International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-8, Issue-11, November- 2022] Page | 13 Effect of Chemical Weed Control on Soil Bio-Chemical Indices- A Review Divya Singh 1 , Atish Yadav 2* , Shivendra Singh 3 , Adesh Kumar 4 , Abhishek Mishra 5 1,2 Department of Agronomy, Acharya Narendra Deva University of Agriculture & Technology, Ayodhya, (UP), India 3,4,5 Department of Agronomy, Chandra Shekhar Azad University of Agriculture & Technology, Ayodhya, (UP), India *Corresponding Author Abstract— The assessment and monitoring of soil life and soil health can be used to develop more sustainable and productive farming systems. Hence, the consequence of herbicide application on soil health is always a concern for the research community. In view of this, the findings available from India in respect to the impact of herbicides on the non-target organisms and important soil bio-chemical processes are reviewed in this paper. There is great variation among the reports showing short term transient depressing to non-inhibitory or even stimulatory effects of herbicides on total soil microbial count and different soil bio-chemical indices. The impact differed depending upon the soil type, experimental conditions, herbicide in question and its dose, and the sensitivity of the non-target species or strains. No severe ill effect on soil flora, soil bio-chemical indices and soil fauna has been observed so far at recommended dose of herbicide under field conditions. However, the available information is based on the short term experiments and there is need to develop data base on long-term field application basis. The paper concludes with some suggested areas for future research requiring urgent attention. Keywords— Actinomycetes, Ammonification, Bacteria, Earthworms, Fungi, Herbicides, India, Nematodes, Nitrification, Nitrogen fixation, Soil enzymes. I. INTRODUCTION Soils contain microorganisms viz. bacteria, fungi, yeasts, photosynthetic organisms including algae and macroorganisms such as protozoa, nematodes, mites, springtails, spiders, insects and earthworms. The functions of this complex array of biota are diverse, and include residue decomposition, nutrient storage and release, soil structure and stability, resistance against disease and degradation or immobilisation of soil pollutants. A minimum of species is necessary to carry out essential tasks. It is believed that high biodiversity leads to a higher soil functional stability and thereby, a greater capacity to recover from perturbation and maintaining environmental sustainability. Weed control in agricultural and non-agricultural lands is rapidly shifting towards chemical methods because of its time, labour and cost advantages. Although herbicides are meant for plants, possibility of a direct effect on other organisms can not be ruled out as a number of basic and universal biochemical processes essential for all forms of life are alike. Direct impacts on sensitive organisms can occur when the chemical reaches the soil due to targeted deposition of pre-emergent herbicides, or through unintentional deposition from spray and spray drift, dripping from plant material, and contaminated plant material falling to the soil. A decrease in the population of sensitive species may cause an increase in the population of resistant soil microorganisms due to relatively lesser competition. Thus, their application may have impacts on organisms that benefit the wider agro-ecosystem. Such concerns from the research community and general population were well documented in June 1992 at the United Nations Conference on the Environment and Development (UNCED) in Rio de Janeiro, which is referred to as the Convention on Biological Diversity. In field conditions, herbicides may also greatly influence soil biota populations indirectly by their effects on vegetation which provide habitat and food for many of them. The soil organisms may respond differentially due to the changes in vegetation rather than to direct herbicide effect (Grossbard and Davies 1976, Haugland 1994). Influence of herbicides on soil biota Received:- 08 November 2022/ Revised:- 16 November 2022/ Accepted:- 20 November 2022/ Published: 30-11-2022 Copyright @ 2022 International Journal of Environmental and Agriculture Research This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted Non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.