Implications of herbicides and plant nutrients continuous usage on soil health and rice yield in acid soils of Assam, India

Abstract

Appropriate weed and fertilizer management is important for sustaining soil health and enhancing crop productivity to achieve food security. Field experiment was conducted for 14 years at Assam Agricultural University, Jorhat, India, in randomized block design with five treatments. The experiment consisted of application of pre-emergence herbicide Butachlor and post emergence herbicide 2,4-D in summer rice and application of pre-emergence herbicide Butachlor and Pretilachlor and post emergence herbicide 2,4-D in winter rice. Continuous use of herbicides for 14 years significantly reduced the weed density and dry matter accumulation by weeds compared to farmers practice (FP). Application of fertilizers and herbicides produced significantly higher grain yield over FP. It can be concluded that sequential application of butachlor/ pretilachlor + 2,4-D at recommended rate along with balanced use of fertilizer either alone or with organic source is required for sustaining soil health and indicated an increase in summer and winter rice yields by 49.92 and 42.80 % over FP.

Bangladesh J. Bot. 55(3): 555-562, 2026 (September)