Vol. 8, Issue 8 (2019)

Author(s):
M Jothi, P Keerthana, S Gomathi, B Priya, T Ramesh and S Rathika

Abstract:
A field experiment was conducted at Department of Agronomy, Anbil Dharmalingam Agricultural College and Research Institute, Tamil Nadu Agricultural University, Tiruchirapalli during Late Samba season (Rabi) 2018-19 to study the effect of foliar application of potassium on rice under sodic soil. Treatments consisted of foliar spray of 2% KCl, 2% K₂SO_4, 2% KNO₃, soil application of K at 50kg/ha and control. Potassium at the rate of 50 kg ha^-1 in the form of muriate of potash was applied in four equal splits as a blanket along with the nitrogen fertilizer during basal, tillering, panicle initiation and flowering stages. Foliar application of different potassium fertilizers viz, KCl, K₂SO₄ and KNO₃ was carried out at 2% concentration during tillering, panicle initiation and flowering stages in the respective treatments. Results of the experiment revealed that soil application of potassium at 50 kg/ha registered significantly taller plants (120.2cm), more number of tillers per hill (26), higher LAI (6.6), dry matter production (14149 kg/ha), more number of productive tillers (324/ m²), more number of filled grains per panicle (188) and grain yield (5440 kg/ha) over foliar spray of 2% K₂SO₄ and control. However, it was comparable with foliar application of 2% KNO₃ and 2% KCl which recorded grain yield of 5260 kg/ha and 5000 kg/ha respectively. Higher agronomic efficiency of 28.6 kg grain / kg of K fertilizer applied were obtained with foliar spray of 2% KNO_3. With reference to return per rupee invested, soil application of potassium at 50 kg/ha in four equal splits as well as foliar spray of 2% KNO₃ at tillering, PI and flowering stages gave similar value (2.8). Thus, foliar spray of 2% KNO₃ at tillering, panicle initiation and flowering stages could be recommended as alternative potassium management strategy against soil application of potassium at 50 kg/ha for higher productivity, agronomic efficiency and benefit cost ratio of rice under sodic soil condition.