D̂ m Xuan Van vd Dtg Jap chl KHOA HQC & CONG NGHE 107(07) 91 96 NGHIEN c i r u SU'''' PHAN BO, KHA NANG SINH TRI/OTNG VA PHAT TRIEN CUA CAY S,^Y (Pliragmiles aulralis) TREN DAT SAU KHAI THAC QUANG TAI Ti[.]
D^m Xuan Van vd Dtg Jap chl KHOA HQC & CONG NGHE 107(07) 91 -96 NGHIEN c i r u SU' PHAN BO, KHA NANG SINH TRI/OTNG VA PHAT TRIEN CUA CAY S,^Y (Pliragmiles aulralis) TREN DAT SAU KHAI THAC QUANG TAI TiNH THAI NGUYEN Diim Xuiin V?n,Tr^n Thj Pha', Dang Van Minh, Hoing V3n Hiing Tnrdng Dai boc \6iig Ldm - DH Thiit \g,i}eii TOMTAT Nghien cuu su phan bo, nting sinh trudng ph^t trien va hap thu kim loai n^ng ciia cay say tren dat sau khai thac qu?ing tai Thai Nguyen cho thay rSng c^c dia hinh khac thi sy phan bo cung khac tan xuat xuat hien cay Say la nhiSu hem tai cdc noi co dig hinh thap, gan nguon nude, cang ien cao thi sy xuat hien cdng giam ddn Cay Say thich nghi va sinh truang, phat Irien tot tren cac mo khai th^c qu?ing, chieu cao trung binh cay dat tir 1.2 - 1,9 m, chieu dai Id dat trung binh 0.35 - 0.45 m chi^u dai re trung binh tir 0.2 - 0.3 m Ham luang kim loai n|ing As, Pb, Cd ddt sau khai thdc khodng san tai mo chi kem Cugi Nac, mo titan cay Chan, mo s3t tral Cau va mo chi k§m L^ng Hich dSu vugt qud nhieu lan tieu chuan cho phep dat nong nghiep ciia quy chuan Viet Nam, Til kh6a: Hdp thu kim toai ndng khai khodng cdy sdy DAT VAN DE CJ Viet Nam hien nay, cay Say fPhragmiles aiitralis) cd nhieu tu nhien d nhieu tinh thdnh va dirge sd dung vdi cdc muc dich khac nhu: chdng \di mdn, sal Id va irng dung sd ly nude thai cira sdng va phong chdng thien tai Vdi nhdng tinh ndng virgt trgi, cay Say cdn su dung de xu ly ddt d nhiem, dd cd d nhiem kim logi nang, Tgi cdc khu vuc md khai thac quang Thdi Nguyen, cay say thich nghi va phan bd nhieu hon tgi cac khu vuc bai thai sau khai thac qudng N O I D U N G V A PHUONG PHAP NGHIEN CU'U Doi tirong nghien cdu Ddi tugng nghien cuu la ca\ Say (Pbruginiies australisj, la mdt loai cay Idn thugc hg Hda thao(Poaceae) cd ngudn gdc d nhung vimg dat lay d ca khu vuc nhiet ddi va dn ddi tren the gidi Noi dung nghien cdu + Dieu tra sy phdn bd, kha nang smh trirdng va phdt trien cua cay Sa\ cdc khu khai thac quang so sanh mat va sy phdn bd d cac md khai thdc khac Tei: 0982.091200 Emad phac-am2004^d>yalwo c + Nghien cdu kha ndng hap thu kim loai ndng CLia cay Say tren dat sau khai thac quang khodng sdn Phu'O'ng phap nghien cuu Phuvngphdp dieu tra thu thgp tdi lieu - Thu thap sd lieu ve dieu kien ty nhien - kinh te - xa hoi ciia cac khu vyc khai thac md quang tren dia ban tinh Thai Nguyen, Phtrffng phdp ke thira - Thu thap tai lieu, sd lieu ve tinhbinh dat bj d nhiem KLN tgi Thai Nguyen Phirong phdp khdo sdt thuc dia vd lap d tieu chudn (OTC) - Phuang phdp lap d tieu chuan (OTC) Lap d tieu chuan de nghien cdu sy phan bd ciia cdy Say khu vyc khai thac md OTC phai bd tri tgi cae vi tri cd tinh dgi dien cao d cdc khu vyc, dia hinh phdi tuang ddi ddng nhdt + Cach lap OTC: Lap d tieu chuan vdi chieu ddi cimg hudng vdi dtrdng ddng muc, chieu rdng vudng gdc vdi dudng ddng muc, dien tich mdi OTC la 1000 m" vdi chi^u dai d la 50m chigu rdng d la 20 m Cac OTC dai dien cho cac dja hinh vimg dat trung ddt bang, sudn rdc, dinh niii khu \uc khai thac Phtrffng phdp xdc dinh sinh khiii thuc vgt Cdc lodi thyc vat lira chgn nghien ciiu sau ldy vg phdng thi nghiem dugc rira va lau bang 107(07}-91 -96 Tap chi KHOA HQC & CONG NGHE Dam Xuan Van vuDig vimg nghien cuu bdng phuang phap lap d tieu chuan OTC dugc bo tri tgi cdc vi tri cd dia hinh tirong ddi ddng nhdt d chan ddi, sudn ddi va dinh doi, Dien tich mdi d tieu chuan Id 1,000 m^ (chieu dai OTC 50 m chieu rgng OTC 20 m) khan sgch roi dem can tren can dii;n tir tgi phdng thi nghigm, Mau dgi di?n cho mirc chidu cao, Sau can xong dem say d dO70''C gid roi dem can Tiep tyc say den khdi lugng khdng doi Can Igi va lay gia tri cuoi cimg Phirtrng phdp phdn tich ilal vd thirc vgt %\\ phan bo ciia cay Sgy dugc trinh bay d bang Bang la kdt qua cho thay sy xuat hien cua cay Say tren cac didm md dieu tra la khac Trong sd cac md dugc khao sat thi cay Say cd sy phan bo rgng Cay Say thich nghi vd phan bo rgng tgi cac khu vuc cd ndng nhiem kim loai ndng cao Md cd sy phan bo cdy Say Idn nhat Id md chi kem Lang Hich (494 khdm /OTC) tiep dd la d md sdt (175 khdm/ OTC) va md Titan (57 khdm/OTC) va md chi kC-m Cudi N^c (37 khdm/OTC) Trong cac dja hinh khac thi su phdn bo cung khac tai cac noi cd dig hinh Ihap gdn nguon nude thi tan xuat xuat hien cay Say Id nhidu hon Cang len cao thi sy xuat hien cang giam dan - pH(KLh: Dugc chicl bdng dung djch KCI IN, bdng may pi I inciet i\ 1^ dai nude la 1/2,5 - Chat hiiu co xac djnh bang phuong phap Dumas tren thicl bj phan lich da nguyen td CNS TruSpec I.IXO USA - Xac djnh ham lugng KLN dat va cac loai thyc vat bdng may ASS M6 Thermo Phirtrng phtip v«' ly \o lieu - So lieu dugc tong hgp, phan tich vd xir ly bdng phan mein MS Excel va SAS 9.0 KRT QUA NGHIEN CUU VA THAO LUAN Di€u tra sy phan bo, kha nang sinh trudng va phat trien cua cay sdv khu vyc nghien ciru Sir phdn bo cua cdy Say Tien hdnh khao sat viing thuc bi tren dat sau khai thdc quang kim loai tai cac md Trong cimg mdt md khai thdc thi tgi cac dia didm gan cdng thdi, be xu ly nude thai thi cay Say xuat hien cdng nhieu 50 mo khai thdc khu virc nghiin cuu Bang Su phdn bd cua cdy Sdy tai mdt M6 chi kem Cuoi Nac So lu-ong la 92 S6 luQ-ng iCdy'OTC) 37 03 04 Dinh ddi 27 Thung liang 57 34 27 15 29 07 Chan doi 175 45 08 Sirdn doi 87 54 1458 09 Dinli doi 77 47 2387 333 408 324 34 Ven suoi 175 175 Bai bang 494 Sir&n d6i 121 Kltd niing sinh trirdng vd phdt trien ctia cdy Sdy Banh gid suphdt trien cuu cdy Sdv Iren khu vice nghien cini Sir sinh truang va phat tnen cua cay Say dugc the hien a bang Mo chl kem Lang Hich khdm) Min Thung liing Sudn doi Vi tri OTC Cay Tram Trai Cau So lu'9'ng (Khdm/OTC) S6TT OTC 01 02 3675 1575 2964 968 Ddm Xuan Vgn vd Dig Tap chi KHOA HQC & CONG NGHE 107(07): 91 -96 Ket qua quan sat cho thdy su phat tridn ciia cay Say tren cac md la khd dong deu, chung td cay cd khd nang thich nghi cao ddi vdi mdi trudng d nhilm kim loai ndng Cay Say tren cac md khai thac quang sinh trudng va phat trien tot, chieu cao trung binh cay dgt tu 1,2 - 1.9 m chidu dai Id dgt trung binh 0,35 - 0.45 m chieu dai re trung binh tir 0.2 - 0,3 m, ngudn nude cd dg am cao thi cay sinh trudng phat trien mgnh hon nhirng noi cao Tgi noi gdn cdc cdng thai, be xu ly nude thai hay giap xudng che bien thi cay Say phat trien mgnh hon cac khu vyc khac, Trong khu vyc nghien cdu dieu tra cay Say ludn cd sy xuat hi^n mgt so loai cay khdc nhu: lau, re, xuyen chi, duong xi Sinh khdi cm cdy Sdv Iren cdc md khai thdc Ket qua xdc djnh sinh khdi thyc vai dugc the Dja hinh cd dnh hudng id ret den su phat tri^n hi^n tren bdng 3, ciia cay Say d nhung noi dja hinh thap gan Bang 2: Su smh tnrang vd pluil Irieiciia cdy Sgy trin khu virc nghien cuu s4 Diem mo S6 OTC So luong (Khdm,' OTC) lugng (Car/ OTC) Ma.v Mm May A fin Mat !l4ln Mo chl 01 37 333 2.32 0.9 65 22 60 02 34 408 1.9 O.S 57 19 40 Nac 03 27 324 1.8 0.8 60 16 40 Mo 04 57 513 1.6 0.6 62 33 45 0.3 Tot Titan Cay Tram 05 34 442 1.8 0,5 57 31 58 12 0.4 Tot 06 27 567 2.2 0,8 51 29 46 0.4 TB Mo sat Trai 07 87 1458 2.7 0,9 47 55 0.3 Tot 08 175 3675 2.67 0.9 45 50 n 0.35 Tot Cau 09 77 2387 2.68 I.l 41 46 0.4 Tot Mo chi 10 175 1575 2,7 0.8 72 55 0.35 Tot 11 494 2964 2.3 0.5 37 52 0.15 Tot 12 121 968 1.7 0.7 59 49 0.3 TB kgm kem Hich Chlcu cao eSy (cm) Chieu dfii 14 Icm) Chiiu ddi re Tinh hinh phat trien Ou6ng kinh thiin TB (cm) 0.3 0.35 0.3 T6t 'Si Tot TB Bang 3: Ket cpid xdc dinh sinh khdi cdy Sdy tren cdc md nghie S& T OTC Mo chl kem Cuoi Nac M6 Titan Cay Tram Mo sat Trai Cau M6 chi kgm Lang Hich 01 02 03 04 05 06 07 08 09 lugng (Khdm/ OTC) 37 34 27 57 34 27 175 87 77 175 494 121 Khoi luong tuoi/khom la 960 1394 850 765 1280 1050 1560 2465 1755 945 126 405 Khoi luong (uoi/OTC (gl 31450 47.396 25 920 43 605 43 520 28.350 273.000 214455 135.135 165.375 62 244 49 005 Khoi luong khS/ofc 6.604.50 9.953.16 5.443.20 14.389.65 14 361.60 9.355.50 66 885.00 52.541.48 33.108.08 58.377.38 21.972.13 17.298.77 Qkm Xuan Van VM Dig Tap chl KHOA HQC & CONG NGHE Can cir vdo ket qua dieu tra thyc dja va bdng ta thay sinh khdi cay tai cac md cd sy khac biet Idn, Tai md sdt Trgi Cau cay sgy phan bo nhieu kha ndng smh trirdng va phdt iricii tot, sinh khoi cay khd Ircii d lieu chuan cao (33.108 - 66.885 kg/0 TC) Md chi kem Lang Hich cd sinh khoi kho dgt 17,298 - 58.377 kg/OTC md litan Ci'i>' Tram cd sinh khoi dgi 9355 - 14.389 kg/OTC va md chi kem t ugi Ndc cd sinh khoi 5.443 - 9.953 kg/OTC, Kha niing hiSp (hii kim loai nang ciia cay Sd> tren diil biii thai suu khiii thac qudng Hien trgng o nhiem liim logi ngng Trong qua trinh khao sdt tgi khu vyc nghien cuu tdi da lien hanh lay mdu dat va tap chung phan tich ham lugng Idng sd cua nguyen td, dd la: As, Pb Cd, Ket qua phdn tich dugc the hien bang Td kdt qua phan tich dat tai bang la thdy tat cd cdc mau phan tich deu chua hdm lugng cua nguyen td kim logi nang Tuy nhien, dieu ddng chii y dd la tat ca cdc mau 107(07): 91 -96 phan tich d6u cd ham lugng kim loai ndng vugt qud quy chuan cho phep, Cu the: Tgi md chi kem Cugi Ndc ham lugng Pb cao hon tu 4,2 - 4.8 Idn, ham lugng Cd cao gdp 10 - 17 Idn ham lugng As cao hon gap 14,6 20.8 lan tieu chudn cho phep Md litan Cay Tram I cd, ham lugng Pb cao hon tu 2.7 - 7.1 ISn hdm lirgng Cd cao gap 13 - 15 lan, ham lugng As cao hon gap 9,5 - 21,3 lan tieu chuan cho phep Md sdt Tral Cau cd ham lugng Pb cao hon tir 2.4 - 5.1 ian ham lugng Cd cao gap 15.5 18.5 Idn ham lugng As cao hon gap 15,1 33.6 lan tieu chuan cho phep Md titan Cay Tram cd ham lugng Zn gdp tir 5.7 - 8,7 Idn, ham lugng Pb cao han tu 10,2 25,8 Idn, ham lucmg Cd cao gap 1.49 - 3,4 Idn ham lugng As cao hon gap 4.4 - 12,8 lan tieu chuan cho phep Md chi kem Lang Hich cd ham lugng Pb cao han tu 14.5 - 18.4 lan ham hrgng Cd cao gap 2.3 - 2,8 lan, ham lugng As cao hon gdp 10.8 lan tieu chuan cho phep loai ndng tui khu vuc nghien ciru Bang Kci qua phdn tich mdu kim Mo chi - kem Cuoi Nac Mo Titan City Tram Mo sat Trai Cau Mo Tiian Cay Tram Mo chi - k5m Lang Hich QCVNO32O08/BTNMT Cdc chi tieu KH Mau Pb (mg/kg) Dl 321.98 34.38 D2 342.80 52.82 176.70 D3 291.24 21.18 250.31 D4 340.56 24.96 114.39 D5 189.92 18.24 141.75 D6 351.68 30.48 2,56.12 D7 225.98 26.34 220.94 B8 375.68 37.14 269.64 D9 357.12 35.22 182.35 DIO 174.84 31.44 404.01 Dii 1566.89 6.81 53.64 DI2 718.23 2.99 154.80 D13 1810.52 5.69 121.05 D14 1293.62 4,64 61.20 D15 1016.24 5.76 122.40 D16 1137.93 2.79 130,05 70 12 Cd (mg/kg) As (mg/kg) 185.49 Dam Xuan Van va Dtg Tgp chi KHOA HQC & CONG NGHE 107(07): 91 -96 Kltd ndng hup thu kim logi ndng ctia city Sgy tren dat bdi thai sau khai iliac qudng De danh gia kha nang hiit kim logi nang tai vimg ddt d nhiem sau khai thac quang Iren mdi diem md nghien cuu tidn hanh ldy loan bg re, than, la cua 03 mau cay Say dgi di^n cho cac didu kien dia hinh khac (chan ddi, su'dn ddi, dinh ddi), bao qudn rdi mang ve xir ly va phan tich ham lugng cac KLN Pb, Cd, As cac bg phan cua cay Ket qua phdn tich trinh bay d bdng 5, Bang 5: Kha ndng hap ihti KLN cua cdy Sgy tren ddt bdi thai sau khai thdc DVT mg/kg Md Khai T h i c Mo chl - kem Cu9i Nac Mo Titan Cay Tram Mo sat Trai Cau Cay Tram Lang Hich KH Than + la Pb Re Cd As 19.68 167.69 68.45 17.48 161.65 144.27 23.03 190.72 163.69 25.93 113.67 24.29 92,51 20.04 172.15 32.39 100.48 27.62 233.81 6.29 16.67 112,36 33.38 187.94 8.08 32.33 97.78 26.13 197.37 33.46 8.49 30.43 102.40 27.35 173.23 CIO 36.48 8.89 34.53 108.96 28.57 308.96 CM 70.47 3.93 8.68 196.21 6.45 60.26 C12 75.54 1.75 25.35 161.86 3.62 80.67 C13 66.63 0.96 22.38 161.05 5.14 C14 72.42 7.43 7.96 137.97 3,33 104.10 Cd As Cl 25.52 7.95 C2 20.42 6.43 16,26 C3 33.47 5,84 31.64 C4 C5 C6 C7 34.75 6.36 15.17 45.31 7.94 47.90 8.83 55,88 C8 30.43 C9 19.67 Pb 80.17 92.42 C15 76.58 2.45 13.27 131.34 5.13 126.64 C16 75.45 1.25 16.20 154.62 2.76 93.93 Ket qud phdn lich cho thdy ham lugng kim loai nang tdt ca cac mau phdn tich ciia cay Say deu rat cao - Ham lugng cac nguyen td kim loai ngng hap thu cac md khai thac Id khdc nhau, cu the' Ham lugng Pb trung binh hap thu md chi kem Cudi Nac la 62,05 mg/kg, md litan Cay Tram I Id 81.61 mg/kg, md sat Trai Cau 68,25 mg/kg, md titan Cay Tram la 121,96 mg/kg vd md chi kem Lang Hich 108,26 mg/kg Ham lugng Cd hap thy trung binh Irong md chi kem Cudi Ndc trung binh la 13,04 mg/kg md titan Cdy Trdm la 17,04 mg/kg, md sat Trgi Cau 17,91 mg/kg, md titan Cdy Trdm la 3,64 mg/kg va md chi kem Lang Hich 3,72 mg/kg Ham lugng As hap Ihu trung binh md chi kem Cugi Ndc trung binh la 97,93 mg/kg, md titan Cay Tram I Id 99.51 mg/kg, md sat Trgi Cau 129,47 mg/kg md titan Cdy Trdm la 48,29 mg/kg va md chi kem Lang Hich 60,35 mg/kg - Ham lirgng kirn loai ndng hap thy ciia cay Say re Idn hon so vdi than la, Tai md chi kem Cudi Ndc ham lugng Pb gdp tu 3.14 - 4,31 lan than id, hdm lirgng Cd gap lu 2,45 - 3,94 lan, hdm lugng As gap td 6,02-9,94 Idn, Md Titan Cay Tram I ham luong Pb gap tu 2.01 - 4.71 Idn than Id, ham lugng Cd gdp tu 2,52 - 4,30 lan ham lugng As gdp tir 7.08- 11,27 Idn Tai md sdt Trai Cau ham hrgng Pb gap lu 2,98 - 3,21 lan than la, ham Itrong Cd gdp tir 3,21 - 3,23 lan, ham lugng As gap tii' 5,69 - 8,94 lan 95 Dam Xuan Vgn vd Dtg Tap chi KHOA HpC & CONG NGHE md Titan Cay Tram ham lugng Pb gap tu 2.14-2,41 Idn than Id, ham hrgng Cd gdp tir 1,64 - 5,35 lan ham lugng As gap tir 4,12 - 6,94 lan Tgi md chi kem Lang Hich hdm lirgng Pb gdp tir 1.71 - 2.54 lan ham lugng Cd gap td 31.61 - 5,35 lan ham Krgng As gdp lir 5,79 - 13.07 lan, KRT LUAN + Trong so khu vyc md khai Ihdc dugc khdo sat thi cay Sgy cd sy phan bo khac Trong cdc dja hinh khac thi sy phan bo ciing khdc nhau, tai cac noi cd dig hinh thdp gan nguon nude thi tan xuat xudt hi?n cay Say la nhieu han, Cang len cao thi sy xudt hi?n cang giam ddn, Trong cimg mgt md khai thdc thi lai cdc dja diem gdn cdng thai, be xu ly nude thdi thi cay Say xuat hien nhieu hon Cay Sa\ tren cdc md khai thdc quang thich nghi va sinh trudng sinh trudng phat trien tdt, chidu cao trung binh cay dgt lu 1,2 - 1,9 m chieu dai la dat trung binh 0.35 - 0.45 m, chieu dai re trung binh tu 0,2 - 0.3 m -(- Hien Irang d nhiem mdi trirdng ddi sau khai thac khodng san tgi md chi kem Cugi Nic md litan Cay Tram, md sal trai Cau vd 107(07): 91 -96 md chi kem Lang Hich dugc ddnh gia thdng qua ham lugng kim loai ngng cua nguyen td Pb Cd, As ddt deu vugt qua quy chudn cho phep dat ndng nghiep ciia Vi?t Nam nhieu lan TAI LIEU THAM KHAO Le VJSn Khoa Nguyen Xudn Cy, Trdn Thien Cudng, Nguyen Dinh Giap, 2010, Gido trinh "0 nhiim mdi Irm'rng dat vd biin phdp xir ty", Nxb Gido dye Vict Nam, Ha Npi2 Le van Khoa 2007 Chi thf smh Hbc mdi trin'rng, Nhi xuat ban Gido dye Hd Ngi Trdn Thj Phd (2009) Su tich lily KLN ddi vd thirc vdl tai khu vuc mo sdt Trgi Cau • huyen Ddng Hy - linh Thdi Nguyin Ky yiu Hpi nghj khoa hpc tre loin Quoc khoi Nong - Lam - Ngu Thuy nam 2009 lan thu trang 359-364 Trdn Thi Pha (2012/ Nghien ciru khd ndnglich t^ mdt so KLN ddt vd ri cdc lodi thirc vgt chu yiu Igi khu virc khai thdc qudng a huyin Ddng Hy tmh Thai Nguyin D€ tai cap Bp ma sfl B20I0-TNO2-I0 Luang Thj Thuy Van (2012), "Nghien cuu su dung CO Veii\cr di cai tgo ddt bi d nhiem Pb As sau khai thdc khodng son a ttnh Thdi Nguyen", Ludn an ti^n s) Khoa hgc mdi trudng Tnrdng Dgi hoc Ndng lam - DH Thai Nguyen SUMMARY RESEARCH ON THE DISTRIBUTION, GROWTH AND DEVELOPMENT ABILITY AND HEAVY METAL ABSORPTION BY REED PLANT {Phragmites autralis) ON LAND AFTER MINED IN THAI NGUYEN PROVINCE Dam Xuan Van, Tran Thi Pha", Dang Van Minh Hoang Van Hung Tlwi \guyfn Lniversity- oJ Agricullure and Forestry Study the distribution, growing and development ability and absorb heavy metals of reed plant on land after mining in Thai Nguyen province has showed that the reed plants were distributed in the different terrain The frequency of the reed is much more al the low topography place and proximity to water and the opposite is descending Reed plants adapted and grown well on ore mines, the average of plant height from 1,2 to 1,9m, leaf length averaged 0,35 - 45m, the average of root length from 0.2 to 0.3m Mca\> metal content of As Pb Cd in the soil after mining lead-zinc mine (Cuoi Nac), titanium mine (Cay Tram), iron mine (Trai Cau) and lead-zinc mines (Lang Hich) are overed several times ihe Vietnamese standard regulation which allowed in agricultural land Key words- absorption, heavy metal, mining, reed Ngdynhdnbdi 29/3/2013; Ngdy phan bien:24-5/2013 Ngdy duyit ddng 10/9/2013 Phdn hiin khoa hoc: TS Nguyin Chi Hieu - Trudng Dgi hoc Ndng Ldm - DH Thdi Nguyei Tei 0982 091200 Email pliauimKm'ayalmo com 96 ... nang sinh trudng va phat trien cua cay sdv khu vyc nghien ciru Sir phdn bo cua cdy Say Tien hdnh khao sat viing thuc bi tren dat sau khai thdc quang kim loai tai cac md Trong cimg mdt md khai. .. hup thu kim logi ndng ctia city Sgy tren dat bdi thai sau khai iliac qudng De danh gia kha nang hiit kim logi nang tai vimg ddt d nhiem sau khai thac quang Iren mdi diem md nghien cuu tidn hanh... Trong cimg mgt md khai thdc thi lai cdc dja diem gdn cdng thai, be xu ly nude thdi thi cay Say xuat hien nhieu hon Cay Sa\ tren cdc md khai thdc quang thich nghi va sinh trudng sinh trudng phat