I Nghien cihi & Trao ddi KHAO SAT AMMONIA VA HYDROGENSULFIDE TRONG CAC MO HINH NUOI TOM SU TREN CAC LOAI DAT KHAC NHAU 6" TINH CA MAU ThS Cao Phu''''O''''ng Nam Vien Thiiy Igi va Moi trudng Dai hpe Thuy Lgi[.]
I Nghien cihi & Trao ddi KHAO SAT AMMONIA VA HYDROGENSULFIDE TRONG CAC MO HINH NUOI TOM SU TREN CAC LOAI D A T K H A C NHAU 6" TINH CA MAU ThS Cao Phu'O'ng Nam Vien Thiiy Igi va Moi trudng - Dai hpe Thuy Lgi Ji # \ I jphien ciru duge tien hanh a 15 hp Mil hp ed dien tich nudi khoang ha/mo hinh, vdi f loai md hinh Quang canh eai tiin (QCCT), Tdm liia (TL) va Tham canh (TC) tren 04 loai dit V ddt phen hoat dpng man trung binh (Sj2M), ddt phen tiim tang ndng man nang (Sp1Mn), ddt man trung binh (M) vd ddt man nang (Mn) (thupc dia ban xa eita bin huyen tinh Ca Mau, nam 2002-2003 va tir thang din thdng 12 nam 2007) Ham lugng trung binh chdt hu'U ca vd dam hu'u ca di phdn hiiy ddt, biin day ao a cae md hinh nudi tdm sit tren dat {Sj2M), dat (SpIMn) cao han tren ddt (M), ddt (Mn) Ning dp trung binh Ammonia (N-NH^ ) , Hydrogen sulfide (H2S) nude d eae md hinh nudi tdm sii tren dit Sj2M, Sp1Mn cao han tren dat M vd Mn, tang cao vao cdc thdi diem thdng S, thdng 6, thdng eita mua vu nudi, tuang irng vdi thdi diim tdm dugc 1-2 thang tudi Nong dp trung binh Ammnonia va Hydrogen sulfide biin day cao gip hang chuc din hang tram ldn so vdi Idp nude phia tren eiia day ao nudi: tren trang va dudi muang ciia ao nudi tdm a cac mo hinh QCCT va TL cao han va biin thien Idn han so vdi md hinh TC Ty le tdm sing d cac md hinh QCCT, TL dat nhd han 20%, dd a md hinh TC ty le tom sing dat tren 70%, ddn din nang suit tdm nuoi a cac md hinh QCCT, TL dat thdp han rat nhiiu so vdi md hinh TC hinh quang canh cai t i l n vd tdm liia Dat van de Tinh Ca Mau cd tong quy dat 520.175 ha, Trong nudi tom su, sy hien dien va tich luy chat dd nhdm d i t man cd dien tfch 208.500 ha, vdi hiru eg quylt djnh r i t Idn den chat lugng mdi 32.600 d i t man nang va 175.900 d i t man trudng nuoi Sau moi vu nudi, Idp biin lang tren cac nhe, chilm 40,0% dien tfch ty nhi§n Nhdm d i t phen vudng, d i m nudi torn tham canh cd the day 40 - 50 ed dien tfch 271.926 ha, g i m : d i t phen t i l m tang cm, quang canh cai t i l n va tdm lua 20 -SO cm phii (190.640 ha), vd d i t phen hoat dpng (81.285 ha) khap dien tfch day cae ao nudi tdm Biin ao bao gom Nhdm dat phen nhiem man khoang 30.387 hon hgp ciia chit hu'u ca cd san dat, tao chit, Nhdm d i t than biin, vdi dien tich khoang 8.698 thire an d u thira Theo Giao trinh Quan ly chat Nhdm d i t bai boi vdi dien tich 15.483 [1] Tir nam lugng nude nudi thiiy san, x u l t ban nam 2002, 2000, phan Idn d i t nong nghiep chu yeu Id liia nudi tham canh tdm ea chl sir dung duge to! da dugc chuyen doi sang nudi tom su va lua da 75% lugng thire an, 10% iugng thire an hda tan luan canh, tinh d i n thdi d i l m c u l i nam 2008 dien nude va 15% lugng thire an thira Trong qua tich nudi td:Ti su tren toan tinh dat tren 248.000 ha, trinh phan hiiy c h i t hu'u ca, dii d d i l u kien hao ehu y l u la ^6 hinh quang canh cai t i l n Theo quy hay y i m thi san pham cuoi ciing deu cd NH3 vd hoach nuoi t i i n g thuy san tinh Cd Mau d i n nam CO2 d cac tl le khac 2020 dien \.i^ dat dugc sir dung cho nudi torn sii la 235.000 v trif lua vdi cae md hinh san xuat: NH2-CH2-COOH + 3/2O2 = NH3 + CO2 + H2O quang canh cai t i l n , tom liia, tham canh va ban NH2-CH2-COOH + 2H2O = NH3 + 2CO2 + 3H2 tham canh, 5d t-§n 222.000 chu y l u la md Trong d i l u kien y I m mot so lodi vi khuan Tap chi Khi tifgfng Thuy van * Thang 4/2009 31 Nghien ciiu & Trao doi Desulfovibrio, Desuifotomaculum sir dung dxy cua giong, l i y nude vao va tha giong, va chd thu hoach, sulphate d l oxy hod c h i t huu ca, san pham tao chu y l u nhd vao t y nhien D i i vdi md hinh nudi thdnh Id acid hu'u ca, nude va Sulfua (S^-) tham canh, dien tich 500 m^/ao, g i m hai ao (ao nudi 2R-CH2-OH + SO42- = R - C 0 H + 2H2O + S2- va ao xij ly nude d l cap eho ao nudi) Dp sau ao nudi tir 1,2 - 1,5 m, mat dp tha gilng 30 con/m^, cho Tat ca cac c h i t ndi tren nhu H2S, NH3, la cae chit d6c eho tdm, gay hai d i n sire khoe tdm Trong nudi tdm sii ndng dp ammonia < 0,1 ppm va khong dugc cd sy hien dien eiia hydrogensulfide De tim hilu mdt s l v i n d l v l N-NH3 va H2S an b i n g thire an cong nghiep, eo he thong cap dxy vao day ao Mdi trudng nude, biin day, cham sdc tdm nudi dugc theo doi vd k i l m soat theo dung quy trinh ky thuat Thdi gian nu6i/vu tir thdng doi vdi m6 hinh TC va 4-6 thang d i i vd'i md hinh QCCT, TL cae md hinh san x u l t tren cac loai dat canh tac khac chiing toi da t i l n hanh d l tai nghien ciru: khao sat d i l n biln n i n g dp H2S, NH3, ao nudi tdm quang canh cai t i l n (QCCT), torn liia (TL) tren cac loai dit: d i t phen hoat dpng man trung binh + Khao sat cac ehi tieu nhiet dp, pH, dp man, chit hiru CO, dam de phan huy (N-NH4''he), NH3, H2S, ghi nhan tinh trang: mau nude, s y phat triln, nang suit san lugng cua tdm nudi (Sj2M), d i t phen tilm tang n6ng man nang (SpIMn), + Thdi d i l m nghien ciru: miia khd va miia mua d i t man trung binh (M) va dat man nang (Mn) tinh nam 2003, t i l n hdnh khao sat vao cac thang Ca Mau 12/2002, thang 3/2003, thang 6/2003, thang 9/2003 Phu'O'ng tien va Phu'O'ng phap nghien cu'u vd thang 12/2003, thang 8-12 nam 2007 a Pham vi nghien b Dung eu thu mau, ky thuat thu mau cii'u + Chpn 15 hp, moi hp cd dien tich nudi tring khoang ha/m6 hinh, vdi cac md hlnh nudi tdm quang canh cai tiln (QCCT), tdm liia (TL), tdm tham canh (TC) d xa thupc b i n huyen tren 04 loai d i t : xa H i Thj Ky (Sj2M), xa Thdi Binh (Sj2M), xa Tan Dung cu thu m l u : Dung cu thu m l u duge thilt k l b i n g vien thoi ( h i ca) hlnh tru dai cm, dudng kinh cm, ben ngdai dugc bao kin mpt ldp t i m lpc nude ho ca, n i l dau vien thoi vdi 01 dau Hung Dong (M), xa Phu Tan (SpIMn), xa Viet Khai I n g nhya (loai diing cho djch truyin hoac t h i i (SpIMn), xa Ta An Khuang (Mn) vd xa Tan Duyet h i ca) va dat vao d i l m e i n thu m l u nude, d i u edn (M) thudc cae huyen Thdi Binh, Cai Nude, Phii Tan lai cua ong nhya ed khda de cd the khda kin hoac vd Dam Doi md can Moi d i l m dat 01 dung cu lay m i u ndi + Md hinh nudi tdm QCCT, TL dugc thilt ke vdi muang bao chu vi d i t , d i t dao dugc diing d i p bd bao giu nude nudi tdm Muong bao thudng sau khoang 1,2 -1,5 m, rdng 2-3 m, thupc dien tfch d i t Idn nhd cd the ddo them muang giira Muang tren Tong so diem thu mau/md hinh: 06 diem Dgng cu eho phep l i y dugc mau diing diem can khac sat, han c h l t i i da dugc s y xam nhap eiia khdng vdo m l u vd s y pha trpn nude mau giu'a cac dilm bao vd muang giCra cd tac dung, c i p thoat nude, la Thu mau: D i n thdi diem l i y mau diing I n g hiit nai tru ngu chii y l u ciia tdm P h i n d i t edn lai gpi la chan khong riit bd h i t nude chira dung cu Ihu trang Trang Id nai tom hoat ddng vd kilm moi Dien m i u , sau dd chd' khoang 15 phut thi t i l n hdnh lay tich trang thudng chiem tren 2/S dien tich ao nudi Nude thud'ng dugc cap true tiep vdo ao nudi md khong qua xir ly Mat dp tha giong 1-S eon P15/m^ m i u , thao tac nhanh.Cach thuc co djnh m l u , bao quan m i u thye hien theo hudng d i n cua Standard Methods 2005 Tdm s i n g b i n g thire an t y nhien ao Ky thuat * Phwang phap phan tfch nudi bao g i m : sen vet biin, phai trang, bdn vdi, chpn + pH : can lOg d i t pha vdi 25ml nude c i t theo ti 32 Tap chi Khi t\iu ca; dinh dudng eao, miin, dam va kali Ket qua va thao luan giau; lan tong so vd de tieu t h i p ; d i t ft chua va ed a Tfnh chit dit thi nghiem dung lugng trao doi cation (CEC) kha cao Miin va D i t phen hoat ddng sau man trung binh: Sj2M, dam t i n g s l trung binh (0,797 - 2,4 % M va 0,070 t i n g phen hpat dpng x u l t hien khoang dp sau - 0,207% N) Dung lugng trao d i i cation kha, len 50 -100 cm, khdng ed tang phen t i l m tang d i n 18,6 -19,6 me/100g dat Mire dp bao hda baza vdng dp sau - cm D i t ed ham lugng cac dat 70-80%, day la loai d i t cd dp bao hda baza cao Tap chi Khi tuftfng Thuy van * Thang 4/2009 33 Nghidn ctfu & Trao dd'i so vdi cae loai d i t tinh va Dong bing song ciru dp c h i t hu'U ca trung binh cua cdc md hinh tren dat long (DBSCL) Cac dpc c h i t chii yeu Id dp Sj2M vd m i u d i t SpIMn tich luy theo thdi gian vd man cao vd s i t hda tan kha cao, lugng Cl- d i t tang qua eae thang: trung binh thang 12/2002: Sj2M theo thir ty len d i n 0,40- 0,47% Cl", 9,80 -16,32 mg (7,81%), SpIMn (7,99%), Mn (3,2%), M (3,33%); trung binh thang 3/2003 Id Sj2M (8,09%), SpIMn Fe'VIOOgdIt (8,22%), Mn (3,29%), M (3,29%) va thang nam b Nhiet dp, pH va dp man moi trwang nw&e Dp man trung binh cdc thang tren cae md hinh thay d i i Idn theo miia, tir 4,73°/oo