fcO CZNlK Î GLEBOZNAW CZE, T. X X X lt, N R 3, W ARSZA W A 1981
S T A N IS Ł A W U Z IA K , K R Y ST Y N A ST E IN B E IC H
ENZYMATIC ACTIVITY OF THE MEADOW SOILS IRRIGATED WITH M UNICIPAL SEWAGE
S o il S c ie n c e D ep artm en t, M aria C u rie-S k ło d o w sk a U n iv e r sity of L u b lin
Because of a rapid grow th in the production of m unicipal and industrial sewage being m ore and m ore commonly used for irrigation, studies of its influence on physico-chemical and biological properties of soils constitute a p articu larly actual problem.
The present paper is another publication dealing w ith the affect of m unicipal sewage on soil environm ent. The studies w ere carried out in m eadow soils in the Bystrzyca riv er valley (near Lublin) and concerned th eir enzym atic activity. This feature may, according to some authors, constitute a cryterion of biological activity of soils, w hich conditions its fertility , and in consequence, its productivity.
Among the g reat num ber of enzymes, phosphatase, urease and sac- charase belonging to the group of hydrolases were chosen. Phosphatase is responsible for unassimilable, organic phosphorus compounds in soil. Urease takes p a rt in decomposition of urea. Saccharase is involved in hydrolysis of carbohydrates constituting a considerably im portant com ponent of p lan t rem ains. F urtherm ore, they occur in large and some of them even in very large amounts, and are not difficult to determ ine and preserve th eir stability for a long time.
M A TE R IA L A N D M ETH O D S
,Soil samples were taken 6 times during the vegetation season in
1976, from 5 surface areas of a plot irrigated and the same num ber of samples from an u nirrigated plot (in each plot light and m edium hum us alluvial soils occurred). A detailed characteristics of the some soils can be found in the paper [13]. The samples as the so-called m ixed ones were taken from horizons 0-10, 15-25 and 40-50 cm.
A ir-dry samples w ere used for analyses. Phosphatase activity was determ ined by the m ethod of K u p r e w i c z and S z c z e r b a k o w a
l i é Ś. Ü ziak , K. S tein b rich
[8] ; liberated phosphates — by the m ethod of F i s к e and S u b b a r o v [9], urease — by the m ethod of H o f m a n n and T e i c h e r {4] and saccharase activity — according to H o f m a n n and S e e g e r e r [5].
The results are presented in the diagrams (Figs 1, 2, 3, 4). D IS C U S S IO N
P h o s p h a t a s e . In the hum us horizons of soils its content ranges 10-30 mg of P/100 g of soil, and in subhum us horizoms i!t decreases to a few mg of iP. The effect of organic substance on phosphatase activity as well as of the other enzymes is very distincs. Some rela tionship between phosphatase activity and the am ount of available phosphorus was also observed. W ith the increase of phosphorus, phos phatase activity decreased, and vice versa, in all soils studied. In the case of higher and m ore frequent variations of the am ount of available phosphorus over the whole period of studies, phosphatase activity was m aintained on a sim ilar level.
The relationship between the content of assimilable phosphorus and phosphatase activity was m entioned by several authors in their papers. According to K u p r e w i c z and S z c z e r b a k o w a [8] plants w ith phosphorus deficiency excrete m ore phosphatase into soil th an plants provided w ith assimilable phosphorus. Soil microorganisms react simi larly to plants, which, as is known, play a great role in decomposition
of hardly available organic phosphorous compounds [6, 7]. H a l s t e a d
[3], however, did not find the above m entioned regularities in his studies. According to his opinion lack of these relationships can account for the m ineralization com plexity of organic substance. Soil reaction suitable for one rate of the decomposition process of organic substance need not constitute optim al conditions for another rate.
It should be stressed th a t the dynamics of phosphatase activity is little differentiated during the vegetation period. Yet in a p a rt of the studied profiles of hum us alluvial soils it could be observed th a t after a certain increase in summer, phosphatase activity decreased in autum n. Irrigation w ith sewage, however, was not found to effect phosphatase activity in the soils studied.
U r e a s e . Its content is differentiated, depending on the kind of soils. In hum us alluvial soils it am ount 40-140 mg of N-NH4/IOO g of soil, while its highest content is found in 15-25 cm horizons. In light
alluvial soils, however, the content of urease ranges from abount 1 0-
50 mg of N-NH4 100 g of soil. The above values point distincly to the dependence of urease activity on organic substance, confirming the studies of other authors [1, 2]. Some of them relate this dependence of adsorpt ion and stability of this enzyme on organic soil colloids as well as to a higher population of m icroorganisms [1, 7, 12].
Enzymatic activity of irrigated meadow soils 117
F ig. 1. E n zym atic a c tiv ity of m ed iu m hu m ou s a llu v ia l soils, u n flood ed 1, 2, 3 — p h o sp h a ta se (in mg/100 g of so il), 4, 5, 6 — u rease (in m g N -N H 4/IOO g of soil), 7, 8, 9 — sa c ćh a ra se (in m g o f h y d r o ly z e d su cr o se/100 g o f soil); a — so il la y er o f 0-10 cm , b — soil layer o f 15-25 cm , с — so il la y e r o f 40-50 cm , I V - X I — th e m on th s o f sa m p le c o lle c tin g , S r — m ean of th e v e g e ta tio n p erio d , P — th e c o n te n t of a v a ila b le p h o sp h o ru s in th e so il la y e r o f
0-10 cm
during the vegetation season, p articu la rly in hum us alluvial soils. In u nirrigated hum us alluvial soils, increased urease activity in m idsum m er was observed to decrease by the end of the vegetation period. However, in unirrigated light alluvial soils a general tendency of its decrease was observed. Irrigation w ith sewage caused an increase of urease activity in hum us alluvial soils by the end of the vegetation period. The absence of its influence in light alluvial soils is ra th e r difficult to elucidate. The results confirm those, obtained earlier [13].
S a c c h a r a s e . D ifferentiated saccharase activity is still higher than in case of urease, which depends on the kind of soil, particu larly on hum us content. In hum us alluvial soils it am ounts about 500-4000 mg
118 S. U ziak, K. S tein b rich
F ig. 2. E n zym atic a c tiv ity of m ed iu m h um ous a llu v ia l soils, flood ed 10 — th e term of ir r ig a tio n b y flo o d w ith se w a g e , o th e r e x p la n a tio n s — as in F ig. 1
F ig. 3. E n zym atic a c tiv ity o f lig h t a llu v ia l soils, u n flood ed
e x p la n a tio n s — as in F ig. 1
of sugar/100 g of soil, w hereas in light ones about 100-3000 mg of sugar/100 g of soil. In the latter, horizons w ith a low hum us content show low values of saccharase and w ith small variations over the whole period.
Despite great fluctuations in the particu lar periods of studies, a higher activity of saccharase was found by the end of the vegetation period, as compared w ith the initial activity (in spring). The data found in the literatu re on the above phenom ena coincide. According to P a n c h o l y and R i c e [10] the highest saccharase activity (after
E n zym atic a c tiv ity of irrigated m ead ow soils 119 seasonal fluctuations) occurs in m idsum m er (July, August) and decrease by the end of the vegetation period. S k u j i n s [11], however, in ter prets a higher activity in autum n by a higher accum ulation of plant rem ains, which causes activation of saccharase.
A distinct increase of saccharase activity in the profiles of the ir rigated alluvial soils (humus and light) occurred after the second and th ird irrigation, though th a t increase was found only in the top layer.
From the above discussion it appears th a t some relationships are quite distinct and in agreem ent w ith other authors results. This concerns among others the correlation of enzym atic activity w ith hum us content and partially the effect of sewage on enzym atic activity. However, the interp retation of the dynamics of the enzymes studied causes difficulties. In most cases the changes have no specified regularities. It is possible th a t m ore frequent studies would give a clearer picture of th eir dynamics. On the other hand, however, it should be rem em bered th a t the studies w er based on field m aterial, and it was difficult to obtain a complete repeatability of results in these conditions.
F ig. 4. E n zym atic a c tiv ity of lig h t a llu v ia l soils, flood ed explanations — as in Fig. 1 and 2
1 20 S. U ziak, K. S tein b rich
CO N C L U SIO N S
1. The enzymatic activity expressed by the am ount of hydrolized
compounds occurs in the following order : saccharase > urease phos
phatase.
2. The activity of the individual enzymes depends on the content of organic substance and is directly proportional to it.
3. Irrigation w ith sewage intensifies urease activity in hum us allu vial soil, and th a t saccharase in both alluvial soils.
4. The dynamics of the activity of the enzymes is differentiated : low of phosphatase, considerable of urease and high of saccharase. In m ost profiles it is characterized by irregular changes, and some regula rities are only p artially observed.
Wc wish to express our gratitude to Mgr E. B l a i m for his assistance in a part oj the laboratory work.
REFERENCES
[1] F r a n z G. : V erg leich en d e U n tersu ch u n g en über die E n zy m a k tiv itä t ein ig er B öden aus N o rd h ein -W estp h a len und R h ein la n d -P fa lz. P ed o b io lo g ia 13, 1973, 423-436.
[2] G a 1 s t y a n A. Sh., A r u t u n y a n K. A. : К o p red elen iu a k tiv n o sti fo sfa ta z y p och vy. B iologich . S h u rn al A rm en ii, 19, 1966, 3, 25-29.
[3] H a l s t e a d R. L. : P h o sp h a ta se a c tiv ity of so ils as in flu en ced by lim e and other treatm en ts. Can. J. S oil Sei. 44, 1964, 1, 137-144.
[4] H o f m a n n G., T e i с h e r K. : Ein k o lo rim etr isch es V erfa h ren zur B e stim m ung der U r e a se k tiv itä t im Boden. Z. P fl. Ernähr., D üng., B odenk. 95, 1961, 55-64.
[5] H o f m a n n E., S e e g e r e r A. : Ü ber das E n zy m sy stem unserer. K u lturboden. H .-S a cch a ra se. B ioch em . Z. 1951, 174-183.
[ 6 ] J a n o s s y G . : T a l a j m i k r o o r g a n i z m u s o k f o s z f a t a z a a k t i v i t a s a n a k v a l t o z a s a a fo sz fo r e lla to ttsa g to l fü g g ö en (C hanges in p h osp h atase a c tiv ity of soil orga
n ism s in rela tio n to th eir su p p ly w ith phosphorus). A grokem . T alajt. 12, 1963, 2, 285-292.
[7] K r a m e r M., E r d e i G. : P rim e n e n ie m ethoda op red elen ia a k tiv n o sti fo s fa tazy v agro ch im ich esk ich issled o v a n ia k h . P o ch v o v ed . 1959, 9, 99-102.
[8] K u p r e v i c h V. F., S h c h e r b a k o q a T. A. : P o ch v en n a ia en zym ologia. Izd. N au k a i T ech n ik a, M insk 1966.
[9] M e j b a u m - K a t z e n e l l e n b o g e n W. , M o c h n a c k a O. : A p ra ctica l cource in b ioch em istry. PW N W arsaw , 1966.
[10] P a n e h o l y S. K., R i c e E. L. : S o il en zy m es in( rela tio n to old fie ld su c cessio n : A m y la se, C ellu la se, In v erta se, D eh y d ro g en a se and U rease. S o il Sei. Soc. A m er. Proc. 37, 1973. 47-50.
[11] S к u j i n s J. J. : E n zym es in soil. In : S oil B io ch em istry . Ed. by A. D. M cL aren, G. H. P eterso n . M arcel D ekker, Inc., N ew Y ork 1967.
[12] T r o j a n o w s k i J. : C h an ges of organic su b sta n ces in soil. PW R iL W arsaw , 1973.
E nzym atic a c tiv ity of irrigated m ead ow soils 121
[13] U z i a к S. e t al. : T he e ffe c t of m u n icip a l w a ste w a te r s on th e h a b ita t and p ro d u ctiv ity on th e m ead ow co m m u n ity in th e B y strzy ca riv e r v a lle y . R ocz. N au k roi. Ser. D, 168, 1978.
S. UZIAK, K. STEINBRICH
A K TY W N O ŚĆ EN ZY M A T Y C Z N A G LEB ŁĄK O W Y C H N A W A D N IA N Y C H Śc i e k a m i m i e j s k i m i
Z akład G leb o zn a w stw a U M CS w L u b lin ie
S t r e s z c z e n i e
B ad an ia p rzep row ad zon o na rpóbkach g leb o w y ch porb an ych sześcio k ro tn ie w ciągu roku z m ad śred n ich p ró ch n iczn y ch oraz lek k ich , za lew a n y ch i n ie z a le w a n y c h ściek a m i. O znaczono a k ty w n o ść fo sfa ta zy , ureazy i sach arazy. U zy sk a n e w y n ik i p o zw o liły na n a stęp u ją ce u o g ó ln ien ia (rys. 1—4 ).
1. A k ty w n o ść en zy m a ty czn a w yrażon a ilo ścią zh y d ro lizo w a n y ch zw ią zk ó w u k ła d a się w n a stęp u ją cy m porządku: sacharaza > ureaza > fosfataza.
2. A k ty w n o ść p o szczeg ó ln y ch en zy m ó w zależy od zaw artości su b sta n cji orga n iczn ej i jest do n iej w p ro st proporcjonalna.
3. N a w a d n ia n ie ściek a m i w zm a g a a k ty w n o ść u reazy w m ad zie p róch n iczn ej oraz sach arazy w obu rod zajach m ad.
4. D y n a m ik a a k ty w n o ści en zy m ó w jest zróżnicow ana: m ała fo sfa ta zy , znaczna ureazy i duża sach arazy. W w ięk szo ści p ro filó w m a ona ch arak ter n iereg u la rn y ch zm ian, ty lk o w części ob serw u je się p ew n e p ra w id ło w o ści.
Prof. dr Sta n isla w U ziak Z a kła d G leboznaw stw a UMCS L u b lin, u l. A k a d e m ick a 12
