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 1975
S. M IK LA SZE W SK I
EFFECT o f d i f f e r e n t d o s e s o f a f a l o n e a n d m a n u r e ON THE ACTIVITY OF CELLULOLYTIC MICROORGANISMS
IN SOIL IN THE FODDER CARROT CULTIVATION Institute of Soil and Plant Cultivation,
Agricultural University of Wrocław, Poland
Contemporary weed control in field crops is based more and more with the passage of time on chemicals eliminating labour-cónsuming and often difficult to perform mechanical cultivation in rows of growing plants. The importance of soil-applied herbicides constantly increases, because the period of their effect on weeds, both emerged and emerging, is rather long and the weed control in this way covers the great part of growing season. The effect of these herbicides is not only limited to weeds; at their long persistence in soil they affect also the soil micro flora. This effect in equal environmental conditions may be different for particular microflora groups: the growth of some groups may be stimulated while that of others inhibited. The cellulolytic microorganisms play an important role in decomposition processes of crop residues. Yet the effect of soil-applied herbicides on this group of microorganisms is not satisfactorily explained.
The purpose of this work was to investigate the effect of the soil- applied preparation from phenylurea group Afalone (linuron) on the activity of cellulolytic microorganisms.
The investigations were carried out in 1972 in two exact experiments: — pot experiment, in which doses of 0, 2, 4 and 20 kg/ha of Afalone were used and activity of cellulolytic microorganisms was determined at three terms: directly after introducing herbicide into soil and three and six months after this date;
— field experiment with cultivation of fodder carrot, in which three doses o f Afalone: 1, 2 and 3 kg/ha, and control treatment without her bicide, as well as two levels o f manure fertilization at the rate o f 300 and 600 q/ha and treatment without this fertilizer were applied.
The field method of K u ź n i a r for estimation of the activity of cellulolytic microorganisms was used [1, 2]. In this method glass plates covered with filter paper were put vertically into soil layer 0-20 cm for three weeks. Afterwards the filter papers were weighed out and a loss of cellulose content was determined.
In the pot experiment determinations were made in 6 replications, in the second (field) experiment — in 8 replications.
The results of pot experiment are presented in Fig 1. From the data obtained it can be concluded that directly after introducing herbicide
Fig. 1. Effect of different doses of Afalone on the activity of celulolytic microorganisms in soil in the pot ex
periment
1 — control treatm ent, 2 — directly after introducing herbicide into soil, 3 — after 3 m onth, 4 — after 6 m onth, 5 — statisti
cally proved difference
Fig. 2. Effect of different doses of Afalone in soil in the field experiment on the activity of celulolytic micro organisms and on the yields of roots
and leaves of fodder carrot 1 — without m anure, 2 — 300 q m anure, 3 — 600 q m anure, 4 — statistically proved
difference in com parison to control
into soil, the doses of 2 kg o f Afalone caused a statistically proved sti mulation in comparison to control, while the doses of 20 kg provoked a slight decrease of microbiological activity. Three months afterwards the stimulating effect of 2 kg of Afalone almost completely disappeared, while a distinct (statistically proved) decrease of the activity in treat ments with 4 and 20 kg of the Afalone was found. A fter 6 months the ,effect of Afalone on the activity of cellulolytic microorganisms markedly
E ffe ct o f d iffe re n t doses... 243
diminished and only in the treatment with the dose o f 20 kg of herbicide it was statistically proved.
The results of field experiment are given in Fig. 2. As it is seen in the Figure, in the treatments without organic fertilizers the activity of cellulolytic microorganisms slightly increased under the influence o f the dose of 2 kg/ha of Afalone while under the influence of 3 kg/ha of Afalone an almost twofold increase (statistically proved) in comparison to control without herbicide took place. In treatments fertilized with 300 and 600 q/ha of manure the rate of cellulose decomposition was about 15% higher than in control treatment without organic fertilizer. In treatments with 300 q/ha of manure the higher doses of Afalone were accompanied with stronger (statistically proved) cellulose decom position process. In treatments with 600 q/ha of manure the highest cellulose-decomposing activity was reached with 1 kg/ha of Afalone. while with further increasing herbicide doses the microbiological activity decreased.
The cellulolytic activity was also determined on the same fields one year later, in 1973, in cultivation of aftercrop — spring barley, but neither herbicide nor manure influence has been found.
Applied doses of Afalone did not influence the yields of roots and leaves of fodder carrot, but the fertilization with manure revealed a distinct positive action.
On the basis of the obtained results the following conclusions can be drawn:
1. Small doses of Afalone (in common use) caused a temporary in crease of the activity of cellulolytic microorganisms.
2. High doses of Afalone (not used in practice) decreased for a long time (6 months) the activity of cellulolytic microorganisms.
3. Both manure fertilization and Afalone in the doses of 1 and 2 kg/ha intensified the process of cellulose decomposition.
4. Afalone in the doses of 1-3 kg/ha did not influence yields of roots leaves of fodder carrot.
REFERENCES
[1] K u ź n i a r K .: Badania nad rozkładem błonnika w glebach leśnych. Ed. Instytut Badań Leśnych, Kraków, 1948.
[2] M i k l a s z e w s k i S.: W pływ współczesnej agrotechniki na aktywność i roz mieszczenie drobnoustrojów celulolitycznych w warstwie ornej gleby. Rocz. glebozn. (in print).
S. M IK L A S Z E W S K I
W P Ł Y W RÓŻNYCH D A W E K A FALO N U I OBORNIKA
N A AK TY W N O ŚĆ DROBNOUSTROJÓW CELULOLITYCZNYCH W GLEBIE W UPRAWIE M ARCHW I PASTEWNEJ
Instytut Produkcji Roślinnej, Akademia Rolnicza, Wrocław
S t r e s z c z e n i e
Pracochłonna uprawa pielęgnacyjna marchwi pastewnej może być w dużym stopniu uproszczona przez zastąpienie zabiegów mechanicznych opryskiem Afalonu. Afalon jednak jako herbicyd doglebowy o długim okresie działania może w y wierać wpływ na środowisko glebowe.
Badania aktywności drobnoustrojów celulolitycznych przeprowadzono na dwóch doświadczeniach ścisłych: wazonowym, w którym zastosowano dawki afalonu: 0, 2, 4 i 20 kg/ha, a aktywność drobnoustrojów celulolitycznych określano w trzech terminach, tj. bezpośrednio po wprowadzeniu herbicydu do gleby, po trzech i po sześciu miesiącach oraz w doświadczeniu polowym z uprawą marchwi pastewnej przy zróżnicowanych dawkach Afalonu: 0, 1, 2 i 3 kg/ha i dwóch poziomach na wożenia obornikiem 300 i 600 q/ha oraz bez obornika. W badaniach zastosowano połową metodę oznaczania aktywności drobnoustrojów celulolitycznych.
Na podstawie uzyskanych wyników można wysnuć następujące wnioski: 1. Niewielkie dawki Afalonu (powszechnie stosowane) spowodowały krótko trwały wzrost aktywności drobnoustrojów celulolitycznych.
2. Duże dawki Afalonu (nie stosowane w praktyce) obniżyły na dłuższy okres (6 miesięcy) działalność tej grupy drobnoustrojów.
3. Nawożenie obornikiem, zarówno samo jak i w połączeniu z dawkami 1 i 2 kg Afalonu na hektar wpłynęły na zwiększenie procesu rozkładu błonnika.
4. Dawki 1-3 kg Afalonu na hektar nie wywarły wpływu na plon korzeni i liści marchwi pastewnej.
с. М И К Л Я Ш Е В С К И ВЛИЯНИЕ РАЗНЫ Х ДОЗ А Ф АЛ О Н А И Н АВО ЗА Н А АКТИВНОСТЬ МИКРООРГАНИЗМОВ РАЗЛАГАЮ Щ И Х К Л Е Т Ч А Т ^ В ПОЧВЕ И В ^ Л Ь ^ Р Е КОРМОВОЙ МОРКОВИ Институт растениеводства Сельскохозяйственной академии во Вроцлаве, Польша Р е з ю м е Трудоёмкая механическая обработка кормовой моркови может быть за менена применением афалона. Однако афалон, являясь гербицидом продолжи тельного действия, может оказывать влияние на почвенный биоценоз. Активность микроорганизмов разлагающих клетчатку исследовали в опыт ных сосудах с афалоном в количестве 0, 2, 4 и 20 кг/га. Активность определяли в трех сроках: после внесения гербицида в почву, а затем через 3 и б ме
E ffe ct o f d ifferen t doses... 245 сяцев'. В полевом опыте афалон применяли в количестве 0, 2 и 3 Ki^ra на фоне 300 и 600 ц/га навоза и без навоза. Активность разлагающей клетчатку микрофлоры определяли полевым методом. Были получены следующие результаты: 1. Небольшие дозы афалона (применяемые в практике) вызывали неко торую стимуляцию активности микроорганизмов. 2. Высокие дозы афалона (не применяемые в практике) снижали актив ность этой группы микроорганизмов в течение б месяцев. 3. Применение навоза ускоряло разложение клетчатки, независимо от наличия гербицида. 4. Афалон в количестве 1-3 кг/га не оказывал влияния на урожай корней и листьев моркови.
