TÍNH CHẤT LÝ - HÓA - SINH HỌC CỦA ĐẤT VÀ NƯỚC TRONG HỆ THỐNG CANH TÁC TỔNG HỢP LÚA CÁ

The content of ammonium, nitrate, P, Fe2+,Fe3+, H2S, BOD and COD in water of Rice- Fish system is increased by time, in which, ammonium concentration is above critical limitation of water quality by Vietnam Standard. Water pH is neutral and around 7. P, K, Ca, Mg in available and exchange forms in the soil of ditches and field is increased by time at different rate. Increase of Exchange K and Mg in soil of ditches is higher than that of field. The content of Fe2+ , Fe3+ and H2S in both soil is observed an increase, but it is still safe for both fish and rice.