Evolving appropriate zinc fertilization strategy for rice-rice {Oryza sativa) cropping system in Cauvery Delta Zone

摘要

Six field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai to evolve suitable zinc fertilization method for rice - rice (Oryza sativa L.) cropping system in Cauvery delta zone. The treatment includes: T_1: Control, T_2: 100g zinc sulphate (ZnSO_4)/cent in nursery alone.T_3: root dipping alone in 2 % zinc oxide (ZnO) solution, T_4: 25 kgZnSO_4ha~(-1), T_5: 37.5 kg ZnSO_4 ha~(-1)( T_6: 25 kg ZnSO _4ha~(-1)+Farm Yard Manure (FYM) 12.5 t ha~(-1)( T_7: 25 kg ZnSO_4ha~(-1) + Green Leaf Manure (GLM) 6.5 t ha~(-1), : T_8:Tamil Nadu Agricultural University Micro Nutrient (TNA UMN) mixture 25 kg ha~(-1) as Enriched Farm Yard Manure (EFYM), T_9: TNAU MN mixture 37.5 kg ha~(-1) as EFYM, T_(10)Foliar spray of 0.5% ZnSO_4 + 1 % urea attillering and panicle initiation stage, T_(11): 100g ZnSO_4 /cent in nursery alone + Foliar spray of 0.5 % ZnSO_4 + 1 % urea at tillering and panicle initiation stage (T_2+ T_(10), T_(12): root dipping alone in 2 %> ZnO_4 solution + Foliar spray of 0.5%ZnSO_4 + 1 % urea at tillering and panicle initiation stage (T_3+ T_(10), T_(13): 100 g ZnSO_4/cent in nursery alone + root dipping alone in 2 % ZnO_4 solution + Foliar spray of 0.5 %> ZnSO + 1 %> urea at tillering and panicle initiation stage (T_2 + T_3 + T_(10). The treatments T_5, T_6, T_7 and T_9 were skipped in rabi season to know the residual effect of these treatments in the subsequent season. Among the treatment combinations, application of 25 kg ZnSO_4 ha~(-1)+ FYM 12.5t ha~(-1) recorded higher grain yield in both kharif (6232 kg ha~(-1)) and rabi (6236 kg ha~(-1)) seasons. The same treatment combination recorded higher Zn content and Zn uptake as well. Regarding soil nutrient content, the same treatment recorded higher N, P and K content. This treatment was followed by application of 25 kg ZnSO_4 ha~(-1) + green leaf manure 6.5 t ha~(-1). The experimental findings suggested that combination of organic and inorganic sources not only increased the yield but also improves soil health in Cauvery delta zone.