NGHIGN C L I U - T R H O B O I
^ KHAO SAT SU BIEN DlNG CUA CAC QUAN THE VI SINH VAT TRONG DAT TRONG S&M NGOC LINH
TRAN BAO TRAM, NGUYEN TH! THANH MAI, NGUYEN TH! HIEN
Ven iJng i^ng C&r^ ngh$. B$ l^toa iKJC va Cong ngjid
Nghiin ci}u auac tien hanii vAI cac miu da't trSng sam Ngoc Linh (6 nam tuoi) lai Quing Nam. IVIiu da't dirgic IS'y vao mua mira va mua l(ha nSm 2013-2014 d cac do sau khac nhau (0-15 cm, 15-30 cm). K6't qui phan tfch mgt so'dac diem cua da't tr£ng sam cho tha'y, da't cd pH tha'p (4-4,5), dp a'm cao (44-55%), dg xo'p Idn (47-67%). Kit qui xac djnh thanh phSn va sO' Itrgrng vi sinh vat cho tha'y, trong da't trdng sam cd mat dai di§n cac nhdm vi sinh vat chfnh: vi l(huan (s6' lirdng ehie'm > 90% tong so' lirang vi sinh v^t), xa Irhuln va na'm md'c. Trong cac nhdm cd chl}c nang chuyin hda khac nhau, nhdm vi sinh vat phan gial xenluld chiem iTu the so vdi nhdm phan giii photphat khd tan va co' djnh nitof. Nhin chung, sS'liT^ng vi sinh vit trong mdi nhdm khdng cd sir khac hiit nhilu tlieo mua nhirng cd xu hirdng giim theo chiiu sau cua da't (so' lirdng giim tir 10-100 la'n khi xuO'ng dd sau 15-30 cm).
Tif khoa: da't, sam Ngoc Linh, vi sinh vat.
Dat v a n da
Sam Ngpc Linh {Panax vietnamesis Ha et.
Grushiv) la ioai dac hOu cOa Viet Nam, dupc phat hien duy ntiS't fi viJng niii Ngpc Linh thudc hai tinh QuSng Nam va Kon Tum 5 dp cao tren 1.500 m.
Vung nui Ngpc Linh thupc Quang Nam nam trong vCing khi hau nhiet dSi, chi cd 2 mua la miia mua va mua kho, chju anh hufing cija mCia dong lanh mien Bac. Nhiet do trung binh nam la 26,4°C. Bp am trung binh trong khong khi dat 84%. Lupng mUa trung binh 2.000-2.500 mm, phan bo khdng deu, tap trung vao cac thang 9-12 (chilm 80% lupng mua cS nam). Chinh dac dilm tU nhien nay da tao nen su da dang d$c trUng cua tham thuc vat cung nhu khu he visinh vat Sdd [1].
Vi sinh vat da't co vai tro quan trpng dpi vdi he sinh thai va CO mo'i quan he mat thiet vdi thSm thuc vSt
ndi cU tru, dp la moi quan he tUdng h6 va la nguon goc cija sti can bang trong he sinh thai. Trong dat cd rat nhilu loai vi sinh vat co nhOng chUc nang khac nhau, su phan bo' cCia chung phu thupc vap dilu ki§n dinh dufing, nudc, pH, dp sSu, mufc dp thpang khi, che dp canh tac, dia hinh cOa dat va tham thuc vat... V(3i mdi ioai da't khac nhau thi khu he vi sinh vat 6 do cung cd nhOng dac diem dac trUng. 6 Viet Nam hien da ce mpt so nghien cUu v l he vi sinh vat trong cac loai da't khac nhau nhu dat trdng lua, trong mia, da't rUng, dat gd doi, da't khai m6... [2, 3, 4, 5, 6]. Tuy nhien, viec tim hieu ve vi sinh vat trong da't trong sam Ngoc Linh chua dUdc cong bo nhieu. Do dd, viec nghien ciru khcio sat sU bien dpng cCia cac quan the vi sinh vat trcng dat trong sam Ngpc Linh se la ket qua budc dau cho cac nghien cufu tie'p theo ve quan xa vi sinh vat trong da't trong sam, lam ca sfi cho viec nghien cUu san xua't phan bon phii hdp vfii ioai cay dUdc ii§u co gia trj cao nay.
=K ,.> „a™ o n i . . T a p c H K H O B H Q I
NGHIGN CQU-TRRO DOI
INVESTIGATION Of THE FLUCTUATION Of MICnOODGANlC POPULATIONS IN SOU CULTIVATED WITII NGOC lINtl GINSENG
SLITlTK-y
The study was carried out on samples of soil cultivated with Ngoc Linti ginseng (6 years old) in Quang Nam. The samples were collected during the rainy/dry seasons in 2013-2014 at different depths (0-15 cm, 15-30 cm). The analysis result of the soil showed that the soil had low pH (4-4.5), liigh humidity (44-55%), high porosity (47-67%).
The determination result of the composition and quantity of microorganisms showed tiiat there existed representatives of the major microorganism groups In Ngoc Linh ginseng cultivating soil:
bacteria (making up more than 90% of ttie total microorganisms), actinomycetes and fungi. With the metabolic function variance, the group of cellulolytic microorganisms was dominant as compared to the groups of phosphate solubilizing and nitrogen-fixing microorganisms. In general, the number of microorganisms in each group did not vary noticeably from season to season but tend to decrease by the depth of the soil (10-100 times less at the depth of 15-30 cm).
Keywords: soil, Ngoc Linh ginseng, microorganism.
moi trudng thach dTa; xac dinh so lifdng vi khuan tren moi tradng MPA; xac djnh s6 IUdng xa khuan tren moi tru'dng Gause; xac dmh so lUdng nam moc tren moi tradng Czapek; xac dmh so IUdng vl sinh v&t CO kha nang ph&n g\k\ xenluld tren mdi trudng Hutchinson; xac dinh so IUdng vi sinh vat cd kha nang phan giai photphat kho tan tren mdi trudng NBRIP; xac djnh s6' luong vi sinh vat cd kha nang cd' djnh nitd tren mdi trudng Thompson-Skerman.
Phan logi vi khuan, xa khuan, nam moc theo khda phSn loai cua Gause va cs (1983), Krasilnhicop (1958), Bergey va cs (1989).
- X^ ly sd' li§u theo phUdng phap thdng ke sinh hpc.
Ket qua va thao luan
Nghien cu'u mgt s6(S0c diem cua dat trdng sam NgQCUnh
SU phan bo va so IUdng vi sinh v^t cd lien quan mat thiet vdi dac diem cua vung dat ma chung cU tru. Trong nghien cUu nay, chung tdi tien hanh phan tfch mot so dac dig'm chinh cua dat trong sam Ngpc Linh, ket qua the hidn 6 bang 1.
Bang 1 • ket qui phan tich dac diim dat trong sSm Nggc Unh
Doi ttftfng va phiTtfng phap nghien cuTu D6i tuang nghiin cOu: cac loai sinh v§t trong dat trdng sam Ngpc Linh.
- Dja diem lay m l u : dat dUdc lay tai khu trdng sam Nggc Linh (6 nam tudi) tren niii Nggc Linh dUdi tan rCfng gia nguydn sinh, thudc huyen Nam Tra My, tinh Quang Nam.
- Thdi gian lay mSu: thang 9-11.2013 (mua mua) va thang 3-6.2014 (mua khd).
Phuang phap nghien cUu:
- Lay mSu dat theo TCVN 5297:1995.
- Ph§n tfch tinh chat dat [7]: pH, dd am, dp xdp.
- Phan tich vi sinh vat [8]: xac dmh sd lUdng vi sinh vat theo phUdng phap pha loang va cay gat tren
TT 1 2 3 4 5
Chi tieu Mau sac T r ^ n g thai pH Do am Ddx6p
Ddn v i
% %
Khoang gia tri Nau den Tdi xop 4,0-4,5 44-55 47-67
Dac diem cua dat dong vai tro quan trpng do'i vdi sinh truflng oCia vi sinh vat. De ton tai va phat trien, vi smh vat can thUc hien rat nhieu qua trinh trao ddi chat. Chung thu nhan va dong hoa cac chS't tit ngoai moi truflng de tong hop cac hop phan cOa te bao.
Hau het vi sinh vat sinh truflng thuSn loi nhat fl pH tit 6 den 8, con mpt so' nSm thi fl pH dudi 5. pH cua dat con anh huflng den l<ha nang chuyin hoa photpho - nguyen to dinh duBng quan trpng doi vfli vi sinh vat.
Thong thuflng, dp hoa tan cua photpho Ifln nhat fl pH 6,5, qua trinh van chuyen l<im loai cOa vi sinh vSt la nhfl nhat fl pH Ifln hon 6 [9], do do vfli dac diem cua da't trong sam^ co pH 4-4,5 la mot dieu ki§n bat lai cho su phat trien cua he vi sinh vat. Do vSy, tfnh da dang cua quan xa vi sinh vat trong da't trflng sam Ngpc Linh co t h i bj anh hi/flng bfll ye'u to nay.
"UN«»---
NGHIGN CLIU-TRnO DOI
Bdn egnh yeu td pH, nUdc la dieu kien thiet yeu de d^m b^o su tdn tai va sinh trudng cDa vi sinh vat.
Ham lUdng nudc trong d^t cd the ^nh hudng den sU thdng khf (van chuyen oxy), do hoa tan cua cac hop ph^n cDa da't va pH. Nd'u do am ciJa dat qua th^p se lam gi^m hoat dgng vi sinh vat, ngUdc lai neu do am qua cao thi su trao ddi khi se giam xudng, tao rajihOng vung ky khf dan d^n su gik\r\ sut cac quan the vi sinh v§t hid'u khi va tang sd IUdng vi sinh v§t ky khf hoac ky khf tuy tien. Khi trong d^t ndi chung ChUa nhi^u CO^ hdn khi quyen phfa tren mat dat do su hd h^p cua vi sinh v§t va cua rd cky, dieu nay han c h ^ nhieu su di chuyen cua khf vao cac Id nho cOa dat. Trong thuc tiln, de dam bko sU sinh trudng tdt nhat cua hau het vi sinh vkX hieu khi, dp am cua d§'t can dam bao tU 50% den 75%. Chi'nh vi vay, vdi cac dac diem; do am (44-55%), dd xdp (47-67%) da dUdc phan tfch cho thay, dat trong sam Ngpc Linh cd didu kidn thu§n ldi cho sU phat tnen ci!ia cac vi sinh vkX.
Bien dgng thanh phan va so lugng cua cAc quan thS vi sinh vat trong dat trong sam Nggc Linh
S\J phan bd va bien ddng mat dp cua cac nhdm vi sinh vat trong dat phy thudc vao khdng gian, b^
mat va chieu sau cua tang d&'t, mua va loai/vung d§'t nen trong nghien cUu nay, chung tdi tid'n hanh xac djnh thanh phan va so' IUdng vi sinh vat trong tang d§'t mat d do sau khac nhau cung nhu theo ddi si^ bien dgng m§t dp vi sinh vat theo mua.
Nhom vi sinh vat tong sd':
Vi sinh vat hidn dien nhleu trong dat nhung tuy thudc loai dat va thanh phan cac chS't dinh dudng ma sd IUdng va chiing loai vi sinh v§t se khac nhau, dai didn cho vung da't do. Trong nghien cUu nay, chung tdi xac djnh so lupng va sU cd mat cac nhdm vi sinh v§t trong dat trong sam Ngpc Linh tU nhien, ke't quk thu dUOc dUdc the hien trong b^ng 2.
Bing 2: s^ Iddng vi sinh v$t trong di't trSng sim Ngpc Linh
Miia
Mua Bo sau l^y m l u (cm)
0-15 15-30 0-15 15-30
Sd iUOng vi sinh vat (CFU/g) Vi khuIn Xa khuan Nam moc
(5.4+0,6) X 10' (4,8+0.6) X 10' (6,2±0,5) X 10«
(1,7±0,5) X 10' (8.9+0,4) X 10" (7,4+0,2) X 10"
(6,0+0,2) X I O ' ( 5 , 5 ± 0 , 6 ) x 1 0 ' (6,1±0,5) X 10' (3,5±0,4) X 10' (4,6±0,5)x10" (4,4*0,2) X 10'
Vdi mau dat thu vao thdi diem mua mUa va mua khd deu cho thay sd IUdng trong cac nhom vi sinh vat 6 dp sau 0-15 cm cao hdn so vdi 6 dp sau 15-30 cm, ket qua nay hoan toan phu hdp ve mat ly thuyet vi 6 Idp dat tren cd dp thoang khf tdt, dp am va pH thfeh hdp, cac chat dinh dudng tfch luy nhi^u va cac qua trinh chuyen hda quan trpng cua rd cay chu yeu xay ra ci day.
Ke't quk phan tfch thanh phan cac nhdm vi sinh vat cho tha'y, trong da't trong sam Nggc Linh, sd IUdng vi khu^n chiem dai da sd (10^-10^ CFU/g, chid'm tren 90% tong sd lUpng cac vi sinh vat), xa khuan chiem khoang 6-8% va nam dUdi 1%. Tuy nhien, khi xudng dp sau hdn (15-30 cm) so' IUdng xa khuan va nam md'c gi&m ro ret (khoang 100 lan), ke't c\uk nay cijng tUdng tu nhu cac nghien cUu ve thanh phan vi sinh v&t theo dd sau trong cac loai dat khac nhau theo cac nghien cUu [10, 11, 3, 4].
Nhom vi sinh vit chuySn hoa:
Vi sinh vat dat ddng vai tro quan trong trong qua trinh chuyen hda cac chat hUu cdvavocd trong dat, tgo ra hang ioat cac skn pham cOa hoat ddng sd'ng, trong dd cd cac hoat chat sinh hpc quan trpng nhU enzyme, vitamin, khang sinh... Trong nghien cUu nay, chung tdi xac djnh su bien ddng ve sd IUdng trong cac nhdm vi sinh vat phan giai xenluld, phan giai photphat khd tan va cd djnh nitd. Ke't qu^ thu dUdc trinh bay 5 bang 3.
Bing 3: sd Idang trong cic nhdm vi sinh v^t chuyen hoa cua dat trdng sim Ngoc Lmh
„ , , So lu'flng VI sinh vat (CFU/g) Miia lay mau VSV phan gidi VSV phan gidi V S V c o d i n h
^'^'"^ xeniuiS photphat kho tan nitd 0-15 (4,3+0,3) X 1 D= (6,2+0,6) x 10= (B±0,5) X 10=
Kho
15-30 (9,7+0,5) X 10^ (1,2±0,2) x 10 (4,4+0,2) X 10 0-15 {1,8+0,2)X10^ {1,5±0,4)x10= (6,1±0,5)x10 Ml/a
15-30 (2.5+0,4)xlO^ (1,6+0,5}x10 (1.e+0,2)x10
Ket qua thu dUdc cho thay, trong cac nhdm vi sinh vat chuyen hoa, so lUdng vi sinh vat nhdm phan g\k\ xenluld Idn nha't so vdi 2 nhom khac (so lupng dat tdi 10^ CFU/g) va co sU gl^m ro ret ve sd lU0ng theo chieu sau tang dat nhUng bien dpng giOa cac mua khdng ro rdt. Ket qua nay hoan toan
So 24 nam 2014 ^ A « I V ? - ^ ^ ' " " ? ' ' " i B -
CONG NGHE VIET N M T
49
NGHIGN COU-TRRO 901
phu hpp vdi tinh chat dac trUng cua dat vung trong sam Ngpc Linh nam dudi tan rUng, do vay cd mdt lupng khdng nhd cac loai canh, la cay rung, dudi tac ddng cua he vi sinh vat phan g\k\ xenluld se chuyen hda thanh dang mun hDu cd cung cap ngudn dinh dudng cho cay sinh trudng.
Vdi hai nhdm vi sinh vat phan giai photphat khd tan va co djnh nitd, phan tfch cho thay sd' IUdng cCia hai nhdm nay khdng nhi^u, chi dat tU 10-10^CFU/g nhUng nhin chung sd IUdng vi sinh vat deu cd xu hudng gi^m dan theo dp sau tang dat (tU 10 dd'n vai tram lan).
Ket qua phan tfch chung cho thay, bien ddng thanh phan va so lupng cac nhdm vi sinh vat trong da't trong sam Ngpc Linh theo mua khdng cd sU khac biet ro ret, dieu nay dupc g\ki thfeh la do dieu kidn tu nhidn dac trUng cua vung rUng tU nhien trdng sam cd dp am khdng khf rat Idn (>80%), nhidt dp giiJfa cac mua cung khdng bid'n ddng Idn, trung binh tu 18-22°C nen dp am va pH dat khdng bie'n dpng Idn va mau lay tai khu vuc trdng sam da dn djnh 6 nam.
Ket luan
- Ket qua phan tfch bUdc dau ve dac diem dat trdng sam Ngpc Linh cho thay, vdi chi so pH tha'p (4-4,5), dd am cao (44-55%), dd xdp Idn (47-67%) lam han che tinh da dgng nhung tong sd IUdng vi sinh vat v l n la kha Idn (>10^ CFU/g).
- Trong da't trong sam Ngpc Linh co mat cija dai dien cac nhdm vi sinh vat chfnh gom; vi khuan (10^- 10« CFU/g, chiem >90%), xa khuan (10^-10^ CFU/g) va nam (lO^-IO" CFU/g).
-Sdludng visinh vat trong nhdm phan giai xenluld la Idn nha't so vdi cac nhdm vi sinh vat chuyen hda photphat va nitd (tUdng Ung dat lO^-IO^CFU/g so vditCf lO-IO^CFU/g).
- Bien dpng sd IUdng cac nhdm vi sinh vat theo mua khdng co sU khac bidt rd ret nhung theo chieu sau cua dat CO xu hudng gi^m (10-100 lan ddp sau 15-30 cm).
Ket qua thu dupc se la cd sd dO lieu phuc vu hudng nghien cUu skn xua't phan bdn vi sinh bo sung cho dat trdng sam Ngoc Linh d cac vung di thUc ^
Tai lieu tfiam Icliao
[1] Nguyin Thiidng Dong, Tran Cong Lu§n, Nguyin Thi Thu Hifdng (2007). Sam Vi§t Nam va m6t s6 cay thu6c hp Nhan sam. Nha xucit biin Khoa hpc va Ky thuat.
[2] L§ Thi Viet Ha, Lg Van Tn (2005). Nghign cilu bi^n dong cdc nhom vi smh vat hUu ich tren dat trong mfa t^i vCing nguyen li§u mia dudng Lam Son, Thanh Hoa. Tgp chf N6ng nghifip v^
Phdt trien N6ng thon, ky I, thang 1.2005, 75-77.
[3] W\a Thi Ngpc Mai, T6ng Kim Thu^n (2005). Nghien cu'u hien trgng vi smh vat dat trong mot so trgng thdi thcim thuc vdt d tram da dgng smh hoc. Hoi thao quo'c gia vi sinh thdi va tai nguySn smh vat lan thiJ nhat, 784-788.
[4] Nguyin Anh Hiing, Le Dong Tan, Ma Thi Ngpc Mai, Tong Kim Thuan (2012) So luong va hoat tinh sinh hpc cia mpt so nhom vi sinh vat dat trong cac trgng thai thSm thi^c vat tgi huyen Dmh Hoa, Thdi Nguyen. Tap chi Cfing nghe sinh hpc
[5] Nguyin Vdn SiJc, Nguyin Viel Higp, Ddm The Chi^n (2009). Mpt so dac diem vi sinh vat da't Ithu vi,fc Ithai thac m6 thiec & Ha Thupng - Dai TCr, Thai Nguyen Tgp chf Khoa hpc d^t, so 31/2009, 39-42,52.
[6] Pham Thi Ngoc Lan (2003). Danh gia s6 li/(3ng, hogt li^c va tuy^n chpn mpt so chung vi smh vat co ich trong dat trong lua d ThCia Thien - Hue. NhQng van de nghien cilu cd bdn trong l<hoa hpc sM song, 1103-1107.
[7] Le Van Khoa, Nguyen Xudn Ci,(, Bui Thj Ngpc Dung, Le Disc. Tran KhSc Hiep, Cdi Van Tranh (2000). PhUdng phap phan tich dgt. nUdc, phdn bon, cay trong. Nha xud't bdn Giao due.
[8] Nguyin Ldn DQng (19 xua't bdn Mir,
[9] Sims J.T. (1990). Nitrogen mineralization and elemental availability in soils amended with cocomposted sewage sludge.
Journal of Environmental Quality 19.669-675.
[10] Alma Pastucha, Barbara Kolodziej (2008). The role of mulch in the formation of microorganisms population in the soil under the cultivation of American ginseng (Panax quinquefoiium L ). Journal of Herba polonica. Vol. 54, No.4, 52-61.
[11 ] Galina Churkina, Kairat Kunanbayev, Galiya Akhmetova (2012). The taxonomic composition of soil micrporganisms in the ecosystems of southern chernozems of Northern Kazakhstan.
Journal of Applied Technologies and Innovations, Vol.8 Issue 3 November 2012, pp 13-19.
). Thac tap Vl smh vdt hpc Nha
50 I T o p c K KHOAHQC s 6 24 ndm ?ni4
