Available Nutrient Status of Soil as Influenced by Combined Application of Humic Acid and Inorganic Nitrogen
K. Sai Manjeera *
Department of Soil Science & Agricultural Chemistry, Agricultural College, Bapatla, Acharya N. G. Ranga Agricultural University, A.P. 522101, India.
P. Venkata Subbaiah
Department of Soil Science & Agricultural Chemistry, Saline Water Scheme, Bapatla, Acharya N. G. Ranga Agricultural University, A.P. 522101, India.
P. R. K. Prasad
Department of Soil Science & Agricultural Chemistry, ARS, Amaravati, Acharya N. G. Ranga Agricultural University, A.P. 522020, India.
M. Sree Rekha
Department of Agronomy, APGC, Lam, Acharya N. G. Ranga Agricultural University, Lam, Guntur, A.P. 522034, India.
*Author to whom correspondence should be addressed.
Abstract
A field experiment was carried out to study the influence of different levels of humic acid (10, 20, 30 kg ha-1) and inorganic N fertilizer viz., 100 % of recommended dose and 75 % of recommended dose on chemical properties of soil under direct sown rice at Agricultural college farm, Bapatla during 2019. The experiment was laid out in RBD with ten treatments replicated thrice with BPT-5204 variety of rice as test crop. Soil samples collected at tillering, panicle initiation and harvest stages of crop were analyzed for chemical properties like available N, P2O5, K2O, Sulphur and cationic micro-nutrients (Fe, Mn, Zn, Cu). Results indicated that increased availability of N, P2O5, K2O, Sulphur and cationic micro-nutrients (Fe, Mn, Zn, Cu) were observed with the treatment T6 involving 100% RDN and HA @ 30 kg ha-1.
Keywords: Humic acid, direct sown rice, soil chemical properties