2024, Vol. 7, Special Issue 3

author(s)
Ramjeet Yadav, Shriman Kumar Patel, A Kohli, YK Singh, AK Jha, PK Yadav and Manish Pandey

abstract
Nutrient use efficiency concept is used to increase the overall performance of rainfed rice by providing economically optimum nutrition to the crops and at same time minimizing nutrient losses from the crop yield. A field experiment was undertaken during wet seasons of 2017 and 2018 to evaluate the response of soil applied Potassium and Nitrogen splitting in rice (Sahbhagi Dhan) under rainfed lowland conditions. The experimental was laid out on a sandy loam soil of Bihar Agricultural College farm, Sabour to derive inputs for rationalizing the use of Potassium (K) and Nitrogen (N) fertilizers by splitting and real time management respectively for making them more suitable for rainfed conditions. Nutrient and water management are important for diversifying and intensifying the rainfed rice based cropping systems. The experiment involved three K splitting schemes viz., K₀ (No K application), K₄₀ (K applied as basal @ 40 kg K₂O per ha) and K₂₀₊₂₀ (K application as basal, and at panicle initiation stage each @ 20 kg K₂O per ha) in main plots, and five N splitting schemes in sub plots viz.,N₀ (No N application), N₅₀₊₅₀ (N application as basal and at active tillering, each @ 50 kg per ha) N_SPAD (N application as basal each application @ 33.33 kg ha^-1 and top dressing as guided by SPAD meter with critical SPAD value of 38, N_GS (N application as basal @ 33.3 kg per ha and top dressing as guided by Green Seeker optical sensor) and N_33+33+33 (N application as basal, at active tillering and at panicle initiation, each @ 33.3 kg per ha.). The results revealed that the overall AE_N, PFP_N, RE_N and partial nutrient balance (PNB) of across all levels of K & N splitting for rainfed rice was comparatively lower than that of control plot which reflects that the nutrient splitting strategy of the effect of application of potassium and nitrogenous fertilizers was more than the direct effects in rainfed rice. Overall, the results indicated that the K & N splitting the use of real time fertilizers splitting in rainfed rice optimizing nitrogen use efficiency, as well as increased rainfed rice production and uptake thereby led to increased nutrient use efficiency of applied nutrients and crops.