Assessment of soil and water quality as affected by herbicide application in the rice field of Bangladesh

Abstract

Weed is a vital constraint for crop especially rice cultivation. Among several techniques herbicidal weed control is thought to be efficient and cost effective method. But herbicide may change soil or water quality in rice field. Taking this into consideration a study was conducted to assess soil and water quality in herbicide applied rice field. The study was conducted in two phases. In first phase a list of herbicide was made according to the uses by the local farmers of Mymensingh district. It was found that among the herbicides wide used two herbicides were i. Laser (Pyrazosulphuron ethyl-10 WP) and ii. Changer (Acetachlor-14% + Bensulfuron methyl-4%). In the second phase, an experiment was conducted at Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh considering these two herbicides. It was found that the application of herbicide in the rice field did not change the nutrient content in the soil or water of rice field. But herbicide significantly reduced the microbial activity and increased the chlorine content (In case of herbicide 2 i.e. Acetachlor-14% + Bensulfuron methyl-4%) in both soil and water of rice field. Therefore, it can be concluded that though the nutrient content of the soil of rice field is not significantly affected by herbicide application but the presence of high amount of Cl content in the rice field may cause burning injury of rice leaf at the early stages of its growth which could affect the yield of rice.