R O C Z N IK I G L E B O Z N A W C Z E T . X X V I , Z . 2, W A R S Z A W A 197S
V. RANKO V, B. VELEV
EFFECT o f t h e h e r b i c i d e r a m r o d
ON THE CELLULOSE-DECOMPOSING ACTIVITY OF SOIL
Maritza Institute for Vegetable Crops, Plovdiv, Bulgaria
The wide use of herbicides in agriculture made it necessary to in vestigate their influence not only on weeds and their phytotoxicity re garding crops, but also the interaction with soil microorganisms. There are some literature data about the effect of the herbicides on the cellu- lose-deeomposing microorganisms [1, 2, 5, 13, 14]. Our previously works were also connected with this problem [7, 8]. In this work, the effect of the herbicide Ramrod (N-isopropyl-a-chloracetamilid) on the activity of cellulose-decomposing bacteria in field and laboratory conditions has been examined.
METHODS
The herbicide, in the doses of 3.25 kg, 4.55 kg and 6.50 kg/ha, has been used in stationary plots of 4 m 2 without crop, non manured with 40 t/ha of FYM (farmyard manure) or peat.
The laboratory experiments have been carried out at 20-22°C in the soil of 65% water capacity. The model experiments has been carried out: the first on the alluvial meadow soil with different fertilization; mineral P240, K 240, organic 40 t/ha of FYM and organo-mineral 40 t/ha of FYM and N240, Рг4<ъ K 240. The second laboratory experiment has been performed in the soils with different physico-chemical properties: allu- vial-meadow soil leached chernozem — smolnitza with a heavy texture, clay silt fraction 51,7% [9] with humus content of 3,3% and neutral re action. In the third model experiment the activity of herbicides in the doses of 5,50 and 500 ppm at different temperatures (2-3° and 20-22°C) has been examined.
C ell u lo se — d ec om p os in g a ct iv it y (C A a ) СЧЭ CO 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 Days 20 50lh 100- 150ъ ■ Non fertilized -5 6 7 5 6 7 5 6 7 20lh 50lh 100lh 150lh 401/ha FYM -8 -8 10 8 9 10 20ih 50lh 100 9 10 lh 8 9 10 150lh ■ 40 i/ha peat
Fig. 1. Effect of the treatment with Ramrod on cellulose-decomposing activity of alluvial-meadow soil
la — basic, 2 a — potential cellulose-decom posing activity; variants: 1 — control, 2 — 3.25 kg/ha of Ramrod, 3 — 4.55 kg/ha o f Ramrod, 4 — 6.50 kg/ha of Ram rod, 5 — 40 t/ha o f F Y M (non-treated), 6 — 40 t/ha o f F Y M +3.25 kg/ha of R a m ro d , 7 — 40 t/ha o f F Y M + 6.50 kg/ha o f Ram
rod, 8 — 40 t/ha of peat (non-treated), 9 — 40 t/ha of peat f 3.25 kg/ha of Ram rod, 10 — 40 t/ha of peat + 6.50 kg/ha of Ramrod
r. R a n k o V , В . V e le v
E ffe ct o f the herbicide... 235
The soil has been analyzed at 20, 50 and 100 days after the herbicide treatment.
The activity of the cellulose-decomposition, basic and potential, has been determined after the method of P o k o r n a - K o z o w a [8]. The results have been calculated according to the formula of G r u n d a [3]
P
CDa = - - , where CDa — activity of cellulose-decomposition, p — amount of decomposed cellulose in °/o, t — time of incubation in days.
RESULTS
The field experiments showed that Ramrod, in the dose of 3,25 kg/ha after 20 days of soil treatment caused an increase in the activity of cel lulose decomposition in the soil (Fig. 1). The similar results have been obtained previously [9]. The herbicide used in the higher doses decreased both basic and potential activity of cellulose-decomposition in the soil layers 0-10 cm and 10-20 cm. The decrease of the basic activity of cellulose decomposition caused by the highest dose o f Ramrod persisted up to the 150th day after soil treatment with this herbicide.
The introduction of 40 t/ha of FYM in the soil reduced the toxic influence of herbicide on the activity of cellulose decomposition to the different extent depending on the incubation time.
When Ramrod in the dose of 3,25 kg/ha with peat was introduced into the soil, the increase in the cellulose decomposition was noted. This stimulating effect of peat addition was reduced in the presence of Ramrod in the dose of 6,50 kg/ha. Generally, the peat addition to the soil reduced the inhibitory effect of Ramrod on the cellulose de composition to a lesser extent than FYM addition.
It has been known that the fertilization accelerates cellulose de composition in soil [7, 4, 16]. The model experiments confirmed it (Fig. 2). The organo-mineral fertilization was found to be most effective in the Ramrod presence of 5 and 50 ppm.
The incubation at different temperature caused some changes in the activity of cellulose-decomposition.
The doses of Ramrod 500 and 1000 ppm were very toxic and inhibited the process of cellulose decomposition.
The inhibiting effect of Ramrod on cellulose decomposition in the chernozem-smolnitza soil was slighter than in the alluvial-meadow soil (Fig. 3). This was probably caused by the humus and silt fraction content in the leached chernozem-smolnitza soil. The humus content in the soil and some physicochemical soil properties changes the toxicity of the others herbicides on soil microflora [11, 12]. too.
2 3 6 V. Rankov, В. Velev Non fertilized Nz4g Ргчо Kz4o т Л “ 1 Г -W l / Ь л FYM I 4 0 ł /h a FYM + N^ąo Ргчо ^гчо 20îh 1 Z 3 ¥ 5 5 0 th 100т
Fig. 2. Change of the cellulose-decomposing activity of alluvial meadow soil treated with Ramrod and manured
la — basic, 2 a — potential; va ria n ts: 1 — control, 2 — 5 ppm of Ram rod, 3 — 50 ppm o f Ram rod, 4 — 500 ppm of R am rod, 5 — 1000 ppm of R am rod (the sam e variants apply to
1 2 3 4 5 Days 20in 1 2 3 4 5 50in 1 2 3 4 5 100 th
Fig. 3. Effect of Ramrod on cellulose-decomposing activity of different soils in controlled conditions
la — stfiuvial-m eadow soil, 2a — leached ch ern ozem -sm oln itza; 1 .... 5 — as in Fig. 2
1 2 3 4 5
Days 20IK 50t h
i 1 r
1 2 3 4 5
10 0 lh
Fig. 4. Effect of Ramrod on cellulose-decomposing activity of alluvial-meadow soil at different temperatures; explanation as in Figs 2 and 3
238 V. R ankov, B. V elev REFERENCES
[1] A m a n t a j e w E., I l e l e t d n i k o w A., K u d y s z e w T.: Agrobiołogija 3, 1963, 462.
[2] D o s t o w a ł o w S., I l a h i n a Z.: Trudy Krasn. 3, Choz. Inst., 1961, 160. [3] G r u n d В.: Zesn. Casop. Ustav Vedeckotechn Inform. 13, 1967, 9, 807. [4] K r a u s e O.: Symp. Mineralization der Zellulose, 24-26.IV.1967, Jena-Berlin
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Jena-Berlin 1968, 53.
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[10] R a n k o v V., E l e n k o E.: Poczwozn. i agroch. 2, 1970, 127. [11] R a n k o v V .: II Congress of Microbiology 1969, 4, 1971, 253.
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[14] S o b i e s z c z a ń s k i J.: Acta microb. pol., Ser. В, 1 (XVIII), 1969, 2, 39. [15] V e l e v В.: Gradinarska i łozarska nauka 2, 1973, 69.
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V. R A N K O V , В. VE L E V
W P Ł Y W HERBICYDU RAMROD N A A K TY W N O ŚĆ CELU LOLITYCZN Ą GLEBY
Instytut Ogrodnictwa Marica, Plovdiv, Bułgaria
S t r e s z c z e n i e
W doświadczeniu połowym i doświadczeniu modelowym badano wpływ N -izo- propyl-a-chloroacetanilidu na celulolityczną aktywność aluwialnej gleby łąkowej. Stwierdzono, że Ramrod w dawkach 3,25 kg/ha stymulował rozkład celulozy, pod czas gdy w dawkach 4,55 i 6,50 kg/ha hamował ten proces. Zahamowanie pod wpływem dawki 4,55 kg/ha było krótkotrwałe, przy podwyższeniu dawki trwało dłużej.
Stosowanie herbicydów na polu nawożonym obornikiem (40 t/ha) przyspieszało rozkład celulozy w stopniu znaczniejszym aniżeli przy nawożeniu torfem. Efekt ten widoczny był po upływie 100-150 dni od zastosowania nawożenia i herbicydu.
W doświadczeniu ścisłym hamujące działanie herbicydu w dawce 5 i 50 ppm zmniejszało się pod wpływem nawożenia oraz w glebach ilastych i o wysokiej zawartości humusu. Zmiany temperatury (od 2-3° do 20-22°C) nie miały wyraźnego wpływu na zmiany w rozkładzie celulozy w obecności herbicydu.
E ffe ct o f the herbicide... 239 В . Р А Н К О В , Б . ВЕЛ ЕВ ВЛИЯНИЕ ГЕРБИЦИДА РАМРОД Н А ЦЕЛЮ ЛОЛИТИЧЕСКУЮ АКТИВНОСТЬ ПОЧВЫ Институт Овощных Культур Марица, Пловдив, Болгария Р е з ю м е Исследовали в полевом и модельном опыте влияние рамрода на целю- лолитическую активность аллювиальной луговой почвы. Рамрод в дозе 3,25 кг/га стимулировал размножение клетчатки а в дозах 4,55 и 6,50 кг/га ингибировал. Ослабление целюлолитической активности было коротковременно при 4,55 кг и несколько дольше при 6,50 кг/га. Применение гербицида на поле удобренном навозом (40 т/га) ускоряло разложение клетчатки сильнее чем при удобрении торфом. Этот эффект был заметен после 100-150 дней от применения гербицида и удобрений. В модельном опыте ингибирующие действие гербицида 5 и 50 ppm умен- шалось особенно в присутствий удобрения и большего количества гумуса. Влияние гербицида на размножение клетчатки не зависит от колебаний температуры: 2 -3° до 20-22°С.
