35(4), 364-373 Tap chi CAC KHOA HQC V£ TRAI S A T ©ANH GIA ANH HU'ONG CUA DIEU KIEN KHI HAU ^ NONG NGHIEP DEN CAY TRONG N G A N N G A Y d KHU VUC NINH THUAN VA BINH THUAN PHAM QUANG VINH', NGUYEN THANH BINH', BUI TH| THANH HU'ONG^ E-mail: qvinhgeoi@yahoo.com ' Viin Dia Ly Vien Hdn ldm Khoa hgc vd Cong nghe Viet Nam Tru&ng Cao ddng Suphgm Hd Ngi Ngay nhan bii: 10 - - 2013 Mddau Ninh Thuin va Binh Thuan la hai tinh nam d cue Nara Trung bfl Vift Nam, cd tdng dien lich khoang I1.165km^, vdi 350km dudng bd bifln {hinh 1) Khu vgc dugc dac trung bdi hau am va bin khd ban, cd khoang gin ragt nua difn tich li khd ban vi ban khd han, do diy Ii khu vuc hing nam da va dang pbii ddi difln vdi linh Irgng thieu nudc keo dii, cd khoing din thing khd moi nim (lugng mua dudi 100mm) Noi day ciing chju inh budng eua diflu kien nhift dfl cao vi gid manh, li nhdng yeu td gdp phin thiic day qua trinh ban ban, hoang mgc bda Ch6 giii Khu VV6 nglMfl cthi Ranh gidi Huy^ I |mnnfli»illnh Hinh Khu v ^ nghifin Cac hi?n tugng bgn ban v i hoang mgc hda dang ngiy mflt lan rflng, d i e biflt bdi cinh bifln dfli hgu, d i l i m i n h hudng ldn d i n vin dfl phat trifln kinh te x i hgi, nhat l i san xuat ndng nghidp Ndng nghiep l i nganh kinh tfl chiu inh hudng va phg thugc nhieu vio c i c yflu td tu nhien, die biflt d cic nudc ngheo nhu Viflt Nam Vi vgy, diflu chinh sin xuat nflng nghiflp, ban ehe dugc nhung tic dgng tieu cgc cua thifln tai, su dgng hiflu qua, hgp ly tii nguyen l i mgc tiflu cua cac nhi khoa hgc, nhi quin ly, n h i sin xuit tu xua den Tuy nhien, d Viflt Nam hien nay, cac nghifln cuu vfl van dl mdi chi dirng lgi d nhQng danh gii dinh tinh (phan tich nguyfln nhan va dfl xuit giai phip thich urng), ma ehua dinh lugng dugc nhiing tic dgng cua cic nhin td lu nhifln Trfln the gidi hifln d i cd mdt sd cdng bd viflc Iugng bda dugc nhirng tie dflng niy Nhdm cic nha khoa hgc ciia trudng Dai hgc Leuven (Bi) v i GS Dirk Raes [1] da xiy dung he thdng nhiing phan mem xu ly cic dii liflu tugng nhim dinh gia anb budng ciia dieu kifln hau den sin xuil ndng ngbi?p trfln co sd sir dung cic thu^t toan, dd rad hinh Budget la md hinh dugc ling dgng rgng rai tinh toan ein bing nudc v i ude tinh raiic suy giira nang suat ciy udng Iheo phin tram Do dd vifle sii dung mo hinh Budget xii ly cic dii liflu tugng ngiy dfl linh toin can bing nudc phgc vg dinh gia tinh Irang khd hgn doi vdi mflt sd ciy trdng ngin ngiy d tinh Ninh Thuin v i Binh Thuin, nhira dua kit qua vl miic dg suy giim ning suit ciy trdng (theo ty lfl %) li ling dgng bit siic cin thilt Kflt qui nghien cuu niy li ca sd khoa hgc eho cie nha quin ly bfl Iri diay dfli co ciu miia vg, thiet kfl c i y Ihieh img vdi hgn ban, hoang mgc hda va bifln ddi h^u Phuvng p h i p va dii' li^u nghien eiru thoii nang suit giai doan cay trdng cin thiflt nudc nhit [3] MLFC dg suy giam ning suit cua cdy bdng ndng nghiflp Dinh g i i miic suy giim ning suit cay trdng thuc tfl so vdi diflu kifln tfli uu dya tren phuong phap ciia Jenssen (1968) [2], Iheo cdng thuc (I): =n(: CTnrtj i« STc^QpJ w Trong do: Ya: li nang suit thuc te; Ym: li nang suit cao nhat (diflu kien trdng toi uu); ETact): la lugng bdc hoi nudc thuc tfl giai doan i; Etcrop,: lugng bde hai nudc khflng bi bgn che ve dieu kifln giai dogn i; X li chi sd nhgy eim Jensen dugc tinh theo phuang Uinh Kipkorir (2002) [3] dua cdng thirc (2) Khi gin bai ky g i i Iri Ky nio sfl cdX: i, = (i.:75Jiiy' -El.l35lA"y= -f0,eJ61ii) 0,0137 R- = 0.99 (2) Du lieu dau vao eua md binh Budget bao gom: - DO' liflu tuvng: dii liflu mua ngiy v i dg bdc thoal hai nudc hi trgm hrgng Phan Rang va Phan Thiet (cd tham khao va bd xung Ihem dd liflu cua tram Nba Trang, Vung Tiu, Xuin Lflc, Bio Lflc) Hai tram tugng dgc trung cho kiflu hau bin khd ciia khu vgc nghifln cim - DO li$u cay trong: bii bio lap trung nghien ciiu cbo mgt sd ciy trdng ndng nghiflp ngin ngiy (nhu: ngd, diu, ) la nhQng loai ciy phd bien tgi khu vgc nghien cuu, Nhin chung, day la loai cay cd Ihdi gian sinh trudng dudi 120 ngiy, cd chieu dii re tfli da li 60cm va chju hgn vira phii 2,1 Phuang phdp nghiin curu De dinh gii miic dfl suy giam ning suit ciy u i n g ngin ngiy, nghien cuu niy chiing tdi sii dgng md hinh Budget kit hgp vdi viflc phan tich cic da ligu biu ndng nghiflp Md hinh Budget li mgt phan m i m bao gom mgi tgp hgp cic chuong trinh md phdng c i c qui trinh hap thg nudc ciia re ciy v i sg v$n chuyen nudc Irong eac ldp dai Bing cic phflp nhiing y l u td inh hudng dfln ning suit ciy trong, nd cd thi ude linh dugc sg suy - DO liflu thd nhu-dng: cac tinh toan d i dugc thgc hifln doi vdi logi dit tuang phan, cd kha nSng thoii nudc tdt v i phd bifln d khu vgc niy la: + Dit set: d i y la logi dil m i ket ciu cd ting, bao gom: ting cat pha set (0-20em); ting miin cit pha set cd dfl day 20-lOOcm; v i ting set pha cat cd dg diy 100-200cm Kiflu dil niy li logi dat dien hinh cho cac nhdm dit dd v i xim (Ferralsols vi 365 Acrisols) Day la nhimg loai dat thoit nudc tdt vi phfl bien biu het d viing niii va ddng banOg ven sdng + Dit cit: mflt ling cd ket ciu cat diy tren 20cm, mflt ting cat pha set cd dd day 20-200cm kieu dat niy dac trung cho cic loai dit cat Arenosols Ihudng dugc tim thay dgc bd bifln khu vgc nghifln ciiu Thdi gian bit diu gieo trdng dugc tinh tir diu thing - Lu-gng bdc thoat hai nudc tiem nang (ETo): Bdc thoii hai nudc Ii su kflt bgp giua bdc boi nudc ciia dit va dd thoat hai nudc eua ciy trdng, Lugng bdc thoat hai nude chiu inh hudng trgc tiflp tir cic thdng sd tuang, linh chat cay trdng, sg cham sdc va diflu kifln mdi trudng, nfln viec dac Iugng bdc thoat bai nudc ngoai thgc te li rat kbd khan De thuan Iai, ngudi la thudng tinh lugng bdc thoai hai nudc tir rapt bflragtthara chieu (beragttham chieu la mdt bfl mat trdng cd, bfl mat niy bao gdra toan bo dac diflra eua dat, diflu kien tudi nudc tdt va dieu kien ndng nghiep tdi uu), Lugng bdc thoat hoi nudc tinh tir be rail dugc goi la Iugng bde tboai hai nudc tham chieu va dugc ky bieu li ETo Cong thirc tinh lugng bflc thoat boi tham chieu ETo theo phuong phap FAO Penman-Monteith [I]: Hi(c,-e.l 0.408A(/e„-G) + / ET 2^3 A-(-?'(l + 0.34Uj) (3) Trong dd: ETo dO bdc - thoit hai nudc Iham chiflu [mm/ngiy]; Ro la biic xg tai bfl mgt cay Irdng [MJ/m^ngiy]; G ty trgng ludng nhiflt dit [MJ/m^ngiy]; T nhiflt dg khong tgi dd cao 2m [C°]; U2 tdc gid tgi dg cao 2m [nVs]; e, ap suat hoi nudc bao hda [kPa]; ejip suit hai nudc th\rc tl [kPa]; Cs-Ca mirc dg thieu hgt ip suat boi nudc bao bda [kPa]; A slope vapour pressure curve [kPa/°C]; Y thdng sd psychrometric [kPa/^CJ Mdt nhung md binh uu vi^l di dugc FAO edng nhin dfl tinh dg bflc thoit hai nudc Iham chiflu la phin mim ETo calculator [I] Mdt nhin td nQa cd anh hudng rit ldn dfln nang suit cay trdng, dd la miia mua va chieu dii Ihdi gian im udt Theo dinh nghla ciia FAO chilu dii thdi gian im udt dugc dua nhu li mgt thdi gian mi lugng mua ldn ban lugng boc thoit hai nudc (hinh 2) Chiflu dai ciia miia gieo trdng dugc dinh nghTa li thai gian mdt nim lugng mua vugt qua mflt nua lugng boc thoit hoi nudc tiem ning Die diem niy duge su dung de xac dinh dd dai chu ky vi ljch gieo trdng vi viflc xic djnh diing thdi gian gieo trlng anh huong trgc tiflp dfln ning suit miia vg> Hinh Chieu dai thwi gian am u61 Trong nghien cuu nay, chiing tdi di thuc hien tinh toan chiflu dai thdi gian am udt trfln ca sd du liflu dekad (1 dekad bang 10 ngiy) bang nam Su khdi dau cua thdi ky ara udl dugc xac dinh tai dau ciia dekad ma lugng mua ldn ban bde thoat boi nudc vi khdng nhiflu han dekad khd Thdi gian ket tbiic cua thdi ky im udt la ngiy cudi cung cua dekad am udt mi sau dd cd it nhit dekad lien hep kho 2.2 BO- lifu su- difng Dii lieu tu trgm tugng quanh khu vgc nghifln cim (Nha Trang, Phan Rang, Phan Thiet, VQng Tail, Xuan Lflc, Bao Lgc) Vifln Khi tugng Thiiy vin vi Mdi trudng Vi^t Nam cung cap Bg du U^u bao gom nhi^t dg khong (tdi da vi Idi thieu), dg am khdng (tdi thiflu va trung binh), thdi ^an chieu sing, tdng lugng mua ngiy va tdc dg gid Idi da Trong nghifln cdu chiing Idi chii yeu sii dung dii lieu ve nhiet do, dd am khdng vi lugng mua Bdng li dii liflu dugc idng hgp tbeo gia tri trung binh nhieu nam BAng DCr lifu cua tram tiryng dirge sO dung cho nghien ci>u Nhi$l dO g^g mu'a, liro-ng boc ho'i tham chieu (Eto) tinh chit khd ndng eiia hau nai diy trung binh nam cua tram tiriyng Bao Nha Trang Phan Rang Phan Thl6l Tau XuSn LOC cOdirliOu) amkh& \Z7 Nam iim 2195 2549 5262 1370 30 803 1266 2552 1590 28 449 638 1332 1868 784 1142 1768 1758 26