EFFECTS OF LIGNITE-DERIVED HUMIC ACID ON SOME SELECTED SOIL PROPERTIES, GROWTH AND NUTRIENT UPTAKE OF WHEAT (TRITICUM AESTIVUM L.) GROWN UNDER GREENHOUSE CONDITIONS

Humic acid (HA) has been reported a promising natural resource showing persistent effects on plant growth promotion, nutrient uptake and soil nutrient status. A greenhouse experiment was conducted to determine the effects of soil and foliar applied HA on the changes in selected soil properties and growth/nutrient accumulation of wheat (Triticum aestivum L.). The experiment comprised of 05 levels of soil applied HA viz., 0, 50, 100, 150 and 200 mg kg(-1); 02 levels of soil+foliar applied HA i.e., 0 and 100 mg kg(-1) tested on two different soils i.e. loam and silt loam. Results indicated that application of HA increased plant growth in terms of shoot length (18%), root length (29%), shoot dry weight (76%), root dry weight (100%) and chlorophyll content (96%). Response of yield and yield components displayed a significant increase in 1000-grain weight (8-16%), biological yield (18-36%), dry matter yield (15-25%) and grain yield (19-58%). The relative increase in NPK uptake in plants grown under HA was 57, 96 and 62%, respectively over the control. HA improved soil nutrient status by increasing organic matter (9%), total N (30%), available P (166%) and available K (52%), indicating a substantial increase in soil nutrient status. The improvement in soil fertility and wheat productivity in response to humic acid observed in this study is critical in the degraded and eroded soils generally exist in the State of Azad Jammu and Kashmir and other parts of the world. The quality and productivity of these degraded and eroded soils may be upgraded by including HA in our agricultural cropping pattern/system.