Đặc điểm phân bố vi sinh vật và ảnh hưởng chế phẩm vi sinh lypomycin m đến khả năng giữ nước vùng bán khô hạn tỉnh ninh thuận

DAI HOC QUOC GIA HA NOI
TRirdNG DAI HOC KHOA HOC TIT NHIEN
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DAC DIEM PHAN BO VI SINH VAT VA ANH
H I T O N G CHE PHAM VI SINH LYPOMYCIN M
DEN KHA NANG G I 0 Nl/OC YUNG BAN KHO
HAN TINH NINH THUAN
MA SO: Q T - 0 6 - 4 1

CHli TRI DE TAI:
CAC CAN BO THAM (ilA:

ThS. TRAN THI TUYET THU.
TS. BUI THI NGOC DUNG
ThS. N G U Y £ N K I E U BANG TAM
CN. NGL YIIX X U A N HLA.N

HA NOI - 2007
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BAO CAO TOM TAT

1. Ten de tai: "Dqc diem phdn bo vi sink vat vd dnh Huang che phdm vi sink

Lypomycin M den khd ndng gin nu&c rung bdn khd hqn tinh Ninh Thuqn'\
Masddetai:QT-06-41
2. Chii tri de tai: ThS. Tran Thj Tuyet Thu
3. Cac can bo tham gia thirc hien:
TS. Biii Thi Ngoc Dung - Vien Quy hoach va Thiet ke Nong nghiep;
ThS. Nguyen Kieu Bang Tarn - Khoa Moi truang, Truang DHKHTN;
CN. Nguyen Xuan Huan - Khoa Moi truang, Trucrng DHKHTN.
4. Muc tieu va noi dung nghien ciru
4J, Muc tieu nghien ctiu
Hien tugng sa mac hoa, hoang mac boa a tinh Ninh Thuan da va dang tra
thanh mot trong nhirng van de can dugc cac nha khoa hoc, nha quan ly quan tam
giai quyet. Mot trong nhung yeu to can tra rat Ian den qua trinh canh tac nong
nghiep a vung nay la nuac tuai. Do dieu kien khi hau kho han, kha nang giu nuac
cLia dat kem nhung kha nang bdc hai nuac lai de dang, lam anh huang khong nho
den qua trinh canh tac cay trong va khu he sinh vat dat tai day. Vi vay, viec nghien
cuu dac diem vi sinh vat va anh huang che pham vi sinh Lypomycin M den kha
nang giiJ nuac vung ban kho han tinh Ninh Thuan nh^m muc dich cai thien dac
tinh dat theo huang c6 Igi cho muc dich su dung la can thiet.
42. Nqi dung nghien cini
- Hien trang sir dung dat tinh Ninh Thuan: dat do vung ban kho han, dat xam nau
vung ban kho han va dat man kiem.
- Cac tinh chat ly - hoa - sinh hoc cua dat.
- Ket qua thi nghiem ve kha nang giu am ciia dat
5. Cac ket qua dat duoc
1. De tai da xac dinh dugc nhom dat do, xam nau va dat man kiem vijng ban kho han
Ninh Thuan c6 thanh phan ca giai nhe den trung hlnh. chu yeu la dat cat pha thit,
ihil pha cat va pha set. Phan ung cua dat a muc rat chua. chua vu'a den trung tinh
tai cac phAu dien dat khac nhau ti;iy thupc vao dieu kien canh tac. Do bao hoa baza
cao. dung tich hap phu va irao doi cation cua dat cao. Ham krano chat huu co va

cac yeu to dinh duang da lugng N, P, K can thiet cho cay trong chi dat a muc
ngheo den trung binh.
2. Tinh trang thieu nude va ham lugng cac chat dinh duang ngheo nan la mot trong
nhung tac nhan han che qua trinh san xuat nong nghiep tai viing nay.
3. Su phan bd cac quan the vi sinh vat khac nhau d tii'ng loai dat va cac dieu kien
canh tac. Quan the sd lugng vi khuan chiem chu yeu, nhung thap han nhieu so vdi
cac dat canh tac thong thudng cd dieu kien am va ham lugng cac chat dinh duang
cao han. Quan the xa khuan, nam mdc, nam men chi nhieu ve sd lugng nhung
khong da dang ve thanh phan loai. Dac biet, sir cd mat cua cac loai nam men d cac
dat trdng cay khac nhau la khac nhau.
4. Ket qua thir nghiem kha nang giu am ciia dat cho thay nhirng phan ling khac nhau
d dat trdng cay dau tuang d 16 thi nghiem va 16 ddi chiing. Cac cay d lo thi nghiem
cd la xanh han, than cay map han so vdi ddi chiing.
6. Tinh hinh kinh phi ciia de tai
De tai dugc hoan thanh nhd su giup da, tao dieu kien ciia Ban chu nhiem Khoa
Moi tru'dng, Phong Khoa hoc C6ng nghe tru'dng Dai hoc Khoa hoc Tu nhien va ngudn
kinh phi hd trg cua Dai hoc Qudc gia Ha Noi.
Kinh phi dugc c^p: 15. 000.000 ddng

BAN CHU NHIEM KHOA MOI T R U O N G

CHU TRI DE TAI

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Summary report
1. Title: '' Distributive characteristics of microorganisms and effect of Lypomycin M
microbial production on water-retaining capacity of middle arid area in Ninh Thuan
province".
Code: Q T - 0 6 - 4 1
2. Head of project: Msc. Tran Thi Tuyet Thu
3. Participants:

Dr. Bui Thi Ngoc Dung - National institute of agricultural planning and
projection.
Msc. Nguyen Kieu Bang Tam - Faculty of Environmental Sciences.
Base. Nguyen Xuan Huan - Faculty of Environmental Sciences.
4. Research purpose and content
4.1. Purpose of Research
The aims of this research included research on distributive characteristics of
microorganisms and effect of Lypomycin M microbial production on water-retaining
capacity of middle arid area in Ninh Thuan province in order to improve soil
characteristics for using in agriculture.
4.2. Contents of Research
For achieving the purposes above, in this study was conducting the following
contents:
- The status of agricultural land use in Ninh Thuan province.
- Biologico - Chemico - Physical Properties of Soils.
- Carry out experiment on water-retaining capacity
5. Results of study
- Biologico - Chemico - Physical Properties of Soils were analized: pH^.Q. PHKCI0M%, N%, P%, K %, CEC, total Microorganisms. Studying soils are low fertility, acid
reaction...
- Water deficiency and low content of nutrional elements in soils are main limited
factors in agricultural production in this area
- Lypomycin M microbial production allows plant grow stronger and develop
better than control due to improvement of water retained capacity of soils in middle arid
area


MUC LUC
Trang
CHUDNG 1. TONG QUAN TAI LIEU

1

1.1. Dieu kien tu nhien va kinh te xa hoi tinh Ninh Thuan

1

1.1.1. Di6u kien tu nhien tinh Ninh Thuan

1

1.1.2. Tinh hinh kinh te xa hoi tinh Ninh Thuan

4

1.2. Hien trang va tiem nang su dung tai nguyen dat tinh Ninh Thuan

5

1.2.1. Hien trang su dung dat

5

1.2.2. Tiem nang sii dung dat nong nghiep

8

1.3. Hieu qua kinh te sir dung dat

8

1.4. Khai quat ve vi sinh vat sinh mang nhay

9

1.4.1. Dinh nghia

9

1.4.2. Chiie nang cua vi sinh vat sinh mang nhay

10

1.4.3. Tac dung cai tao dat ciia che pham Lypomycin M

10

CHUONG 2. DOI T U G N G VA PHUDNG PHAP NGHIEN CUU

12

2.1. Ddi tugng, dja diem nghien cuu

12

2.2. Phuang phap nghien euru

12

2.2.1. Phuang phap bd tri thi nghiem ehau vai

12

2.2.2. Phuang phap nghien euru trong phong thi nghiem

12

CHUDNG 3. KET QUA NGHIEN CUU VA THAO LUAN

14

3.1. Mot sd dac diem ly hoa hoc ciia cac nhom dat nghien cuu

14

3.1.1. Nhom dat do viing ban kho han

14

3.1.2. Nhom dat xam nau viing ban kho han

16


3.1.3. Nhom da't man
3.2. Dac diem phan bd vi sinh vat

23
23

3.2.1. Sir phan bd cua quan thi vi khuan

24

3.2.2. Su phan bd cua quan the xa khuan

25

3.2.3. Su phan bd cua quan the nam mdc

26

3.2.4. Su phan bd ciia quan the nam men

27

3.3. Anh hudng eiia che pham lypomycin M den kha nang giu nude ciia dat 28
KET LUAN VA KIEN NGHI

30

TAI LIEU THAM KHAO

31

PHU LUC

32


DANH MUC BANG VA HINH MINH HOA

DANH MUC BANG
Phu luc 1: Cac tinh chat ly hoa hoc ca ban cua dat Ninh Thuan
Phu lue 2: Ket qua xac dinh vi sinh vat tong sd trong dat d Ninh Thuan
Phu lue 3: Thang danh gia cac tinh chat ly hoa hge ca ban cua dat nghien cuu
DANH MUC HINH MINH HOA
Trang
Hinh 1. Do chua cua dat dd d My San, Ninh San, Ninh Thuan

14

Hinh 2. Ham lugng chat huu ca, N, P, K tong sd cua dat dd d My San,
Ninh San, Ninh Thuan

15

Hinh 3. Do chua ciia dat xam nau viang ban kho han Lam San, Ninh
Son, Ninh Thuan

17

Hinh 4. Do chua ciia dat xam nau viing ban kho han Quang San, Ninh
San, Ninh Thuan

18

Hinh 5. Do chua ciia dat xam nau vung ban kho han huyen Ninh Phude

19

Hinh 6. Ham lugng chat huu ca, N, P, K tong sd trong dat xam nau

vdng ban kho han Lam San, Ninh San, Ninh Thuan

20

Hinh 7. Ham lugng chat huu ca, N, P, K tong sd trong dat xam nau
viing ban kho han Quang San, Ninh San, Ninh Thuan

21

Hinh 8. Ham lugng chat huu ca, N, P, K tong sd trong dat xam nau

22

viing ban kho han Ninh Phude, Ninh Thuan
Hinh 9. Sd lugng vi khuan trong cac nhom dat nghien eiru

24

Hinh 10. Sd lugng xa khuan trong cac nhdm dat nghien ciru

25

Hinh 11. Sd lugng nam mdc trong cac nhdm dat nghien cuu

26

Hinh 16. Sd lugng nam men trong cac dat nghien cuu

27

MO DAU
Thieu nude, han han la mot trong nhung nguyen nhan ca ban din den
hoang mac hoa ddi vdi nhieu viang dat tren the gidi. Theo thong ke cua
FAO_UNESCO, tai nguyen dat the gidi hang nam cd khoang tir 5 - 7 trieu ha bi
ma't kha nang san xuat do thoai hoa, kho han. Han ban da lam giam nang suat
miia mang, nhieu nai mat trang va gay nen nan ddi cho hang tram trieu ngudi d
Chau Phi, viing Trung can Dong. Hoang mac hoa da Ian rgng den ca nhirng
viing nhiet ddi am nhu d Viet Nam. Do vay, nghien cuu cac tinh chat ly - hda sinh hoc dat, bao ve ngudn nude, giir am dat va cung cap nude cho trdng trot da
va dang la nhiem vu cap bach ddi vdi moi qudc gia tren the gidi.
Viing cd nguy ca han han cao dugc quan tam d nude ta la tinh Ninh
Thuan. Day la dia phuang cd khf hau kho han nhat cua ca nude. Viec dam bao
ngudn nude tudi cho san xuat nong nghiep luon la van de cap thiet, nhat la trong
thdi gian ban keo dai. Hien nay da cd nhieu mo hinh canh tac tiet kiem nude
dugc ap dung ciang vdi mot sd chat giu am hda hge cd kha nang giu nude trong
dat tai mot sd dia phuang trong tinh. Tuy nhien, hieu qua mang lai chua cao.
Trong giai doan hien nay, yeu eau dat ra ddi vdi cac san pham chat gifi
am khong chi la kha nang giO nude trong dat ma eon phai dap ung dugc yeu eau
ve duy tri can bang he sinh thai dat. Viec tim hieu nghien euru cac dac diem sinh
hoc dat ket hgp vdi viec su dung cac san pham sinh hge da dugc nghien cuu ung
dung la rat can thiet ddi vdi viing dat kho han nhu d Ninh Thuan. Vi vay, de tai:
""Dac diem phdn bo vi sinh vat vd dnh huang che phdm vi sinh Lypomycin M
den khd ndng giir nu&c viing bdn kho hqn tinh Ninh Thuan'' dugc dat ra
nham tim hieu ve dac diem phan bd cua vi sinh vat trong mot sd loai dat chinh
va anh hudng ciia che pham den kha nang giu nude trong dat.


CHUONG 1. TONG QUAN TAI LIEU

1.1.

Dieu kien tir nhien va kinh te xa hoi tinh Ninh Thuan

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7.7.7. Dieu kien tu nhientinhNinh Thuan
al Vi tri dia ly - dia hinh
Ninh Thuan la tinh cue Nam Trung Eg, d vi tri dia ly iri8'14" den
ir09'15" vT do Bae va tu 108W08" den 109^1475" kinh Dong. Phia Bk giap


tinh Khanh Hoa, phia Nam giap tinh Binh Thuan, phia Tay giap tinh Lam Dong,
Phia dong cd bd bien dai 105km. Nam d vi tri trgng diem giao thong doe qudc
16 1 A, dudng sat Bac - Nam, qudc Ig 27 len Tay Nguyen.
Ninh Thuan dugc bao bgc bdi ba mat niii va mot mat bien. Phia tay la

viing niii eao giap vdi Da Lat, phia bac va phia nam cd hai day nui cao Ian ra sat
biin. Cd ba dang dia hinh chinh la mien niii, ddng bang, viing ven bien. Dia
hinh tuang ddi doc va ed hudng thap dan tit tay sang dong va tir tay bac xudng
dong nam. Viing nui cao chiem 63,2% tong dien tich tu nhien toan tinh, viing
go ddi chiem 14,4% va ddng bang la 22,4%.
Toan tinh ed 8 dinh nui cao tix 1000 m trd len so vdi mat nude bien, trong
dd huyen Ninh San cd cac niii Phude Binh (1926m), Bonnonh (1652m), Marai
(1637m), Chaidion (1542m), Lang Ma Bio (1282m); huyen Ninh Hai ed niii
Hao Chu Hy (1451m), niii ehiia (1040m).
bl Dieu kien khi hau, thiiy van
Nam trong vanh dai khi hau nhiet ddi am, tuy nhien khi hau Ninh Thuan
lai ed nhung net rat dac biet, dugc xep vao che do nhiet ddi dien hinh vdi cac
dac trung: ed nen nhiet do eao deu quanh nam, lugng mua nhd, lugng bdc hai
Idn i\i 1.670 - 1.827 mm, gid nhieu, am do khong khi thap, khong cd mua dong
va suang mudi. Vi vay, Ninh Thuan dugc xem la viing kho ban nhat ca nude.
Nhiet do trung binh 27^C, ed hai miia ro ret, miia mua \\i thang 5 den
thang 11, miia kho xvi thang 12 den thang 4 nam sau. Lugng mua trung binh 705
mm va tang dan theo do cao tren 1.100 mm d viing mien niii. Do am khong khi
tir 71 - 75%. Nang lugng biie xa Idn, tong tich on 9.500 - lO.OOO^C. Nhirng ket
qua nay cho thay Ninh Thuan la khu vue ed miia kho keo dai va khac nghiet,
trong vdng 8 thang, tir thang 1 den thang 8, lugng mua trung binh chi dat 270
mm bang lugng mua trung binh mot thang trong miia mua cua phan Idn cac khu
vue khac d nude ta.
Dieu kien khi hau kho ban da gay khong it khd khan cho san xuat nong
nghiep, anh hudng den sir phat trien ciia dat, gay ra tinh trang man hda, kiem
hda va chai cung dat be mat.


Luu virc cac song chinh cd tdng chieu dai 430km, gdm 2 he thdng song
chinh:

- He thdng song cai dai 105 km va cac song nhanh bao gdm: song Me Lam,
song Sat, song 6ng, song Cha d viing trung luu (thuge huyen Ninh San), song
La, song Quao d mien ha luu (thuge huyen Ninh Phude).
- He thdng cac song sudi nhd: phan bd d phia bac va phia nam tinh, song
Quan The (Ninh Phude), song Trau, song Ba Rau (Ninh Hai).
Nhin chung cac he thdng song ngan deu bat ngudn va ket thiie trong noi
tinh, do doe binh quan luu vue tii 7 - 15.
Tinh ed Dam Nai vdi dien tich Idn nhat la 650 ha da va dang khai thae
dua vao nuoi trdng thuy hai san, ngoai Dam Nai eon cd kha nhieu dam, hd nhd
khac.
7.7.2. Tinh hinh kinh te xd hoi tinh Ninh Thuan
Ninh Thuan nam tren cac true dudng giao thong xuyen viet khong xa dia
ban kinh te trgng diem Nam Bg va thanh phd Hd Chi Minh va nam trong cum
du lich Da Lat - Phan Rang - Nha Trang, ed cac ciia ngo ra bien, cd dieu kien
phat trien cang thuang mai va du lich.
Day la mot trong nhirng dia ban sinh sdng ciia ngudi Viet co, hien tai ed
khoang 28 dan toe, nhung dong nhat la ngudi kinh, ngudi Cham va ngudi
Rawcklai. Dan sd phan bd khong deu, tap trung chu yeu d cac dai ddng bang
ven song, gan cac true dudng giao thong va cac thi xa, thi tran. Viing mien niii,
dat rgng, ngudi thua, mat do dan sd 25 ngudi/km^ ngudn lao dong 23.873 ngudi.
chiem 49,2% dan sd. Lao dong viec lam trong nen kinh te qudc dan la 179 ngan
ngudi, chiem 76% tdng ngudn lao dong. Chat lugng ngudi lao dong cua tinh con
thap, khong ddng deu, can dugc dao tao va dao tao lai.
Ninh Thuan cdn la viing cd lanh hai rgng 18.000km^ la mot trong nhiJng
ngu trudng quan trgng cua Viet Nam vdi 500 loai hai san, cho phep khai thae
mdi nam 5 - 6 van tan. Day cung la dia phuang san xuat mudi Idn nhat ca nude
vdi san lugng 130.000 tan/nam. Ngoai ra vdi dien tich riing Idn, lam nghiep
cung dugc coi la the manh nhung khai thae chua hieu qua.

Trong phat tviin cay trong vat nuoi, Ninh Thuan bi ban che rat Idn ve
ngudn nude tudi. Cay liia chi dugc tham canh d Ninh Phude 4.500 ha, Ninh Hai
3.500 ha, Phan Rang 2.000 ha, Ninh San 1.000 ha. Dien tich trdng bap khoang
S.OOOha, trdng mi khoang 1.000 ha/ nam.
Cay thuc pham chu yeu la hanh, tdi vdi dien tich 450 - 500 ha/nam. Hanh
tay 200 - 300 ha phue vu noi tinh va xuat khau.
cay eong nghiep va cay an qua ehii yeu la cay nho, khoang 2.500 ha, san
lugng 62.500 tan/nam; cay mia den nam 2010 cd 9.100 ha; cay thude la khoang
2.000 ha dat san lugng 5.000 tan/nam; cay bong vai mdi nam trdng dugc
2.000ha.
Cac vat nuoi chinh la bd, du tinh den nam 2010 cd 110.000 con, san
lugng xuat chudng 9,5 ngan tan; de ciru ed khoang 30.000 con va vSn tiep tuc on
dinh cho cac nam sau; du kien den nam 2010 cd khoang 100.000 con Ign, san
lugng xuat chudng 6,37 ngan tan.
1.2.

Hien trang va tiem nang sir dung tai nguyen dat tinh Ninh Thuan

7.2.7. Hien trang sudung dat
Tinh Ninh Thuan nam d phia Nam viing Duyen hai Nam Trung bg
(DHNTB), d vi tri trung diem giao thong doc theo QL lA, dudng sat Thdng
Nhat va QL 27 len Tay nguyen. Toan tinh cd 5 huyen va 1 thi xa vdi 62 xa,
phudng, thi tran (mdi thanh lap them huyen Thuan Bac va 3 xa). Theo ket qua
kiem ke dat dai nam 2005, dien tich dat tu nhien toan tinh la 335.799,87 ha,
chiem 1,02 % dien tich toan qudc, chiem 7,54 % tong dien tich viing DHNTB.
Dat nong nghiep cd dien tich 261.961,51 ha, chiem 78,01 % tdng dien tich tu
nhien (DTTN) toan tinh (trong dd: dat san xuat nong nghiep la 70.382,65 ha,
chiem 20,96 % DTTN toan tinh; dien tich dat lam nghiep la 187.778,33 ha,
chiem 55,92 % DTTN toan tinh); dien tich dat phi nong nghiep cd 21.060,29 ha,
chiem 6,27 % DTTN. Dien tich dat chua su dung cdn 52.778,07 ha, chiem

15,72 % DTTN; trong dd dien tich dat ed the khai thae vao san xuat nong
nghiep khoang 19.300 ha, nuoi trdng thuy san 105 ha, lam mudi 540 ha va san
xuat lam nghiep khoang 14.000 ha.


Ddi vdi da't trong cay hang nam, cac he thdng canh tac can chiem den
69,4%, da't rugng liia - Iiia mau chi chiem 30,6%, trong dd dat trdng mot vu liia
mau chiem 27,38% dien tich. Ddi vdi dien tich dat nuang rSy chu yeu la nhd
nude trdi, vSn cdn quy mo kha Idn, len den 16.066ha (chiem 31,18% dat trdng
cay hang nam. Dieu nay cho thay, dau tu thuy Igi de giai quyet nude tudi, tim
giai phap giu am cho dat de tang vu cay trdng la can thiet.
Cac cay trdng lau nam, nho va dieu la 2 loai cay trdng phd bien, sau dd
den cay bong va cay thude la.
Trong dat lam nghiep, rirng tu nhien bao phii gan het, chiem 95,24% dien
tich, tuy nhien phan Idn la rimg tai sinh ed do che phu thap. Dat cd rirng trdng
chiem 4,76% dien tich dat lam nghiep, trong dd khoang 70% dien tich rung
dugc trong tren dat eat hoac tren them phii sa cd it ddc.
Theo he thdng phan loai dat Viet Nam, Ninh Thuan ed 8 nhdm dat chinh
chia thanh 24 dan vi phan loai dat. Dat dd va nau vang (dat niii) vdi tren 200
ngan ha chiem 58% dien tich dat toan tinh. Chi ed dat phii sa cd do phi tuang
ddi kha cdn lai phan Idn la cac dat ngheo dinh duang.
Cac loai dat thuge viing ddng bang ven bien:
+ Nhdm dat eat: gdm 3 loai, dien tich 13.418 ha, chiem 3,83% dien tich
dat tu nhien. Trong dd dat cdn eat trang vang: 2.169 ha; dat cat bien: 6.727 ha;
eon cat dd: 4.252 ha. Nhin chung phan dien tich tuang ddi ddng nhat, thanh
phan ehii yeu la cat va cat min da cd tich liiy miin. Dat bi kho ban nang, muc
nude ngam sau, dat cd phan ling chua, ngheo mim. Loai dat nay ehii yeu trdng
rirng phdng ho. Mot sd dien tich vung dat thap cd dieu kien tudi dugc dua vao
trdng cac loai hoa mau nhu hanh, tdi, nho.
-I- Nhdm dat man:

Nhdm dat man gdm 4 loai, dien tich 2.294 ha, chiem 0,67% dien tich tu
nhien, trong do dat man sii vet 417 ha d Dam Nai huyen Ninh Hai; dat man
nhieu 252 ha d Ca Na - Ninh Phude; dat man it va trung binh 1.150 ha d xa Hd
Hai, Phuang Hai, Nhan Hai, huyen Ninh Hai. Dat man kiem 202 ha d Ninh Hai.
Cac loai dat man thudng phan bd d dia hinh thap hoac ven cac song dd ra bien
bi anh hudng cua thuy trieu. Ddi vdi nhdm dat nay d viing chu dong nude,


khong bi anh hudng cua thuy trieu ed the trdng liia va hoa mau, viing khong chu
dong nude thi san xua't mudi va nuoi trdng thuy san.
+ Nhdm dat phu sa:
Nhdm da't phu sa gdm 4 loai, dien tich 17.922 ha, chiem 5,2% dien tich
dat tu nhien. Da't phu sa dugc bdi hang nam 690 ha, phan bd ven song cai. Dat
phii sa khong dugc bdi 11.736 ha, phan bd kha tap trung d hau het vung ddng
bang cua cac huyen, thi. Dat phu sa ngoai sudi 321 ha, phan bd rai rac ven cac
song sudi d viing ddi niii. Dat phu sa gley 5.184h, phan bd d cac viing trung thap,
thudng bi ngap nude d huyen Ninh Phude.
Da't phu sa la nhdm dat tdt ciia tinh, neu ehii dong dugc ngudn nude tudi
ed the thieh hgp vdi nhieu loai cay trdng. Nhdm dat nay dugc sir dung de trdng
Ilia, ngo va cac loai hoa mau khac.
Cac loai dat viing ddi niii:
4- Nhdm dat xam gdm 3 loai, dien tich 87.343 ha, chiem 25,5% dien tich
tu nhien. Dat xam bac mau phii sa cd 27.454 ha; dat xam bac mau tren da mac
ma va da cat 29.289 ha; dat xam nau ban kho ban 30.700 ha.
+ Nhdm da't dd vang gdm 7 loai, dien tich 184.477 ha chiem 53,8% dien
tich tu nhien. Dat dd viing ban kho ban chiem 2.230 ha, dat dd nau tren da
bazan 3.990 ha, dat dd vang tren da set va bien chat 9.054 ha, dat dd vang tren
da Granit 154.895 ha, dat vang nhat tren da cat 2.959 ha, dat nau vang tren phii
sa ed 9.119 ha, dat vang dd bien ddi do trdng liia 2.230 ha.
+ Nhdm da't mau vang dd tren da mac ma axit cd dien tich 15.000ha,

chiem 4,4% dien tich dat tu nhien, phan bd d do cao tren 1000m.
+ Nhdm dat thung lung ddc tu cd dien tich 873 ha, chiem 0,25% dien tich
tu nhien, phan bd rai rac d cac khe sudi, thung lung, thieh hgp trdng liia nude va
mot sd hoa mau.
+ Nhdm dat xdi mdn tra sdi da cd dien tich 16.953 ha, chiem 4,9% dien
tich tu nhien. Dat bi rira troi bao mdn rat nhanh, tang da't mat bi trdi het, mat kha
nang san xuat ndng nghiep.


7.2.2. Tiem nang svtdung dat ndng nghiep
Tiem nang sir dung dat nong nghiep dugc tinh toan dua tren ca sd xem
xet mot sd yeu to da't dai nhu: dac diem tinh chat dat, do day tang dat va phan
bd do ddc dia hinh. Theo cac ket qua nghien eiiii cho thay da't cd kha nang sir
dung cho muc dich nong nghiep cua tinh nhin chung chiem mot ty le khiem ton,
chi chiem 42, 92% tdng quy da't, trong dd dien tich ed kha nang bd tri cac loai
hinh sir dung dat nong nghiep dat khoang 87.500 ha (26,04% tdng dien tich
tren).
Loai da't khong hoac it cd ban che chiem 6,96% tdng dien tich tu nhien,
ehii yeu la dat phii sa song sudi, cd kha nang thieh ung cao vdi cac loai hinh sir
dung nong nghiep nhu cay an qua (tren dat phu sa khong dugc bdi), hoa mau va
cay an qua (tren dat phii sa ngdi sudi) va liia hoac liia mau (tren cac dat phii sa
gley hoac loang id).
Loai da't cd ban che trung binh chiem 31,54% tdng dien tich tu nhien, chu
yeu la dat xam, dat ddc tu, dat man trung binh va it, cac dat dd va dat xam nau
viing ban kho ban, dat dd vang tren da set va bien chat, phan bd d dia hinh ddc
( < 8^) va ed tang dat day > 50 cm. Cac loai dat nay ed kha nang thieh hgp d
muc trung binh den kha vdi cac loai hinh sir dung nong nghiep nhu liia hoac liia
mau (tren dat xam gley, xam loang Id va dat ddc tu); nuoi trdng thiiy san nude
man va liia nude (tren dat man trung binh va it); hoa mau, cay eong nghiep hang
nam hoac lau nam, hoac lam ddng cd chan tha (tren cac dat dd va xam nau viing

ban kho ban, dat dd vang tren da set va bien chat, da't vang dd tren da mac ma
axit).
Loai dat cd ban che nhieu chiem 4,41% tdng dien tich tu nhien. Dien tich
cd kha nang bd tri cho san xuat nong nghiep dat khoang 7.400 ha.
1.3.

Hieu qua kinh te su dung dat vung ban kho han

Trong nhirng nam qua, ciing vdi viec ung dung nhirng tien bg khoa hoc ky
thuat vao san xuat, nhieu mo hinh canh tac tren viing dat ban kho ban da dugc
ap dung nhu: mo hinh tudi tiet kiem nude cho cac loai cay trdng, sir dung vat
lieu giir nude tren cay trdng da dugc ap dung va mang lai hieu qua thiet thuc cho
san xuat nong nghiep ciia ngudi dan.

8


Theo danh gia cua Sd Nong nghiep va Phat trien nong thon, du kien tiem
nang san xuat nong nghiep cua Ninh Thuan den nam 2010, 2012 khoang 80.000
ha, tang 16.000 ha so vdi nam 2005, trong khi dd cac eong trinh thiiy Igi tren dia
ban tinh mdi chi dap ling khoang 48 - 49% dien tich da't nong nghiep. De cai
thien tinh hinh nay, Ninh Thuan da xay dung nhirng mo hinh tudi tiet kiem nude
cho cay trdng. Hien tai mo hinh nay da va dang dugc trien khai rgng khap tren
toan tinh. Hinh thiic tudi tiet kiem nude tren cay nho, tren cd phuc vu chan nuoi,
tren cay an qua, tren cay liia da gdp phan dang ke trong viec nang eao hieu qua
kinh te va tiet kiem lugng nude vao miia kho ban.
Ket qua nghien ciiii cho thay, neu ap dung phuang phap tudi truyen thdng
phai can den 9.072 m^ nude/ha/vu san xuat nho, thi ddi vdi mo hinh tudi nhd
gigt la 1.608 m^ nude/ha/vu, tiic la chi bang 17,8% (giam 82,2% lugng nude
tudi), lugng phan bdn cung giam tir 20 - 25%, cac chi tieu sinh hge va nang suat

ciia mo hinh tudi nhd gigt hau nhu khong khac gi so vdi mo hinh tudi truyen
thdng cua ndng dan. Do tiet kiem dugc phan bdn va nude tudi nen chi phi giam,
cho lai xuat khoang 1 trieu ddng/ha nho so vdi phuang phap tudi truyen thdng.
Rieng vdi cay liia, viec ap dung hinh thiic tudi tiet kiem da cho san lugng tang
tir 8,8 ta den 23 ta, giiip ngudi san xuat tang Igi nhuan tir 2,4 trieu ddng den han
6 trieu ddng/ha/vu.
Qua trinh sir dung nhung vat lieu giu nude trong san xuat cay mau (cay
bap lai) cd the cho nang suat tang tir 10 den 15%, hieu qua kinh te so vdi cac
phuang phap tudi truyen thdng tang tir 1,2 den 2 trieu ddng/ha/vu. Tuy nhien
viec sir dung cac dang che pham hda hoc chi mang lai hieu qua trong thdi gian
tir 2 den 3 nam dau sir dung, sau dd se ed cac phan litig phan giai cac hgp chat
hda hge gay chua hda dat.
Viec ap dung cac hinh thiic tudi tiet kiem ket hgp vdi sir dung cac che
pham vi sinh lam tang kha nang giir am cho dat la can thiet de nang cao hieu
qua sir dung dat.
1.4.

Khai quat ve vi sinh vat sinh mang nhay

7.^.7. Dinh nghia
Vi sinh vat sinh mang nhay la nhirng vi sinh vat ma ben ngoai thanh te
bao ed mot lap nhay hay dich nhay. Dd la mot lap chat dang keo cd do nhay bat


dinh (cdn ggi la giac mac) bao nhay ehii yeu la polisaccarit, ngoai ra cdn cd
polipeptit va protein.
Theo dieu tra ciia mot sd tac gia thi mat do cua mot sd vi sinh vat mang
nhay trong mot sd loai dat ddi niii d Viet Nam khoang 10^-10"^ CFU/g dat, tuy
thuge vao timg loai dat. Ngoai ra thi cac vi sinh vat ed kha nang sinh mang nhay
dang polisaccarit cd kha nang lam tang ket eau dat, lam giam su bay hai ciia

nude trong dat.
7.-^.2. ChUc ndng sinh mang nhay cua vi sinh vat
Mang nhay bao ve vi sinh vat khdi su tdn thuang khi dieu kien moi
trudng khac nghiet, bao ve te bao vi khuan gay benh khdi hien tugng thuc bao
ciia bach eau. Nguge lai khi khong cd mang nhay chiing nhanh chdng bi bach
eau tieu diet.
Mang nhay la nai du tru* nang lugng, de phdng khi thieu thiic an cd the sir
dung vd nhay nhu mot ngudn chat dinh duang. Khi thiic an can kiet vi sinh vat
se tieu thu dan chat dinh dudng cd trong vd nhay va lam cho vd nhay teo dan lai.
Vi sinh vat sinh mang nhay cdn ed nhieu iru diem dang dugc nghien ciiu
va img dung, dac biet la kha nang cai thien do am cua cac viing dat ddc va kho
ban. Ddi vdi cac viing dat ddc va kho can, chiing cd kha nang giu nude, lam
tang do ben eau triie dat va lam giam xdi mdn.
1.43. Tac dung cai tao dat cua che phdm Lipomycin M
Hien tai cd nhieu phuang phap de cai tao dat kho ban nhu: cac phuang
phap hda ly, ca ly, sinh hge, nhung ngay nay phuang phap sinh hoc dugc danh
gia la ed trien vgng ban ca. Cac phuang phap hda hge mac dii cd hieu qua
nhung van the hien nhieu khia canh han che. Vi du nhu cac chat giir am hda hoc
cd kha nang hiit nude gap hang tram Ian khdi lugng cua nd nhung hieu qua lai
phu thuge vao lugng bdn dau vao va kha nang giu nude giam dan theo thdi gian
vi chiing bj phan hiiy sau thdi gian khoang 8 den 12 thang.
Cac vi sinh vat tham gia hau het vao cac qua trinh ehuyen hda vat chat
trong he sinh thai dat, trong dd ddng vai trd khong nhd ddi vdi qua trinh cai tao
dat va dam bao cho sir phat trien mot nen nong nghiep ben \arng.

10


Theo ket qua nghien ciili eiia Phdng nghien cuu cac chat cd boat tinh sinh
hoc (Vien eong nghe sinh hge - Vien Khoa hoc va Cong nghe Viet Nam) da

phan lap dugc mot bg chiing gidng vi sinh vat sinh mang nhay, trong do ed
chung na'm men da't Lipomyces starkeyi PT7.1. Chiing nam men nay ed dac
diixn la sinh mang nhay, sir dung it N2, trao ddi nang lugng bang qua trinh oxi
hda chii khong len men cac ngudn ca chat. Do su trao ddi nang lugng ban che
nen nd sir dung cac ngudn cac bon rat phong phii.
Nam men Lipomyces cd kha nang tdng hgp Lipit rat manh va tich luy
trong te bao dudi dang gigt md, dac biet la chiing khong tiet chat beo ra ngoai
moi trudng nhu nhieu chung nam men khac ma nam trong te bao. Qua trinh
tdng hgp Lipit chiu anh hudng cua nhieu yeu td, quan trgng nhat la ty le C/N
trong moi trudng. Tat ca cac chung nam men Lipomyces trir L.anonahis deu the
hien kha nang tao polisacarit ngoai bao manh. Nhd ed kha nang tao mang nhay
ma nhirng chiing nam men nay dugc phan lap tu dat cd y nghia Idn trong viec
cai tao dat trdng ddi niii trge, dac biet la cac viing dat kho ban.
Dua tren dac tinh sinh hge cua chung nam men nay, cac nha nghien ciiu
da xay dung quy trinh eong nghe san xuat che pham giu am dat ed ten thuang
pham la Lipomycin M va da thanh eong d quy mo thir nghiem. Che pham nay cd
y nghia rat Idn trong eong tac cai tao va bao ve dat, do cd kha nang giam sir bay
hai nude va tang do am dat, giiip cho dat tai xdp ban, tang sd lugng giun dat,
ddng vat khong xuang sdng va cac nhdm vi sinh vat cd ich khac d trong dat.
Che pham khong doc hai, an toan vdi he sinh thai dat va cdn cd kha nang cai
thien mot sd tinh chat ly, hda hge cua dat nhu: do chua ciia dat cd xu hudng
giam, ham lugng phot pho de tieu va cac cation trao ddi tang.
Che pham giii am dat Lipomycin M dugc eau thanh tir 2 thanh phan chu
yeu la vi sinh vat - Nam men Lipomyces va chat mang tinh bgt. Che pham nay
da dam bao dugc cac yeu eau: Khong lam anh hudng den su sinh trudng cua cac
nhdm sinh vat khac; ban than nhdm vi sinh vat trong che pham cd kha nang tdn
tai va canh tranh sinh trudng dugc vdi cac khu he sinh vat trong moi trudng dat
tu nhien.

11

CHUONG 2. DOI TUONG VA PHUONG PHAP NGHIEN CUU

2.1. Doi tirgng, dia diem nghien euru
Ddi tugng nghien ciiu la 3 loai dat chinh: dat xam nau viing ban kho ban
va da't man kiem dugc lay d huyen Ninh San, Ninh Phude, tinh Binh Thuan.
Che pham giu am dat "Lipomycin M" (Vien Cong Nghe Sinh hoc)
Dia diem nghien eiiii la Bg mon Thd nhudng va Mdi trudng dat, Khoa
Mdi trudng, trudng DHKHTN Ha Noi; Phdng Thd nhudng, Vien Quy hoach va
thiet ke ndng nghiep.
2.2. Phuong phap nghien cihi
2.2.7. Phuang phdp bo tri thi nghiem chau vai
Bd tri 12 chau vai, mdi chau dung 10 kg da't xam nau dugc lay tir huyen
Ninh San, tinh Binh Thuan. Tren mdi chau deu trdng cay dau tuang va dugc
chia lam 2 16: L6 ddi chiing khong bdn che' pham giiJ am, 16 thi nghiem (TN)
bdn che' pham giir am Lipomycin M vdi lieu lugng 5 g/ chau, cac chau vai dugc
dat tren san thugng cd mai che va khong tudi nude trong sudt thdi gian thi
nghiem.
Do am cua da't dugc xac dinh tai cac thdi diem 15; 30; 45; 60 ngay sau
khi bdn che pham.
2.2.2. Phuang phdp nghien ciiti trong phdng thi nghiem
' Cac chi tieu hda ly dugc phan tich tai phdng Thd nhudng, Vien Quy
hoach va Thiet ke Nong nghiep.
- Cac chi tieu hda ly dugc xac dinh theo nhung phuang phap thdng dung
hien nay trong cac phdng thi nghiem phan tich dat.
•

Xac dinh thanh phan ca gidi theo phuang phap phan loai cua My

•

pH^ci va pHnoH dugc do bang may pH Metter

•

0 M % dugc xac dinh bang phuang phap Walkley - Black

12


•

Xac dinh Nita tdng sd bang phuang phap Kendan

•

Xac dinh Phot pho tdng sd bang phuang phap phuang phap so mau
xanh Molipden

•

Xac dinh Kali tdng sd bang phuang phap quang ke' nggn lira

Cac chi tieu sinh vat dugc xac dinh tren mdi trudng thach dia Petri
theo ehudn ap dung cua Hiep hoi Khoa hge Dat My. Cac mdi trudng
dugc ap dung:
•

Vi khuan: Moi trudng thach dinh dudng

•

Xa khuan: Moi trudng Kuster va Williams

•

Nam mdc: Moi trudng Czapek - Dox

•

Nam men: Czapek - Dox - Propionate.

13


CHUONG 3. KET QUA NGHIEN CUU VA THAO LUAN
3.1. Mot so dac diem ly hoa hoc ciia cac nhom dat nghien euru
3.7.7. Nhdm dat do viing bdn khd hqn
Nhdm dat dd vung ban kho ban ed dien tich: 1.840,05 ha, chiem: 0,55%
dien tich toan tinh. Phan bd chu yeu d huyen Ninh San 877,70 ha va huyen Ninh
Phude 769,60 ha, dudi dang cac ddi dat dd.
Toan bg dien tich dat dd vung ban kho ban phan bd d cac cap do ddc <
20^; trong do cd den 71% dien tich phan bd d do ddc < 8^ va chi cd 13,41%
dien tich la cd do ddc tir 15 den 20^.
Cac ket qua phan tich tinh chat ly hda hge cua dat dugc the hien nhu sau:
al Thdnh phdn cagidi
Dat dugc lay tai cac thon d xa My San, huyen Ninh San la da't thit pha cat
vdi ham lugng eat dao dong tir 31.11 - 76.60%; limon tir 8.53 - 39.45%; set tir
14.87-26.59%.

b/ Dd chua cua dat

D pHH20
• pHKCI

NS-10 NS-12 NS-14 NS-15 NS-16 NS-17 NS-19 NS-21

M^u

Hinh 1. Do chua cua dat do d My Son, Ninh Son, Ninh Thuan

14


Tren hinh 1 cho tha'y do chua cua d^it d miie chua vira den gan trung tinh.
PHHOH dao dong tir 5.68 - 7.47, trung binh 6.83; pH^a tir 4.46 - 6.54, trung binh
5.84. Gia tri pH nude cho thay day la dieu kien thuan Igi cho viec trdng cac cay
bg dau, cay thude la va trdng mia, luan canh dieu tai dat nay. Tuy nhien su
chenh lech cua gia tri pH nude va pH^ci 1^ 0'^9 - 1,27 d muc tuang ddi cao, cho
biet da't dugc hinh thanh trong dieu kien khi hau nhiet ddi am cd su rira troi dang
ke cac cation kim loai kiem va kiem thd, tich luy nhieu sat nhdm la nguy ca gay
dat, anh hudng den su bat Igi ciia cay trdng. Tir ket qua phan tich nay can cd
dinh hudng cai tao va bao ve dat, tang cudng bdn phan chudng, bdn vdi va ban
che nhung tac dong gay chua dat.
cl Hdm luang chat hihi cavd N, F, K tdng so

{%)
2.500

0.90

(%

2.000
0.60

1.500
1.000
0.30
0.500
0.000

NS-t)

NS-T2

NS-14

NS-15

NS-B

NS-17

NS-19

NS-21

• OM %
=1N%

P205%
K20%

0 821
0.089
0,03
018

1.88
0134
0.201
056

2 24
0.151
0.178
0.61

117
0.101
0118
0.61

152
0,106
0153
0 76

0 94
0.078

0,044
0,26

188
0.123
0.150
0,55

199
0.140
0.175
068

0M%
N%
P205%
K20%

0.00

Hinh 2. Ham lirgng chat huu ca, N, P, K tong sd cua dat do
d My Son, Ninh Son, Ninh Thuan
Tren hinh 2 cho thay dat ed ham lugng chat hiru ca d mure rat ngheo den
ngheo, dao dong tir 0.821 - 2.24%; ham lugng nita tdng sd d miic ngheo den
trung binh, dao dong tir 0.078 - 0.151%; ham lugng photpho tdng sd d miic

15


ngheo den kha, dao ddng tir 0.03 - 0.201%; ham lugng kali tdng sd d miic

ngheo, dao dong tir 0.018 - 0.76%.
Theo ket qua dieu tra cho thay d^x a mau NS-10, NS-16 la da't ddng cd
dudng nhu khong cd su cham bdn bd sung chat dinh duang tu qua trinh canh
tac. Mau NS-14, NS-21 la dat trdng dau xen thude la; NS-12, NS-15, NS-17 la
da't trdng thude la; NS-19 la dat trdng tao. Nhung thong tin nay la ca sd giai
thieh tai sao ham lugng chat hiiu ca va nita tdng sd d cac mau dat khac nhau.
Ham lugng chat hiru ca tai dat d day thap vi diiu kien khi hau dia phuang ed
nhiet do cao, thuan Igi cho cac boat dong phan buy cac chat bdi vi sinh vat
thanh CO2. Ham lugng nita tdng sd trong dat thudng cd tuang quan ty le thuan
vdi chat hiju ca da dugc the hien kha ro net tren hinh 2. Ham lugng chat bun ca
va nita tdng sd d cac mau trdng dau xen thude la cao ban cac miu khac la do
sinh khdi cdn lai sau thu hoach va cd su bd sung nita tir qua trinh canh tac ket
hgp vdi ngudn nita dugc thuc hien bdi cac nhdm vi sinh vat sdng eong sinh vdi
r6 cay ho dau cung cap cho dat. Ham lugng P, K tdng sd trong da't rat thap la do
kali la nguyen td kim loai kiem dt bi rira troi bdi dieu kien tu nhien, ddng thdi
cac nguyen td nay bi lay ra khdi dat bdi cac san pham thu hoach nhung lai
khong dugc bdn bd sung trd lai.
Cac ket qua phan tich cac tinh chat ly hda cho thay dat dd vting ban khd
ban ed ham lugng cac chat dinh dudng thap, lai phan bd tren nhirng bac dia hinh
cao, da sd la ddi niii thap va it ddc, ban niia lai nam trong khu vue khi hau ban
kho ban, khan hiem ve ngudn nude nen da gay rat nhieu khd khan cho viec canh
tac cung nhu khai thae cho nong nghiep ndi chung.
3.1.2. Nhdm dat xdm ndu viing bdn khd hqn
Nhdm dat xam nau vung ban kho ban phan bd rgng d tat ca cac huyen
trong tinh, chiing chiem hau het cac dang dia hinh eao hoac phang trude niii va
mot sd niii sdt trong viing bac them nay. Dien tich dat xam nau len den 94.570
ha; chiem 28,15% tdng dien tich tu nhien toan tinh, trong do: huyen Ninh Hai:
12.899 ha; huyen Ninh Phude: 29.162 ha; huyen Bac Ai : 23.660 ha; huyen
Ninh San : 28.651 ha; Phan Rang - Thap Cham: 198 ha.

16


Cac sd lieu nghien ciJH cho thay cd den 99,26% dien tich dat xam nau
vimg ban kho ban phan bd d cac ca'p do ddc < 20^, trong do chu yeu la cd do
ddc < 8^ dien tich cd do ddc > 20^ chi chiem 0,74% dien tich dat xam nau.
Cac ket qua phan tich tinh chat ly hda hge cua dat dugc the hien nhu sau:
a/ Thdnh phdn cagidi
Cac mau da't lay d cac thon thuge xa Lam Son, huyen Ninh San la dat thit
pha cat va pha set vdi ham lugng cat dao dong tir 66.33 - 87.67%; limon tir 5.76
- 14.44%; set tir 6.27 - 27.91%. Dat lay d cac thon thuge xa Quang San, huyen
Ninh Son cung la da't thit pha cat va pha set vdi ham lugng cat dao dong tir 53.33
- 88.09%; limon tir 3.86% - 8.65%; set 8.23% - 39.19%. Dat lay d cac xa Nhi
Ha, Phude San, Phude Vinh, huyen Ninh phude la dat thit vdi ham lugng cat dao
ddng tir 18.43 - 65.83%; limon 13.17 - 48.15%; set 7.63 - 48.29%.
Cac dat xam nau viing ban kho ban Ninh Thuan cd thanh phan ca gidi
thay ddi giira cac phau dien kha Idn, tir thit nhe den thit trung binh. Do dat dugc
hinh thanh tren nhieu loai da me mSu chat khac nhau nhu sudn tich hoac lu tich
granit, cac thanh tao xam nhap mawema axit, hoac tren cac tram tich cd thanh
phan hat thd, phan bd tren cac be mat bdc mdn san phang trong dieu kien khi
hau ban kho ban vdi Idp phu thuc vat ngheo nan.
b/ Dd chua cua ddt
pH

n

pHH20

•pHKCI

Mau
NS-01

NS-02

NS-03

NS-05

NS-07

NS-09

NS-1 1

NS-13

Hinh 3. Do chua cua dat xam nau viing ban kho han
Lam Son, Ninh Son, Ninh Thuan
17

•RijNG T A ' /

DT/ ? i i


Da't d Lam Son, Ninh San d miic chua vira den rat chua (hinh 3), pHnon
dao ddng tir 5.34 - 6.72, trung binh 6.28; pH^a dao dong tir 3.97 - 5.31, trung
binh 4.74. Gia tri chenh lech giira pHnoH ^^ P^KCI tuang ddi cao, dao dong tir
1.37 - 1.54, cho biet dat c6 tich luy nhieu sat nhdm. Ket qua nay cung phan anh

nhirng tac dong bat Igi ciia dieu kien dat ddi vdi nhu eau sinh trudng va phat
trien eiia cay trdng. Dat chua cd the tang cudng hda tan AF"", cac kim loai nang
gay doc cho cay trdng, lam tang kha nang cd dinh lan trong dat, anh hudng den
viec cung cap lan dt tieu cho cay trdng, ddng thdi anh hudng den qua trinh sinh
trudng va phat trien ciia sinh vat dat. De tang nang suat cay trdng va tao dieu
kien thuan Igi cho cac sinh vat dat e^n phai cd cac bien phap cai tao dat nhu bdn
voi va bd sung them phan hiru ca vao dat.

pH

DpHH20
• pHKCI

NS-22

NS-24

NS-26

NS-28

NS-29

NS-31

NS

M^u

Hinh 4. Do chua cua dat xam nau vung ban kho han

Quang San, Ninh Son, Ninh Thuan
Dat xam nau d Quang San, Ninh San d miic chua it den rat chua (hinh 4),
PHHOH dao dong tir 5.53 - 8.08, trung binh 6.48; pH^a tir 3.94 - 6.46, trung binh
4.94, chenh lech giira pHnoH ^^ PHRCI tir 1.12 - 1.62, cho thay do chua tiem tang
eiia dat kha cao. MSu NS-24 la dat trdng liia 3 vu, mau NS-26 va NS-31 la dat
trdng mia + san, vdi cac dieu kien canh tac khong tdt la nguyen nhan ca ban gia
tang do chua ciia dat. Mau NS-28 la dat chua sir dung, chua cd sir tac dong dang
ke ciia boat dong nhan tac, lam tang tinh dem ciia dat nen dat it chua, cd pH
nude d miic kiem yeu la di su cd mat dang ke ciia cac cation kim loai kiem va

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