The resource use efficiency of paddy in selected agricultural systems during 1997-98 in Tungabhadra Project (TBP) area of Karnataka state, clearly revealed that the use of chemical fertilizers and plant protection chemicals were found to be over-utilized in kharif paddy under Highly Intensive Agricultural System (HIAS) and Semi-Intensive Agricultural Systems (SIAS). However, they were under used in Ancient Irrigated Agricultural Systems (AIAS). In the case of rabi / summer, land and labour had significant influence in AIAS as against chemical fertilizers in HIAS. Therefore, over use of chemical fertilizers and plant protection chemicals in HIAS and SIAS needs to be rationalized through intensive extension activities and practice of irrigated agriculture as in AIAS with higher use of organic manures, appropriate crop rotation and plant protection chemicals which appear to be sustained over years needs to be extended in other parts of irrigated command areas.