KHOA HOC
C 6 N GNGHfi
X A C OilMH CAC Y E U TO K Y T H U A T CO
B A I MD E CHUYEI\i H O A RUIXIG IVIO {MAIMELIETIA COIMIFERA OAIXIDY]
TROIMG CUIMG CAP
G A I X I H O5AIMG KIIMH DOAIMH GO LOIM T A I CdlMG T Y LAIVI IMGHIEP YEIM 50IV -
TilMH TUYEIM QUAIMG
Nguyln HthiTTiiOni T6MTAT
Tren ca sd nghidn cuu 50 lam phan rimg trdng Mo va hiOn trang thuc t l cua cac lam phan Ma tai Cdng ty Lam nghiep Ydn Son cho thay, cac lam phan tir khi trdng din khi khai thac diu khdng ap dung mot biOn phap ky thuat thdng nhat tac dpng nao vao rimg; dan din mat dp cSy rimg cdn lai kha day. hd so giao tan Idn, tao ra su canh tranh khdng gian dinh du&ng giira cac ca thi trong iSm phan, mang hinh phan bd giira cac ca the khdng deu, da sd la phan bd cum, xay ra su phdn hoa ro rOt; d cac d p tudi cang cao thi su phan hoa giira cac ca the trong lam phan cang r6, tat ca cac ylu td nay se lam giam nang xuat va chit lugng rimg din den lam giam gia tri kinh t l cua rimg. Do do, nghidn ciiu va xac dinh cac ylu td ky thuat iSm sinh nhir phuang thiic, phuong phap, thoi diem, chu ky, cudng dd, ddi tugng cac ca thi cdy dl thuc hidn trong chuyin hoa rimg trdng cung cap gd nho thanh rimg cung cap gd idn, nhlm tao ra mot lam phin rimg cho hieu qua kinh te tdi iru nhat la viec lam mang y nghia thuc tiln.
Tir khda: Xac dinh cacyiu tdky thuat, ning m& trong, chuyen hoa ning.
I. DAT VAN o i
Ngudn gd cung d p eho cdng nghiOp ehi biln d nude ta chu ylu II tir rimg trdng. tuy nhidn rimg trdng chu ylu cung elp gd nhd. HiOn nay cd nhilu lodi edy ed kha ndng cung d p gd Idn nhung hiln dang duge trdng dl kinh doanh gd nhd, ede di|n tich ndy cd thi chuyin sang cung d p gd Idn thdng qua ehuyin hda rimg. Md la loli ely tra sing, smh trudng nhanh H> 20 m, Dl,3> 60 em vl ed kha ndng cung d p gd Idn. Md hiln dang dugc trdng trdn hlu hit di|n tieh d Cdng ty Lam nghiOp Ydn Son tinh Tuydn Quang dl cung d p gd nhd, hieu qua kinh doanh chua cao. Xuat phIt tir thue tidn dd nghidn ciiu chuydn dl nay nhdm: Xic dinh cicyiu tdky thuat co
ban di chuyin hoa rimg Mo (MangUetia coniferaDandyy> tiong cung cap gd nhd sang kinh doanh gd
Idn tai Cdng ty Lim nghiip Yin Son tinh Tuyin QuangXk rIt eIn thilt.L N$l DUNG VA PHUONG P H A P NGHIEN CUU
1. Ndi dung nghiin cixu
Xle djnh dirge cle ylu td ky thuat lam co sd khoa hgc eho vile ehuyin hda rimg trdng Md tir tudi 5 din 15 thdnh rimg cung d p gd Idn ti-ln dja bin Cdng ty Lim nghiip Yin Son.
' Tong Cvic Lam nghiOp
Nghien cuu tap trung vdo rimg trdng Md tiiuln loli tren d e d p dit tdt (dp dit I, II, III) vl trong eae elp tudi tir 5 15 tai Cdng ty Ldm nghiip Yin Son tinh TuyIn Quang vdi nhirng ndi dung chinh sau:
Xdc dinh phuong thiie ehuyin hda; xdc djnh thdi dilm bit diu ehuyin hda; xle djnh chu ky chdt ehuyin hda; Xde djnh eudng dd chdt ehuyin hda; xde dinh edy ehdt.
2. Phuang phdp nghiin eihi
Thu thap sd U|u ngodi hi|n trudng: Vdi mdi elp tudi nghien eiiu lap 10 d tidu ehuIn diin hinh ed diOn tieh 1.000 m^ (40 m x 25 m) dl do dim, tiiu tiiap sd liOu. Dilu tra d c ehi tieu sinh trudng D1.3. Hvn. Dt, phdn d p Kraft theo phuong phip dilu tra rimg trdng.
Phdn tieh vd xir ly sd Ulu bdng phtrong phdp toan thdng kl.
Kl thira cdc tii hkxx dd ed.
1 . KET QUA NGHEN CUU VA THAO LOAN
1. Xle djnh phuong thiic ehuyin hda.
Cdn cii vdo ddc dilm ldm phin ehuyin hda: Do bi tie dgng khdng theo quy tic ndn mdt do, phdn bd khdng gian dmh dirdng giira cdc d thi cdy rimg trong timg ldm phin khdng diu, kich thude edy khdng diu, da sd cdy ed kich thude nhd phdn bd d ting dudi eiia rimg. Xde djnh phtrong thiic ehuyin hda: dilu chinh mat dd, khdng gian dmh dudng ciia
N 6 N G
NGHIEP VA PHAT TRIEN NONG
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lam phin Qoai bd d c d t h i d d p IV, V theo phan d p Kraft).
2. Xlc dinh tiidi dilm b i t diu ehdt chuyin hda a. Can cii xic dinh
Cdn eii vdo k i t qua phdn tieh tdng trudng tilt diOn ngang d y bmh qudn ldm phin: Thdi dilm bit diu ehdt la thdi dilm tdng trudng tilt diOn ngang d y bmh qudn lam phin bit dau giam siit Kit qua thi hiOndbangl.
Bang 1. Kit qua phdn tieh tang tiirdng tilt dipn ngang ldm phin Md
Chi tidu
1) Dudng kinh binh quan lam phin (D - em) 2) Tdng trudng binh quan dudng kinh trung bmh lam phin (A D - em/ndm)
3) Tilt diOn ngang d y binh quan (G - em^
4) Tang trudng binh quan G edy trung binh (AG - em^/ndm)
d p tudi III
8,6 1,4 58,05
9,68
IV 10,4
1,3 84,91 10,61
V 11,3
1,1 100,2
10,0
VI 12,1
1,0 114,9
9,58
VII 12,8
0,9 128,6
9,19
Qua bang 1 cho thly, tdng trudng binh qudn tilt diOn ngang edy trung binh eiia lam phin Md thude cap tudi III bat diu giam siit. Tdng trudng binh qudn G trung binh dat cao nhlt d elp tudi IV, edn tdng trudng binh quan dudng kinh trung binh dat cue dai d elp tudi III. Nhu vay cd the xac djnh thdi diem bit diu ehdt ehuyin hda la d p tudi III (5 - <7 tudi).
Cdn eii vIo miie do phin h o i cdy rimg: Khi trong lam phin cay elp IV vl V theo phin d p Kraft dat 3%
trd lln ndn bit diu ehdt chuyin hda. Kit qua phdn elp Kraft cho thly trIn d c lam phin thuge d p tudi III sd edy thuge d p FV vd V deu vugt qud 3%.
Cdn cii vdo ty 10 sd edy trong ldm phin theo elp kinh: Sd edy cd dudng kinh nhd hon dudng kinh bmh qudn chiem 33% ndn tiln hanh chdt ehuyin hda. Kit qua do dudng kinh d y trIn eac Ilm phin tiiudc elp tudi III cho thly sd ely ed dudng kinh nhd hon dudng kinh bmh quan Ilm phan ehilm trIn 33%.
Cdn cii vdo hiOn trang lam phin: Cdy rimg trong lam phan bit diu khep tan can tiln hinh ehdt ehuyin hda. Cdc lam phan Md thude elp tudi III tuy phdn bd
khdng gian khdng diu nhung ed nhilu dam cdy bit diu ed hidn tugng giao tan.
b. Xic dinh thdi diim bit dau chit chuyin hoa.
Cdn eii vdo eac k i t qua phan tieh trIn, thdi dilm bit diu ehdt ehuyin hda duge xde dinh vdo tiidi dilm d p tiidi III (5 - < 7 tudi). Kit qua dilu ti-a ti-ln 40 ldm phan Ma tiiudc 4 d p tudi edn lai (IV din VII) diu eho thly cae lam phan mIt do ely edn khi Idn, >1000 cay/ha va diu ed hiln tugng giao tan vd cdc dilu kiOn khae tuong ttr nhu d p tudi III, vi vdy tit ca cac lam phin nly diu ed till tiln hinh bit diu chdt chuyin hda.
3. Xlc dinh k^ giSn d c h giiia 2 lln eh^t ehuyin hda
a. Cin cii xic dinh
Cdn eti vdo lugng tdng trudng binh quIn cua dudng kinh tan (A£)^ va khoang d c h binh qudn giira cae tan ely (L) d l xle dmh dugc bao nhilu ndm sau khi ehdt lan diu thi tan cay rimg khep lai va lai phai ehdt lln 2. Kit qua till hiln d bang 2.
Bing 2. Tinh toln tdng trudng bmh qudn eiia dudng kmh tdn ldm phin Md v l thdi gian khip tin sau khi ch$t ehuyin hda
Cap tudi
III
OTC A B C D E G H I K
Tudi d p dit AZ)is(em) 6
6 6 6 6 6 6 6 6
1,28 1,26 1,28 1,25 1,20 1,35 1,33 1,31 1,28
A D t ( m )
0,94 0,93 0,96 1,57 1,61 1,28 1,27 1,30 1,18
L(m) 3,8 3,6 4,1 5,2 4,8 2,5 2,3 2,2 2,1
NC(ndm)
4.1 _
3,9
4.3 _
3,3
3,0
3,0
2,8
2,2 _
2,4
90 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 THANG 9/2011KHOA HQC
C 6 N GNGHfi
IV
V
VI
VII
L A B C D E G H I K
L A B C D E G H I K L A B C D E G H I K L A B C D E G H I K L
6 7 7 8 8 8 8 8 8 8 8 9 9 10 10 10 10 10 10 10 10 11 11 12 12 12 12 12 12 12 12 13 13 14 14 14 14 14 14 14 14
I II II I II I II II II II II II II I II II III III III III III II II II I II II II II II II II III III II II I I I I I
1,23 1,25 1,20 1,15 1,20 1,30 1,20 1,22 1,05 1,25 1,25 1,20 1.20 1.28 1.26 1.30 1.21 1.12 1,28 1,15 1,26 1,28 1,25 1,25 1,20 1,15 1,22 1,30 1,18 1,15 1,15 1,20 1,25 1,30 1,35 1,20 1,18 1,28 1,28 1,29 1,22
1,15 1,55 1,30 1,10 1,18 1,25 1,23 1,12 1.22 1.25 1.30 1.28 1.25 1,30 1,35 1,25 1,20 1,05 1,18 1,09 1,18 1,20 1,22 1,20 1,25 1,18 1,15 1,22 1,13 1,20 1,08 1,20 1,22 1,25 1,22 1,28 1.23 1,28 1,30 1,27 1,10
2,4 2,6 3,4 4,1 2,3 2,5 2,5 2,8 3,1 3,2 3,4 3,8 4,2 3,5 4.5 3,8 3,5 3,4 3,3 3.4 3,2 4,3 4,2 4,1 3,6 4,0 3,6 3,3 4,2 3,7 4.0 3.5 3.8 4.5 4.6 3.5 3.2 3,8 4.0 3.4 3,6
3,0 3,5 3,5 4,2 3,8 4,2 3,0 3,5 2,5 3,4 3,6 4,2 4,3 3,8 4,3 3,9 2,9 3.2 3,4 3,8 3,5 4.1 4,0 4,0 3,8 4,0 4,8 4,9 4,1 2,7 4,8 3,6 3,8 4,2 4,3 3,8 3,5 4,0 4,3 3,6 3,8
Trong dd: A D 1.3: Tdng tnrdng bmh quan dudng kinh 1,3; A £),: Tdng trudng binh qudn dirdng kinh tan; L:
Khoing dch trung binh giua ele tin cay trong lam phin; NC: Thdi gian khep tin sau khi ehdt ehuyin hda.
Tir bing 2 eho thly, thdi gian khIp tan sau khi b. Xic djnh k^ gian dch. Dl thuIn tiln trong ch^t ehuyin hda ti-ln ele d tilu chuan biln dgng tii tinh toln vl td ehuc ch^t ehuyin hda, dl tdi dd xlc 2,2 din 4,3 ndm. Thdi gian khIp tdn ciing chinh II tiidi djnh ky gidn edch giiia cle lln eh^t chuyin hda gian tir lln ch^ thii nhlt din ch$t chuyin hda lln 2. thdng nhlt II4 ndm.
N C ^ ' C
MeH!!" VA »"^T TDicM
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. . , „"\ , ' V i . 0 1 ,
KHOA HOC CdNG NGHfi
Cdn cii vdo ky gian each da tiln hanh xle dinh thi hiln d bang 3 thdi dilm va sd lln chdt ehuyin hda. Kit qua dugc
Bang 3. TTidi dilm vl sd lln ehdt ehuyin hda
Tuoi6 6 6 6 6 6 6 6 6 6 7 7 8 8 8 8 8 8 8 8 9 9 10 10 10 10 10 10 10 10 11 11 12 12 12 12 12 12 12' 12 13 13
OTC 3A 3B 3C 3D 3E 3G 3H 31 3K 3L 4A 4B 4C 4D 4E 4G 4H 41 4K 4L 5A 5B 5C 5D 5E 5G 5H 51 5K 5L 6A 6B 6C 6D 6E 6G 6H 61 6K 6L 7A 7B
Mat do hidn tai (N/ha)
2130 1980 1980 1480 1970 2570 2430 2800 2150 1190 1550 1530 1140 1370 1260 1250 1110 1310 1410 1070 1330 1190 1580 1240 1330 1520 1520 1950 1810 2300 1660 1620 1500 1110 1150 1370 1270 1750 1140 1300 1310 1180
d p dit I I I I I I I I I I II II I II
I II II II II II II II I 11 11 III III III III III II II II I II II II II II II II III
Chdt lln 1 (tiidi)
6 6 6 6 6 6 6 6 6 6 7 7 8 8 8 8 8 8 8 8 9 9 10 10 10 10 10 10 10 10 11 11 12 12 12 12 12 12 12 12 13 13
Chdt lln 2 (tudi)
10 10 10 10 10 10 10 10 10 10 11 11 12 12 12 12 12 12 12 12 13 13 14 14 14 14 14 14 14 14 15 15 16 16 16 16 16 16 16 16
Chdt lln 3 (tudi)
14 14 14 14 14 14 14 14 14 14 15 1*
16 16 16 16 16 16 16 16
Tdng sd lln ehdt chuyin hod
3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1
92
NONG NGHIEP VA PHAT TRIEN NONG T H 6 N KY 2 - THANG 9/2011KHOA HQC CdNG NGHfi
14 14 14 14 14 14 14 14
7C 7D 7E 7G 7H 71 7K 7L
1220 1390 1030 860 1410 1590 1000 940
III II II I I I I I
14 14 14 14 14 14 14 14
Qua bang 3 cho thly, sd lln ehdt chuyin hda eua ldm phin d d e d p tudi khae nhau II khic nhau, eu till: sd lln ehdt ehuyin hda eho d p tudi III vl IVII3 lln; eho d p hidi V, VIII2 lln va eho elp tudi VIIII1 lln.
4. Xle dinh eudng dd chdt ehuyin hda
a. Cin cuxic dinhCdn eii vdo trie dd ngang lam phin: Chdt tit el ele edy nhd ban khi giao tan vdi cdy khae (hmh 1).
+ Cdn eii vdo phdn d p Kraft vd do dly ciia rimg:
Chdt tit el d e edy thude d p IV vd d p V; ehdt ehuyin hda ede lam phin khi ed do tin ehe eiia ldm phln>0,7vldddly>0,6.
b. Xac dinh cudng dd chit chuyin hda
Cudng do ehdt tinh theo sd cay duge thi hiln d bang 4.
•ij/S.^^p,
Hmh 1. Xdc djnh d y ch$t chuyin hda trdn trie dd ngang
Ghi chii: Chdt nhirng edy ddnh dau
Tudi 6 6 6 6 6 6 6 6 6 6 7 7 8 8 8 8 8 8 8 8
N/ha 2130 1980 1980 1480 1970 2570 2430 2800 2150 1190 1550 1530 1140 1370 1260 1250 1110 1310 1410 1070
B d n g 4. C u d n g dd ch$t ehuyin hda tinh theo sd d y Cip dat Ncl
810 800 760 590 740 950 900 1110
820 390 460 390 300 330 330 280 210
•280 320 220
Nc2 300 400 450 200 400 530 500 640 310 150 400 420 250 410 300 160 140 150 250 150
Nc3 220 180 200 150 220 320 300 350 220 115 200 170 190 230 210 110 110 130 120 100
Ndi 1320 1180 1220 890 1230 1620 1530 1690 1330 800 1090 1140 840 1040
930 970 900 1030 1090 850
Nd2 1020
780 770 690 830 1090 1030 1050 1020 650 690 720 590 630 630 810 760 880 840 700
Nd3 800 600 570 540 610 770 730 700 800 535 490 550 400 400 420 700 650 750 720 600
Pnl (96) 38,01 40,43 38,45 39.92 37,66 36.96 37,04 39,64 38,14 32,77 29.68 25.49 26.32 24.09 26.19 22.40 18,92 21,37 22,70 20,56
Pn2 (%) 22,73 33,94 36,95 22,57 32.54 20.62 20.58 22.86 14.42 12.61 36.70 36.84 29,76 39,42 32,26 16,49 15,56 14,56 22,94 17,65
Pn3 (%) 21,63 23,12 26,02 21,78 26.54 12.45 12.35 12.50 10.23 9.66 28.99 23,61 32,20 36,51 33,33 18,58 14,47 14.77 14.29 14.29
N6N<^ WISMIEP V A PHAT
TRIEN
N 6 N G T H 6 NKY 2-THANG 9/2011
;«»
f ^
93
KHOA HQC CdNG NGHfi
9 9 10 10 10 10 10 10 10 10 11 11 12 12 12 12 12 12 12 12 13 13 14 14 14 14 14 14 14 14
1330 1190 1580 1240 1330 1520 1520 1950 1810 2300 1660 1620 1500 1110 1150 1370 1270 1750 1140 1300 1310 1180 1220 1390 1030 860 1410 1590 1000 940
II II I II II III III III III III II II II I II II II II II I II III III II II I I I I I
430 390 490 330 410 204 199 251 244 280 670 580 480 310 450 390 350 550 290 350 640 640 490 570 370 290 620 740 340 330
200 120 340 200 190 110 117 99 109 122 300 280 290 170 120 300 270 450 200 280
900 800 1090 910 920 1316 1321 1699 1566 2020 990 1040 1020 800 700 980 920 1200 850 950 670 540 730 820 660 570 790 850 660 610
700 680 750 710 730 1206 1204 1600 1457 1898 690 760 730 630 580 680 650 750 650 670
32,33 32,77 31,01 26,61 30,83 13,42 13,09 12,87 13,48 12,17 40,36 35,80 32,00 27,93 39,13 28,47 27,56 31,43 25,44 26,92 48,85 54.23 40,16 41,00 35,92 33,72 43,97 46,54 34,00 35,11
22.22 15,00 3L19 21,98 20,65 8,36 8,86 5,83 6.96 6.04 30,30 26,92 28,43 21.25 17.14 30.61 29,35 37,50 23.53 29.47
Trong dd: Ncl, Ne2 va Ne3 II sd cdy ehdt/ha d lln ehdt tiiii 1,2,3 (dy/ha);Ndl, Nd2, Nd3 Id sd d y dl lai sau cle lln ehdt 1,2, 3 {ciy/ha);Fnl, Pn2, Pn3 la cudng dg ehdt nudi dudng tinh theo ty 10 sd edy tiiudc mdi lln ehdt chilm trong tdng sd edy trong ldm phin (%).
- Cirdng do ehdt tinh theo trii lugng (m^).
Tudi 6 6 6 6 6 6 6 6 6
M / h a 62.894 58.465 47.845 43.701 39.847 75.886 56.817 82.678 69.377
B^
d p
dit
ing 5. Cudng dd Mel
(m^
19,62 22.50 18,22 17.13 14.34 26,39 20,10 32,21 25.39
M c 2 (m') 33,38 36,03 44,07 18,14 34.45 22.00 19.61 25.37 11.60
ch^tchu]
M c 3 (m') 44.88 30.04 37.91 26,21 37,25 14,59 12.79 15.04 8.88
rin h d a tinh tiieo trii lugng ( m ^ M d i
(m') 43.27 35,96 29,62 26,57 25,50 49,49 36,71 50,46 43.98
M d 2 (m') 115.00 106,27 119,48 80,72 105,93
109,13 97,42 100,41
92,07
Md3
161,20 130,20 145,97 120,56 140,53 119.85 105.91 108.86 99,32
Pvl {%) 31,20 38,50 38,10 39,20 36,00 34.78 35,39 38.97 36.60
Pv2 (%) 20,00 33.90 36,90 22,50 32.50 16.78 16,76 20.18 11,19
Pv3 {%) 20,80 23,10 26.00 21.70 26,50 10.85 10,77 12.14 8.20
94
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 9/2011KHOA HQC CbNG NGHfi
6 7 7 8 8 8 8 8 8 8 8 9 9 10 10 10 10 10 10 10 10 11 11 12 12 12 12 12 12 12 12 13 13 14 14 14 14 14 14 14 14
35.138 53.915 42.845 77.164 60.844 85.287 34.519 49.297 36.176 62.621 47.520 50.957 71.908 88.76 98.205 105.33 77.575 81.59 99.520 92.375 117.38 162.59 158.67 115.28 220.54 136.15 272.20 97.60 207.19 134.96 258.29 203.61 107.22 125.77 248.17 183.89 223.16 251.74 163.92 259.49 243.92
I II II I II I II 11 11 11 11 II II I II II III III III III III II II II I II II II II II II II III III II II I I I I I
10,05 13,03 8.59 14,23 14,49 20,90 5,52 8,67 6,51 15.53 10.11 12,41 18,63 15,18 17,28 21,14 9,77 9.91 12.07 10.39 13.19 44,45 40,27 26,01 56,87 51.50 77.40 26.89 65.11 34,33 69,53 47,88 30,34 29,25 44,59 43.78 69,04 57,09 39,76 35,29 37,83
6,00 38,24 33,66 26,92 38,58 29,59 11.70 32,66 26,92 18,58 19,59 28.30 18,40 33,00 22.60 24.50 25,30 18,40 18.60 24,50 27,43 29,43 27.64 32,00 23,41 12.85 27,34 23,40 18,85 17,49 23,75
5,16 28,35 20,32 29,40 30,18 28,01 10,50 20,32 29,40 30,78 28,10
25,08 40,88 34,25 62,93 46,35 64,68 28,99 40,62 29,66 47.09 37,41 38,54 53,27 73.18 80.92 84,19 67,80 71,68 86.82 81.98 104,19 118.14 118,40 89,27 163.67
84.65 194,80
70,71 142,08 100,63 188.76 155.73 76.88 96.52 203,58 140,11 154,12 194,65 124,16 224,20 206,09
62,78 69,72 62,86 72,20 67,23 67,67 47,59 47,59 50,11 32,50 31,02 121,7 124,2 150,1 137,3 154,4 36,34 38,34 47.26 48,77 110,64
77.58 86.17 91.09 100.90
79.64 111.72
86.94 98.37 121.92 150.52
70.37 75.83 71,43 73,61 62,26 67,55 70.50 70,50 66,12 45,05 46,73
28.62 24.18 20.05 18.45 23.82 24,51 17,60 17,60 18,02 24,81 21.28 24,36 25,91 17,11 17,60 23,82 12,60 12,15 12,14 11,25 11,24 27,34 25.38 22.57 25.79 37.83 28.47 27,56 31,43 25,44 26,92 23,52 28,30 23.26 17.97 23.81 30,94 22,68 24,26 13,60 15,51
8,73 35,42 34,87 27,16 36,46 30,42 16,48 16,48 15.54 22.33 22.06 18,86 12,91 18,01 14,13 13,69 7,57 7,93 6,90 8.10 6.78 27,50 24,29 25,99 18,84 13,90 30,00 28,05 35,25 20,50 28,17
6,83 27,21 22,15 28,54 32,65 29,31 17,71 14,71 16,08 17,61 17,49
Trong dd: Mel, Mc2 vd Me3 la sd m* / h a sau d c lln ehdt 1,2,3 {m^/hd); Pvl, Pv2, Pv3 ch^t chilm tdng trir lugng/ha (%).
5. Xlc d)nh d y ch$t chuyin hda
Chdt nhung d y tiiude d p IV vl V Kraft.
Chdt nhiing cly phlm chit xlu v l smh tiirdng kIm.
Ch$t nhiing d y bj slu bOnh.
d lln ehdt tiiii 1,2,3 {nf/hi); Mdi, Md2, Md3 Id sd m M I lai Id eudng dd chdt nudi dudng tinh theo ty 10 m' trong mdi lln
Chdt nhiing d y nhd hon chen tdn vdi d y khdc.
•V.K^rUIANVAKtiVNGII
Nghiin ciiu dd xlc dinh dugc phuong thiic ehuyin hda II phuong tinic ehdt nudi dudng. Phuang phdp dugc sii dung II eh$t nudi dudng tang dudi.
Thdi dilm ehuyin hda theo phuong phip phin tieh
N O N ' ^
MriHiFP VA PHAT
TP||N N 6 N G T H 6 N KY2 - THANG 9/2011
95KHOA HQC C 6 N G NGHfi san lugng tir d p tudi IV, theo miic do phan hda cly
rimg v l theo ty 11 sd d y trong Ilm phin theo d p kmh la tir elp tudi III. Kit qua xle dinh chu ky chdt chuyin hda la 4 ndm. Sd lln chdt ehuyin hda eho cap tiidi III vl IV la 3 lln; eho d p tiidi V, VIII 2 lln vl cho d p tudi V I I I I 1 lln. Cirdng do ehdt ehuyin hda tinh theo ty 10 the tieh gd v l theo ty 10 so cay trong mdi lln chdt Cly ehdt la d e d y thuge d p chilu eao IV va V trong phdn d p Kraft, d y cong queo, sau, bOnh, cut nggn,...
Nghiin eiiu mdi ehi dimg lai d vile xle dinh d c ylu td ky thuat eho vile ehuyin hda rimg, ehua ed dilu kiln kilm ehiing ngoli thue tiln.
Do vdy, d n tilp tuc xay dung ele d dinh vi d l dilu tra, theo ddi, gilm sit va quan ly d l dinh gii chinh xlc hilu qui ciia d c biln phip ky tiiuat tde dgng vIo rimg chuyin hoi. Bin canh vile xle dmh d e ylu td ky thuat eho vile chdt chuyin hda thi vile quy hoach, xdy dung phuang In ehuyin hda II vile Ilm can thilt d l thuc hiOn ehuyin hda rimg tai dia phuong.
TAIUEUTHAMKHAO
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IDENTIFYING SOME BASIC TECHNICAL FACTORS FOR TRANSFORMING THE SMALL TIMBER FORESTS OF MANGUETIA CONIFERA DANDY INTO THE SAW TIMBER FORESTS IN YEN SON
FORESTRY COMPANY, TUYEN QUANG PROVINCE
Nguyen Huu Thien Summary
The findings of this study in 50 stands of the Manglietia conifera Dandy plantations and actual situations of the MangUetia conifera Dandy stands in Yen Son Forestry Company show that stands with no technical measures applied from planting to harvesting period, have the remaining forest individuals of the relatively high density and high crown interactive ratio. These conditions create a completing environment for nutrition among individuals in the stands with uneven distribution of individuals, which is so called individual grouping. The older the stand, the clearer the differentials of individuals. These factors will decrease the productivity and quality of the forests. Consequently, the economic value of the forests is also decreased. Therefore, this study with an aim to identify silviculture techniques such as methods, measures, timing, cycle, intensify, objects to be transformed from the small timber forests into saw timber forests, will establish stands with the optimal ecnomic effectiveness.
Key words: Identifying technical factors. Manglietia conifera. plantation forests, transformation of forests.
Ngudi phin biOn: PGS.TS. TriOu Vdn Hung
96 N O N G NGHIEP VA PHAT TRIEN N 6 N G T H O N - K Y 2 THANG 9/2011