KHOA HOC CONG N G H t
IVGHIEIXI ClAJ M O T S O O A C DIEIVI CIJA T Y LE SIIXIH KHQI K H d / S i l V H KHOI T U O I C A Y GO RLTIVG TIJ IVHltlV
LA ROIXIG THUOIXIG XAIXIH O X^ET IXIAIVI
VQ Tidn Hung^ VQ Thd Hdng^ Nguydn Minh ThanhS Hodng Van Ho^
T6MTAT
Tir sd lidu didu tia 1267 cay, thudc 283 loai d cac vimg Bdc bd, Bdc Trung bd, Nam Trung bo vd Tay Nguydn, qua xti I;^ sd lidu da xac dinh duo'c gia tn binh quan cua ty 1? sinh khdi kho/sinb khdi turn tinh chung cho cac loai va cac viing tuong ung vdi cac bd phan than, cdnh, la la: 0,547, 0,486, 0,343. He sd bien ddng cua dai lugng PK cua bo pbSn than, canh, la tuong ling bdng 10,62%, 13,7%, 23,39%. Dai luong PK cua mdi b6 phan than, canh, la phu thudc vao dirdng kinh theo quy lugt chung Id: PK tang theo dudng kinh. Sd cay can lay mlu xac dinh smh khdi khd cho bp phan than, canb, la tuong ung la: 18 dly (sai sd uoc lupng 5%), 30 cdy (sai sd uoc lupng 5%) va 41 cay (sai sd udc lupng 10%). Cay lay mlu dupc phdn deu d cdc cdp kinh.
Tir khda: 5mA AAdi, dudng ldnh, tmng binh, sai tieu chuin, h$ sd bidn ddng, cay heu chuin.
I . B A T V A N B ^
Khi didu ha sinh khdi rimg hdng hay ning tu nhidn, chiing ta cd thd dp dung phirong phdp cdy tidu chudn hay sir dung phuong trinh sinh khdi. Tuy v4y, dd ed sd Hdu sinh khdi cdy tidu ehuan hay sd lidu dimg eho xdy dung phuong trinh smh khdi, hay sd lidu dd ude lugng ty Id sinh khdi khd/sinh khdi tuoi cho moi bg phdn cdy rimg, cdn thidt phai chat ha mdt sd lugng cay thudc ddi tupng nghidn ciiu. Vdi mdi ddi tugng nghidn ciiu, sd cay chat ha bang bao nhidu la du, nhung edy chat ha ed can thidt phai ldy mdu de say khd d tat ca ede bd phan hay khdng va khi can udc Iupng ty Id sinh khdi khd/sinh khdi hroi mdi bd phdn cdn lay d bao nhidu cdy la du. Kdt qua nghidn cuu dugc dd cap d bdi bdo ndy se gdp phdn lam rd mgt hong nhung vdn dd dat ra d trdn.
2. NQI DUW VA n M i K PHAP NGHHI CUU 2.1. NOi dung nghidn cihi
Tinh mOt sd dac ti-ung co ban eiia ty Id smh khdi khd/smh khdi tuoi (Pg) cua cac bd phan.
Kidm ha su phu thugc cua ty Id smh khdi khd/sinh khdi tuoi (PK) cua cdc bg phdn vao dudng kinh.
2.2. Phuong phdp xu ty sd lidu
Sd Iidu dung eho nghidn ciiu dupc phep kd thiia bi cae ngudn sau:
Tdng sd cdy didu ha 1267, tiiudc 283 loai, trong dd: 983 cdy tir ngudn sd lieu cua UN-REED VN (Chuong tiinh giam phdt ttiai khi nha kinh do mat rimg va suy ttiodi rimg cua Uen hgp qude tai Vidt Nam), 224 edy tir ngudn sd Udu cua Bao Huy (2013).
Tmdng Dai hpc LSm nghifip
60 cay didu h a d Thai Nguydn tir ngudn sd lieu cua Nguydn Thanh Tidn (2012).
Phin theo vung. Vimg Bae bg: 275 cdy, vung Bic Trung bd: 310 cdy, vimg Nam Trung bp: 275 cdy, vimg Tdy Nguydn: 407 eay.
Nhihig cdy didu h a suih khdi la nhiing cay dugt chpn ngdu nhidn theo cdp kinh hong cae d tidu ehuan ed didn tich 1 ha. Cay hdu ehuan sau khi du<7c chgn, tidn hanh chat nga vd didu tra sinh khdi theo phuong phap ciia UN- REED Vidt Nam.
Sd lidu d cdc vimg dupc tap hop ttianh 1 don vj dd tinh todn, dai didn cho rung tu la rdng thudng xanh d Vidt nam. Sii dung phirong phdp thdng k€
thieh hpp dd kidm tra sir phu thude eua ty Id sinh khdi timg bO phan vao kieh thude cua cay.
Ty Id sinh khdi khd/sinh khdi tuoi cua bg ph|n i (thdn, cdnh, la) dupc ky hidu la PK,
3. KFT QUA N6HBI CUU VA THAO LUAN
3.1. Tinh mOt sd dac tnmg co ban ciia ly 1§ sinh khdi khd/sinh khdi tuoi (PRI) cha cdc bO p h ^
Tir sd lieu 1267 cay didu h a d cdc vimg, ty Id sinh khdi khd/smh khdi tiroi ciia cae bd ph§n thdn cdy hdn mat ddt dupc tinh cu thd d bang 1.
Bdng 1. Ty 1§ sinh khdi khd/smh khdi hroi (PH) ciia cdc bp phan hdn mat AAt
Dac tnmg ca ban Trung binh Sai so
He so hiin dOng (SS) Gia tri nho nhat Gia tri lon nhat
Ty le sinh kh6i kho/tuoi PK, theo bo ohan a'la r^v Than
0,547 0,058 10,62 0,349 0,703
Canh 0,486 0 , 0 6 7 1 13,70 0,?ti?
0,f
u
0,343 0,080 23,39 0,103 0,852 124 NONG NGHIEP VA PHAT TRIEN NONG T H 6 N - KY 1 - THAi
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KHOA HOC C 6 N G N G H |
Bang 1 cho thay: Eg phdn thdn: PK cd gid tri ttr 0,349 den 0,703, binh qudn la 0,547, he sd bidn ddng la 10,62%. Bg phan cdnh: PK cd gia tii tii 0,293 ddn 0,874, bmh qudn Id 0,486, he sd bidn ddng Id 13,7%.
Bd phan la: PK cd gia tri tir 0,103 ddn 0,853, bmh qudn Id 0,343, he sd bidn dgng Id 23,3996. Tir kdt qua hen nhdn thdy PK cao nhdt thude bd phan thdn, sau dd ddn bd phan canh vd bd phdn Id. Hd so bidn dgng cua PK tang dan bi bd phan ttian (10,62%), ddn bd phan canh (13,7%) vd bd phan la (23,39%).
3.2. Kidm tra su phu thudc cAa t^ Id sinh Ididi khd/sinh khdi tuoi (PR) cua cdc bd p h | n vdo dudng kinh
Vdi rimg hdng kdt qua nghidn eiiu eua mdt sd tdc gid cho thdy, ty Id sinh khdi khd/sinh khdi tuoi cua cae bd phan cay rimg phu thupe vao tudi hay phu thude vao giai doan phat tridn ciia rimg. Nguydn Nggc Lung va Dao Cdng Khanh (1999) eho thay, vdi rimg Thdng ba Id, ty Id sinh khdi khd/sinh khdi tuoi cua timg bd phdn thay ddi theo giai doan phat tridn Idm phdn (chua khep tan <5 tudi, ning non (6-15), ning Bang 2. Kdt qud kidm tra si; phy ttiuQc oia PR
sdo (16-25), tinng nidn (2640), tiidnh ttiuc >40). Ty le sinh khdi khd/tuoi chung eua cdy tuong iing vdi 5 cdp tiidi la 47,7%, 49,8%, 51,8%, 52,9%, 53,2%. Den hidi thanh thuc, ty Id smh khdi khd/tuoi tirong img vdi eae bd phan: than khdng vd, vd, cdnh, goc rd, ndn qua, Id la 55,25%, 78,52%, 52,63%, 56,1%, 82,07%, 24,47%.
Mdt hong nhiing dac diem khdc bidt so vdi rung trong la rimg tu nhidn hdn loai khde tudi, vi tiid dudng kmh dugc ehgn Id dai luong thay the cho tudi cay eho rimg tu nhidn.
Ndi dung nay dugc thue hidn nhdm muc dich ddnh gid xem ty Id sinh khdi khd/sinh khdi tuoi cua cac bd phan cdy rimg tu nhidn cd phu thugc vdo dirdng kinh cua cdy hay khdng, qua dd cd co sd dd xuat phuong phdp dieu h a va xdc dinh ty Id sinh khdi khd/sinh khdi tuoi cho cay rimg tu nhidn sao cho hoply.
Sd Hdu didu h a PK dugc sdp xdp theo cap ldnh vdi cu ly 10 cm, sau dd dimg phuong phdp phan tieh phuong sai mpt nhan td dd kiem h a sir phu thudc ciia PK vao dudng kinh. Kdt qua kidm h a duge d bang 2.
bp phdn than cdy vdo D ciia cdy rihig tu nhidn Ngudn bi^n dong
Gitia cac cap kinh Trong cap kinh Chung
Bien dong 0,125555 2,569402 2,694957
Bac tu do 7 1259 1266
Phmmg sai 0,0179364 0,0032442
Ftinh 5,528778
Sig.
3,16E-06
Kdt qua tinh d bdng hdn eho thay, miic y nghia (Sig) ciia dai lugng kidm ti^ F nhd hon 0,05 rat nhieu. Tir dd cd the kdt luan, dai lugng PK bd phdn
Bdng 3. l ^ t qud phdn nhdm tiiudn nhdt PR bd phdn ttidn ciy theo cdp kinh
than eay phu thude vdo dudng kinh. Day la co sd phan nhdm thudn nhat ve PK theo cdp kinh (bang 3).
Czipkinh 1 3 2 5 4 7 6 8
Mlicyn S6cAy
200 241 355 116 200 55 78 24 ghiaSig
Phan nhon thuan nh^t vai miic y nghia 0,05 1
0,5361269 0,5394963 0,5419804 0,5515074 0,5518824
0,219101
2
0,539496 0,541980 0,551507 0,551882 0,562474
0,068585
3
0,562474 0,576690
0,207042
4
0,5989008 1 Ket qua tinh d bang 3 chi ra, dai lugng PR cua bd
phdn ttidn cdy rung tu nhidn dupc phan thanh 4 nhdm thudn nhat theo quy ludt chung la, PK tdng theo dirdng kinh. Cae nhdm thudn nhdt vd PK duoc xdp theo cap kinh nhu sau: Nhdm 1 gdm nhiing cay
thudc cap kmh 1 (D<10 cm); nhdm 2 gdm nhiing cay tir cap kinh 2 ddn cdp kinh 5 (10<D<50 cm); nhdm 3 gdm nhung cdy thude cdp kinh 6 vd cap kinh 7 (50<D<70 cm); nhdm 4 gdm nhimg cay tii cap kinh 8 ti-dlen(D>80cm).
NONG NGHIEP VA PHAT TRIEN NONGTHON - KY 1 - THANG 1/2015 125
KHOA HOC C d N G N G H t
Bang 4. K^t qui ki^m tra su phu thuOc cua PK bo p h ^ csmh cHy vAn n n'la cAy n'mfr far nh- • i Nguon bien dong
Giiia cac cap kinh Trong cap kinh Chung
Bien dong 0,095307 3,446123 3,54143
Bac tu do 7 1259 1266
Phuong sai 0,0136154 0,0043512
Flinh 3,129128
r
Sig.
_JX00289__
Tu kdt qua phdn tieh phuong sai d bang 4 nhan bd phan canh phu thugc vdo dudng kinh than cdy.
thdy, miic y nghia (Sig) eua dai lupng kidm ha F nho Ket qua phan nhdm thuan nhdt PR theo cap ldnh hon 0,05 rat nhidu. Didu dd co nghia la, dai lirgng PK dupe cho tiinh bay d bang 5.
Clip kinh 1 2 3 5 6 4 8 7
S6 cay 200 241 355 116 200 55 78 24 Miic y nghia Sig
N h 6 m l 0,4707391 0,4822779 0,4855255 0,4881612 0,4905983 0,4910077
0,219101
Nhom 2 0,482278 0,485526 0,488161 0,490598 0,491008 0,510303 0,1797951
Nhom 3
0,490598 0,491008 0,510303 0,517857 0,059217 Kdt qud phan tich phuong sai d bang 5 cho
bidt, dai lupng Pg bd phan eanh dugc phdn thanh 3 nhdm thudn nhat theo cap kinh. Tuy nhidn khdng ed su khac bidt rd rdt, vi nhidu cdp kinh giiia thupc vdo hai nhdm thudn nhdt PR. Cdc nhdm thudn nhdt
vd PK dupc xdp theo cap kinh nhu sau: Nhdm 1 gdm nhung eay thudc cap kinh 1 (D<10 cm); nhom 2 gdm nhirng cdy tii cap kmh 2 den cdp kinh 6 (10<D<60 cm); nhdm 3 gdm nhimg eay ttr cdp ldnh 7 ti-d ldn (D>70cm).
B ^ 6 . K ^ t q u a k i ^ t r a s u p h Nguon bi^n dpng
Giiia cac cap kinh Trong c^p ldnh Chung
Bi^n dong 0,091374 5,037597 5,128971
u thuOc c&a PK bo phjn U c ^ vio Bac tu do
7 1259 1266
Phuong sai 0,0130534 0,0063606
D d i a ciy ribu Ftinh 2,052229
; t u nhifin Sig.
0,046392
(Sig) ciia d^ luang kiem tra F nho hon 0,05 Ket qua nay khing dinh, dai luong P^ bo phan la cay phu
thugc vao duang kinh. Kft qua phan nhom PK theo D duqc trinh bay a bang 7.
Cip kinh 1
Bing 7. K^t q u i phan nh6m thuin nhit PK bp phan Id ciy tfaeo c^p D So cay
200 355
24 Miic y nghia Sig
N h o m l 0,3319138 0,3359921 0,3390602 0,341126 0,3495814 0,3597821
Nhom 2 0,335992 0,341126 0,349581 0,359782 0,369324 0,1250442
Nhom 3
0,33906 0,341126 0,349581 0,359782 0, 0,373686 0,063778 ffit qua phan tich phuong sai a bang 7 chobiet, nhom thuin nhat ve PK. Cac nh6m th^SJTiSit'vi P ty 16 sinh khdi kho PK bo phan la duoc phan thanh 3 duac phan cu the nhu sau: Nhom 1 gim nhun cav nhom thuan nhat theo cap kinh Tuy nhito khong CO thuoc cip kinh 1 (D<10 cm); nhom 2 g6mnl,- * •!
su khac biSt ro net, vi nhiSu cap kinh giiia thu6c ba ™^ '^
126 N O N G NGHIEP V A PHAT TRIEN N O N G THON - K V 1 - THANG l / j n i s
KHOA HOC C 6 N G NGHE
tii cdp kinh 2 ddn cdp kinh 7 (10<D<70 cm); nhdm 3 gdm nhirng eay ttr cdp kinh 8 trd ldn (D>70 cm).
3.3. Kidm tra su phi^ thudc ciia dgi lupng PK vdo dudng kinh ttieo lodi cdy
Ngodi vide kidm tra su phu Ihudc cua dai lupng PK cdc bd phdn trdn mat ddt eua eay chung cho cac vimg, nghidn ciiu cdn kidm h a su phu thude ciia dai lupng PK timg bd phan theo don vi lodi (tinh eho nhihig lodi cd sd cdy didu tra >10).
Kdt qua phdn tich phuong sai cho thay:
- Cd 2/23 lodi ty Id sinh khdi khd/sinh khdi tiroi bd phdn thdn phi;i thugc vdo dudng kinh, do Id lodi:
Ddu Idng, Ngat.
- Cd 6/23 lodi ty Id smh khdi khd/smh khdi tiroi bo phdn cdnh phu thudc vdo dudng kinh, dd Id loai:
Cam xe, Ddu ldng, Gidi xanh, Ngat, Tau mat, Tram hdng.
- Cd 3/23 lodi ty Id sinh khdi khd/sinh khdi tuoi bd phdn cdnh phu thudc vdo dudng kinh, dd la lodi:
cam xe, Dau ldng, De bdc giang.
Tir kdt qua phdn tich phuong sai d trdn, cd the nit ra nhan xdt chung Id:
- Tnrdng hgp chung cho cdc lodi: Dai lirpng Pg phu thupc vdo dudng kinh than cay theo quy luat, Pg tang theo dudng kinh. Kdt qua phan nhdm thuan nhdt vd Pk theo cdp ldnh cu the nhu sau: Ddi vdi bd phan thdn cd 4 nhdm thudn nhdt vd Pjo ddi vdi bp phan cdnh cd 3 nhdm thuan nhdt vd PK; ddi vdi bd phdn Id ed 3 nhdm thudn nhat vd PR.
- Trudng hgp xet theo timg loai, miie dp phu thude cua PK vdo D cu thd nhu sau: Ddi vdi bp phan ttian cd 2/23 lodi PKphu tiiupc vdo D, ehiem 8,7%; ddi vdi bg phdn canh cd 6/23 loai PKphu thupc vdo D, chidm 26,1%; ddi vdi bp phan la ed 3/23 loai Pxphu ttiudc vdo D, chidm 13,0%.
Kdt qua hen cho thdy, hong sd ede bd phdn hen mat dat eiia cdy thi bp phan than sd lodi cay md dai lugng PK phu thudc vao D Id thap nhdt, chua den 10%, ddi vdi bp phdn eanh ty Id so lodi cd PK phu thupe vdo dirdng kmh eao nhdt vd bang 26,1%.
3.4. Dd xudt ling di;ing kdt qua nghidn ciht Khi xet chung cho cae lodi thi dai lupng PK cac bg phdn ti-dn mat dat phu thupe vao dudng kirdi va phdn thdnh tir 3 ddn 4 nhdm thudn nhdt. Trong phan vi timg loai mac du miic dp phu thupe cua dai Iupng PK vao dudng kinh khdng eao. Tuy vay, hong qua trinh didu ha lay mau, chua thd bidt dtroc loai nao dai lupng PK cua bp phdn ndo dpc lap vdi dudng kinh. Vi thd khi didu tra sinh khdi rimg tu nhidn theo don vi
loai hay ehung cho cdc loai, cdy Idy mdu dtrgc phdn ddu theo cap kinh.
Vdi gia thidt dai Iugng PR cd phdn bd chudn thi sd lupng cdy lay mdu theo timg bp phan than, canh.
Id dupc tilth theo edng thiic sau:
'0^-
* A % " (3.1)O edng thiic (3.1), t(a/2) Id gia tri t h a bdng iing voi miic y nghfe a; A% Id sai sd tuong ddi cho tnrdc, S% la he sd bien dpng. Ung vdi sai sd 5% va 10%, sd cay cdn lay mdu xde dinh ty Id sinh khdi khd/smh khdi tuoi PR dupe trinh bdy d bang 8.
Bang 8. Kdt qud tinh sd cay cdn ldy mdu xdc djnh ty Id sinh khdi PR theo cdc bp phdn TMD ciia c ^ ting voi miic y nghia 5%, sai sd tuong ddi bdng 5% vd 10%
Tidu chi
A%=10%
Than Cdnh
10,62 13,70 18 edy 30 cay 5 cdy 8 cdy
La 23,39 87 cay 41 edy Kdt qua nghien ciiu cdu tnie sinh khdi cho thay, ty Id sinh khdi khd cua cdc bp phan than, eanh, la tinh chung cho cdc lodi cdy rimg tu nhidn hdn pham vi toan qudc cu the nhu sau: Than: 80,5%, cdnh:
15,7%, la: 3,8%. Tir kdt qua nay nhan thay, sinh khdi bp phan Id chidm ty Id khdng dang kd so vdi sinh khdi chung phdn trdn mat ddt cua cay, nhung do bidn dpng cua dai lugng PR ldn dan den sd cdy edn lay mdu rat cao so vdi cac bp phdn khdc. Vi thd khi didu ha sinh khdi rimg ttr nhidn d khu vuc nao dd, sd eay cdn ldy mdu cho bp phdn ndy tirong iing vdi sai sd 10%. Vdi bg phan than va canh, sai sd tirong ddi vdn giii 5%. Trong tnrdng hgp nay sd cay cdn Idy mdu xde dinb siidi khdi khd cho bp phdn ttidn, eanh, Id tuong ling la: 18,30 vd 41 cay.
Vdi cdc loai cay khae nhau thi hd sd bidn dpng cua dai lugng PK se khac rttiau vd ve ly thuydt hd sd bidn dpng cua dai lugng ndy theo lodi cay se nhd hon tnrdng hpp xet chung cho ede loai. Vi ttid hong khi chua ed didu kidn tinh sd eay edn lay mdu cho timg lodi thi tdt nhat dua vao kdt qua tinh sd edy chung cho ede loai.
4. KET LUAN
Ty Id sinh khdi khd/sinh khdi tuoi ciia cay rimg tu nhidn cd su khdc bidt giua cac bp phan than, canh, la. Gia tri binh qudn eua dai lupng PK tinh chtmg cho cae Ioai va cac vung tuong iing vdi cdc bd phan ndy la: 0,547, 0,486, 0,343.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1/2015 127
KHOA HOC CONG NGHl
He sd bien ddng cua dai lupng PK khde nhau giua cdc bd phan cua cay, tang dan tii bd phdn ttidn (10,62%), den bd phan cdnh (13,7%) va bd phdn la (23,39%).
Khi tinh chung eho edc loai va cac viing, dai Iupng PK cua mdi bd phan than, canh. Id cdy phu thupc vdo dudng kinh theo quy luat ehung la: PK tang theo dudng kinh.
Khi xii ly theo don vi lodi cay thi dai lugng PR ciia moi bp phdn than, cdnh. Id it phu thude vdo dudng kinh.
Khi xdt ehung cho cac lodi thi dai Iupng PR edc bd phdn hdn mat dat phu thude vao dudng kinh va phdn ttianh tir 3 ddn 4 nhdm thuan nhat. Vi thd khi dieu tra sinh khdi rimg tu nhidn theo don vi loai hay ehung eho cdc Ioai, edy ldy mdu dupc phan ddu theo cap kinh.
Sd cdy cdn lay mdu xac dinh sinh khdi khd cho bp phdn than, cdnh Id tuong ting la: 18 cay (sai sd udc
lupng 5%), 30 cdy (sai sd udc lupng 5%) v:- cay (sai sd udc lupng 10%).
TAI L P THAM KHAO
1. FAO (2011). Guidehnes on Destiuctive Measurement for Forest Biomass Estimation.
2. Bao Huy (2013). Mo hmh smh tiic va viin thim GIS ddxic dinh CO2 hip thu cua rimg li rdng thudng xanh viing Tiy Nguyen. NXB Khoa hge va Ky ttiuat
3. Nguydn Nggc Lung va Dao Cdng Khanh (1999). Nghidn cuu ting trudng vi sin lugng rung tidng (ap dung cho ning Thdng ba li a Vidt Nam).
NXB Ndng nghidp.
4. Nguydn Thanh Tidn (2012). Nghidn cuu kha ning hip tiiu CO2 cua tiang thai rung thii smh phuc hdi tu nhidn sau khai thic kiet tai tinh Thii Nguydn.
Ludn an tien si Idm nghidp. Trudng Dai hge Ndi^
ldm Thdi Nguydn.
RESEARCH ON SOME CHARACTERISTICS OF DRY/FRESH BIOMASS PERCENTAGE OF NATURAL EVERGREEN BROADLEVES FORESTTREES IN VIETNAM
Vu Tien Hung. Vu The Hong, Nguyen Minh Thanh, Hoang Van Hoan Sununaiy
From the survey data of 1267 tiees, of the 283 species in the Northern, North Cential, South Central and Central Highlands regions and data processing, the average value of dry/fresh biomass ratio is identified for the all species and the regions corresponding trunks, branches and leaves as 0.547, 0.486, and 0.343 respectively. The vanation coefficient of PR of trunks, branches and leaves is 10.62%, 13.7%, and 23.39%
respectively. The PK of trunks, branches and leaves depends on the diameter under a general rule: P^
increases with diameter. The number of tiees is required for samplmg to determine dry biomass of trunks, branches and leaves is 18 trees (estimated error of 5%), 30 tiees (estimated 5% error) and 41 tiees (10%
estimated error) respectively. The sampled tiees are equally selected in diameter classes.
l^yworAs: Average, biomass, coe^cient of variation, diameter, standard error, standard trees.
Ngudi phan bidn: PGS.TS. Hodng Kun NgO Ngdy nhan bdi: 19/11/2014
Ngdy ttidng qua phdn bipn: 19/12/2014 Ngdy duydt dang: 26/12/2014
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 1 / - Q I 5
