13

NNG CAO HIU QU S DNG PHN BN

VIT NAM

Nguyn Vn B1

I. T VN

Vit Nam l mt quc gia nng nghip v v lu di vn da

vo nng nghip, cho d ng gp ca nng nghip (bao gm c

nng, lm, thy sn) vo GDP ch khong 20%. i vi chng ta,

nng nghip khng ch l mt ngnh kinh t quan trng, cung cp

lng thc, thc phm, nguyn liu cho cng nghip m cn l ch

da vng chc cho cng nghip ha, m bo an sinh x hi. Cc

t khng khong kinh t va qua cng cho thy iu .

Vit Nam vi ti nguyn hn ch, ch c 10,126 triu ha t

sn xut nng nghip (Nin gim thng k 2012). Tuy nhin, nh

chnh sch i mi chng ta chuyn t mt nc nhp khu

lng thc thnh nc xut khu go v nhiu nng, lm, thy sn

hng u th gii vi kim ngch t 27,5 t USD nm 2012, chim

gn 25% tng kim ngch xut khu ca c nc. Mt iu c bit

na, duy nht ch c nng nghip xut siu trn 9,2 t USD lm cho

nhp siu c nc gim dn.

Gn y, ti Din n kinh t Th gii, Vit Nam cam kt

trin khai Tm nhn mi trong nng nghip vi mc tiu tng

trng 20% cho mi thp k, trong khi m bo pht trin bn

vng, gim thiu tc ng v thch ng vi bin i kh hu, p

ng nhu cu v lng thc, thc phm tng thm cho 1 triu

ngi/nm. t c mc tiu ny, ngoi vic y mnh ng

dng ging mi, cc k thut canh tc tin tin th phn bn c vai

tr v cng quan trng.

II. S DNG PHN BN V SN XUT NNG NGHIP

VIT NAM

Khi chng ti vit nhng dng ny (0h00 ngy 18/2/2013)

th trn trang web ca Vin Nghin cu La Quc t2 cho thy dn

s ton cu l 7.100.649.960 ngi, sng trn 8.538.843.863 ha t

1 Gim c Vin Khoa hc Nng nghip Vit Nam 2 www.irri.org

http://www.irri.org/

14

sn xut nng nghip. Nh vy, trung bnh trn th gii c 1,2 ha

t sn xut nng nghip/u ngi, trong khi con s ny Vit

Nam ch l 0,104 ha, bng 8,7% trung bnh th gii3.

nui sng dn s ang tng ln, mi quc gia c th p

dng mt hoc nhiu bin php sau y: i) Tng din tch thng qua

khai hoang cc vng t mi; ii) Tng v v iii) Thm canh (ging

mi, bn phn, qun l su bnh v p dng cc bin php thu

nng thch hp). Tuy nhin vi Vit Nam, t sn xut nng nghip

ni chung v t sn xut cy lng thc cy thc phm ni ring

khng nhng khng tng m cn ang gim i nhanh chng c v

s lng v cht lng. Trong giai on nm 2000 - 2007, din tch

t trng la gim i 361.935 ha4. Cn theo bo co ca cc a

phng, t 2004 n 2009 th 29 ngn d n thu hi gn

750.000 ha, trong trn 80% l t nng nghip5.

Vic m rng din tch canh tc gn nh l khng th, c

nc hin ch cn 327 ngn ha t bng cha s dng6, song phn

ln li nm vng ven bin, hoc nhim mn hoc l cn ct nn

khai thc cho nng nghip rt kh khn. Vic tng v cng khng

kh thi, nhiu ni trng 2-3 v la/nm; mt s vng trng rau

mu t 4-5 v/nm. H s s dng t tng t 1,49 nm

1990 ln 1,92 nm 2007 (Theo nin gim thng k, 2010). Do vy,

gii php gn nh duy nht tng sn lng ch c th l tng

nng sut thng qua thm canh, m trc ht l s dng phn bn.

C th thy ngay rng sn lng nhiu loi cy trng Vit

nam tng ng k trong thi gian qua (nht l cy lng thc) ch

yu l do nng sut cy trng tng. Ly 4 cy trng i din cho 2

nhm cy lng thc v cy cng nghip, c din tch ln v tiu

th nhiu phn bn lm v d, l cy la, ng, c ph v ch.

Bn cy trng ny ph 9,65 triu ha gieo trng (chim 66% tng

din tch gieo trng cy nng nghip) v tiu th gn 90% lng

phn bn ton quc (Ph lc 1). Tnh t 1921-2012 (91 nm), din

3 Tnh ton theo s liu thng k t ai ca Vin QH-TKNN, 2011 trong Bo co: Hin

trng s dng t n 31/12/2010. 4 Bo Nng nghip Vit Nam, 11/07/2008 5 Thi bo kinh t VN, 15/5/2009 6 Bo co: Hin trng s dng t n 31/12/2010. Vin QHTKNN, 2011

15

tch gieo trng la tng 1,64 ln; sn lng tng 7,07 ln, trong

nng sut tng 4,35 ln. Vi cc cy trng khc cng c chung qui

lut: Ng nng sut tng 3,75 ln trong 36 nm; c ph tng 2,88

ln trong 22 nm; cn ch tng 14,1 ln trong 68 nm (Bng 1).

Bng 1. Bin ng din tch, nng sut v sn lng mt s cy

trng chnh ti Vit Nam

Cy

trng Thi gian

Din tch,

1000 ha

Nng sut,

tn/ha

Sn lng,

1000 tn

La 1921 4.732 1,31 6.211

2012 7.769 5,66 43.965

2012 vs 1921,

ln

1,64 4,35 7,07

Ng 1976 337 1,15 387

2012 1.140 4,32 4.925

2012 vs 1976,

ln

3,38 3,75 12,7

C ph 1990 119 0,77* 92

2012 614 2,22* 1.366

2012 vs 1990,

ln

5,15 2,88 14,8

Ch 1944 16 0,49* 8

2012 131 6,92* 905

2012 vs 1944,

ln

8,18 14,1 11,3

* C ph nhn v ch bp ti

Ngun: S liu thng k Vit Nam th k 20, cun 1,2. NXB Thng k,

nm 2004. Nin gim thng k hng nm. 2011, 2012: Bo co tng kt

B Nng nghip v PTNT v tnh ton ca tc gi.

Thi gian ti, khi dn s tng ln, trung bnh 1 triu

ngi/nm (Ph lc 4), trong khi din tch t canh tc thu hp li do

cng nghip ha, giao thng, th, bnh qun din tch t trn u

ngi gim (Ph lc 2) th tng nng sut l con ng duy nht

m bo an ninh lng thc v an sinh x hi.

Theo Balu L. Bumb and Carlos A. Banante (1996), nng

sut ng gp trn 80% sn lng cy trng, 20% cn li l do tng

din tch. Hin nay, gn nh 100% sn lng tng thm ca cc

cy trng chnh ti Vit Nam l nh tng nng sut.

16

C 3 con ng tng nng sut, l: i) Ci thin ging;

ii) Tng cng u t, trong ch yu l h thng thy li v

phn bn v iii) Ci tin k thut canh tc. Cc nh khoa hc Trung

Quc cho bit, phn bn ng gp 40% trong tng nng sut cy

trng trn phm vi ton quc (Bng 2). Vi Vit Nam, chng ti

cho rng phn bn ng gp cao hn bi v trong 40 nm (1970-

2010), nng sut la (Cy trng chim n 33 triu ha ti Trung

Quc) tng c 1,92 ln cn Vit Nam tng tng ng 2,66 ln

(Bng 3). Tc tng nng sut ca Vit Nam cao hn trung bnh

ca th gii v hu ht cc nc trng la (Bng 3, Ph lc 3).

Bng 2. Cc yu t ng gp vo tng nng sut cy trng ti

Trung Quc

STT Yu t % ng gp

1 Phn bn 40,0

2 Ging cy trng 30,0

3 Bo v thc vt 20,0

4 C gii ha 10,0

Ngun: Dongxin FENG, 2012

Bng 3. S dng phn ho hc v nng sut la ti mt s nc

Nc Kg N+P2O5+K2O/ha canh tc Nng sut la, t/ha

1970 1980 1990 2000 2007 1970 1980 1990 2000 2010

Trung Quc 44,0 158,2 220,4 256,9 366,9 3,42 4,14 5,72 6,26 6,55

Nht Bn 376,3 372,6 385,5 324,5 272,1 5,63 5,13 6,38 6,70 6,51

Hn Quc 261,9 351,4 418,7 301,1 257,9 4,55 4,31 6,21 6,71 6,51

Thi Lan 6,6 16,7 59,7 99,7 133,4 2,02 1,89 1,96 2,61 2,88

Vit Nam 55,2 26,1 104,9 365,6 400,3* 2,01 2,08 3,19 4,24 5,34

* S liu 2010

- Ngun: Tiu th phn bn: FAOSTAT Database, (1961-2001 data: FAO update 06 Sept 2006/30 Aug 2007). Patrick Heffer, 2008. IFA, 2008.

Assessment of Fertilizer Use by Crop at the Global Level. Nng sut la:

http://ricestat.irri.org: 8080/wrs/

Theo s liu thng k, nng sut v sn lng cc cy trng

chnh ti Vit Nam c mi quan h cht ch vi lng phn bn s

dng. Qui lut tng t cng xy ra vi cc nc trng la ch yu

khu vc chu (Bng 3 v 4).

http://ricestat.irri.org/

17

Mt iu l th l, nhng nc c nn thm canh sm nh

Nht Bn, Hn Quc u s dng phn bn rt cao, t 300-400

kg N+P2O5+K2O/ha canh tc t nhng nm 70-80 ca th k 20. Hn

Quc tng bn 418 kg cht dinh dng/ha canh tc cch y 23

nm, khi lng bn ca Vit Nam mi ch t 104 kg/ha. Tuy

nhin cc nc thm canh sm nh Nht Bn, Hn Quc li ang

gim nhanh lng phn bn s dng/ha canh tc. Mt phn do chi

ph cao, song phn ln do cng ngh phn bn v k thut bn

phn c ci thin nn hiu qu s dng tng v c th gim

lng bn. Lng bn ca Vit Nam nm 2010 thuc loi cao trn

th gii, song chng ta c h s s dng t t gn 2 ln, do vy,

thc cht lng dinh dng bn cho cy trng cng ch khong 200

kg N+P2O5+K2O/ha/v. Lng bn ca Thi Lan hin thuc loi

thp, ch yu do nc ny c trn 10 triu ha la s dng ging

cht lng cao nn khng chu thm canh.

Bng 4. S dng phn bn v nng sut cy trng Vit Nam

n v: 1000 tn N+P2O5+K2O

Nm Tiu th phn bn Nng sut cy trng, tn/ha

Ton cu Vit Nam La Ng C ph Ch

1961 31.182 89 1,34

1965 47.003 78 1,90

1970 69.308 311 2,01

1975 91.399 330 2,12 1,15

1980 116.720 155 2,08 1,10 2,01

1985 129.490 469 2,78 1,48 2,43

1990 137.829 560 3,19 1,55 0,77 2,41

1995 129.681 1.224 3,68 2,11 1,16 2,71

2000 135.198 2.267 4,24 2,75 1,42 3,58

2005 161.358 1.985 4,89 3,60 1,56 4,51

2010 163.500 2.582 5,34 4,11 1,98 6,42

2011 172.600 2.935 5,53 4,29 2,04 7,03

2012 176.600 2.774 5,66 4,32 1,97 7,80

2012 vs

1961, % 566 3.116 422 375*

255*

*

388*

**

* So vi nm 1970; ** So vi 1990 v *** so vi 1980

Ngun: IFA, 2012; S liu thng k Vit Nam th k 20, cun 1,2. NXB

Thng k, nm 2004. Nin gim thng k hng nm. Bo co tng kt B

Nng nghip v PTNT

18

III. HIU QU S DNG PHN BN TI VIT NAM

3.1. Yu t dinh dng hn ch

Nhn li lch s s dng phn bn ti Vit Nam c th thy,

chng ta thc s mi chuyn t nn nng nghip qung canh da

vo t sang nn nng nghip thm canh da vo phn bn t

nhng nm 70 ca th k trc. Trc , c nc mi s dng

khong 80 ngn tn cht dinh dng/nm (Bng 4) v nu chia bnh

qun cho tt c cc cy trng th ch t khong 12 kg cht dinh

dng/ha v tt nhin, cng ch c phn m. Phn ln cha c

s dng, phn kali th gn nh c? Do vy, ngay c th nghim v

mi quan h gia bn phn vi bnh o n ca Vin Bo v Thc

vt thc hin trc nm 1980 cng ch c bn phn ur v phn

chung, do vy t l nhim bnh rt cao (Bng 11). S lng phn

ha hc nu trn ch yu bn cho cy cng nghip (cao su, c ph).

Cc cy trng khc nht l la s dng phn hu c (phn chung,

phn bc, tro bp...) v phn xanh (bo du, in thanh...) l chnh.

Trong nhng nm 1960-1970 vi cc ging c truyn, nhu cu dinh

dng thp th cht dinh dng trong t cng vi phn hu c c

th p ng nhu cu dinh dng ca cy trng (Bng 5).

Bng 5. Lng ht dinh dng lin quan n ging la

Ging la Lng ht, kg/ha

N P2O5 K2O

La a phng, c

truyn

15-25 2,5-4,0 30-35

La thun ci tin 80-100 40-50 100-120

La lai 120-150 60-75 150-180

Ngun: ti 02A-0601, 1990 v Nguyn Vn B, 2003

Nh vy, c th ni nhng nm 60 ca th k trc, m l

yu t hn ch nng sut hng u. Chnh v vy, ngoi vic bn

phn m ha hc, mi hot ng u tp trung to ra m m

in hnh l phong tro bn phn ln cho cy phn xanh Bin

ln thnh m nh sn xut bo hoa du, in thanh m... Phn ln

thi k ny cha c s dng nh mt loi phn bn ng ngha.

Tnh trng dng SSP ri ng, sn phi kh ph bin cc tnh

pha Bc.

19

Vi vic s dng cc ging ci tin c xut x t IRRI v

Trung Quc u nhng nm 1970 lm thay i ng k sn xut

nng nghip ca Vit Nam. Nng sut la tng t 1,31 tn/ha nm

1961 ln 2,01 tn/ha nm 1970. Thi k ny, phn m c s

dng tng rt nhanh v lin tc cho n nm 2005 (Hnh 1). Vic

tng lng m bn khng cn i vi cc yu t dinh dng khc,

trong khi dinh dng t t v phn hu c khng p ng nhu

cu ca cy trng nn vic bn m ring r khng lm tng

hiu qu nh mong mun. Nng sut la trong sut 10 nm t

1970-1980 gn nh khng tng, ch xoay quanh 2,01-2,08 tn/ha

(Bng 4).

Sau gii phng, Nh nc y mnh pht trin nng nghip

ti pha Nam v ci to t phn ti BSH v BSCL tng din

tch, ch yu cho sn xut lng thc. Nu nh t nm 1961 n

1974, din tch gieo trng la ch tng c 112 ngn ha, th t 1975

n 1985 din tch ny tng thm 844 ngn ha (trung bnh 84

ngn ha/nm so vi 8 ngn ha/nm ca giai on 1961-1974).

Nh vy, cng vi vic khai ph t phn trng la, m rng

sn xut cy cng nghip trn vng cao nguyn vn t thiu ln v

s dng ging mi to ra tin cho xut hin yu t hn ch

mi, l ln. Vi c im khc bit ca mnh m phn ln trong

t Vit Nam d l t ngho hay giu ln u lun trong tnh trng

thiu ht ln d tiu. Vic cung cp ln t ngun phn ha hc l

rt cn thit. Nhng nghin cu ca Vin Th nhng Nng ha

(1995) cho thy ln b thiu vi t l cao nht trong cc loi t Vit

Nam. C th l, c ti 87% t Vit Nam ngho ln, trong khi ch

khong 50% t ngho m.

T nhng nm 1990, khi ging la lai vo Vit Nam, c ph

v cc cy cng nghip khc pht trin vi tc nhanh th nhu cu

v phn bn cng tng rt nhanh (Hnh 1). C th thy, giai on

1990-2012, din tch gieo trng la tng 1.726 ngn ha (28%) ch

yu do tng v, t 6.043 ngn ha ln 7.769 ngn ha, trong c

khong 700 ngn ha la lai; tng t din tch ng tng 708 ngn

ha (163%), t 432 ngn ha ln 1140 ngn ha; Din tch c ph tng

496 ngn ha (417%), t 119 ngn ha ln 614 ngn ha. V vy, c

th ni, giai on nhng nm 90 ca th k trc kali xut hin nh

20

l yu t hn ch tip theo sau m v ln. Cc kt qu nghin cu

trong sut 10 nm ca Chng trnh BalCrop v BalCof chng

minh iu ny. (Nguyen Van Bo, Ernst Mutert, Cong Doan Sat,

2003).

0

200

400

600

800

1000

1200

1400

1600

1962

1966

1970

1974

1978

1982

1986

1990

1994

1998

2002

2005

2007

2009

Nm

ng

hn

t

n

N

P2O5

K2O

Hnh 1. Tiu th phn bn ha hc Vit Nam giai on 1962-

2009 (IFA, 2011)

Nh vy, c th thy, cc yu t dinh dng hn ch trong

sn xut nng nghip Vit Nam xut hin sut na th k qua lun

phin xut hin l m, ln v kali. Hin nay, cc yu t hn ch

trung v vi lng cng xut hin cc mc khc nhau.

Nguyn nhn xut hin cc yu t hn ch ch yu l do: i) Gieo

trng ging mi, k c cc ging lai nn nhu cu dinh dng tng

ln (Bng 6); ii) Tng v; iii) Bn phn khng cn i v iv) Hn

ch vic s dng phn hu c do thay i tp qun chn nui, s

dng ph ph phm nng nghip. Tt nhin, yu t t nhin vn

c trong mi loi t u gp phn vo vic thc y nhanh hay

chm hn s hnh thnh cc yu t hn ch mi.

21

Bng 6. Lng ht cht dinh dng ca cy la7 (kg/ha)

Giai on N P2O5 K2O Cng

1975-1980 30,7 12,2 33,6 76,5

1981-1990 46,4 18,7 50,8 115,9

1991-2000 64,9 25,5 77,9 168,3

2001-2010 83,8 32,9 100,6 217,3

Tng, ln 2,72 2,69 2,99 2,84

Ngun: Vin TNNH, 2005; Nguyn Vn B, 2001 v Doberman, 2000.

3.2. Nghin cu cn i dinh dng v qun l dinh dng

tng hp

Bn phn cn i c hiu l cung cp cho cy trng cc

nguyn t dinh dng thit yu vi liu lng ng, t l thch

hp, thi gian bn hp l cho tng i tng cy trng, t, ma

v c th m bo nng sut cao, cht lng nng sn tt v an

ton mi trng sinh thi. Kt qu tng kt ca FAO trn phm vi

ton th gii cho thy c t nht 10 nguyn nhn chnh lm gim

hiu lc phn bn, trong bn phn cn i gi vai tr quan

trng nht, c th lm gim ti 50% cho cng mt lng bn

(Nguyn Vn B, 2003).

Da trn nhng nghin cu thuc Chng trnh

BALCROP/IPI-PPI-PPIC ti cc vng ca Vit Nam (Nguyen Van

Bo, E.Mutert, Cong Doan Sat, 2003), chng ti tng kt rng, c

rt nhiu mi quan h rng buc, nh hng ln nhau khi bn phn.

V mi tng quan hu c-v c, t l dinh dng tt nht

t hai ngun ny l 30-70%, nht l i vi cy cng nghip di

ngy. Khi c bn hu c, hiu sut s dng m ca cy c ph

tng thm 15,6% (t 37,2% khi khng c bn hu c ln 52,8% khi

c bn hu c). Ngc li, phn ha hc cng lm tng hiu qu

ca phn hu c. Trn nn c bn phn khong, hiu sut 1 tn

phn hu c t 53-89 kg thc ty theo loi t v ma v, cn trn

nn khng c phn khong, ch s ny ch t 32-52 kg thc. Phn

hu c cng lm tng hiu qu s dng phn ln do hn ch ln kt

ta vi cc ion Fe, Al v Ca. Bn phn hu c, nht l phn chung,

7 Theo tnh ton trn c s 300 th nghim ca h nng dn ca Dobermann (2000), th

c sn xut 1 tn thc, cng vi rm r, cy la ly i 17,5 kg N; 7 kg P2O5 v 21 kg

K2O

22

phn c cht n l rm r cn lm gim ng k lng kali cn

bn do hm lng kali trong rm r rt cao, t t 1,5-1,7% K2O.

Cc yu t dinh dng cng c mi tc ng qua li, khi th

tng h, lc li i khng v c mi lin quan rt cht vi ph

nhiu t nhin/loi t. Trn t phn, gi tr hiu lc tng h N-P

c th t trn 2 tn thc/ha, gim ng k lng N tiu tn to

ra mt tn thc (Bng 7). Cn trn t vng, gi tr tng h N-

P c th t 1,4-1,6 tn ng ht/ha (Nguyn Vn B, 2003).

Bng 7. Mi quan h N-P v loi t

Loi t Lng N cn sn xut 1 tn thc, kg

Khng bn ln C bn ln

Ph sa sng Hng 23-27 19-23

Ph sa sng Cu Long 18-20 16-18

t phn min Bc 34-36 26-28

t phn min Nam 30-34 17-20

Ngun: ti 02A-06-01, 1990

Bng 8. Mi quan h N-K v loi t

Loi t

Bi thu do bn K

Ng La

tn/ha % tn/ha %

Ph sa sng Hng 0,95 33,0 0,23 5,0

Ph sa sng Cu Long - - 0,45 11,0

Bc mu 3,76 83,5 1,05 46,0

t xm 1,17 47,0 1,20 41,0

t vng trn Granit 0,39 7,0

Ngun: Nguyn Vn B, 2003; Trung Bnh, 1995 (dn theo N.V.B, 2003)

Vi t ph sa, giu kali, gi tr hiu lc tng h N-K v

NP-NPK ch t khong 0,3-0,5 tn thc/ha hay 0,5-1,0 tn ng/ha;

song trn t ct bin, t bc mu, gi tr tng h c th t tng

ng 1,0-1,5 tn thc/ha v 3-4 tn ng ht/ha (Bng 8). Vi cc loi

t ny, hiu lc phn m c th tng ln gp 2 ln khi c bn kali.

Thm na, ma v, nht l ti BSH khi c s khc bit ln v iu

kin kh hu, thi tit th cng cn quan tm n liu lng, thi k

v phng php bn phn m nng cao hiu qu (Bng 9).

23

Chnh nhng hn ch trong qun l phn bn ni chung v phn m

ni ring m h s s dng phn m trung bnh mi ch t 40-45%.

Bng 9. nh hng ca kali n hiu lc phn m vi la trn t

bc mu

V Hiu lc, kg thc/kg N

Khng bn kali C bn kali

V xun 8,1 13,2

V ma 2,1 4,7

Ngun: Nguyn Vn B, 2003

Bng 10. Bn phn cn i v nng sut ng ti M

Nm Nng sut, tn/ha

NPK (168-74-139) N (168) Gim nng sut, tn/ha

1974 9,48 9,16 0,32

1975 9,35 8,72 0,63

1976 9,98 7,28 2,70

1977 9,60 5,02 4,58

1978 8,41 6,53 1,88

1979 9,98 2,32 7,66

1980 7,66 0,82 6,84

1981 11,93 3,26 8,67

1982 11,42 1,44 9,98

1983 7,85 1,32 6,53

1984 11,55 2,01 9,54

Tng sn lng mt trong 11 nm, tn/ha 59,33

Ngun: Tp ch NC Phn bn s 26/1990, dn theo Nguyn Vn B, 2003

Mi quan h tng h v i khng cn th hin cc liu

lng khi p dng. Vi liu lng thp v ti u, cc mi quan h

gia N-P-K l tng h, song khi vt qu t l thch hp, chng

tr nn i khng. y cng chnh l c s khoa hc bn kali

nhm hn ch lp hoc tng kh nng chu lnh khi bn qu d

tha m. Trong mi quan h ny, kali lm tng h s s dng

m ca cy la. Khng bn kali h s s dng m ch t 15-

30%, trong khi c bn kali h s ny tng ln n 39-49%. Nh vy,

trong nhiu trng hp, nng sut tng khng hn l do bn kali m

l kali c tc dng tng h, lm cy ht c nhiu m v cc

24

cht dinh dng khc hn t t v phn bn. Ngc li, thiu m

trong thi gian di, lm cho nng sut cy trng gim i r rt

(Bng 10).

Cn i m-kali cho la cng rt cn xem xt n nh

hng ca yu t ma v. Nhng nghin cu gn y cho thy

trong v ma, h thu khi nhit khng kh cao hn, cht lng

nh sng tt hn, cy trng c kh nng huy ng ngun kali t t

nhiu hn nn hiu lc phn kali thp hn. Ngc li trong v

ng Xun (nht l min Bc), nhit thp, thi tit thng m u

nn hiu lc phn kali cao hn. y chnh l cc l do cn bn kali

nhiu hn trong v ng Xun.

Mt vn cn cn nghin cu tip l vai tr ca kali trn

t ph sa thuc h thng sng Hng v sng Cu Long. Nhiu

nghin cu gn y cho thy hiu lc kali rt thp. Hiu lc kali ch

c th thy r trong cc th nghim di hn, nht l vi cc c cu

cy trng c tng sn lng cao, nhiu v trng trong nm. Do vy,

vic s dng mt lng kali ti thiu m bo cn bng dinh

dng trong t, nht l nhng ni khng c hoc qu thiu phn

hu c, hoc bn cch v l rt cn thit.

Bng 11. nh hng ca bn phn cn i n mc nhim bnh

trn la ti H Ni (H Ty c)

a im

Kh vn Bc l

T l bnh, % Ch s bnh T l bnh, % Ch s bnh

NP NPK NP NPK NP NPK NP NPK

H.Quc Oai 21,0 14,1 5,3 3,3 22,0 11,0 8,2 4,7

H.Thanh Oai 11,2 10,0 2,7 2,2 32,0 16,0 11,0 6,5

TX.H ng 18,0 12,1 5,2 2,8 28,0 11,0 8,4 4,5

Ngun: Nguyn Tin Huy, 1995

Bn phn cn i m-kali v v c hu c ngoi tc dng

tng nng sut cn c ngha rt ln trong vic tng kh nng

chng chu su bnh ca cy trng. Thng thng, do s dng m

qu tha hoc qu mun lm cho qu trnh chn chm li, lm

mng cc v t bo v do cy trng d b cc su bnh thm

nhp v ph hoi. Nh kh nng i khng trong quan h m-kali

m chng ta hon ton c th dng phn kali thc y qu trnh

25

hnh thnh lignin, cc b mch, lm thnh t bo dy ln nn kh

nng chng bnh cng tng ln (Bng 11). Phn chung c kh

nng iu tit qu trnh gii phng m v cung cp mt lng kali

nht nh nn cng tng kh nng chng chu su bnh ca cy la.

Cc kt qu nghin cu chng minh kh nng ny (Bng 12).

Bng 12. Cn i hu c-v c v bnh o n trn la

Cng thc bn Cp bnh giai on lm

ng (thang 9 cp)

T l nhim bnh

o n c bng

Khng bn phn 2 45,5

Bn phn chung 2 57,1

Bn ur 4 79,0

Bn ur+phn chung 3 69,8

Ngun: Nguyn Hu Thy, 1980

Vic bn phn khng cn i, thiu khoa hc lm cho su

bnh pht trin nhiu hn, tn sut cao hn v mc nghim

trng hn. Cc dch ln nh vng ln, ln xon l trn la ti

BSCL hay la ln sc en ti BSH, bnh chi rng trn nhn,

sn... l nhng v d c mt phn nguyn nhn t bn phn cha

hp l. Theo Nguyn Hng Sn, nm 2000 Vit Nam mi s dng

33.637 tn thuc BVTV nhng nm 2005 s dng 51.764 tn,

nm 2008 s dng 105.900 tn8.

Hin ti, khi cc nguyn t a lng ti nhiu vng c

p ng tng i y th nhu cu v cc nguyn t trung lng

v vi lng bt u tng ln. Nguyn nhn c nhiu song phn

ln do s dng cc loi phn khng c hoc cha qu t cc nguyn

t trung v vi lng... Vic s dng lin tc ur, DAP, phn ln nung

chy chc chn s dn n thiu lu hunh, hay s dng DAP v

supe ln cng s dn n thiu Mg... Nhiu th nghim cho bit, bn

kt hp ur v SA lm tng nng sut c ph 16%, cn bn Supe-

Tecmo (phi hp SSP-FMP) lm tng nng sut la 5,8% so vi bn

SSP v 9,2% so vi bn FMP ring r (Nguyn Vn B, 2001 v

1997). Do vy, trong cn i dinh dng, vic lun lun b sung cc

loi phn c cha nhiu thnh phn dinh dng bao gi cng cho

hiu qu cao nht. Vic hnh thnh cc loi phn bn chuyn dng

8 Bo Nng nghip Vit Nam,18/1/2013

26

NPK, phn chc nng hay Super-Tecmo cng gip gii quyt s mt

cn i dinh dng. Cc nguyn t vi lng c th c b sung

bng cc loi phn phun qua l.

Chnh nh chng trnh nghin cu nhiu nm ca cc nh

khoa hc trong v ngoi nc m s dng phn bn cho cy trng

c s ci thin ng k, cn i cho tng cy trng, trn tng loi

t u c cp v a ra cc khuyn co. Cc t l ngy

cng cn i hn gia NPK cho chng ta thy thnh qu lu di y

(Bng 13, 14). Vic cn i trong cung cp dinh dng, ngoi tng

nng sut cy trng cn gip n nh ph nhiu t, lm hm

lng mn tng ln c ngha (Bng 15, ph lc 5).

Bng 13. Thay i t l bn N : P2O5 : K2O theo thi gian

Ch tiu 1990 2000 2012

N + P2O5 + K2O, kg/ha 57,8 117,8 190,0

N : P2O5 : K2O 1 : 0,12 : 0,05 1 : 0,44 : 0,37 1 : 0,51 : 0,39

Ngun: Nguyn Vn B, 2001 v tng hp t cc ngun

Bng 14. Thay i t l bn N : P2O5 : K2O cho la ti min Bc

Vit Nam

Loi t Nm iu tra N : P2O5 : K2O

Ph sa 1992 1 : 0,35 : 0,03

1998 1 : 0,50 : 0,43

Bc mu 1992 1 : 0,53 : 0,19

1998 1 : 0,38 : 0,72

Ct bin 1992 1 : 0,49 : 0,18

1998 1 : 0,45 : 0,53

Ngun: Nguyn Vn B, 1998

Bng 15. nh hng ca bn phn n hm lng mn trong t trng

la ti Aizu, Fukushima, Nht Bn. TB 4 th nghim trong 50 nm

Cng thc phn bn Hm lng mn, theo gi tr tng i

Chay 100%

NPK 110%

Phn chung 130%

Phn chung + NPK 140%

Ngun: Ilka Kimo, 1995

27

III. GII PHP NNG CAO HIU QU S DNG PHN BN

TI VIT NAM

3.1. Pht trin cng ngh mi

C th ni, nn nng nghip thm canh da vo phn bn

ca nc nh tri qua trn 30 nm. Rt nhiu thnh tu nghin

cu c chuyn ha thnh tin b k thut v ng dng hiu

qu trong sn xut. Chnh nhng thnh tu trong nghin cu

gip nng dn thm canh hiu qu hn v gp phn lm tng lng

phn bn s dng trong 30 nm qua gn 10 ln, tc thuc loi

cao nht th gii.

Va nghin cu trong nc, va tip nhn thnh tu ca

nc ngoi, cc chng trnh nh qun l dinh dng tng hp

(Integrated Nutrient Management), h thng dinh dng cy trng

tng hp (Integrated Plant Nutrient System-IPNS), h thng qun

l dinh dng cy trng tng hp (Integrated Plant Nutrient

Management -IPNM), Bn phn cn i (Balanced Fertilization for

Better Crop-BALCROP) v gn y nht l bn phn theo vng

chuyn bit (Site-Specific Nutrient Management -SSNM) thc

s thay i hin trng nghin cu v s dng phn bn Vit Nam.

Nh cc kt qu nghin cu ny m cc loi phn bn hn hp, hu

c khong, hu c vi sinh, phn bn chc nng, phn phun l...

c sn xut v nhp khu lm cho th trng phn bn tht s a

dng v si ng. Bn thn mi loi phn bn cng c thay i

theo nhu cu ca sn xut cn c vo kt qu nghin cu, l ur

vin to (2-3 g/vin) dng cho bn di gc (hin nay, tng bn

di gc ca IRRI nhng nm 70 ca th k trc vi ur vin to

(Urea Super Granule) v ur bc lu hunh (Sulphur Coated Urea),

ang c pht trin thnh chng trnh phn vin di bao gm c

m, ln v kali vi hng vn nng dn ang p dng, nht l ti

cc tnh min ni), ur bc PE... v gn y l s dng Agrotain,

NEB-26 sn xut m ht vng, ht xanh, hn ch qu trnh gii

phng m. Vi ln, ch phm Avail ang ha hn mang li nhng

t ph mi v sn xut phn ln cht lng v hiu qu cao. Nu

nh tt c cc loi phn bn ca Vit Nam u c ng dng cng

ngh Agrotain, NEB, Avail... th chc chn v kinh t chng ta c

th tit kim thm hng triu tn phn bn/nm, cha tnh n cht

lng sn phm c ci thin v mi trng c bo v. Cc kt

28

qu nghin cu v phn bn nu c ng dng rng ri hn trong

cc chng trnh 3 gim-3 tng; 1 phi-5 gim; ICM, SRI...

chc chn s cn mang li hiu qu cao hn.

Hin nay, do phn bn v c mang li hiu qu cao v tc

th nn vic lm dng loi phn ny rt ph bin. Khi gi nng sn

ln, nng dn sn sng bn vi liu lng cao hn gp nhiu ln

nhu cu ca cy trng m c ph l v d in hnh. Theo Trng

Hng (2012), s liu iu tra 2011 cho thy, lng m bn cho c

ph vi trung bnh 518 kg N/ha, cho c ph ch 639 kg N/ha. Trong

, t l h bn m cao t 501-1.000 kg N/ha cho c ph vi

chim 36,3% v cho c ph ch chim 54%. y l nhng con s

cao khng khip, vt 2-4 ln mc khuyn co.

Vi ln, lng bn cho c ph vi trung bnh 269 kg

P2O5/ha; cho c ph ch l 489 kg P2O5/ha v c ti 82% s h bn

cho c ph vi hn so vi khuyn co, trong khi con s ny vi c

ph ch l 88,6%.

Lng kali bn cho c ph vi a phn vt mc khuyn

co v trung bnh t 425 kg K2O/ha. C ti 40% s h bn tha

kali cho c ph ch (401-800 kg K2O/ha) v 39,4 % s h bn tha

kali cho c ph vi.

Vi la, cng tng c nhng m hnh trnh din t 14

tn/ha/v ti BSH vi mc bn khng tng theo qui trnh ca

Cng ty Ging cy trng Khoa Nng, T Xuyn, Trung Quc. M

hnh c thc hin trn t ph sa sng Hng ti HTX nng nghip

Xun Kin, Xun Trng, Nam nh trong V Xun 2005. Ging

th nghim l ging la lai My Sn 2 v My Sn 4. M hnh qui m

0,5 ha do chuyn gia Trung Quc thc hin v m hnh 50 ha do

chuyn gia Vit Nam thc hin (c iu chnh qui trnh ca bn cho

ph hp hn).

iu c bit theo qui trnh ca Trung Quc v phn bn l

s dng ti 60 tn phn chung/ha. Mc bn m khng cao hn so

khuyn co song mc bn ln cao gp 1,5 ln (124 kg P205/ha) v

kali cao gp 4-5 ln (329 kg K20/ha), t l N: P205: K20 l 1 : 0,44 :

1,17 (kali cao hn m), trong khi t l ny theo khuyn co ch l

1 : 0,5 : 0,3. c bit hn na, phn m bn ti 7 ln (khuyn co

3 ln), trong 6 ln bn thc v 1 ln thc nui ht, khng bn

29

lt. Vi bn thc , ch bn khi nhit trn 150C v c chiu

hng n nh trong vi ngy ti. Mi 1 l bn thc 1 ln, bn nh

khi la 3-4 l v 6-7 l, bn nng khi la 5-6 l. Hon thnh bn

m thc khi la 7 l. Kt qu m hnh ca chuyn gia Trung

Quc t 13 tn/ha v ca chuyn gia Vit Nam t 9,6 tn/ha (S

NN-PTNT Nam nh, 2006).

Vic lm dng phn khong cng vi vic thay i m hnh chn nui, thiu ht lao ng, p lc v ma v... m phn hu c ngy cng t c s dng. Vi n gia sc ln nh hin nay (nm 2012 c 26,5 triu con ln; 308,5 triu con gia cm; 2,63 triu con tru; 5,03 triu con b tht v 167 ngn con b sa) th hng nm chng ta c th cung cp cho sn xut khong 120-150 triu tn phn chung, song thc t, con s ny khng t 30%, do hnh thc chn nui cng nghip, khng s dng cht n chung... Chnh y cng l mt trong cc nguyn nhn m chng ta ang lng ph thm 45-50 triu tn rm r khng c ti s dng m phn ln b t lng ph. Vi s lng rm r ny nu c ti s dng th ngoi cht hu c to nn thm canh, cc cht dinh dng trung v vi lng khc cho cy trng cn c th c cung cp 315-350 ngn tn N, 100-115 ngn tn P205 v 780-870 ngn tn K20/nm. l cha k khi hn ch t rm r, chng ta cn gp phn gim thiu pht thi CO2.

3.2. Nng cao nng lc qun l Nh nc

Phn bn ngy cng ng gp vai tr quan trng trong nng

cao nng sut v gi tr nng sn, l vt t khng th thiu ca mi

ngi dn. Do vy, sn xut phn bn tr thnh lnh vc hp dn

cho cc doanh nhn. Theo thng k cha y , c nc hin c

khong 500 c s sn xut ra trn 2.000 loi phn bn khc nhau;

trong khong 1.700 loi phn hn hp NPK, phn hu c khong

v hu c sinh hc.

Loi tr cc loi phn bn ho hc n hoc phc hp (ur,

SA, DAP, KCl, SSP, FMP), hoc phn hn hp NPK nhp khu

hoc do cc doanh nghip cng nghip trong nc sn xut m

bo ng cht lng, a phn cc loi khc u c cht lng

khng n nh. Theo iu tra ca Cc Trng trt, s lng phn

bn khng t cht lng rt ln, ln ti 54% vi phn NPK v trn

30

70% phn hu c sinh hc. Vy lm th no qun l loi sn

phm ny mt cch hiu qu.

Trc ht, phi coi sn xut phn bn l lnh vc sn xut

kinh doanh c iu kin. Ngh nh s 113/2003/ N-CP, Ngh

nh s 59/2006/N-CP v Ngh nh s 191/2007/N-CP v cc

vn bn hng dn thi hnh u a phn bn vo danh mc

kinh doanh c iu kin nhng li khng phi cp giy chng nhn

iu kin kinh doanh, do vy hin khng c c quan no thm

nh iu kin sn xut ti c s sn xut phn bn v vic chp

hnh iu kin sn xut ti c s sn xut l ty vo s t gic ca

DN. Do vy, cng ngh qu th s, nguyn liu khng n nh,

cng thc thiu c s khoa hc, sao chp... lm cho th trng

hn lon. Cc loi phn bn km cht lng, phn gi, nhi khng

c qun l bi bn. S trng cho, khng r rng trong qun l

gia B Cng thng v B Nng nghip v PTNT cng l mt nguyn nhn lm cho tnh trng ln xn ny thm trm trng. Vic

ch giao B Nng nghip v PTNT qun l phn hu c v hng dn s dng l khng hp l v khng qun l c t gc, xut x

ca sn phm.

Th hai, cn thay i phng thc qun l phn bn, chuyn

t qun l theo Danh mc sang qun l theo qui chun, tiu chun.

Bi b qui nh v kho nghim, tr phn bn l v cht ci to t,

bi gn nh 100% cc loi phn bn kho nghim u c cng

nhn, mt th tc khng tng thm cht lng phn bn cng nh

hiu qu qun l. c th qun l c, Nh nc ch cn thc

hin 3 cng vic sau: i) Doanh nghip (c sn xut v xut nhp

khu) bo co danh mc sn phm v tiu chun cht lng km

theo, sn lng tng loi v lng tiu th hng nm; Doanh

nghip khng bo co v thc trng sn xut kinh doanh s b rt

giy php; ii) Thng xuyn kim tra iu kin sn xut v lu gi

phn bn; iii) Thng xuyn kim tra cht lng sn phm v i

khi c nguyn liu. Nhng sn phm t cht lng c Nh nc

chi tr tin phn tch, cn nhng sn phm khng t cht lng th

doanh nghip ngoi vic phi chi tr 100% chi ph kim tra, phn

tch, chu pht theo qui nh m cn b nu tn cng sn phm ca

mnh trn phng tin thng tin bo ch. Bc u, Nh nc thnh

lp qu qun l cht lng, cc khon thu do x pht s c b

31

sung cho qu hng nm. Ngn sch ca Qu c dng chi ph

kim tra, phn tch, tng cng nng lc phng kim nghim cht

lng phn bn, xy dng tiu chun, qui chun, phng php th,

o to nghip v v cng tc kim tra, ly mu, phn tch, t chc

hi ngh, hi tho v qun l phn bn. Vic x hi ha cng tc

phn tch cht lng cng cn c m rng.

Th ba, cn hon thin, thng nht v cp nht thng k v

sn xut, xut nhp khu v s dng phn bn c th cn i

cung cu v iu tit th trng hiu qu. Hin nay, vic cha tnh

ht lng ur, DAP, SA, kali v c phn ln ch bin c s dng

cho sn xut phn NPK, nn vic cn i cung cu cha chnh xc.

Th t, qui hoch hp l h thng sn xut v cung ng phn

bn (c nhp khu), trnh tnh trng cng mt loi phn bn song li

vn chuyn ngc chiu nhau lm tng chi ph, gim chi ph lu kho,

hn ch tn ng. Khp kn h thng t sn xut n i l, ca hng

ca mi doanh nghip qun l cht lng, chng hng gi.

Th nm, cho php doanh nghip sn xut phn bn nhp

khu nguyn liu v nhin liu cng nh cc loi phn m ta khng

sn xut c (kali, SA) vi mc thu 0% m bo h gi thnh

sn xut v bo v ngun ti nguyn (vn gn cn kit nh vi

apatit, than). Trong kh , khuyn khch doanh nghip xut khu

ur, ng thi vi phn ln ch bin nn p thu 100% ( khuyn

khch nhp khu v hn ch khai thc ti nguyn).

3.3. Nng cao nng lc nghin cu v khuyn nng phn bn

Hin nay, mi nm chng ta s dng trn 10 triu tn phn

bn cc loi. Phn bn mang li t nht 30-35% gi tr sn lng

ca nng nghip. Ch tnh ring phn bn nhp khu, nm 2012

tiu tn ca ngn sch gn 2 t USD. Nu tnh c lng phn bn

sn xut trong nc th chng ta tiu th lng phn bn c ga tr

tng ng khong 4 t USD. Vi ng gp v gi tr cao nh vy,

nhng chng ta cha quan tm ng mc n nghin cu ch

to ra cc loi phn bn mi cng nh k thut s dng hiu qu.

Nhn vo danh mc ti liu khoa hc cng b lin quan n phn

bn, hoc l qu c, hu ht cch y hng chc nm, hoc

thng qua h tr quc t. Mi nm 2006-2016, B Nng nghip

v PTNT ch u t cho nghin cu 3 ti c lin quan n phn

32

bn, ch thc t khng c ti no trc tip v phn bn ha hc.

Trong 3 ti th c 2 ti v x l ph ph phm, 1 ti v

phn vi sinh vt chc nng vi tng kinh ph l 4,4 t ng, bng

0,11% tng kinh ph nghin cu ca cc ti cp B thuc lnh

vc Trng trt v Bo v thc vt. ng bun hn na, c 3 ti

ny cng kt thc t 2008 v 2011, ngha l hin nay cho ti

2016, khng c ti nghin cu cp B no v phn bn. Trong

khi , chng ta u t cho 85 ti chn to ging vi 64% kinh

ph v 21 ti v bo v thc vt vi 10% kinh ph ca lnh vc

(Bng 16). ti cp Nh nc v phn bn gn y nht c

thc hin l ti Nghin cu phn vng a l sinh thi hiu lc

phn bn Vit Nam, do GS. V Tng Xun ch tr, giai on

1996-2000. Rt may, B Khoa hc v Cng ngh, nhn thy s bt

cp ny nn u t cho 1 ti cp Nh nc giai on 2011-

2015 Nghin cu hiu lc trc tip v tn d ca phn v c a

lng i vi la, ng, c ph lm c s cn i cung cu phn bn

Vit Nam, do Vin Khoa hc K thut Nng nghip min Nam

ch tr.

Bng 16. ti cp B Nng nghip v PTNT thuc lnh vc trng

trt v bo v thc vt kt thc v ang thc hin giai on 2006-

2016

Stt Lnh vc S ti Kinh ph, t ng T l (%)

1 Chn to ging 85 256,15 64,0

2 Bo v thc vt 21 40,66 10,0

3 Phn bn 3* 4,40 0,11

4 Khc 49 98,42 24,89

Cng 157 399,43 100,0

Ngun: Tng hp t Danh mc ti ca B Nng nghip v PTNT.

* C th xem ph lc 6

Nhng thnh tu nghin cu c p dng hiu qu v tr

thnh tin b k thut li hu ht nh s tr gip ca Quc t vi

s cng tc ca cc nh khoa hc Vit Nam. l: Qun l dinh

dng tng hp vi s tr gip ca FAO, Bn phn cn i v

nghin cu yu t hn ch dinh dng vi s tr gip ca IPI/PPI

(IPNI)/PPIC/IFA, TSI, IMPOS...; RTOP, SSNM, gi k thut 3

Gim-3 Tng vi s tr gip ca IRRI, Phn bn di vi s tr

33

gip ca T chc phi chnh ph ca Chnh ph Ty Ban Nha

Codespa v T chc T vn Pht trin Quc t IDE v gn y vic

a Agrotain, Avail nh s h tr ca Cng ty TNHH Hu C,

Cng ty C phn phn bn Bnh in v NEB-26 vi s tr gip

ca cng ty CPTM Ph Bc.

Vic chuyn giao tin b k thut v phn bn qua h thng

khuyn nng Nh nc cng gn nh khng c ngoi mt vi Din

n Khuyn nng @ Cng ngh. Gn nh ton b vic khuyn co

s dng phn bn khon trng cho doanh nghip. Do vy vic Con

ht, M khen hay l kh trnh khi. Tng hp K hoch 2011-

2013, B Nng nghip v PTNT thc hin 29 D n khuyn nng

thuc lnh vc Trng trt v Bo v thc vt vi kinh ph l 153,34

t ng, cng khng c d n khuyn nng no v phn bn!

IV. THAY CHO LI KT

Hin nay, rt nhiu vn lin quan n phn bn c t

ra cn phi nghin cu, t chnh sch v m, h thng qun l quc

gia, ngnh; vn cht lng, hiu qu s dng. Chng ta cng cn

tng cng u t cho nghin cu cng ngh hoc nhp khu cng

ngh mi trong cng nghip phn bn (nh Doanh nghip ang lm

vi Agrotain, NEB-36, Avail...), cng nh nghin cu nng cao

hm lng cht dinh dng trong phn bn, sn xut phn bn

chc nng, chuyn dng; nghin cu gii php nng cao hiu qu

s dng, ci thin cht lng nng sn, bo v t v gim pht thi

kh nh knh, gim ph dng ngun nc mt v nc ngm...

Khong trng mnh mng v nghin cu s dng phn bn cha

c quan tm ng mc. Trn 10 triu tn phn bn s dng 1

nm, gi tr tng ng 26% kim ngch xut khu ca ngnh

trng trt (nm 2012 gi tr xut khu nng sn t xp x 15 t

USD), mt ngnh m gn nh tiu th 100% phn bn cc loi.

l cha k, hiu sut s dng phn bn cha cao, mi t 40-45%

vi m v chung cho cc loi phn bn (k c hiu lc tn d)

cng khng vt qu 50%. Mt lng dinh dng tht thot qu

ln. S mt mt ny khng ch v kinh t m cn nh hng n

mi trng, tng pht thi kh nh knh (lu NXO c ch s GWP

cao gp 310 ln CO2) v gy ra ph dng ngun nc, tc nhn

gy ung th cho con ngi cng nh tc ng tiu cc n ngnh

34

thy sn. Hnh nh mi ngi cho rng, phn bn v bn phn c

g phi nghin cu, chuyn c nh tri t, nng dn ta lm c i

ri? Khng c quan tm t cp v m n c s nn ti B Nng

nghip v PTNT ch c khong 1,5 ngi cho qun l s dng ca khong 10 triu tn phn bn, tr gi gn 4 t USD. Lu , ngnh

Bo v thc vt, qun l c trn 100 ngn tn thuc, tr gi 700

triu USD (2012), song li c hn mt cc chuyn ngnh vi h

thng khp kn t Trung ng n c s vi hng ngn ngi. Tt

nhin mi so snh u khp khing, song cng l vn m chng

ta phi suy ngh. Cn ti n v c giao chuyn nghin cu s

dng phn bn (Trung tm Nghin cu Phn bn v Dinh dng

cy trng, Vin Th nhng Nng ha) cng ch c cha y 10

cn b i hc v 2 tin s. Ti c s o to Nng nghip ln nh

i hc Nng nghip H Ni cng ch c 2 gio vin dy v Nng

ha.

Khng c u t nghin cu n ni, khi c Hi ngh

quc gia, tm chuyn gia vit bi v phn bn v bn phn tht kh

khn. Nhiu Vin nghin cu ln v cy trng m khng vit ni

mt bo co v bn phn cho cy trng m mnh ph trch. Cn

nu c, hu ht cc bo co u s dng s liu c hng chc, thm

ch vi chc nm. Khng c u t, cc nh khoa hc v nng

ha ch i lm mt vic c ch song li rt ng bun, ch l

Kho nghim phn bn cho cc doanh nghip. Vy ai s gii

quyt s bt cp ny v gii quyt ra sao?

35

PHN PH LC

Ph lc 1. S dng phn bn ti mt s nc, 2007

Quc gia Dinh

dng

Tng La Ng Rau qu Cy khc (cng

nghip)

1000t % TG A B A B A B A B

Vit Nam

N 1.432 1.5 969 67.7 175 12.2 18 1.3 189 13.2

P2O5 634 1.6 460 72.5 46 7.3 13 2.1 71 11.2

K2O 538 2.0 354 65.9 36 6.6 9 1.7 83 15.4

Cng 2.604 1.6 1.783 68.5 256 9.8 41 1.6 343 13.2

Trung

Quc

N 31.000 31.7 5.673 18.3 5.053 16.3 9.787 31.6 2.018 6.5

P2O5 11.700 30.1 1.860 15.9 807 6.9 4.012 34.3 1.205 10.3

K2O 6.100 22.5 1.623 26.6 116 1.9 2.928 48.0 665 10.9

Cng 48.800 29.8 9.156 18.8 5.976 12.2 16.727 34.3 3.888 8.0

n

N 14.048 14.4 4.664 33.2 351 2.5 562 4.0 2.179 15.5

P2O5 5.663 14.6 1.495 26.4 136 2.4 481 8.5 989 17.5

K2O 2.334 8.6 864 37.0 37 1.6 381 16.3 236 10.1

Cng 22.045 13.5 7.023 31.9 524 2.4 1.424 6.5 3.045 15.4

M

N 11.794 12.0 224 1.9 5.307 45.0 495 4.2 2.713 23.0

P2O5 4.355 11.2 26 0.6 1.916 44.0 244 5.6 636 14.6

K2O 4.672 17.2 28 0.6 2.196 47.0 243 5.2 766 16.4

Cng 20.821 12.7 278 1.3 9.419 45.2 982 4.7 4.115 19.8

EU-15

N 8.459 8.6 42 0.5 893 10.6 720 8.5 2.268 26.8

P2O5 2.530 6.5 13 0.5 304 12.0 442 17.5 573 22.7

K2O 2.871 10.6 29 1.0 269 9.4 528 18.4 896 31.2

Cng 13.860 8.5 84 0.6 1.466 10.6 1.690 12.2 3.737 27.0

Indonesia

N 2.500 2.6 1.125 45.0 375 15.0 Na Na 589 23.6

P2O5 470 1.2 103 22.0 71 15.0 Na Na 126 26.9

K2O 590 2.2 83 14.0 59 10.0 Na Na 91 15.4

Cng 3.560 2.2 1.311 36.8 505 14.2 Na Na 806 22.6

Thi Lan

N 992 1.0 299 30.1 60 6.0 275 27.7 277 28.0

P2O5 345 0.9 82 23.7 24 7.0 110 32.0 60 17.5

K2O 353 1.3 4 1.0 35 10.0 130 36.7 112 31.8

Cng 1.690 1.0 384 22.7 119 7.0 515 30.5 450 26.6

Philippines

N 534 0.5 197 37.0 107 20.0 43 8.0 159 29.7

P2O5 109 0.3 19 17.0 12 11.0 26 24.0 34 31.5

K2O 115 0.4 10 9.0 8 7.0 58 50.0 20 17.0

Cng 758 0.5 226 29.9 127 16.7 127 16.7 213 28.0

ROW (Rest

of the

World)

N 15.510 15.8 853 5.5 1.861 12.0 1.551 10.0 2.482 16.0

P2O5 6.376 16.4 351 5.5 797 12.5 638 10.0 925 14.5

K2O 3.995 14.7 220 5.5 439 11.0 479 12.0 599 15.0

Cng 25.882 15.8 1.424 5.5 3.098 12.0 2.669 10.3 4.006 15.5

Ton cu

N 97.892 100.0 15.790 16.1 15.42 15.8 14.050 14.4 14.724 15.0

P2O5 38.856 100.0 5.025 12.9 4.898 12.6 6.332 16.3 5.676 14.6

K2O 27.148 100.0 3.492 12.9 3.814 14.1 5.137 18.9 4.155 15.3

Cng 163.895 100.0 24.308 14.8 24.132 14.7 25.518 15.6 24.555 15.0

Ngun: Patrick Heffer, 2008

A: 1.000 tn; B: % so tng (Vi tng nc, so tng lng phn bn tiu

th ca nc )

36

Ph lc 2. Tiu th phn bn Vit Nam v th gii t canh tc: 1.000 ha. Tiu th phn bn: 1.000 tn N, P2O5, K2O.

S dng: kg N+P2O5+K2O/ha canh tc/nm

Ch s 1961 1970 1980 1990 2000 2007*

2007 so

1961,

ln

Th

gii

t CT 1.281.338 1.329.244 1.352.386 1.404.176 1.397.959 1.411.117 1,10

Tiu th PB 31.182 69.308 116.720 137.829 135.198 161.358 5,17

S dng PB 24,3 52,1 86,3 98,2 96,7 114,3 4,70

Chu

t CT 410.424 418.670 422.615 458.688 497.482 504.537 1,23

Tiu th PB 3.809 11.823 30.948 56.004 72.291 92.325 24,2

S dng PB 9,3 28,2 73,2 122,1 145,3 183,0 19,7

Trung

Quc

t CT 103.397 100.072 96.964 123.726 133.191 140.630 1,36

Tiu th PB 728 4.407 15.335 27.274 34.218 48.866 67,1

S dng PB 7,0 44,0 158,2 220,4 256,9 366,9 52,4

Nht

Bn

t CT 5.660 5.196 4.874 4.768 4.474 4.326 0,76

Tiu th PB 1.584 1.955 1.816 1.838 1.452 1.177 0,74

S dng PB 279,8 376,3 372,6 385,5 324,5 272,1 97,2

Hn

Quc

t CT 2.033 2.150 2.285 2.288 2.600 2.800 1,38

Tiu th PB 316 563 803 958 783 722 2,28

S dng PB 155,4 261,9 351,4 418,7 301,1 257,9 1,66

Thi

Lan

t CT 10.400 12.300 16.515 17.494 15.654 15.210 1,46

Tiu th PB 18 81 275 1.044 1.561 1.724 95,8

S dng PB 1,7 6,6 16,7 59,7 99,7 133,4 78,5

Vit

Nam

t CT 5.550 5.630 5.940 5.339 6.200 6.350 1,14

Tiu th PB 89 311 155 560 2.267 1.955 22,0

S dng PB 16,0 55,2 26,1 104,9 365,6 307,9 19,2

VN so TG v s

dng phn bn, %

65,8 105,8 30,1 106,8 378.1 318,4 -

* Vi t canh tc, s liu ca 2007 v tiu th phn bn ca 2005.

Ngun: i) t canh tc: FAOSTAT, 2002 and FAOSTAT, 2009 of FAO

ii) Tiu th phn bn: FAOSTAT Database, online. (1961-2001

data: FAO update 06 Sept 2006/ 30 Aug 2007). Patrick Heffer, 2008

37

Ph lc 3. Nng sut la ca Vit Nam v th gii (Tn/ha)

Nm Th gii Chu Vit Nam

Tn/ha % so TG

1990 3,53 3,61 3,18 90,1

1995 3,66 3,73 3,69 100,8

2000 3,88 3,95 4,24 109,3

2005 4,08 4,17 4,88 119,6

2006 4,12 4,19 4,89 118,6

2010 4,37 4,45 5,32 121,7

Tng, 2010 vs 1990% 23,8 23,3 67,3

Ngun: http://www.irri.org/statistics

Ph lc 4. Dn s Vit Nam 2021-2011

Nm Dn s,

1000

ngi

Tng so vi k

trc, TB ngn

ngi/nm

t canh tc/ngi

m2/ngi % so

1960

1921 15.584 -

1930 17.582 222,0

1960 30.172 419,6 1.839 -

1965 33.295 624,6

1970 37.891 919,2 1.485 80,7

1980 53.722 1.583,0 1.106 60,1

1985 59.872 1.230,0

1990 66.016 1.228,8 808 43,9

1995 71.995 1.195,8

2000 77.635 1.128,0 799 43,4

2005 83.120 1.097,0

2010 86.928 761,6 730 39,7

2011 87,840 912,0

-

-

2011 so 1921, % 563,7

Ngun: S liu thng k Vit Nam th k 20, cun 1, 2. NXB Thng k,

nm 2004 v Nin gim thng k hng nm. FAOSTAT, 2002 and

FAOSTAT, 2009

http://www.irri.org/statistics

38

Ph lc 5. nh hng ca cn i v c v v c-hu c n

nng sut la ti Aizu, Fukushima, Nht Bn

Cng thc 1920-1921 1951-1955 1971-1975 1986-1988

NPK 4,35 6,66 7,68 7,74

PK 2,61 3,17 4,71 4,68

NK 4,15 5,42 5,07 6,15

NP 4,03 5,10 6,52 5,39

Chay 2,23 2,49 3,79 3,85

NPK+Phn

chung

8,64 8,81

NPK+Rm r 7,70 8,44

Ngun: Ilka Kimo, 1995

Ph lc 6. Danh mc ti cp B lin quan n phn bn

giai on 2006-2015

Tn ti Thc

hin

Kinh ph,

tr. ng Ch tr

1. Nghin cu s dng ph ph

phm nng nghip nng cao

nng sut, cht lng, nng sn

v ci thin ph nhiu ca t.

2006-

2008 1.200

TS. Trn Th

Tm, Vin

TNNH.

2. Nghin cu phn bn chc

nng, chuyn dng cho cy trng

v phng php s dng thch

hp

2006-

2008 1.200

TS. Bi Huy

Hin, Vin

TNNH

3. Nghin cu xy dng quy trnh

x l rm r trn ng rung lm

phn bn hu c BSCL v

BSH.

2009-

2011 2.000

TS. Trn Th

Ngc Sn,

Vin La

BSCL

TI LIU THAM KHO

Ting Vit

1. B Nng nghip v PTNT, 2012. Bo co tng kt thc hin k hoch nm 2011 v trin khai k hoch 2012.

2. B Nng nghip v PTNT, 2013. Bo co tng kt thc hin k hoch nm 2012 v trin khai k hoch 2013.

39

3. Nin gim thng k nm 2005, 2010 v 2011. NXB Thng k 2006, 2011 v 2012.

4. S liu thng k VN th k 20, Quyn 1, t 1921 n 1975 v Quyn 2, t 1976 n 2000. NXB Thng k, 2004

5. S Nng nghip v PTNT Nam nh. 10/2006. Bo co D n: Xy dng m hnh la cao sn ging My Son 2, My Son 4, D.u

527 bng quy trnh canh tc mi ca cng ty Ging cy trng Khoa

Nng T Xuyn, Trung Quc nhm xc nh tim nng nng sut

v la xun, tng bc hon thin quy trnh k thut thm canh to

bc t ph mi v nng sut, sn lng la Xun.

6. Vin Th nhng Nng ha (1990). Nghin cu c s khoa hc ca cc bin php nng cao ph nhiu thc t mt s loi t ( ti

02A-0601 thuc chng trnh 02A).

7. Vin Th nhng Nng ha, 1995. Yu t dinh dng hn ch nng sut v chin lc qun l dinh dng cy trng. Bo co ti cp

Nh nc KN-01-10. NXB Nng nghip.

8. Vin Th nhng Nng ha, 2005. S tay phn bn. NXB Nng nghip.

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1997.

10. Nguyn Vn B v ctv. Hin trng s dng phn bn ca h nng dn min Bc Vit nam. Bo co Hi tho quc t "Quan im v

qun l dinh dng tng hp cho cy trng min Bc Vit Nam".

H Ni, 26-27/5/1998.

11. Nguyn Vn B, 2003. Bn phn cn i cho cy trng Vit Nam: T l lun n thc tin. NXB Nng nghip.

12. Nguyn Vn B, 2009. Khoa hc cng ngh v sn xut la go Vit Nam gp phn m bo an ninh lng thc quc gia. Bo co

trnh by ti Hi tho: Khoa hc v cng ngh vi pht trin Kinh

t-X hi v hi nhp quc t nhn k nim 50 nm B Khoa hc

v cng ngh. H Ni, ngy 26 thng 12 nm 2009.

13. Trng Hng, 2012. Bo co chuyn : iu tra, nh gi thc trng cung ng, s dng v nguyn nhn gy tht thot phn bn v

c a lng i vi c ph vi v c ph ch thuc ti khoa hc

cp Nh nc Nghin cu hiu lc trc tip v tn d ca phn v

c a lng i vi la, ng, c ph lm c s cn i cung cu phn

bn Vit Nam, thc hin trong giai on 2011-2015.

40

14. Nguyn Hun, 2012. TKV o p doanh nghip sn xut phn bn. Tp ch Ma Vng, s 2, ngy 25/12/2012, trang 14-15.

15. Nguyn Tin Huy, 1995. My nhn xt v dinh dng la lai trong qu trnh m rng sn xut H Ty. Bo co Hi tho: Dinh dng

cho la lai, H Ni, 30/11/1995

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thc vt. NXB Nng nghip, H Ni.

Ting Anh

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Association Paris, France. 2012

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IFPRI, Washington D.C.

21. Nguyen Van Bo, Ernst Mutert, Cong Doan Sat, 2003. Balcrop: Balanced fertilization for better crops in Vietnam. - 1st ed. Oxford

Graphic Printers.

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23. Dongxin FENG, 2012. Agricultural Researh for Development at CAAS. Roundtable Consultation on Agricultural Extension. Beijing,

March 15-17, 2012

24. I. Kimmo, 1992. Balanced fertilization. FADINAP, Bangkok.

25. Patrick Heffer, 2008. IFA, 2008. Assessment of Fertilizer Use by Crop at the Global Level.

26. Nguyen Cong Thanh, Baldeo Singh, 2006. Trend in rice production and export in Vietnam. Omonrice 14, p.111-123. 2006

http://www.fertilizer.org/

41

SUMMARY

IMPROVING FERTILIZER USE EFFICIENCY FOR CROPS

IN VIETNAM

Nguyen Van Bo9

Vietnam is an agricultural-based economy with limited land

resources and a high population. The average cultivated land per capita

in Vietnam is only 0.104 ha, which is only 8.7% of the world average. In

order to feed an increasing population with such low and reducing land

resoures the only solution is to improve crop productivity.

Vietnamese farmers started using inorganic fertilizer very late,

commencing in the 1960s. The adoption of fertilizers turned agriculture

in Vietnam from farming based on extensive management of inherent soil

fertility to one based on intensive use of fertilizers.

According to a recent survey, fertilizers use and crop yield are

highly positively correlated. Over a period of 91 years the area sown to

rice increased by only 1.64 times, but yield has increased 4.35 times. The

same tendency can be seen with other crops. The yield of coffee has

increased 2.88 times in 22 years; tea 14.1 times in 68 years, and maize

3.75 times in 36 years. As for fertilizer use, consumption has increased

from 89,000 tonnes of N+P2O5+K2O in 1961 to 2,774,000 tonnes in

2012. In combination with the increase in the area under agriculture, the

average fertilizers rates have increased from 12-15kg of nutrients per ha

to 200kg per ha during the same period. According to the Chinese

Academy of Agricultural Sciences (2012), fertilizers have contributed up

to 40% of the observed crop productivity increase in China. The same or

higher is probably true in Vitenam.

Due to the high demand for fertilizers and associated benefits for

fertilizer businesses, many small fertilizers companies have used

simple equipments and technologies to produce fake and low quality

fertilizers, causing chaos in the fertilizer market. The state has

introduced a registered fertilizer list to limit the impact of fake

fertilizers, but this has proved to be ineffective.

Low fertilizer use efficiency is one of the main concern in

agriculture. On average, the recovery rate for applied N is only 40-45%;

for P is about 25-30 % (including the residual effect) and for K it is 55-

9 President, Vietnam Academy of Agricultural Sciences

42

60%. Inefficient fertilizer use and subsequent losses not only increase

production costs, so reducing farmer incomes, but they also cause

negative environmental impacts, such as eutrophication of ground and

surface water, increased GHG emmissions, and more.

Despite the importance of fertilizers in agriculture, research on

fertilizer use efficiency in Vietnam has not been paid attention to and

funded appropriately. For the last 10 years, most of the achievements in

fertilizer use and management have come from international cooperation,

especially with PPI/PPIC/IPNI, IPI, IFA, IFDC, IRRI, CIAT, ACIAR,

and other universities or research institutions. A higher national and

international support for research in this critical area is a necessity.