. Agri Eosyst Environ 67: