ROCZNIKI GLEBOZNAW CZE, T. X X X II, NR 3, W A RSZA W A 1981
H E N R Y K P A N A K , T E R E SA W O JN O W SK A
PHOSPHORUS MIGRATION DEEP INTO SONDY AND LOAMY SOIL COLUMNS AT AN INTENSIVE PERCOLATION WITH
WATER
D ep a rtm en t o f A g ricu ltu ra l C h em istry, A g ricu ltu ra l U n iv e r sity of O lsztyn
Soluble phosphates introduced into soil w ith m ineral fertilizers are liable to m any kinetic reactions, comprising the absorption, desorption, precipitation and decomposition processes. These reactions m ake th a t phosphate ions pass very quickly from the soil solution into hardly soluble compounds. Among them iron and alum inium or calcium phosphates prevail, depending on soil conditions. In consequence of the above transform ations the phosphorus m igration ability becomes very weak. On the whole, it has been assumed th a t this elem ent accumulates in the fertilizer introduction places. According to Czekatzki [2], in clayey
soils phosphorus is translocating at the ra te of 0 . 2 cm and in sandy
soils — a t th a t of 1.1 cm a year. Thus practically phosphorus translo cates almost exclusively in consequence of mixing soil in the course of tillage m easures.
On the other hand, in circles interested in the w ater protection the problem of eutrophization of waste w aters (and w ater resorvoirs in consequence of growing utilization of m ineral fertilizers in agriculture, is often put forw ard. Phosphorus, beside nitrogen, is a decisive factor of w ater eutrophization. In this connection the problem of phosphorus m igration in soils deserves a p articular attention. In the literatu re, p articularly recent one, the occurrence of the phenomenon in qustion under definite soil and w ater conditions is rep o rted as well [1, 3-6].
M A TE R IA L A N D M ETH ODS
To determ ine the phosphorus m igration rate in cultivated soils, a model experim ent on two soil kinds, at application of the 82P isotope
68 H. Panak, T. W ojliowska
brow n soil developed from fluvioglacial sand, another — typical brow n
soil developed from heavy loam underlain by loose sand (Table 1).
T a b 1 о 1 f.Techanical c o m p o sitio n and r e a c t i o n o f s o i l s
Kesh ДП1СП1 D e p t łi, cm
f r a c t i o n s
mu 0 -2 13-15 20-22 38-40 45-47 63 -65 70 -72 8 8 -9 0 95-97 113-115
L eached brown a o i l d e v e lo p e d from 1 о езе f lu v i o £ j l a c i a l sand
> 1 2 . В 2 .0 1 .6 2 . 5 2 . 5 1 .0 1. 5 0 . 8 0 . 2 0 . 1 1 -0 .5 1J.0 3 .5 6 .7 6 . 7 5 . 2 6 . 2 6 . 2 7 . 0 2 . 5 2 . 5 0 .5 - 0 .2 5 34.2 2 3 .0 2 S .5 26 . 2 2 7 . 0 3 2 . 0 2 9 . 2 2 7 . 0 17 .0 13 .2 0 .2 5 - 0.1 42.Ö 5 0 .5 5 3 .8 53.1 5 0. 8 4 8 . 8 47 .6 4 8 .0 6 1 . 5 5 9 . 3 0 .1 - 0c05 3 . o 7 . 0 5 . 0 9 . 0 10.0 8 . 0 13. 0 9 . 0 15.0 19.0 0 .0 5 - 0 .0 2 3.Û 2 .0 2 .0 2 . 0 3 . 0 1 .0 4 . 0 4 . 0 1 .0 2 . 0 0 .0 2 - 0 .0 0 6 1 .0 1 .0 2 .0 1.0 1. 0 1 .0 1 .0 3 . 0 1. 0 1. 0 0 .0 0 6 - 0 .0 0 2 1 .0 2 .0 1. 0 1 .0 2 . 0 1.0 1.0 1 .0 1 .0 2 . 0 £ 0 .0 0 2 2 .0 1 .0 1 .0 1. 0 КО 2 . 0 1.0 1.0 1 .0 1.0 5 . 0 5.1 5 . 0 5.1 4 . 8 5 . 0 5 . 0 4 . 9 4 . 9 5 .2
T y p ic a l brown s o i l d e v e lo p e d from h eav y loam u n d e r l a i n by lo o s e sand
> 1 0 .1 0 . 3 0 . 1 0 . 2 0 . 1 0 . 1 0 . 5 2 . 6 2 . 6 1. 5 1 -0 . 5 1 . 0 1 .2 1 . 0 0 . 7 0 . 2 0 . 2 5 . 7 14.5 8 . 7 7 . 0 0 . 5 - 0 . 2 5 3 . 7 5 . 3 2 . 7 2 . 5 0 . 7 4 . 3 2 8 . 0 35 .2 2 7 . 5 2 4 . 7 0 . 2 5 - 0 .1 1 1 . 3 15.5 9 . 3 15.8 1 6 .1 37.5 3 3 . 3 4 4 . 3 5 3 . 8 5 5 . 3 0 . 1 - 0 . 0 5 13 .0 11.0 6 . 0 11.0 1 9 .0 2 2 . 0 14.0 2 .0 6 . 0 9 . 0 0 . 0 5 - 0 . 0 2 14 .0 17.0 2 3 . 0 18.0 3 0 .0 17 .0 7 . 0 1 .0 1 . 0 1.0 0 . 0 2 - 0.006 2 8 . 0 2 3 . 0 2 6 . 0 2 5 . 0 13.0 6 . 0 7 . 0 1 . 0 1 .0 1. 0 O . O O o -0 . 0 0 2 11 .0 10.0 12 .0 9 . 0 2 . 0 3 . 0 1 .0 2 . 0 1. 0 1.0 * ^4 0*002 18 .0 17 .0 2 0 . 0 18.0 15. 0 10 .0 4 . 0 - 1 . 0 1 . 0 pH 6 . 3 6o0 6 . 0 6. 1 5 .6 5 . 4 5 . 2 5 . 3 5 . 5 5 . 6
The experim ent has been established in PVC ,columns of 10 cm in dia. These columns consisted of altern ately arranger 20- and 5-cm segments. A t establishm ent of the .experiment a n atu ral arrangem ent of genetic horizons has been preserved, while trying to pu t into columns soil from the whole profile w ith the thickness of 120 cm. At the same
time soil samples were taken from the 1 0 horizons for the mechanical
composition determ ination (Table 1). Of both soils by four columns were prepared, into w hich two phosphorus rates were introduced and two levels of intensive sprinkler irrigation were .applied. The first
phosphorus ra te was very high, am ounting to 300 kg P205 per hectare
(235.5 mg P205 per column). It was introduced on the surface in the
form of the w ater solution of Na2H P 0 4. The second rate, instead, was
1 Of old higher, so as to present still дпоге distinctly the phosphorus m igration process in the soil profile under extrem sprinkler irrigation
Phosphorus migration into some soils 69
conditions. One of the sprinkler irrigation levels corresponded, namely, w ith 600 mm of rain for 15 dlays, batched everyday in two portions by
2 0 mm, another — w ith 1 2 0 0 mm of ra in applied in the same portions
thrice a day for 2 0 days.
A fter the above percolation periods, the columns were dism ounted and soil samples .were taken from 10 horizons presented in Table 1. The content of total phosphorus and its available forms were determ ined radiom etrically in the samples. Total phosphorus was determ ined after
the 4-hour burning of 1 0 g of soil, at 450°C, at consecutive boiling of
the m ixture of this soil w ith 50 m l of 2N H2S 04 for one hour. The
available phosphorus compounds w ere determ ined after Egner-Riehm.
R E SU L T S
C ontrary to accepted views and investigation results ,[2], the m igra
tion of labelled phosphorus into deeper sandy soil horizons ran relatively easily (Fig. 1). This process was affected by both the phosphorus rate
Fig. 1. L eb elled phosp h oru s m ig ra tio n deep into th e colu m n w ith san d y soil 1 — РгОБ elu a te d w ith w a ter, 600 m m , P2O5 rate 2355 m g per colu m n, 2 — P 20 5 elu ated w ith w a te r , 1200 m m , P2O5 rate 2355 m g per colu m n, 3 — P 2O5 elu a ted w ith w ater, 600 m m , P 2O5 rate o f 235.5 m g per co lu m n , 4 — P2O5 elu a ted w ith w a ter, 1200 m m , P 2O5 rate 235,5 m g per
co lu m n
and the am ount of w ater passed through the column. A t the rate of
235.5 mg P205 and irrigation am ount of 600 m m phosphorus reached
the depth of 47 cm in the soil profile. Twice higher irrigation level resulted in a stronger broadening of the labelled phosphorus transloca tion fron t and increased its occurrence range in soil to the depth of 65 cm.
C ontrary to the above, the tenfold higher labelled phosphorus rate was broadened over the whole soil profile as early as at a single irrig at ion rate, w hereas under the effect of the double am ount of percolating
70 H. Panak, T. Wojnowska
w ater the labelled phosphorus translocation front was strongly broad ened over the whole soil profile under study. That resulted in a nearly eightfold higher phosphorus concentration in soil a t the depth of 115 cm than in the column w ith a single irrigation rate. A characteristic phenom enon occurred in columns w ith a very high am ount of phospho ru s (2355 mg per column), w here under influence of both single and double percolating w ater rate labelled phosphates were translocated in the highest am ounts into th e 13-15-cm layer from soil surface. Sim ilar
results w ere obtained also by other authors [4].
D ifferently ran the labelled phosphorus m igration into deeper hori
zons of brow n soil developed from loam (Fig. 2). Phosphates introduced
Fig. 2. E ffe c t of the lea ch in g action of w a ter (600 m m ) on th e la b elled p h osp h oru s m ig ra tio n deep in to th e colu m n w ith lo a m y soil
A — 235.5 m g P2O5 per colu m n, В — 2355 m g P 2O5 p er co lu m n 1 — to ta l lea ch ed p h osp h oru s,
2 — P2O6 so lu b le in calciu m la cta te
into this soil at the rate of 300 kg P205 per hectare, despite an intensive
sprinkler irrigation (600 mm of w ater) were practically retained in the upper 15-cm layer, at th eir highest concentration on the soil surface (0-2 cm). However, tre ran g e of labelled phosphorus in the soil profile reached the level of 40 cm, below w hich even th eir traces w ere not detected.
The distribution of phosphorus in the profile of this soil a t application of the 1 Of old rate of the fertilizer bears evidence of its strong sorption abilitier (Fig. 2B). The m axim um range of labelled phosphates reached, namely, also here the level of 40 cm. In the subsequent layer (45-47 cm) its occurrence was not detected any more. The curve of distribution of phosphates ra n here sim ilarly as in the column w ith a single phospho rus rate. The difference consisted only in an appropriately higher phos phorus concentration in soil of the horizons investigated. A lack of any
Phosphorus m igration into some soils 71
peak in the translocation of phosphates into deeper soil profile horizons, like in case of sandy soil, is connected probably w ith a too little dis m em berm ent of the column in the upper layer of loamy soil, character ized by a much stronger sorption ability. In this connection the tran s- location front of the basic mass of phosphates was retain ed at the depths less th an 13-15 cm.
On the other hand, the experim ent w ith a twice higher irrigation level failed. The increased daily w ater rate resulted, namely, in silting of soil pores, and concequently in the w ater stagnation in columns on the soil surface, elim inating thus them off the experim ent.
In all soil profile horizons investigated, w ith the labelled total phosphorus occurrence, also its compounds soluble in calcium lactate w ere determ ined after Egner-Riehm (Figs 2 and 3). In particular sandy
F ig. 3. M igration of la b elled p h osphorus so lu b le in calciu m la cta te deep in to th e colu m n w ith san d y soil
e x p la n a tio n — as in Fig. 1
soil profiles about 40% of labelled phosphorus occurred in a readily
soluble form, in case of the rate of 300 kg P205 per hectare. On the
other hand, the 1 Of old ra te of the phosphorus fertilizer resulted in an increase of the percentage of available phosphates up to about 70*/o of labelled total phosphorus. The irrigation intensity did not exert any distinct effect on the percentage of readily soluble phosphorus forms.
In loamy soil the respective differences were still higher (Fig. 2).
In soil a t application of the ra te of 300~kg P20 5/ha only about 30
percentage of labelled phosphorus occured in read ily soluble form whilo
72 H. Panak, T. Wojnowska
phosphorus form in particular soil profile horizons op to about 75% of its total content.
The resu lts obtained prove th a t in case of introduction of phosphorus fertilizers into spils directly before the rainy period, the translocation of this elem ent can be m uch higher than th a t corresponding w ith the h ith erto view confirmed by curren t investigations [1]. A lthough the m igration of phosphorus deep into the soil profile is possible, the experim ent results prove relatively little m igration abilities and exclude possibility of any significant phosphorus losses, and thus oaf a signifi cant contam ination of ground w aters in connectio w ith intensive fertili zation. Results of the experim ent proved, namely, th a t such th re a t would be possible only at the 30fold level of the cu rren t inteasive fertilization, and at th a t exclusively on light soils in catastrophically wet years.
C O N C L U SIO N S
1. Under the effect of an intensive sprinkler irrigation (600 mm)
w ater-soluble phosphates applied as a reserve (300 kg P205 per hectare)
on light soil were translocated in the soil profile to the depth of 45 cm, w hereas on cohesive soils the translocation practically did not exceed the arable soil layer.
2. In a cohesive soil the phosphorus m igration did not take place even at the tenfold phosphorus rate, w hereas on light soil, under the same conditions, phosphorus was leached in the soil profile to the depth of more than 115 cm.
3. The experim ent results exclude the occurrence of any significant losses of phosphorus fertilizers in consequence of their penetration into ground w aters in connection w ith intensive fertilizatio.
4. The content of h ard ly soluble forms of labelled phosphorus am ounted to 25-70%, depending on the am ount of phosphates introduced into soil.
REFEREN CES
[1] C a m e r o n D. R., К 1 u t e A. : C o n v e c tiv e -d isp e r s iv e so lu tio n transport w ith a com bined eq u ilib riu m and k in etic ad sorp tion m odel. W ater R esou rces Res. 1971, 13, 183-188.
[2] С z e r a t z к i W. : T ransport v o n N ä h rsto ffen aus der m in era lisch en D ü n gu ng durch B od en p erk oolation under den W u rzelhorizont. B erich te über L an d w irtsch . 1972, 50, 2, 465-476.
[3] M a n s e l l R. S., S e l i m H. K., К a n с h a n a s u t P., D a v i d s o n J. N., F i s к e 11 J. G. A. : E x p erim en ta l and sim u la ted tran sp ort of ph osp h oru s through san d y soils. W ater R esou rces Res. 1977, 13, 189-194.
Phosphorus m igration into some soils 73
of P and other ions th rou gh an u n d istu rb ed colu m n of an acid b row n earth . Z. P fla n zen er n ., B odenk. 1979, 142, 562-569.
[5] M a r g o w s k i Z., B a r t o s z e w i c z A. : M igration of p h osphorus com p ou n d s in to ground w a te r in d iffe r e n t soil con d ition s. P race N auk. A E w e W rocław iu 1976, 91, 87-92.
[6] R u s s e l J. S. : Soil fertility changes in the lon g-term ex p erim en tal plots at K y b y b o lite, S o u th A u stra lia . II. C hanges in p hosphorus. A ust. J. A gr. R es. I960, 11, 927-947.
H. P A N A K , T, W OJNOW SKA
M IG R A C JA FO SFO R U W G Ł Ą B K O LUM N Y G L EBY P IA SZ C Z Y ST E J I G L IN IA ST E J PR Z Y IN T E N SY W N E J PER K O LA C JI W ODĄ
In sty tu t C h em izacji R o ln ictw a ART w O lsztyn ie
S t r e s z c z e n i e
D o k olu m n o śred n icy 10 cm , sk ła d a ją cy ch się na p rzem ian z seg m en tó w 20 i 5 cm , p rzen iesio n o g leb y p ia szczy ste i g lin ia ste z całego p rzekroju p ro filu g le b ow ego m iąszości 120 cm . D o k olu m n w p row ad zon o N a4H P 0 2 znaczony izotopem MP w d aw k ach 0,2335 i 2,335 g. N a g leb ie p ia szczy stej za sto so w a n o dw a p oziom y n a w a d n ia n ia (600 i 1200 m m ), a na g lin iastej tylk o 600 mm, p on iew aż pory g le b o w e przy drugim p oziom ie n a w a d n ia n ia u le g ły szy b k iem u zam u len iu . W odę d a w k o w a n o w ciągu 15 dni po 4X3l m m d z ie n n ie i po 60 m m w ciągu 20 dni (1200 mm ). N a g le b ie p ia szczy stej fo sfo r z d a w k i 0,2335 g na k olu m n ę p rzem ieścił się do g łęb o k o ści 45 cm (600 m m w ody) i 65 cm (1200 m m w od y), a z d a w k i 2,335 g na k olu m n ę zn alezion o go w ca ły m p ro filu g leb o w y m . N a g leb ie g lin ia stej p rzem ieszcza n ie fo sfo ru z o b yd w u za sto so w a n y ch d a w ek n aw ozu o sią g n ęło poziom ty lk o 40 cm . W za leż n o ści od ilo ści w p ro w a d zo n eg o do g leb y fo sfo ru u d ział ła tw o rozp u szczaln ych form zn aczon ego fo sfo ru w y n o sił 30-37°/©.
Pr of. d r Henryk, P a n a k
I n s t y t u t C h e m i z a c j i R o l n i c t w a A R T O l s z t y n - K o r t o w o
