Nutrient uptake and nitrogen use efficiency of rice genotypes under LCC- based N application during summer

Abstract

A field experiment was undertaken at Research Farm, Department of Agronomy, OUAT Bhubaneswar to study the response of rice (Oryza sativa L.) varieties to LCC based nitrogen application under Real Time Nitrogen Management (RTNM) during summer 2015 in split plot design with three replications. Four varieties (V1- Lalat, V2- Naveen, V3- Hiranmayee and V4- Gobinda) were in main plot and sub plots were assigned with six N- management practices (N1- Control, N2- RDN@ 80 kg N ha-1 while in treatment N3 to N6, 20 kg N was applied in each split at LCC level 3 ( N3), LCC level 4( N4), LCC level 5(N5) and LCC level 6 (N6). A uniform dose of phosphorous and potassium @ 40 kg ha-1 each along with well decomposed FYM @ 5t ha-1 were applied to all the plots as basal. Nitrogen uptake was maximum (88.59 kg ha-1) in variety Naveen, whereas, the variety Gobinda had maximum agronomic efficiency (24.12 kg kg-1), recovery efficiency (37.23 kg kg-1), physiological efficiency (53.33 kg kg-1) and partial factor productivity (44.58 kg kg-1).Application of RDF resulted in maximum uptake of nitrogen (94.20 kg ha-1) and registered the highest agronomic efficiency (32.86 kg kg-1), recovery efficiency (55.40 kg ka-1)and partial factor productivity (65.61 kg ka-1). The highest physiological efficiency of 63.93 kg ha-1 and minimum N loss of 29.35 kg ha-1 was recorded forLCC 4 (N4) threshold value.

Evaluation of Nutrient Levels, Optical Sensors and Decision Support Tools for Nitrogen Optimization in Rice during Dry Season

“…Nevertheless, the improvement in straw quality and rigidity due to these factors was statistically insignificant when compared to treatments with sufficient nitrogen supply. These results corroborate the findings of Moharana et al (2019) and Mohanta et al (2021). The highest mean biological yield was recorded by T 9 and this result did not significantly differ from T 4 and T 8 .…”

“…This superior performance might be attributed to the former treatment, through its grain yield and enhanced nitrogen concentration in the grain dry matter due to precise and consistent nitrogen supply at adequate levels of phosphorus and potassium through real-time monitoring of chlorophyll index at regular intervals. These findings corroborate with the findings of (Moharana et al, 2019;Baral et al, 2021). However, it's worth mentioning that T 4 recorded the highest nitrogen uptake in rice straw in 2021 and 2022, respectively.…”

The Role of Net Assimilation Rate and Nitrogen Management in Optimizing Rice (Oryza sativa L.) Yield

“…In this study, IPB 3S exhibited lower productivity, potentially linked to a higher incidence of grain emptiness. These differential varietal responses concur with past evidence that genotypic variability in nitrogen response might be influenced by factors such as nutrient availability, application timing and concurrent growth-limiting stresseshighlighting the importance of strategic nitrogen management tailored to each variety in fully capturing its yield potential (Moharana et al, 2019).…”