Abstract

                                Field experiment conducted at the Tamil Nadu Rice Research Institute, Aduthurai, Tamil Nadu for two years (1985-87) revealed that the computed nitrogen balance was positive (20.8 kg ha) in the system of rice-cotton. Net loss of nitrogen was observed in system encompassing rice-soybean (-24,4 kg ha'') and -214.6 kg ha in systems of finger millet -rice -cotton. The computed balance for phosphorus was positive in all the systems and the highest was 196.3 kg ha' in system possessing rice -soybean. The potassium balance was very much negative (-441.8 kg ha¹) in the system of maize-rice-cotton Wherever cotton constituted a component in the sequence, there was considerable enhancement in soil nutrient status (system 5 and 6) Cotton and finger millets are not less efficient than legume crop in enhancing soil nutrient status especially nitrogen balance.

Key words : Cropping System, Rice-based, Influence, Soil, Cauvery Delta Zone