521

NGHIN CU NH HNG CA RM R X L

BNG CH PHM Trichoderma N NNG SUT LA

V HIU QU KINH T TRNG LA NG BNG

SNG CU LONG

Trn Th Ngc Sn1, Trn Th Anh Th2,

Nguyn Ngc Nam2, Lu Hng Mn3

1. T VN

Vit Nam cung nh nhiu quc gia trn th gii, cy la l

cy lng thc chnh vi sn lng trung bnh hng nm khong 38

- 40 triu tn trn din tch gieo trng khong 7,44 triu ha, trong

gm hai vng trng la trng im ca c nc l ng bng sng

Cu Long (BSCL) c din tch l 3,87 triu ha v ng bng sng

Hng (BSH) c 1,115 triu ha (Nin gim thng k, 2009).

Nng dn c tp qun canh tc la hai n ba v trong nm

v vy nu trung bnh mt tn la cho ra 1-1,2 tn rm r th vi sn

lng la hin nay, c tnh lng rm r thi ra c th ln n 40

- 46 triu tn/nm. Tuy nhin, vn x l rm r sau mi v thu

hoch la trn thc t li cha c cch lm hiu qu. V vy, ty

thuc vo iu kin thi tit c th m ngi nng dn s chn la

bin php x l rm r thch hp. Nu nh thu hoch la vo ma

kh, ngi nng dn s t ng tranh th ma v v gim

lng rm r ny nhanh chng. Cn thu hoch la vo ma ma

ngi nng dn khng ngn ngi sut phun rm ngay cnh b

knh, rch. Nh vy s gy tc nghn giao thng thy v gy

nhim mi trng, nh hng n sc khe ca con ngi.

Rm r cha khong 0,6% N, 0,1% P cung nh S, 1,5% K,

5% Si v 40%C... Rm r c xem l ngun dinh dng quan

trng lm gia tng nng sut la (0,4 tn/ha/v khi rm r c vi

vo trong t) v lm gia tng mu m ca t theo thi gian

(Ponnamperuma, 1984). Mc d vy, rm r ti khng th vi

1 Trng BM, Vin la BSCL 2 Vin La BSCL 3 Ph Vin trng, Vin La BSCL

522

ngay vo trong t v t l C:N rt cao c th dn n gim lng

dinh dng hu dng quan trng i vi sinh trng ca cy trng.

Mt s kt qu nghin cu trc y cho thy khi b sung

VSV vo rm r nh Arpergillus, Trichoderma, Penicillium,

Pseudomonas, Bacillus v Azotobacter, Pleurotus sojarcaju v

Trichoderma viride th rm r phn hy nhanh hn, gim t l C/N

v gia tng hm lng cc cht N, P, K (Gaur v ctv. 1990,

Ramaswami v Tran thi Ngoc Son, 1996 v 1997; L Th Thanh

Thy v Phm Vn Ton, 2001, Luu Hong Man v ctv. 2005, Luu

Hong Man v Nguyen Ngoc Ha, 2006, Trn Th L Th Thanh

Thy, 2008; Trn Th Ngc Sn v ctv. 2009).

Trong nhng nm gn y, vic nghin cu s dng cc ch

phm sinh hc x l rm r rt c quan tm, trong , vic s

dng ch phm Trichoderma cung c ch . Mt trong nhng

thnh tu gn y ca Vin La BSCL l nghin cu, tuyn chn

v sn xut thnh cng ch phm Trichoderma c kh nng x k

rm r trc tip ngoi ng, vi quy m ln, gim chi ph thu gom

rm, vn chuyn v nh ng . Kt qu bc u tn dng

ngun rm r ti ch phc v cho sn xut la, gp phn n nh s

bn vng cho t la thm canh v nng sut, gim chi ph phn

bn ha hc v gp phn gia tng hiu qu kinh t trng la, p

ng chin lc sn xut nng nghip bn vng v bo v tt mi

trng. ti: Nghin cu nh hng ca rm r x l bng ch

phm Trichoderma n nng sut la v hiu qu kinh t trng la

ng bng sng Cu Long" thc hin thnh cng v nh gi

c kh nng phn hy rm r ca cc ch phm Trichoderma

trc tip ngoi ng, nh gi nh hng n sinh trng v pht

trin ca cy lu, ng thi xy dng cc m hnh v x l rm r

trc tip trn ng rung ti rung nng dn.

2. Vt liu v phng php nghin cu

2.1. Vt liu nghin cu

- Ch phm Trichodema dng x l rm r c ngun gc

bn a do Vin La BSCL phn lp v sn xut dng x l

rm r cho s phn hy nhanh. Cc chng nm Trichodema sp.

c thu thp v phn lp t cc h thng canh tc la BSCL,

ch phm c mt t bo VSV t t 108 n 109 CFU/g ch

523

phm. Ch phm c kh nng s dng ph hp vi tng iu kin

sn xut cc a bn nghin cu c th, c hiu qu x l rm r

nhanh vi hiu sut cao.

- Rm r c thu thp sau v thu hoch la ng Xun

2009-2010 c cc thnh phn dinh dng ch yu nh carbon,

NPK tng s tng ng 49,5% C, 0,59% N, 0,137% P2O5, 2,49%

K2O v C/N l 84,8.

Cc ging la thch hp cho tng a bn nghin cu.

Phn ha hc: super ln (16% P2O5); chlorua kali (60%

K2O); ur (46% N).

- Thi gian thc hin: t thng 3/2010 n 7/2011.

2.3. Phng php nghin cu

- nh gi hiu qua x ly rm ra cua ch phm Trichoderma trong iu kin ng rung

Xy dng th nghim ngoi ng nh gi hiu qu x l

rm r ca tng ch phm An Giang, Cn Th. Mi th nghim

gm 2 nghim thc, 4 ln lp li bao gm c x l ch phm v

khng x l ch phm. Theo di nh k hng tun v sau 4 tun

thu mu rm phn hy phn tch N, P, K tng s.

- Anh hng cua vi rm ra x l bng ch phm Trichoderma

trn ng rung i vi nng sut la v ph nhiu t: xy

dng cc th nghim ng rung trn h thng canh tc ph bin l

la 2 v v 3 v vo v H Thu 2010 2 im An Giang v Cn

Th. Mi th nghim gm 8 nghim thc, 3 lp li vi cc nghim

thc nh: (1) Rm r khng x l ch phm, (2) Rm r x l ch

phm, (3) Rm r khng x l + 70% NPK (70N-42 P2O5-21K2O

kg/ha), (4) Rm r x l ch phm+70% NPK, (5) t rm + 70%

NPK, (6) t rm + 100% NPK (100N-60 P2O5-30 K2O kg/ha), (7)

Rm r khng x l ch phm + 100% NPK, (8) Rm r x l ch

phm + 100% NPK. Ti An Giang: s dng ging la OM1490 v

ti Cn Th s dng ging la OM5981

- Cng thc phn bn:

+ 100% NPK= 100 N - 60 P2O5 - 30 K2O (kg/ha)

524

+ 70% NPK = 70 N - 42 P2O5 - 21 K2O (kg/ha)

- Phng php x l rm r: rm r sau khi thu hach v la

trc c tri u trn ng rung. Ha tan trc tip ch phm

Trichoderma vo nc sch liu lng 4 kg ch phm/ha v phun

t u vo rm r. Sau tin hnh cy vi vo t, cho nc vo

trc trc cho bng phng, tho cn nc v tin hnh gieo la.

- Ging la th nghim: OM5981 (Cn Th) v OM1490 (An

Giang).

- Cc ch tiu theo di: sinh trng v pht trin cy la, yu

t cu thnh nng sut v nng sut la, ph nhiu t (NPK hu

dng, cht hu c).

- Xy dng m hnh

T nhng kt qu t c tin hnh xy dng m hnh x l

rm r trc tip trn ng rung ti huyn Ch Mi tnh An Giang

v huyn Thi Lai, TP Cn Th trn hai h thng canh tc ch yu

l la 3 v ( vng c bao khp kn huyn Ch Mi tnh An

Giang) v la 2 v (vng khng c bao huyn Thi Lai, TP.

Cn Th).

M hnh c xy dng vo v ng Xun 2010 2011 v

H Thu 2011.

mi a bn nghin cu, chn 10-20 h nng dn (ty vo

din tch m hnh c th tng a phng). Mi nng h thc

hin 2 l canh tc, din tch mi l t 1.000 m2 2.000 m2. Tng

din tch m hnh l 10 ha.

L 1: M hnh khuyn co: rm r x l bng ch phm

Trichoderma + 70% NPK so vi canh tc theo nng dn

L 2: M hnh nng dn: t rm r v bn phn theo tp

qun nng dn.

Cng thc phn bn theo tp qun nng dn

+ V ng Xun 2010 2011, ti An Giang: 115,3N76,5

P2O570,1K2O (kg/ha); ti Cn Th: 106,7N 78 P2O5 47K2O

(kg/ha).

525

+ V H Thu 2011, ti An Giang: 140 N 103 P2O5 71,1

K2O (kg/ha); ti Cn Th: 105,7N 84,1 P2O5 46,9 K2O (kg/ha).

- Phng php phn tch: N tng s bng phng php Kjeldahl

(c iu chnh) (Jackson, 1958); P2O5 tng s, xc nh bng

phng php Olsen (Olsen v ctv., 1954); K2O tng s, xc nh

bng my hp thu nguyn t bc sng 767 nm; C hu c: xc

nh bng phng php Walkley-Black (Walkley v Black, 1934).

- Phng php tnh hiu qu kinh t: Chi ph vt t : ging +

phn bn + thuc bo v thc vt; Tng chi ph: chi ph vt t + chi

ph lao ng; Li nhun) = Tng thu nhp Tng chi ph; T sut

li nhun = Li nhun/tng chi ph.

- Phng php phn tch s liu: Thu thp v x l thng k bng

Excel, IRRISTAT v SPSS, kim nh khc bit gia cc trung

bnh nghim thc bng php th Duncan, dng T-test so snh s

khc bit gia 2 trung bnh trong phn tch thng k bng SPSS.

3. Kt qu v tho lun

3.1. Hiu qu x l rm ra cua cc ch phm

Rm r c x l bng ch phm Trichoderma c hm lng

dinh dng cao hn so vi khng x l ch phm tt c cc a

bn nghin cu (bng 2 v 3).

Bng 2. Hm lng dinh dng trong rm r sau khi x l ch

phm Trichoderma (%) iu kin ng rung sau 4 tun x l

TT Nghim thc An Giang Cn Th

N

tng s

P2O5

tng s

K2O

tng s

N tng

s

P2O5

tng s

K2O

tng s

NT1 Rm r khng x

l ch phm

Trichoderma 0,65b 0,14 b 2,96 0,884 b 0,163 b 2,820

NT2 Rm r x l ch

phm Trichoderma 0,97a 0,20 a 3,59 1,043 a 0,222 a 3,301

CV (%) 9,0 9,4 9,5 11 11,3 7,7

F ** ** * * * ns

X l ch phm Trichoderma spp. liu lng 0,8 kg/ tn rm ti v o 2 ln.

526

Kt qu ghi nhn c cho thy, khi x l bng ch phm

Trichoderma sau 4 tun liu lng 2 kg ch phm (mt s 108

109CFU/g)/1 tn rm r hoc 0,8 kg ch phm/tn rm r lm gia tng

hm lng N, P2O5, K2O tng s v gim t s C/N t 20,1-21,4.

47.3 46.5

0

10

20

30

40

50

An Giang Cn Th

Khng x l

c x l

Hnh 1. T l C/N ca rm r c x l ch phm Trichoderma sau

4 tun

X l ch phm Trichoderma spp. liu lng 0,8 kg/tn rm ti v

o 2 ln.

(An Giang: F= *** v CV=9,9%; Cn Th: F=** v CV=14%)

3.2. Anh hng cua rm ra x l bng ch phm trn ng rung

n nng sut la v H Thu 2010

Kt qu trnh by ti bng 3 cho thy khi x l rm r bng

ch phm Trichoderma lm gia tng nng sut ti c 2 im An

Giang v Cn Th. Nghim thc NT4, rm r x l ch phm

Trichoderma + 70% NPK t nng sut la t 3,9-5,32 T/ha tng

ng vi cc nghim thc 100% NPK.

T s

C/N

527

Bng 3. nh hng ca vi rm r x l bng ch phm Trichoderma

n nng sut la ti An Giang v Cn Th v H thu 2010

TT Nghim thc

Nng sut la (tn/ha)

An Giang Cn Th

NT1 Rm r khng x l 2,83c 2,69c

NT2 Rm r x l ch phm 2,95c 2,73c

NT3 Rm r khng x l + 70% NPK 4,71b 3,57ab

NT4 Rm r x l ch phm+70% NPK 5,32a 3,9a

NT5 t rm + 70% NPK 4,77b 3,95a

NT6 t rm + 100% NPK 5,11ab 3,55ab

NT7 Rm r khng x l +100% NPK 5,3 a 3,37b

NT8 Rm r x l ch phm + 100% NPK 5,33a 3,94a

CV (%) 5,7 7,8

F *** ***

***: khc bit c ngha thng k mc ngha 1. Cc s c ch

ging nhau khc bit khng ngha thng k theo php th Duncan,

100%NPK = 100N-60P2O5-30K2O kg/ha; 70% NPK = 70N -42P2O5-

21K2O kg/ha

3.3. Anh hng cua rm ra x l bng ch phm n ph

nhiu t la

Khi c x l rm r bng ch phm lm gia tng hm lng

NPK hu dng ti c An Giang v Cn Th. C th nghim thc

NT4, rm r x l bng ch phm Trichoderma + 70% NPK c N

t 41 153 ppm, P hu dng 28,9- 68,5 ppm v K: 90,8-259 ppm

v khc bit c ngha thng k so vi cc nghim thc cn li.

528

Bng 4. nh hng ca chn vi rm r x l trc tip bng

ch phm Trichoderma n ph nhiu t la ti An Giang

v H Thu 2010

TT Nghim thc pH C

hu c

(%)

N

hu dng

(ppm)

P2O5 hu dng

(ppm)

K2O

trao i

(ppm)

NT1 Rm r khng x l 4,23 2,76 cd 15,4 d 44,9 c 127 b

NT2 Rm r c x l 4,37 2,39 d 24,8 c 51,9 c 136 b

NT3 Rm r khng

x l+70%NPK 4,34 3,51abc 35,2 ab 51,9 c 199 a

NT4 Rm r c x l +

70% NPK 4,20 3,80 a 41,0 a 68,5ab 259 a

NT5 t rm + 70% NPK 4,25 3,34abc 34,7 b 57,1 bc 220 a

NT6 t rm + 100% NPK 4,33 2,97bcd 36,0 ab 50,2 c 245 a

NT7 Rm r khng

x l+100%NPK 4,51 3,67ab 37,8ab 72,6 a 255 a

NT8 Rm r c x

l+100% NPK 4,52 3,09abc 33,0 b 72,7 a 229 a

CV (%) 3,3 12,7 10,2 11,5 15,4

F ns ** *** *** ***

100% NPK = 100N-60P2O5-30K2O kg/ha; 70% NPK = 70N-42P2O5-

21K2O kg/ha. ns: khc bit khng ngha thng k; **: khc bit c

ngha thng k mc ngha 1%; ***: khc bit c ngha thng k

mc ngha 1. Cc s c ch ging nhau trong cng 1 ct khc bit

khng ngha thng k theo php th Duncan

529

Bng 5. nh hng ca chn vi rm r x l trc tip bng ch phm

Trichoderma n ph nhiu t la ti Cn Th v H Thu 2010

TT Nghim thc pH C

hu c

(%)

N

hu dng

(ppm)

P2O5 hu dng

(ppm)

K2O

trao i

(ppm)

NT1 Rm r khng x l 4,84 2,95 bc 83,3 b 20,9 72,0

NT2 Rm r c x l 4,90 3,18 bc 116 ab 25,8 66,4

NT3 Rm r khng x l +

70% NPK 4,87 3,26 bc 88,7 b 22,5 75,2

NT4 Rm r c x l + 70%

NPK 4,59 4,37 a 153 a 28,9 90,8

NT5 t rm + 70% NPK 4,70 3,12 bc 112 b 23,9 68,8

NT6 t rm + 100% NPK 4,68 2,66 c 117ab 21,3 65,6

NT7 Rm r khng x l +

100% NPK 5,04 3,32 bc 88,7 b 23,5 81,6

NT8 Rm r c x l + 100%

NPK 4,63 3,80 ab 98,0 b 31,4 72,8

CV (%) 5 13,8 20,1 18,9 14,4

F ns * * ns ns

(Ngun phn tch: b mn Khoa hc t - Vi sinh, Vin La ng bng sng

Cu Long, 2010)

100% NPK = 100N-60P2O5-30K2O kg/ha; 70% NPK = 70N-42P2O5-21K2O

kg/ha, ns: khc bit khng ngha thng k; *: khc bit c ngha thng k

mc ngha 5%. Cc s c ch ging nhau trong cng 1 ct khc bit khng

ngha thng k theo php th Duncan

3.4. Hiu qu kinh t trng la c bn rm ra x l bng ch

phm Trichoderma

- Tng chi ph: Tng chi ph bin ng t 3.497.500 ng/ha n

8.057.000 ng/ha, thp nht nghim thc NT1 v cao nht

nghim thc NT8. T cho thy khi bn phn ha hc cng cao

th cng gia tng chi ph sn xut la.

- Tng thu nhp: Thu nhp t 11.615.300 /ha (nghim thc NT1)

n 21.865.300/ha (nghim thc NT8).

- Li nhun: Li nhun ghi nhn t 8.117.800 /ha (nghim thc

NT1) n 15.611.700 /ha (nghim thc NT4). nhng nghim

thc u t cao, nhng nng sut la khng cao nh NT6 - t rm,

bn 100% NPK theo phng php ca nng dn- th li nhun t

thp hn so vi NT4- Rm r x l bng ch phm Trichoderma +

530

70% NPK- nng sut cao hn, chi ph thp nn li nhun vn c

m bo mc cao hn.

- T sut li nhun: T sut li nhun t thp nht l 1,66 (NT6-

t rm + 100%NPK) n cao nht l 2,52 (NT4: rm r x l

bng ch phm Trichoderma + 70% NPK). nhng nghim thc

bn NPK cao (100%) th cho t sut li nhun thp hn.

Bng 6. Hiu qu kinh t trng la khi c x l rm r bng ch

phm Trichoderma v H Thu 2010 (i) (1000 )

TT Nghim thc Tng

chi ph

Tng

thu nhp

Li

nhun

T sut

li nhun

NT1 Rm r khng x l 3.497 11.615 8.118 2,32

NT2 Rm r c x l 3.677 12.107 8.430 2,29

NT3 Rm r khng x l+70%NPK 6.020 19.323 13.303 2,21

NT4 Rm r c x l + 70% NPK 6.200 21.812 15.612 2,52

NT5 t rm + 70% NPK 6.020 19.569 13.549 2,25

NT6 t rm + 100% NPK 7.877 20.938 13.061 1,66

NT7 Rm r khng x l + 100%NPK 7.877 21.709 13.832 1,76

NT8 Rm r c x l + 100% NPK 8.057 21.865 13.808 1,71

- i: s liu trung bnh ca 2 im An Giang v Cn Th; 100% NPK = 100N-

60P2O5-30K2O kg/ha, 70% NPK = 70N-42P2O5-21K2O kg/ha; Ure:6500

ng/kg; DAP: 13.000 ng/kg, Kali: 13.000 ng/kg, Ch phm Trichoderma:

70.000 ng/kg, Gi bn la: 4100 /kg.

3.5. Xy dng m hnh x l rm ra sau thu hoach trc tip trn

ng rung

Kt qu trnh by ti bng 7 v hnh 1 cho thy:

- Ti An Giang: (6 ha/2 v): V ng Xun 2010-2011 vi

m hnh cy vi rm r c x l ch phm Trichoderma lm gim

lng phn bn N, P2O5 v K2O gim c trung bnh l 40,7 -

26,9 - 21 kg/ha, gim chi ph phn bn 1.818.200 /ha v tng nng

sut la l 0,33 tn/ha (3,9%), tng li nhun 4.250.900 /ha v t

sut li nhun tng 29,3% so vi m hnh canh tc theo nng dn.

v H Thu 2011 gim chi ph phn bn 1.617.000 /ha v

tng li nhun c 2.570.000 /ha (10,3%) so vi canh tc theo

nng dn.

531

M hnh ti An Giang

3.956

6.927

5.774

8.544

0

1

2

3

4

5

6

7

8

9

X 2010-2011 HT 2011

V

ch

i p

hi

ph

n

b

n (

tri

u

/ha)

MHKC

MHND

M hnh ti Cn Th

3.3944.034

5.074

6.457

0

1

2

3

4

5

6

7

X 2010-2011 HT 2011

V

ch

i p

hi

ph

n

b

n (

tri

u

/ha)

MHKC

MHND

Hnh 1. Gim chi ph phn bn gia m hnh khuyn co v nng

dn ti BSCL

Bng 7. Hiu qu kinh t ca m hnh cy vi rm r x l ch

phm trong sn xut la ti BSCL

Khon

mc

An Giang Cn Th

V ng Xun

2010- 2011 He Thu 2011

V ng Xun

2010- 2011 He Thu 2011

MHKC MHND MHKC MHND MHKC MHND MHKC MHND

Tng chi 16.345 18.625 17.963 19.890 13.179 15.323 13.189 15.712 Nng sut

(kg/ha)

8.475 8.155 7.235 7.133 7.541 7.206 6.870 6.611

Tng thu,

1000/ha

52.206 50.234 45.580 44.937 44.491 42.515 37.787 36.361

Li nhun,

1000/ha

35.860 16.095 27.617 25.047 31.312 27.192 24.598 20.649

T sut li

nhun

2,19 1,70 1,54 1,26 2,38 1,77 1,87 1,31

MH KC: Rm r x l ch phm + 70 % NPK; MHND: Bn phn theo tp qun

nng dn

An Giang: v ng Xun 2010-2011: Gi bn la: 6160 /kg; Ure:10000 /kg;

DAP 12.000/kg; Kali 13.000 /kg,ch phm Trichoderma 70.000 /kg v V H

Thu 2011, gi bn la: 6250 /kg, ure:12.500 /kg; DAP 18.500/kg; Kali 14.000

/kg, ch phm Trichoderma 70.000/kg. Cn Th: v ng Xun 2010-2011:

Gi bn la: 6160 /kg, Nng sut la trung bnh trong m hnh khuyn co:

8.475 kg/ha v ngoi m hnh nng dn: 8.155 kg/ha. Ure: 9.000 /kg; DAP

15.000 /kg; Kali 10.000 /kg, ch phm Trichoderma 70.000 /kg. V H Thu

2011: Gi bn la 5500 /kg, Nng sut la trung bnh trong m hnh khuyn

co: 6.870 kg/ha v ngoi m hnh nng dn: 6.611 kg/ha; Ure: 12500 /kg;

DAP 18500 /kg; Kali 14.000 /kg, ch phm Trichoderma 70.000 /kg

532

- Ti Cn Th (4 ha/2v): v ng Xun 2010-2011 vi

m hnh bn rm r x l ch phm lm gim lng phn bn

35,4N- 33,1P2O5 - 20 kg/ha K2O, gim chi ph phn bn c

1.680.000 /ha v tng nng sut la l 0,335 tn/ha (4,45%), tng

li nhun 4.120.500 /ha v t sut li nhun tng 33,9% so vi m

hnh nng dn. v H Thu 2011, gim c chi ph phn bn

ha hc 2.423.000 /ha (37,5%) v tng li nhun c 3.949.000

/ha (19,1%) so vi canh tc theo nng dn.

4. KT LUN V NGH

4.1. Kt lun

Ch phm Trichoderma c hiu qu x l rm r nhanh trn

ng rung, ph hp vi iu kin canh tc BSCL, lm gim t

l C/N trong rm r cn 20,4 n 21,4 v gia tng hm lng NPK.

X l rm r bng ch phm gp phn gim khong 30% NPK

phn ha hc v gia tng nng sut la cung nh tng hiu qu kinh

t trng la v ci thin ph nhiu t. Cc m hnh cho nng

sut la v li nhun kinh t cao hn so vi canh tc theo nng dn,

bnh qun nng sut tng 3,9-4,45% vo v ng Xun v 1,43-3,

9% vo v H Thu v li nhun tng tng ng 13,5-15,2% v

10,3-19,1%. T sut li nhun trong m hnh khuyn co cao hn

canh tc ca nng dn t 22,2- 42,7%.

4.2. ngh

Tip tc nghin cu ng dng x l rm r bng ch phm

Trichoderma c ngun gc bn a trn quy m m rng v nhiu

loi t canh tc khc nhau nhm p ng nhu cu sn xut la ti ch

nhm gp phn gim chi ph phn bn, gim nhim mi trng.

TI LIU THAM KHO

1. Gaur A. C., Neelakantan S. & Dargan K. S. (1990), Organic manures. I.C.A.R. Newdlhi. India.

2. Jackson, M. L. (1958). Soil chemical analysis. PrenticeHall of India, Private Ltd., New Delhi.

3. L Th Thanh Thy v Phm Vn Ton (2001), Bc u nghin cu kh nng s dng VSV phn gii cellulose trong chuyn ha

nhanh rm r lm phn bn. Hi tho quc t sinh hc, H Ni, Vit

Nam. Tr: 443-448.

533

4. Luu Hong Man and Nguyen Ngoc Ha (2006), Effect of decomposed rice straw at different times on rice yield. OMONRICE (Cuu Long

delta rice research Institute, Vietnam). Agricultural Publishing

House Ho Chi Minh City (2006), Issue. 14 (2006), pp. 58-63

5. Luu Hong Man, Nguyen Ngoc Ha, Pham Sy Tan, T. Kon, H. Hiraoka, H. Kobayashi (2003), Integrated nutrient management for a

sustainable agriculture at O Mon - Can Tho, Vietnam. Omonrice

(10), pp. 87-93 (2002)

6. Luu Hong Man, Nguyen Ngoc Ha, Pham Sy Tan, Takao Kon and Hiroyuki Hiraoka (2001), Integrated nutrient management for a

sustainable agriculture at O Mon - Can Tho, Vietnam. O Mon Rice

9; 62 67.

7. Luu Hong Man, Vu Tien Khang and Takeshi Watanabe (2005), Improvement of soil fertility by rice straw manure. Omonrice (13),

pp. 52 62

8. Luu Hong Man, Vu Tien Khang and Takeshi Watanabe (2007), Improvement of soil fertility by rice straw manure. Omonrice (15),

pp. 124-134 (2007)

9. Nguyn Ln Dung. 1978. Phng php nghin cu VSV hc, tp 1-2, NXB khoa hc v K thut.

10. Ramaswami P.P. and Tran thi Ngoc Son (1996). Quality compost from agricultural wastes. Paper presented at the National workshop

on Organic farming for sustainable agriculture held at Hyderabad,

A.P., India: 18-20, Jan

11. Olsen, S R, C. L. Cole, E S Wattanabe and D.A. Dean (1954) Estimation of available phosphorus in soil by extraction with sodium

bicarbonate. USDA Circ.939

12. Tran thi Ngoc Son and P.P. Ramaswami (1997), Bioconversion of organic wastes for substainable agriculture. Omonrice journal, No. 5,

1997. Cuu Long Rice Research Institute, O Mon, Can Tho, Vietnam.

pp. 56-61.

13. Trn Th Ngc Sn, Cao Ngc ip, Lu Hng Mn v Trn Th Anh Th (2009), Nghin cu s dng phn rm hu c v phn sinh

hc phc v cc h thng sn xut la ng bng sng Cu Long.

Trong: Tuyn tp Cy La Vit Nam (tp II). NXB Nng nghip H

ni (2009). Tr: 225-238.

14. Walkley A. J. and I. A. Black, (1934) Estimation of organic carbon by chromic acid and titration method, Soil Sci. 37:29-38.