Precision Nitrogen Management on Nutrient Uptake and Nitrogen Use Efficiency in Irrigated Wheat

Abstract

A field experiment was conducted during rabi season 2017-18 at Research Farm of Birsa Agricultural University, Ranchi, Jharkhand to evaluate the nutrient uptake and nitrogen use efficiency of wheat variety HD2967 under precision nitrogen management guided by Greenseeker. The crop was sown on 25thNovember and was laid out in randomised block design replicated thrice. The soil of experimental plot was sandy loam in texture having low nitrogen (175.6 kg/ha), medium in phosphorous (15.38 kg/ha) and potassium (183.46 kg/ha) with slightly acidic having soil pH 5.5. The twelve treatments comprised of: T1- absolute control, T2 to T4 - application of 120 kg N in two and three split doses, T5 to T7 - application of 150 kg N in two and three split doses, T8 to T10 - application of 180 kg N in two and three split doses and T11andT12 (guided by Greenseeker by NDVI technique taken at 45DAS and 65DAS) were applied with 136 kg N and 140 kg N in three split doses respectively. The two splits of nitrogen given at sowing and at CRI and for three splits nitrogen was applied at sowing, CRI and at tillering stage (45 DAS). Application of 140 kg N in three split doses i.e. 30 kg N as basal, 60 kg N at CRI and Greenseeker guided nitrogen application of 40 kg at 45 DAS (second irrigation) and 10 kg at 65 DAS (third irrigation) recorded the highest nitrogen uptake in grain (86.76 kg/ha), nitrogen uptake in straw (39.68 kg/ha), total nitrogen uptake (126.44 kg/ha), phosphorus uptake in grain (16.25 kg/ha), phosphorus uptake in straw (2.91 kg/ha), total phosphorus uptake (19.16 kg/ha), potassium uptake in grain (19.38 kg/ha), potassium uptake in straw (106.17 kg/ha), total potassium uptake(125.56 kg/ha), agronomic efficiency (19.68 %) and recovery efficiency (53.46 %).