Effect of Linz-Donawitz (LD) steel slag on soil properties and yield of cereal, vegetable and oilseed crops

Linz-Donawitz (LD) steel slag, a byproduct of steel industry produced in huge amount is a rich source of plant essential and beneficial mineral nutrients. This study aims to evaluate the impact of LD slag (ranging from 0.5-1.0 t ha-1) given with and without 80 per cent recommended dose of NPK fertilizers (RDF) on yield and physico-chemical and biological characteristics of soil under wheat, rice, maize, brinjal, tomato, amaranthus and mustard. The application of LD slag without RDF reduced the soil quality and crop growth and yield significantly. However, in comparison to control, the LD slag applied along with 80 per cent RDF significantly increased soil pH, electrical conductivity, organic carbon, urease and phosphatase activities across majority of crops. The total microbial count (TMC) was reduced in the soil under all crops except wheat and maize under the slag alone treatment. The slag application with 80 per cent RDF enhanced plant biomass and yield of maize and brinjal, but increased biomass and fruit yield alone in mustard and tomato, respectively. The study evidenced that the application of LD slag is useful in improving soil physical and biological status, and improves the crop growth and yield, selectively, even with less NPK fertilizer application.