KHOA HOC CbNG N G H £
IXIGHIEIV CUU X A C D|!\IH GIA T H £ GILT C A Y TROIMG THLIY CAIMH T H i C H H O P D O I V O I R A U AlM LA
Nguydn Minh Chung*, Trdn Kh^Tl, Nguydn Khde Thdi Son', Hodng Minh Chdu*, NguySnThj Ai T6MTAT
Da lien hanh troii^ cii x.mh. x:i lach v.i can tAy tnii lir thong thuy canh tiian ho.in. nuoi cSy bang dung dich dinh dufmg cu.i Vicii N^'liK-n cihi Rau Qua, vm 7 Ki<'i th^ nghien ciru la: (1)- Gia IIK- ciia Vien Tho nhufing Nong hon (Lim doi chimg goi '<> K"'' die g(>c); (L') giA th^ trAu bun; (3)- gid th^ mun xa dira; (4)- 50% gia the K'<H- + 50% mill hun; (5)- 50% gia the* goc + .50'% mun xa dira; (6)- .50% ti,iu bun + .50% mun xa dira; (7)-1/3 gia the KOC + 1/3 gi.i the la trku hun + 1/3 myn xa dira. Kf^t qua nghidn cdu cho thdy. cac gia th^ di/c^y khac nhau anh hmVng khac nhau d^n sinh trudng. nang sudt, ch^t lugng cai xanh. xa lach va can tay. Ca 7 gia th^ nghidn ciru ddu cho san phdm cai xanh, xa l.ic h vn cdn t^y c6 ham lugng nitrat. chi va catmi thdp hon nhieu so ven ngirong cho ph(^p ndn an loan vai ngiriri sir dung. I'hoi tron 50% gia th^ cua Vien Th6 nhu&ng Nong hoa + 50% win xa dira lam gid da trong cdy b.ing phirong ph.ip thuy canh cho k^t qua tot nhat voi ca cai xanh, xa lach v,i cdn tiy. Tren giA tlu- nay, n.ing suait cai xanh dat 29,3 ta/1000 in', cao hon ddi chirng
17.2%; nang suat xa lach d?t 28.2 tg/1000 in', cao hmi doi chmig 8%; n.uig sunt can tay dat 25,8 ta/1000 m", cao han doi chimg 15,2%.
Tir kh6a: Cai xanh, cin lay, dung djch, gii tiid, tiiuy canh, trau hun, xi lich. xcr dira.
L Ma DAU
O nude ta rau xanh ducic frdng frdn dat ndng nghiep tai 2 vimg chinh: vung rau tap trung chuyen canh ven thdnh phd. khu cdng nghiep va vung rau vu ddng xuan luan canh vdi cay luong thue. Viing rau thii nhat hien dang bj thu hep dien tich bdi qua trinh dd thj hod va phdt trien cac khu cdng nghidp. Phan dat frdng rau cdn lai bi nguy co d nhiem hod chat (thudc bao ve thuc vdt, kim loai ndng, phdn bod hpc...) ngay cang gia tSng [ 2 ].
De dam bao dii lupng rau cho cu ddn thdnh phd.
nhieu nude dd chpn giai phdp iing dung cdng ngh^
cao de frdng rau quanh ndm, kiem sodt an ti)an thuc pham. Mdt frong nhimg cdng nghd cd uu the hon ca la thuy canh tuan hoan NFT (Nufrient Film Technique). Bdng cdng nghd nay san pham an toan vd cd thd tdng san lupng rau frdn don vj didn tich lir 7-10 ldn (3); tuy nhien, muc ddu tu ban dau kha cao.
Dd giai quydt nhimg ban che neu tren va dap ling nhu cau ciia ngudi dan. trong nhiing ndm qua, ngdnh rau qua Vidt Nam dd va dang nd luc cai tidn cdng nghe nhdm md rpng thdi vu, khdng ngung nang cao ndng sudt vd chat lupng. Dd dp dung phuong phdp ndy frong thuc tidn san xuat vide ha gid
' Nghien ciru sinh. Vi$n Nghien ciru Rau Qua
^ Vifn Nghien ciru Rau Qua
' Trudng Dai hpc Nong Lam Thai Nguyen
thanh cac vdt lidu dau vao dd ha gia thdnh san pham la mpt muc tidu rat quan frpng, frong dd co viec nghien cihi ha gia thanh gia the giir cay. Xuat phatti muc tieu dd, di tai nghidn cOru xac dinh gid th^ giu cdy frdng thich hpp ddi vdi rau dn id da dupe tien hdnh.
L VAT L i u , ni)l DUNG VA PHUnS PHtf WHEN CUU
l.Vdt hdu nghidn cuu
* Gii thd: Thi nghiem tidn hdnh vdi 7 cdng thiK gid thd sau: (1)- gid the ciia Vien Thd nhudng Nong boa (Lam ddi chiing gpi la gid thd gdc); (2)- gia the trdu hun; (3)- gid thd mun xo dira; (4)- 50% gia the gdc + 50% frau hun; (5)- 50% gia the gdc + 50% mun xo dira; (6)- 50'X) frau hun + 50% mun xo dira; (7)-1/3 gia tiie gdc + 1/3 gia Uid la frau hun •»• 1/3 mun xff dira(l].[41.
* Ci'iy tivng: Tiin hanh nghidn ciiu 3 loai rau Sn Id sau: xd lach, cai xanh va can tay.
* Hi thdng thay canh va dung dich dinh duonf Nghidn ciiu su dyng thiiy canh tuan hoan. He thong nay gdm cdc dng nhi^a (Ong cap va tiioat dung dich) dudng kinh 110 mm, dai 24 m; ddt frdn gid sdtchSc chdn, cao 80 cm. Cdc dng nhua dupe due sdn cacli 6,5 cm, cdch nhau 15 cm dd dua cay vao dd. Cdc ong ddt cdch nhau 10 -12 cm, nghidng vd phia bd thu, dJt ddc 1° so vdi mdt daL 6 ddu cdp cdc dng c6 he thong cung cap dung dich dinh duong duoc dieu chinh 52 NONG NGHlfP VA PHAT TRIEN NONG THON - KY 2 - THANG 3/2012
KHOA HOC CdNG N G H £
luong vd toe dp bdi khoa didu chinh. Sii dung dung dich dinh dudng ciia Vidn Nghien ciiu Rau Qua, dung frong tec nhua, ddt cao hon dng dan dung dich 0,7 m. Cho dung dich chay qua cdc dng nhua rdi vdo b^ chiia. Khi dung dich frong tec chay bet 2/3 thi van phao ddng bom 2 chidu day dung dich tir be thu ngupc lai bd cap.
Cii nhu th^, dung dich chay tuan hodn frong suot thdi gian smh trudng ciia cdy. Cdy con dupe ,uom tiong rp nhua cd dudng kinh 6,5 em, cao 10 cm, j 3 cay/1 rp khi dupe 2 3 Id that dua vao hd tiidng
; thuy canh tuan hoan.
^ 2. Ndi dung nghidn cuu: Nghien ciiu tidn hanh 'vdi 7 cdng thiic, mdi cdng thiic Id mdt gid th^ (Nhu
dd neu d phan ddi tupng nghidn ciiu).
3. Dia didm vd thdi gian nghidn cuu: Nghidn ciiu dupe tien hdnh tai nhd ludi ciia Vidn Nghien ciiu Rau Qua (Ha Npi); frong khoang thdi gian tir thdng 5 den tiiang 8 ndm 2009.
4. Phuong pht^) nghien ciiu a. Phuang phip bd tri thi nghiim
Cdc thi nghiem deu dupe bd tri theo kieu khdi
^ngau nhien, 4 lan nhdc lai. Dinh cay theo phuong
phdp dudng cheo 5 diem, mdi d tiieo doi 5 cay. Tdng didn tich thi nghidm tiong nhd ludi 150 m^; dien tich thi nghiem Id 5 mVd.
b. Cic ehi tiiu nghiin cuu
Theo ddi 3 nhdm chi tieu sau: (1)- Cdc chi tieu v^ smh tiirdng: thdi gian sinh tiirdng (ngay), sd Id/cdy Gd), chi^u cao cdy vd dudng kinh tan (cm);
(2)- cdc chi tieu v^ ndng sudt: khdi lupng cdy (g), ndng suat li tiiuydt vd ndng suat tiiuc tiiu (ta/1000 m^; (3)- cdc chi tieu v^ chat lupng san phdm: Dudng tdng sd (%): Theo phuong phdp Bectrand; chat khd (%): Theo phuong phdp say khd kiet; vitamin C (mg/l g tuoi): Theo phuong phdp Tilman; NO3 (mg/l g tuoi): Theo phuong phdp sdc ki ion; Pb vd Cd (mg/l g tuoi): Theo phuong phdp do tien mdy cue phd.
c. Phuang phip xu U sd lieu
Cdc sd lieu nghien curu dupe xu li thong ke bdng phan men IRRISTATE vd Excel.
• . KET QUA niGHEN CUU VA THAO LUAN
1. Anh hudng ciia gid thd db cdy ddn sinh truong, ndng sudt vd chdt lupng cdi xanh
Cong thiic CTl (d/c)
CT2 CT3 CT4 CT5 CT6
cn
Bang 1. Anh huong ciia gid thd do cdy ddn sinh trudn^
T Tir gieo den
nay mam 3 3 3 3 3 3 3
Tidi gian sinh trudng (ngdy) Tii mpc den
ra Id thdt 7 7 7 7 7 7 7
Tu mpc den dua len gid do
10 10 10 10 10 10 10
Tdng thdi gian
35 37 35 34 32 33 33
g ciia cai xanh Chieu cao
cay (cm) 32,5 33,6 32,6 32,5 35,5 34,5 33,4
Sd Id/cdy Od) 9,0 9,5 8,6 10,0 11,5 11,0 10,4
Dudng kinh tdn
(cm) 27,8 24,5 25,5 23,1 32,0 27,9 26,4 K^t qua nghien ciiu tai bang 1 cho thay:
'* 0 tat ca cdc cdng thiie sau khi gieo 3 ngay, hat cai canh bdt dau nay mam va sau 7 ngay bdt dau ra Id that, (:^au 10 ngdy tiii dua ldn he tiidng thuy canh tuan hodn.
^ Tong thdi gian sinh trudng d cdng thue 5 la ngdn
<hhat, chi 32 ngay; tidp den la cdng thuc 6 va cdng thiie '^^ diu CO tong thdi gian sinh truong la 33 ngay, ngdn Kion so vdi cdng tinic ddi chiing tii 2 ngay; dai nhat la i*iT2 CO tong tiidi gian sinh trudng la 37 ngdy, ddi hon s loi chiing 2 ngdy.
Chi^u cao cdy d cdc cdng tinic cd su khac nhau khd rd rdt. 6 cdng thiic 5 cai xanh cd chieu cao ldn nhat dat 35,5 cm; tiep dd Id cdng thiic 6 dat 34,5 cm, cao hon so vdi ddi chiing tir 2-3 cm; d CT2 chieu cao cdy dat 33,6 cm; 0 cdc cdng tinic cdn lai chieu cao cdy chi dat 32,5-32,6 cm. Tuong iing vdi su tdng trudng chi^u cao cay, 0 CT5 sd la vd dudng kinh tan dat cao nhat, tuong iing la 11,5 Id/cdy vd 32,0 cm; cdc cdng thiic cdn lai khac ddi chiing khdng nhieu, dao ddng tir 8,6 den 11,0 Id/cdy vd tir 23,1 den 27,9 em dudng kinh tdn.
5)J6NG
NGHIEP VA PHAT TRIEN NONG THON KY 2 THANG 3/2012
53KHOA HQC C 6 N G *4%»HZ
Bdng 2. An!
Cdng thirc CTl (d/c)
CT2 CT3
cr4
CT5
ere
CT7
LSDyyj
cv,%
K. lupng cay (g/cay)
85.5 79.3 78.6 87.5 92.4 87.4 88,5
1 hudng ciia gid thd dd cdy ddr NSLT
(ta/1000 m ^ 31.8 28.8 28,5 28.2 33.2 32.6 25,3
NSTT (la/1000
m2) 25.0 22,8*
22,9*
25.9' 29.3' 28,7*
26.6*
0.15 2.4
Dudng tdng sd
(%)
2.00 1,53 1.75 1.85 2.35 1,74 2.45
I ndng sudt vd chdt lugrng ciia cdi xanh Chat
khd
(%)
10.51 9,37 11,82 11,44 12,09 11.61 11,69
VTMC (mg/kg
tuoi) 2.00 1,,53 1,75 1,85 2,45 1.79 2.35
N03- ^'^
(mg/kg tuoi)
456 444 432 420 425 384 432
Pb (mg/kg
tuoi) 0,044 0.047 0.044 0.053 0,060 0,063 0,060
Cd (mg/kg
tuoi) 0,006 0.008 0.007 0.009 0,006 0,004 0,007
''> Gun ban toi da Uieo (TCVN 5247:1990): NO} - 600mg; Pb-0,3 mg; Cd=0,lmg Sd lieu b bang 2 cho tiiay nSng sudt cai xanh d
cac cong thuc thi nghiem dao dpng tir 22,8 d^n 29,3 ta/1000 m". Nang suat d 6 cdng thirc thi nghiem d^u sai khac doi chung d miic xac sudt 95%. Trong dd, khdi lupng cay (Nang suat ca tii^) cung nhu ndng suat thuc thu cua cai xanh d cdng thiic 5 cao nhat.
chdt lupng cai xanh. Hdm luprng cdc chat nay hrong ling x^p theo thii tu nhu sau: Ham lupng chat kho:
CT5 -> CT3 -> CT7 -> CT6 -> Cll -> CT4 -> Crr2; ham lupng dudng tdng sd: CT7 -> CT5 -> CTl -> CT4 ->
CT3 -> CT6 -> CT2; hdm luong vitamin C: CTTS -> CT7 -> c m -> CT6 -> CT4 -> CT3 -> CT2; ham lupng nitiat- : CTl -> CT2 -> CT3 = CT7 -> CT5 -> CT4 -> CT6; ham tuong ling dat 92.4 g/cay vd 29.3 ta/1000 m^ cao hon
d cdng tinic ddi chimg den 4.3 ta/1000 m^ tirong img l^<?^g P^: CT6 -> CT5 = CT7 -> CT4 -> CT2 -> CTl = vdi 17,2%. Nang sudt cai xanh d cdng thiic 2 vd cdng CT3; ^dm lupng Cd: CT4 -> CT2 -> CT3 = CT7 -> Cll thiic 3 la thap nhat, tuong iing chi dat 22,8 va 22,9
ta/1000 m^. Nhu vay, cd the ket ludn gid the d cdng thiic 5 cd anh hudng tdt nhat den ndng suat cai xanh.
Ket qua d bang 2 cung cho thay anh hudng cua gid the den chat lupng rau cai xanh fren he thdng thuy canh. Kha ndng tich luy chat khd, dudng tdng sd, vitamm C, nifrat, chi va catmi d 7 cdng thiic gid the la khac nhau. Tuy nhidn, so vdi ngudng cho phdp thi cai xanh d ca 7 cdng thirc thi nghiem deu cd nifrat, chi vd catmi dudi ngudng rat xa. Nhu vay, ca 7
= CT5 -> CT6.
N^u xet tdng the thi cdng thurc 5 (50% gid the gdc + 50% vun xo dira) td ra uu viet hon ca, ndng suat cao nhat (29,3 ta/1000 m^; chat khd vd vitamin C cao nhat (12,09% vd 2,45 mg/kg tuoi); dudng tdng sd xep tiiir 2, dat 2,35%; nifrat la 425 mg/kg tiioi; chi la 0,06 mg/kg tuoi; catmi la 0,006 mg/kg tuoi; d^u diroi ngudng cho phep nhieu.
2. Anh hudng dia gid did ddr c ^ ddn sinh tiudng, ndng sudt vd chdt hipng xd Idch
cdng tinic gid th^ nghidn curu khdng anh hudng d^n
Bdng 3. Anh hudng ciia gid thd dd cdy ddn sinh trudng cua xd Idch Cdng thiirc
CTl (d/c) CT3 CT3 CT4 CT5 CT6 CT7
Tu gieo d^n nay mam
3 3 3 3 3 3 3
Thdi gian sinh Tir mpc d^n
ra Id thdt 7 7 7 7 7 7 7
trudng (ngay) Tir mpc d^n dua len gid dd
10 10 10 10 10 10 10
Tdng thdi gian
36 35 38 36 33 37 35
Chidu cao cay
(cm) 23,6 21,3 22,1 21,4 24,5 23,2 23,5
Sold Id/eay Od)
12,5 11,6 12,3 13,3 15,4 13,6 14,0
Dudng kinh tdn
(cm) 27,0 28,2 22.7 26,5 32,5 30,1 28,5 Sd lieu d bang 3 cho thay, gidng nhu cai xanh, hat xa Idch nay mam, sau 7 ngay bdt dau ra la that d tat ca cdc cdng thiic gid thd, sau khi gieo 3 ngay Tuy nhidn, tdng thdi gian sinh trudng d tat ca cac 54
NONG NGHlfP VA PHAT TRIEN NONG THON - KY 2 - THANG 3/2012
KHOA HOC CbNG NGHl
cong thiic gid the cd su sai khac khd rd rdt, chung tdn ciia rau xd Idch dupe trinh bay tiong bang 3 cho dao ddng tir 33 den 38 ngdy. Trong dd, d cdng thiic thay, d cdng tiiirc 5 xd lach sinh trudng tdt nhat. cdy 5. xa lach cd tdng thdi gian sinh trudng ngdn nhat, cao nhat, nhi^u Id nhat vd dudng kinh tan rdng nhat;
chi la 33 ngay, ngdn hon ddi chiing 3 ngay. Ket qua cdc chi tieu ndy tuong iing la 24.5 em, 15.4 la/cay va theo doi ve chieu cao cay, sd Id/cay va dudng kinh 32,5 cm.
Ba Cong thiic CTl (d/c)
CT2 CT3 CT4 CT5 CT6 CT7 LSDo.05
cv,%
n g 4. Anh K.lupng
cdy (g/cdy)
76,5 74,6 72,3 75.7 82.3 78,7 80,1
I h u d n g cua gid thd NSLT
(ta/1000 m2) 37,4 36,5 35,4 37,1 40,3 38.5 39.2
NSTT (ta/1000
m2) 26,1 25,5' 24,7*
25,9*
28,2*
26,9*
27,4*
0,2 4,8
dd cdy d6i Dudng
tong sd(%)
2,20 2,75 2,70 2,41 2,13 2,05 2,65
1 ndng suc Chat
khd
(%)
7,71 7,62 8,07 7,23 8,84 7,33 7.99
it vd chdt]
VTMC (mg/kg
tuoi) 2,42 3,23 2,70 2,41 2,65 2,05 2,13
upngciia NOs- ''^
(mg/kg tuoi)
316 312 427 416 412 420 414
xdldch Pb (mg/kg
tuoi) 0,046 0,057 0,070 0,043 0,042 0,067 0,005
Cd (mg/kg
tuoi) 0,006 0,008 0.060 0.050 0.009 0.030 0.040
^'-^ Gidi han tdi da tiieo (TCVN5247:1990): NO3 = 600mg; Pb = 0,3mg; Cd=0,l mg.
Sd lieu 0 bang 4 cho thay. ndng suat gitra cdc cong thuK; khde nhau Id khac nhau vd dao ddng tir 24,7 den 28,2 ta/1000 ml Trong dd, 0 cdng tiiirc 5, xa lach CO khdi lupng cay (Ndng suat cd thd) vd ndng suat thuc thu cao nhat, tuong img Id 82,3 g/cdy vd dat 28,2 ta/1000 m^, cao hon ddi chiing 8%; tiiap nhat la cong thiic 3, khdi lupng cdy vd ndng suat thuc thu hrong img chi dat 72,3 g/cdy va 24,7 ta/1000 m^
CT4 -> CT7 -> CT5 -> CTl -> CT2; bam lupng Pb: CT3 -> CT6 -> CT2 -> CTl -> CT4 -> Crr5 -> CT7; ham lupng Cd: CT3 -> CT4 -> CT6 -> CT7 -> CT5 -> CT2 ->
CTl.
Nhu vay, xet frdn tat ca cdc chi tieu thi cdng tinic 5 (50% gid the gdc + 50% vun xo dira) td ra uu viet hon ca, ndng suat cao nhat (28,2 ta/1000 m^; chat khd cao nhat (8,84%); nifrat Id 412 mg/kg tuoi; chi la Sd Ueu 0 bang 4 cdn cho tiiay gid tiie cung cd 0,042 mg/kg tuoi; catini Id 0,009 mg/kg hroi; deu anh hudng den chat lupng xa Idch, cu the cdc chi tieu dudi ngudng cho phep nhieu. Tuy nhien, dudng tong ve chat lupng ciia xd Idch xep tiiii tir tii cao xudng sd chi dat 2,13% (Xep tiiii 6 frong 7 cong tinic) lam tiiap nhu sau: Ham lupng chat khd: CT5 -> CT3 -> cho cd cam gide "hoi nhat" khi dn xd Idch 0 cdng CT7 -> CTl -> CT2 -> CT6 -> CT4; ham lupng dudng tiiirc ndy.
tong sd: CT2 -> CT3 -> CTV -> CT4 -> CTl -> CT5 -> 3 ^nh hudng ciia gid tiid dd cdy ddn sinh tiirdng, CT6; ham lupng vitamin C: CT2 -> CT3 -> CT5 -> CTl ^^ng gudt vd chdt lupng cdn tdy
-> CT4 -> CT7 -> CT6; ham luong nifrat: CT3 -> CT6 ->
C6ng thiic CTl (d/c)
CT2 CT3 CT4 CT5 CT6 CT7
Thdi gian sinh tnrdng (ngay) Tir gieo den
nay mam 12 12 12 12 12 12 12
Tir mpc den ra la that
5 5 5 5 5 5 5
Tir mpc den dua len gia dd
17 17 17 17 17 17 17
Tdng thdi gian
59 58 50 57 48 48 56
Chieu cao cay (cm) 22,7 23,6 21,5 23,6 24,7 22,8 23,5
So la/cay Od) 9,0 8,0 8,5 7,5 9.2 8.4 8,6
Dudng kinh tan
(cm) 21,3 20,1 22.4 20.5 26,5 25,0 21,0
K^t qua d bang 5 cho thay d cac cdng thiic gid thi khac nhau ddu cd thdi gian tir gieo den mpc la 12
ngay, tii mpc den ra la tiiat la 5 ngay. Tuy nhidn, tiing thdi gian sinh trudng cua can tay 0 cdc cdng thuc ed
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 3/2012
55KHOA HQC CbNG N G H j
su sai khac dang k^. Cdng thiic cd tiidi gian sinh cdng thiirc 5 dat cao nhat, tuong iing la 24,7 cm, 9,2 tiirdng ngdn nhat la cdng thiic 5 vd cdng thiic 6, chi Id/cdy, 26,5 cm. Chidu cao edn tdy tiidp nhat d cong 48 ngay la dupe thu hoach. ngdn hon so vdi cdng tiiirc 3 (21,5 cm). Sd Id cdn tdy tiidp nhdt d cdng thiic thiic ddi chiing 9 ngdy. Sd li^u d bang 5 cung cho 4 (7,5 Id). Dudng kinh tdn cdn tdy thap nhdt d cong thay chieu cao, sd Id vd dudng kinh tdn cdn tdy b thirc 2 (20,1 cm).
E Cdng thirc CTl (d/c)
CT2 CT3 CT4 CT5 CT6 CT7 LSDo.o.'i
CV.%
tdng 6. An K.lupng
cdy (g/cay)
66,2 70,2 70.0 71,4 75,2 72.5 73,4
1 hudng cua gid thd dd cdy ddn ndng sudt vd chdt NSLT
(til/1000 m2) 32,0 34,3 34.3 34.9 36,8 36,9 35.9
NSTT (ta/1000
m2) 22,4 24,0 24,0 24,4*
25,8*
25,7*
25.1*
0,19 3,8
Duimg tdng sd
(%)
0,9 0,8 0,6 0,9 1,0 0,9 0,6
Chat khd (%)
7,5 7,5 5,7 7,2 7,5 7,1 5,3
VTMC (mg/kg
tuoi) 132,0 124,0 135.0 120,0 142,0 136,0 122,0
upngciia NO:r '' (mg/kg
tuoi) 430 315 421 453 376 428 432
cdn tdy Pb (mg/kg
tuoi) 0,060 0,062 0,005 0.054 0,050 0,040 0,005
Cd (mg/kg
tuoi) 0.005 0,065 0,045 0,067 0.078 0.062 0.056
o Gidi han tdi da tiieo (TCVN 5247:1990): NO3 - Kii qua d bang 6 eho thdy khdi lupng cdy (Ndng suat ca the) vd ning sudt thue thu ciia can tay 0 cdng thirc 5 la cao nhat. tuong img dat 75.2 g/cay vd 25,8 ta/1000 ml cao hon ddi chiing 15,2%; tiep sau dd la cdng thiic 6 dat 25,7 ta/1000 ml thap nhat la ndng suat 0 cdng thiirc 1 ^ d i chiing), chi dat 22,4 ta/1000 ml Ket qua xu h thdng kd cho thay, ndng suat cdn tdy 0 cdng thiie 4, 5, 6, 7 ddu cao hon ddi chimg mdt cdch chdc chdn.
Bang 6 cdn cho thay, hdm lupng dudng tdng sd, chat khd vd vitamm C ciia can tdy 0 cdng thiic 5 cung cao nhat, tuong iing dat 1,0%, 7,5% vd 142 mg/lOOg tuoi. Ham lupng dudng tdng sd thap nhat 0 cdng thiirc 3 vd cdng thiie 7, chi dat 0,6%. Ham lupng chat khd thap nhat Id cdng thiic 7, chi dat 5,3%. Vitamin C thap nhdt 0 cdng thiic 4, ehi dat 120 mg/lOOg tuoi. Hdm lupng nifrat, chi vd catmi d^u dudi ngudng cho phep nhidu. Trong dd, ham lupng nifrat dao ddng tir 315 ddn 453 mg/kg tuoi; ham lupng chi dao ddng tii 0,05 ddn 0,062 mg/kg tuoi;
ham lupng catini dao dpng tir 0,05 ddn 0,078 mg/kg tuoi.
Kdt qua phan tich d bang 6 cho thdy can tdy d cdng thiic gia thd 5 (50% gid thd gdc + 50% vun xo dira) uu viet hon ca, eho ndng suat, ham lupng dudng tdng sd, chat khd va vitamin C cao nhat; nifrat va kim loai ndng ddu dudi ngudng cho phep rat nhidu;
chiing td san pham dam bao an toan vdi ngudi sOr dung.
600 mg; Pb = 0,3 mg; Cd'0,1 mg.
IV. K ^ LUAN
1- Bay gid thd nghien ciiru sau: (1)- Gid the ciia Vien Thd nhudng Ndng hda (Lam ddi chimg - gpi la gid th^ gdc); (2)- gid thd frau hun; (3)- gid the mun xo dira; (4)- 50% gid the gdc + 50% trau hun; (5)- 50%
gid thd gdc + 50% mun xo dira; (6)- 50% tiau hun + 50% mun xo dira; (7)-1/3 gid the gdc + 1/3 gid tiie la frau hun + 1/3 mun xo dira anh hudng khde nhau ddn smh trudng, ndng suat, chat lupng cai xanh, xa Idch vd can tdy frdng bdng phuong phdp thuy canh.
2- Ca 7 gid thd nghidn ciiu ddu cho san pham cai xanh, xa Idch vd cdn tdy an toan vdi ngudi sii dung v^
nifrat, chi vd catmi.
3- Phdi frpn 50% gid thd cua Vidn Thd nhudng Ndng hda + 50% vun xo dira lam gid dd frdng cay bdng phuong phdp thuy canh cho kdt qua tot nhat voi ca cai xanh, xd Idch vd cdn tdy. Trdn gid thi nay, ndng sudt cai xanh d?it 29,3 ta/1000 m l cao hon doi chimg 17,2%; ndng sudt xa lach dat 28,2 ta/1000 ml cao hon ddi chiing 8%; ndng suat can tay dat 25,8 t^/lOOO m l cao hon ddi chiing 15,2%.
TAI LJ$U THAM KHAO
1. Nguydn Thi An, 2008. Nghiin cuu ung dung cic giai phap khoa hpc cong nghe tien tien dd sin xudt rau tiii vu an toan tai Ha Ndi.
2. Hoang Minh Chau, 2010. Nghien cuu xac dinh gidng va gii thd thich hop nhim ting ning su^t va chit luong xa lach, cai xanh, can tiy trong bing cong nghi thuy canh tuin hoan (NFT) trong aha
56 N O N G
NGHlfP VA PHAT TRIEN
N O N GTHON - KY 2 - THANG 3/2012
KHOA HOC C 6 N G NGHl
ludi. Luan vdn cao hpc. Vidn Nghien ciiu Rau Qua, nghiep I.
^^^^^- 4. Trdn Khde Thi, 2007. 7V^//;^/7 c m / c A e > o ^ a 3. Vo Kun Oanh, 1996. Nghiin cuu khi ning thd phuc vu sin xui't ciy con gidng rau, hoa vi rau, ung dung ky thuit tiong ciy tiong dung djch cho hoa tiiuong phdm chdt luQng cao. Dd tdi khoa hpc mot sd loai ciy rau a vung Gia Lam Hi Ndi Ludn dn cdng ngh^ cdp tiidnh phd 2006-2007. Vien Nghien thac si khoa hpc ndng nghidp. Trudng Dai hpc Ndng ciiru Rau Qua.
THE RESEARCH TO DEFINE THE SUITABLE SUBSTRATES FOR HYDROPONIC CULTIVATE FOR LEVEAS VEGETABLES
Nguyen Minh Chung, Traii Khac Thi, Nguyen Khac Thai Son, Hoang Minh Chau, Nguyen Thi An
Summary
The research was conducted on broccoli, lettuce and celery on the circulatory system of hydroponics which grows vegetables in the nutrient solution of the Horticulture Research Institute. Seven studied substrates included: (1) - Substrate from soil Institute (for reference - called the original subsfrate); (2) - smoked rice husk substrate; (3) coconut fiber subsfrate; (4) mbcture of 50% smoked rice husk and 50% original substrate; (5) - mbcture of 50% coconut fiber and 50% original subsfrate; (6) mbcture of 50% smoked rice husk and 50% coconut fiber subsfrate; (7) - mbcture of 1/3 original. 1/3 smoked rice husk and 1/3 coconut fiber substrate. The research results revealed that different kinds of substrates have different effects on the growth, productivity and quality of broccob, lettuce and celery. Broccoli, lettuce and celery grown on all seven studied substrates have lower levels of nitrate, lead and cadmium than the standard level, which means they are much safer for customers. The best result can be found in the mixture of 50% of the original substrate and 50% of coconut fiber substrate for all broccoli, lettuce and celery. To be more specific, the productivity was 29.3 quintal/1000 m^ for broccoli (17.2% higher than tiie reference); 28.2 quintal/1000 m^
for lettuce (8% higher than reference) and 25.8 quintal/1000 m^ for celery (15.2% higher than reference).
Keyword: Broccoli, celery, coconut dber, hydroponic, lettuce, nutrition, rice husk, substrates.
Ngudi phan bidn: TS. Biu Huy Hidn
