Mineralizacja związków azotowych w odsłoniętym złożu torfowym

H EN R Y K FRĄ CK O W IA K

M IN ER A LIZA TIO N OF NITR O G EN COM POUNDS IN AN O PEN PEA T

D E PO SIT

In stitu te of A g ricu ltu re M elioration and G rassland C u ltivation , L ocal R esearch Branch, B yd goszcz

IN TR O D U C TO R Y NO TES

C onsiderable areas of open p eat deposits, w ith o u t biologically active

horizons, are form ed d u rin g levelling th e m oor su rfaces, d e v a sta te d by

th e planless or in d u stria l p e a t ex plo itatio n . It is m ore and m ore im p o rta n t

to gain back those u n p ro d u ctiv e areas.

The process of re-fo rm in g soil on th e open peat deposits tak es place

v e ry slow ly in th e n a tu ra l conditions [3, 4, 5], b u t it m ay be accelerated

if s tru c tu ra l and p h y sic a l-w ate r p ro p erties are changed by m eans of

a g ro techn ical tre a tm e n ts [5].

The th erm al, air and chem ical soil conditions are eq u ally adv entageous

for p la n t g ro w th an d developm ent of n itro g en -fix in g b acteria. T herefore,

rese a rc h on th e in te n sity of th e n itro g en m in eralizatio n in field con­

d itions and u n d e r the in flu en ce of ag ro tech nical tre a tm e n t m ay be con­

sidered as an a tte m p t at an ap p reciatio n of the degree and ra te of

a c tiv atin g of those “d e a d ” and biologically in active soils.

LO C A T IO N A N D M ETH ODS

In v estig atio n s w ere p erfo rm ed in I960— 1964 and took place on

undecom posed or slig h tly m in eralized an d h u m ificated (mucked) ree d -

-sedge — p eat-m o or and on th e m ead o w -p lan ted research site situ a te d in

th e Bydgoszcz C anal V alley. Som e physical and chem ical c h aracteristics

of th e soils are show n in th e Tab. 1.

Some Ph ysical and Chemical S o i l P r o p e r tie s in the Sod Horizon

Bulk den sity kg/cubic decimeter Max. water capacity * by volume Ash content

%

The m ethod adopted in th e in v estig atio n p e rm itte d d ire c tly (w itho ut

incubation) d eterm in e chem ically th e in crem en ts of m in e ral nitro g en per

u n it of tim e in field conditions. The p rin cip le of the m ethod discussed

fu lly in sev eral papers [1, 2, 6] is to in d icate the d ifferences in the c o n ten t

of m in e ral n itro g en at in te rv a ls over a few days w hen the p la n t roots

w ere isolated and th e n itro g en en su red ag ain st leaching (by m eans of

u n ta rre d roofing paper). A ll o th e r ecological conditions w ere left u n ­

changed. R epeated d e te rm in a tio n s of th is k in d in th e veg etatio n period

provide a fa irly clear p ictu re of th e co n ten t and in crem en ts of m in eral

n itro gen as an effect of am on ificatio n and n itrific a tio n processes. M in eral

n itro gen w as d e te rm in e d in th e 1% K 2S 0 4 e x tra c t am m onium n itro g en

by m eans of a titra tio n m ethod a fte r d istila tio n in th e P a rn a s a p p a ra tu s,

n itra te n itro g en colo rim etrically using C olem an’s sp ectro p h o to m eter by

th e phenoldisup h onic acid m ethod. O nly deionized w a te r h a d been used

fo r th e analysis (A m brelite and Dowex).

In th e ex p erim en ts, m in e ra l fertiliz e rs w ere added as follows:

N — 60 kg, P 20 5 — 55 kg, K 20 — 80 k g/h ectare.

R E SU L T S A N D D IS C U S S IO N

The inv estig atio n s on m in eralizatio n of n itro g en com pounds w ere

ca rrie d out on tw o d iffe re n t re se a rc h sites. In th e firs t of th em an e x p e r­

im ent w as m ade of p la n tin g a m eadow on a d e v a sta te d p e a te ry . It w as

s ta rte d in 1957 w hen th e su rface of th e p e a te ry h a d been levelled (th ree

y ears p rio r to the n itro g e n m in eralizatio n rese a rc h in 1960). The su rface

levelling re su lte d in form ing tw o e n tire ly d iffe re n t objects:

— an open peat deposit w ith w eak ly m in eralized p eat on the surface,

— exploited p e a t-p its filled up w ith d isin teg ra te d an d a e ra te d peat.

S c h em e of th e le v e llin g op eration on th e p ea tery d ev a sta ted by p la n le ss e x p lo ita tio n of p eat

a — a n o p e n p e a t d e p o s i t , b — a f i l l e d u p p e a t p it ;

1 — o r i g i n a l l e v e l o f t h e p e a t e r y , 2 — p e a t - l a n d s u r f a ­ c e a f t e r l e v e l l i n g

F u ll cu ltiv a tio n (ploughing + sow ing m ixed grasses), N P K fertilizin g ,

and P K fertilizin g in th e follow ing y e a rs w ere applied for p la n tin g th e

m eadow .

The d e te rm in a tio n re su lts of period ical m in e ral n itrogen in crem en ts

g a th e re d in Tab. 2 w ere com piled on th e basis of 24-hours in cre m e n ts

no ted d u rin g th e v eg etatio n period. T he firs t period covers th e tim e form

th e “s ta rtin g ” of v eg etatio n to th e day of th e firs t m ow ing, th e second

period covers th e tim e from th e firs t m oving to th e day of th e a fte rm a th

and th e th ird period covers th e rem ain in g p a rt of th e vegetation

period.

T a b l e

2

_

_

'

'

In th e firs t y e a rs a fte r p lan tin g of m eadow , the h ay crops from th e

tw o objects w ere conspiciously d iffe re n t. C o nsiderably h ig h er crops w ere

o btained fro m th e “fille d -u p -e x p lo ite d -p e a t-p it” . A t late as th e th ird

y e a r a fte r p lan tin g th e m eadow th e crops resp e c tiv e ly am o u n ted to 37,2

an d 83,4 q u in ta ls of h a y p er h ectare. S im ilar d ifferen ces o ccu rred in th e

periodical in cre m e n ts of m in e ral n itro g en (28,6 and 66.0 kg N hectare).

equal. Corps and n itro g e n in crem en ts g ra d u a lly in creased in case of “th e

open p eat dep o sit” w hile th e crops and n itro g e n in cre m e n ts decreased

on “the fille d -u p -e x p lo ite d -p e a t-p it” . In 1964, th a t is 7 y e a rs a fte r g rass­

ing, crops from both th e objects w ere alm ost identical. C ontrol in v esti­

gation of m in eralizatio n show ed h ig h er d evelopm ent of th is process on th e

open p eat d ep osits” (0,43 kg N (hectare/24 h o urs again st 0,29 kg on th e

“fille d -u p -e x p lo ite d -p e a t-p it”). This phenom enon is p ro b ab ly due to bio­

logical “a c tiv a tin g ” th e ra w p eat soil on th e one hand , w hich re su lts in

im p ro v em en t of th e p h y sical pro p erties of th e soil in “th e open p eat

dep osits” and on th e o th er h a n d to a decrease of the m in eralizatio n p ro ­

cess in th e “fille d -u p -e x p lo ite d -p e a t-p it” caused by subsidence of the o ri­

gin ally loose peat m ass and a decrease of its p orosity to g eth e r w ith p e rm e ­

a b ility to air.

In th e follow ing e x p e rim e n t a m eadow w as p lan te d on an open peat

deposit in o rd er to exam ine th e in flu ence of c u ltiv atio n and m in eral f e r ti­

lizing upon h ay crops as w ell as on th e course of the process of n itro g en

m in eralizatio n th ere. The m eadow w as p lan te d in 1959 th a t is tw o y ears

before sta rtin g research es on m in eralizatio n (1961).

T hree d iffe re n t com binations w ere applied:

— fu ll cu ltiv atio n (ploughing + sow ing m ixed grasses), m in eral N PK

fertilizin g,

— self-seeding -b m in eral N P K fertilizing ,

— self-seeding w ith o u t fertilizing.

The d e te rm in a tio n s of periodical in crem en ts of m in e ra l nitro g en w ere

com piled on th e basis of 24 ho u rs in crem en ts in the v egetation period

w hile th e e x p e rim e n tal periods w ere se p ara te d in ex a ctly in the sam e w ay

as in th e firs t ex p erim en t.

The h ig h er a c tu a l co n ten t of th e m in e ral n itro g en in case of th e

com bination w ith o u t fertilizing , w ith in th e w hole season, w as p ro bably

caused by th e sm aller consum ption of n itro g en by th e underdevelo p ed

p lan t cover.

T here w ere some ch a ra c te ristic reg u la ritie s observed in the in crem en ts

of the m in e ral nitrogen. N am ely, th e in crem en ts of th e m in eral n itro g en

in a com bination w ith fertilizing , w ere high in e a rly spring, especially if

fu ll cu ltiv atio n w as applied (0,65 mg N/cu. dem p er 24 hours). In case of

a com bination w ith o u t fertilizin g th e in te n sity of m in eralizatio n w as v ery

low in e a rly spring, in creasin g g rad u a lly as late as at th e end of M ay and

th e begining of Ju n e . D urin g su m m er m onths and a u tu m n the m in e ra li­

zation of n itrog en w as alw ays m ore in tesive in case of th e com bination

above m en tio n ed th a n in the o th er ones.

T a b l e 3

p e r i o d i c a l m in e r a l n it r o g e n in c r e m e n ts in open p e a t d e p o s i t in k g /h a in 0 - 1 0 cm l a y e r

Per iod Mineral К F u l l c u l t i v a t i o n - NPK S e l f - s e e d i n g - KPK S e l f - s e e d i n g w ith out 1 f e r t i l i z a t i o n | 1 ---1 9 ol 1963 1961 196З 1961 1963 ; I _{K-KH4 1 6 .1 1 1. 2} 7 . 1 - 9.4 _{Ъ . 9} 1

1

It can be rea d from Tab. 3 w h ere periodical in crem en ts of m in e ral n i­

tro g en are listed th a t stro n g e r m in eralizatio n (considering th e w hole

v eg etation period) takes place in case of th e com bination w ith o u t fe r til­

izing. This m ay be connected w ith fa r w eak er sod fo rm ation in th is com bi­

nation, w hich caused stro n g e r insolation, hig h er soil tem p e ra tu re s, easier

soil freezin g and aeration. C on seq u ently th e re m ig h t occur ce rtain changes

of s tru c tu re and o th er p eat p ro p erties. It should be assum ed th a t the

acceleratio n of th e activ atin g process of th e open p eat deposits can be

expected by causing periodical aeratin g , th a t is leaving a deposit (ploughed

top layer) w ith o u t sod form ation u n d e r th e in flu ence of atm o sp h erical

factors. S im ilar conclusions m ay be d raw n on th e basis of o th er e x p e ri­

m en ts [5] p erfo rm ed on th e sam e object.

C O N C LU SIO N S

In th e first y ears of cu ltiv atio n th e re occurs a v e ry w eak m in eralizatio n

of n itro g e n com pounds in an open p eat deposit w ith w eakly m ineralized

p eat of th e top layer. The period of n a tu ra l “a c tiv a tin g ” of such e n v iro n ­

m ents is estim ated to last for 7 y e a rs in conditions of th e p erfo rm ed

ex p erim en ts. This process can be accelerated by d isin teg ra tin g an d a e ra ­

tin g th e p eat and also by periodical w e a th erin g of an open, not sodded

deposit.

M ineral fe rtiliz a tio n , allow ing to a tta in q u ite hig h crops of hay , does

not accelerate th e m in eralizatio n processes of n itro gen , b u t m ay be favo ­

u rab le in th e course of these processes in th e spring.

[2] F r ą с к o w i a к H.: M ateriały k o n fe r e n c y jn e NOT, B yd goszcz, 5—7.VI.1967, s. 114— 135.

[3] P a w l a k T.: Z eszy ty P roblem . P ost. N auk R oln., z. 27, 1961, 197— 207. [4J P a w l a k T.: Z eszy ty P roblem . P ost. N auk R oln., z. 34, 1961, 221— 234.

[5] S с h o 1 z R.: Ł ą k o w e zagosp od arow an ie d o łó w p o to rfo w y ch w P a w łó w k u — rękopis.

[6] Ś w i ę t o c h o w s k i B.: Z entr. B akt. Par. Inf. H yg., 1963, II, vol. 116, 259/267.

H . F R Ą C K O W I A K

LE M IN É R A L ISA T IO N D ES M A TIER E S O R G A N IQ U E A ZO TÉES D A N S U NE COUCHE DE TO U RBE

I n s t i t u t d ’A m é l i o r a t i o n e t d e s H e r b a g e s S e c t i o n R e g i o n a l e d e s R e c h e r c h e s à B y d g o s z c z

R é s u m é

A u cours des a n n ées 1960— 1964 on a fa it des rech erch es ta n t a u x cham ps q u ’au la b o ra to ire a y a n t pour b ut l ’éstim a tio n de la cap acité de la m in éra lisa tio n m a tières organ iq u e azotées sous l ’in flu e n c e des a c tiv ité s ag ro tech n iq u es rela tifs à la m ise en prairies des tou rb ières d e v a sté e s par une e x p lo ita tio n ir r a tio n e lle de la tourbe. C ertain es p rop riétés p h y siq u es et ch im iq u es des sols ex a m in é s on t été p résen tés dans la ta b le 1.

On a ap p liq u é dans ces étu d es la m éth o d e de d éterm in a tio n ch im iq u e d irecte (sans in cu b ation ) des a ccro issem en ts de l ’azote m in éra l dans u n e u n ité de tem ps dans des con d ition s du so l en p la ce p en d a n t la p ériod e de v é g éta tio n . L e p rin cip e de cette m éth o d e [1, 4] co n siste à la d éterm in a tio n de la d iffé r e n c e de ten eu r en azote m in éra l (l’éta t d ’am m on iq u e et n itrique) à in te r v a lle s de q u elq u es jours — les racin es des p la n tes éta n t iso lé e s et les sols p rotégés contre le le s siv a g e . L ’azote m in éra l fu t d éterm in é dans un e e x tra ctio n de 1 °/o de K 2S 0 4, N -N H 4 par titra g e après d istilla tio n dans l ’a p p a reil de P arn as, et le N -N H 3 par colorim étrie au sp ectro - p h otom étre de C olem an d ’après la m éth o d e à l ’acid e du p h en ol b isu lp h on iq u e. On n ’a em p lo y é pour les a n a ly ses q u e l ’eau d éio n isée. On a ap p liq u e dans les ex p é r ie n c e s les doses su iv a n te s d’en grais m in éra u x : N — 60 k g/h a, P 20 5 — 55 k g/h a, K 20 — 80 kg/ha.

D ’après le s étu d es e ffe c tu é e s on p eu t co n clu re q u e dans le so l tou rb eu x fa ib le ­ m en t m in éra lisée, p riv é de la cou ch e su p e r fic ie lle , dans le s p rem ières an n ées après la m ise en v a le u r n ’a lie u q u ’u n e très fa ib le m in éra lisa tio n m a tières organ iq u e azotées (ta b le 2). On a estim é que dans le s con d ition s d’étu d es e ffe c tu é e s, la p ériode „d’a c tiv isa tio n ” n a tu relle de tels sols to u rb eu x a été en v iro n 7 ans. On p eu t accélerer ce p rocessu s par é m ie tte m e n t et a éra tio n de la tourbe (dess. 1 et ta b le 2), so it par u n e d écom p osition su p e r fic ie lle p ério d iq u e de la co u ch e de tou rb e d écou verte.

L ’em p loi des en grais m in éra u x , p erm ette d’ob ten ir des réco ltes assez é le v é e s de foin , ce qui n ’a ccélère pas de m in éra lisa tio n des m a tières organ iq u e a zo tées du sol m ais p eu t con trib u er au d év elo p p em en t fa v o r a b le de ces processu s pour leu rs in te n sific a tio n au p rin tem p s (table 3).

H . F R Ą C K O W I A K

M IN E R A L ISIE R U N G V O N ST IC K ST O F F V E R B IN D U N G E N IN A U FG E D EC K T E N T O R FA B L A G E R U N G E N

I n s t i t u t f ü r L a n d w i r t s c h a f t s m e l i o r a t i o n u n d G r ü n l a n d k u l t u r , A u s s e n s t e l l e in B y d g o s z c z

Z u s a m m e n f a s s u n g

In den Jah ren I960— 1964 w u rd en d ie F e ld - und L a b o ru n tersch u n g en zw eck s B estim m u n g der In te n sitä t der S tic k sto ffv e r b in d u n g e n m in e r a lisa tio n u n ter dem E in flu ss von agro tech n isch en M assn ah m en , die m it der G rü n la n d b ew irtsch a ftu n g a u f den durch p la n lo se T o r fg e w in n u n g zerstörten M oorfläch en v e rb u n d en en sind durch gefü h rt. M an ch e p h y sik a lisc h e n und ch em isch en E ig en sch a ften der u n ter­ su ch ten B öden sind in der T a b e lle 1 d a rg estellt.

In den U n tersu ch u n g en w u rd e die M eth od e der u n m ittelb a ren (d.h. ohne In k u b ation ) ch em isch en B estim m u n g der M in era lstick sto ffzu n a h m e im L a u fe ein es Z eita b sch n ittes in F eld b ed in g u n g en in der V eg eta tio n sp erio d e an g ew a n d t. D iese M eth od e [1, 4] b e ste h t in der B estim m u n g der U n tersch ied e im G eh a lt des M in era l­ stic k sto ffe s (A m m on - und N itratform ) im A b stan d v o n e in ig e n T agen, b ei iso lieru n g der P fla n z e n w u r z e l und b eim S ch u tz des S tic k sto ffs v o r der A u sw a sch u n g . D er M in era lstick sto ff w u r d e im A u szu g von l°/o K 2S 0 4, N -N H 4 m itte ls T itrieru n g nach der D e stilla tio n im P a rn a s-A p p a ra t und N - N 0 3 k o lo rim etr isch au f dem C o lem a n - S p ek tro p h o to m eter n ach der M eth od e m it der P h en o ld isu lfo n sä u re, b estim m t. In den A n a ly se n w u r d e a u ss c h lie s slic h das e n tio n isie r te W asser a n g ew a n d t. In den V ersu ch en w u rd e m in e r a lisc h e D üngung’ in den G aben: N — 60 kg, P 20 5 — 55 kg, K 20 — 80 kg'/ha a n gew an d t.

D ie U n tersu ch u n g serg eb n isse zeigten , d ass in a u fg ed eck ten T orfab lageru n gen , m it sch w a ch m in era lisiertem T orf in der oberen S ch ich t, in den ersten Jah ren nach der B e w ir tsc h a ftu n g e in e seh r sch w a ch e M in era lisieru n g von S tic k sto ffv e r b in d u n g e n e rfo lg t (Tab. 2). D ie P eriod e ein er n a tü rlich en „ A k tiv ieru n g ” solch er S tan d orte w ar in B ed in g u n g en der g efü h rten U n tersu ch u n g en fü r e tw a 7 Jah re gesch ätzt. D ieser P rozess k a n n m itte ls Z erkleinerung' und B e lü ftu n g des T orfes (Abb. 1 und Tab. 2) b esch leu n ig t w erd en .

M in era lisch e D ü ngung, d ie ziem lich h ohe H eu erträ g e zu erh a lten erm öglich t, k ann die M in era lisieru n g sp ro zesse der org a n isch en S to c k sto ffv erb in d u n g en n ich t b esch leu n ig en , sie k an n aber den V erlau f d ieser P rozesse, h in sich tlich ein er In te n ­ siv ie r u n g d erselb en im F rü h jah r (Tab. 3) b eg ü n stig en .

H . F R Ą C K O W I A K

M IN E R A L IZ A C JA ZW IĄ ZK Ó W AZO TO W YCH W O D SŁO N IĘTY M ZŁOŻU TORFO W YM

I n s t y t u t M e l i o r a c j i i U ż y t k ó w Z i e l o n y c h , T e r e n o w y O d d z ia ł B a d a w c z y , B y d g o s z c z

S t r e s z c z e n i e

W la ta ch I960— 1964 prow adzono b ad an ia p o lo w o -la b o ra to ry jn e, m a ją ce na celu zb ad an ie n a tężen ia m in era liza cji zw ią zk ó w a zo to w y ch pod w p ły w e m za b ieg ó w agro­ tech n iczn y ch , z w ią za n y ch z zagosp od arow an iem łą k o w y m to rfo w isk z d e w a sto w a

ozn aczan ia p rzyrostów azotu m in era ln eg o w jed n o stce czasu w w a ru n k a ch p o lo w y ch w ciągu ok resu w eg e ta c y jn e g o . Z asada m etod y [1, 4] p olega na ozn aczan iu różnicy w zaw artości azotu m in era ln eg o (form y a m on ow ej i azotan ow ej) w od stęp ach k ilk u dni przy o d izo lo w a n iu k orzen i roślin oraz zab ezp ieczen iu azotu przed w y p łu k iw a ­ n iem . A zot m in era ln y oznaczano w w y c ią g u l°/o K 2S 0 4 — N -N H 4 — m iareczk ow an o po d e sty la c ji w ap aracie P arn asa, a N - N 0 3 — k o lo ry m etry czn ie na sp ek tro fo to m etrze C olem an a m etod ą z k w a sem fe n o lo d w u su lfo n o w y m . P rzy an alizach sto so w a n o w y ­ łą c z n ie w o d ę d ejon izow an ą. W d o św ia d czen ia ch sto so w a n o n a w o ż e n ie m in era ln e w n a stęp u ją cy ch d aw kach: N — 60 kg, P 20 5 — 55 kg, K 20 — 80 kg/ha.

W w y n ik u p rzep row ad zon ych badań stw ierd zon o, że w o d sło n ięty m złożu to r­ fo w y m ze słabo zm in era lizo w a n y m torfem w w ierzch n ie j w a r stw ie , w p ierw szy ch la ta ch po zagosp od arow an iu zachodzi bardzo słab a m in era liza cja zw ią zk ó w azo to ­ w y c h (tab. 2). O kres n a tu ra ln ej „ a k ty w iz a c ji” ta k ich sta n o w isk ocen ion o w w a r u n ­ k ach p row ad zon ych d ośw iad czeń n a około 7 lat. P r z y sp ie sz e n ie tego p rocesu jest m o żliw e p rzez rozd rob n ien ie i n a p o w ietrzen ie torfu (rys. 1 i tab. 2) bądź przez o k reso w e w ie tr z e n ie o d sło n ięteg o złoża.

N a w o ż e n ie m in era ln e, p o zw a la ją ce na u zy sk a n ie dość w y so k ic h p lon ów siana, n ie p rzysp iesza p ro cesó w m in era liza cji o rgan iczn ych zw ią zk ó w azotow ych , m oże b yć n a to m ia st k o rzy stn e dla p rzeb iegu ty ch p ro cesó w w se n sie ich in te n sy fik a c ji w o k resie w io se n n y m (tab. 3). г . Ф Р О Н Ц К О В Я К М И Н Е РА Л И ЗА Ц И Я А ЗО Т Н Ы Х С ОЕДИН ЕН ИЙ Б О Т К РЫ ТО Й ТО РФ Я Н О Й З А Л Е Ж И И н с т и т у т М е л и о р а ц и и и З е л е н ы х У г о д и й , И с с л е д о в а т е л ь с к о е О т д е л е н и е в г. Б ы д г о щ

Р е з ю м е

п ользовали сь только д ем и н ер ал и зован н ой водой. В опы тах вносились м и н е­ ральн ы е удобр ен и я в сл ед у ю щ и х д о за х на гектар: N — 60 кг, P 2Os — 55 кг. К 20 — 80 кг. В итоге иссл едован и й устан овлен о, что на откры той т ор ф я н ой за л е ж и , со слабо м инерализованом тор ф ом в п оверхностн ом горизонте, в п ер в ы х го д а х после освоен ия азотны е соеди н ен и я м и н ер ал и зую тся очень м едл ен н о (таб. 2). П ери од естеств енной „активи зации” такого тор ф я н и к а оцени вается, согласно р езул ьтатам опытов, на около 7 лет. У скорить х о д этого проц есса возм ож н о путем р а здр обл ен и я и аэраци и то р ф а (рис. 1, таб. 2) или путем п ер и оди ч еск ой аэраци и (проветривания) откры той за л е ж и . В н есен и е м и неральны х удобрен и й , способствую щ ее п олучени ю достаточно вы сокого у р о ж а я , не уск ор я ет процессов м и н ерализации орган и ческ и х соед и н е­ ний азота, однако оно м о ж ет быть полезны м дл я протек ан и я эти х процессов в см ы сле и х и н т ен си ф и к ац и и в весен нем п ер и оде (таб. 3).