I.Tac hai,nguyen nhan va cac loai chay R:

1.Tac hai cua chay R:

-Thiet hai tai nguyen R:

*Doi voi TVR:

+Huy diet tham TV,cac loai loai cay bui,cay tai sinh,cay go

+Lam xuat hien cac loai cay ua sang kem gtri

+Cay tai sinh hoac cay co gtri cao kho puc hoi

+Lam thay doi thanh pan loai cay ahg den dien the R,lam cay R chet hang loat or strg kem

+Lam ahg den tih trag ve sinh R

+Lam cho cac kieu R bi thay doi lon anh hg den cac puog thuc khthac va tai sinh R

+Lam giam tinh o dih of R,fa vo can bang sthai

*Doi voi DVR:

-Lam thay doi so lg va thanh pan cac loai DV hoang da,chim,con trung...

-Huy diet cac DV co ich nhu:giun,kien,ong...

-Lam cho nguon thuc an of DV bi mat di or giam xuog gay anh huog den doi sog of DV

*Doi voi dat R:

Dat dan dan xau di do mat tham muc,giam kha nang dieu hoa nguon nc,tang dong chay be mat,giam lg nc tham,dat R bi xoi mon,rua troi rat manh va thoai hoa nhanh chong

-Lam tang kuog chat khoang,lg muoi hoa tan va cac ion trao doi sau do tang do pH dat

-1 so VSV bi tieu diet lam giam do phi nhieu dat anh hg den tham canh R

-Fa vo mtrg song

2.Nguyen nhan cua Chay R:

-Do con ng:Dot R lam nuong ray,dung lua ko can than khi o trog R,dung lua de xu ly thuc bi trog sxlnghiep...(95%)

-Do hien tg tu nhien:do sam set,nui lua(5%)

3.Cac loai Chay R:

a.Chay duoi tan R:(Chay lan tren mat dat):tieu huy cay tai sinh va 1 so sv nhat dinh

b.Chay tren ngon(Chay tan cay):gay nhieu thiet hai,R ko co kha nang puc hoi

c.Chay ngam:hau het re cay bi fa huy lam cay chet dung va de do hang loat do gio manh

II.Cac Nhan To Anh Huong Den Chay R:

-Thuc bi-VLC

-Thoi tiet va cac nhan to khi hau

+Do am:do am ko khi,do am VLC,Do am cua dat

+Gio

3.Dia Hinh