Effect of slow release nitrogenous fertilizers and biochar on growth, physiology, yield, and nitrogen use efficiency of sunflower under arid climate

Abstract

Sunflower plants need nitrogen consistently and in higher amount for optimum growth and development. However, nitrogen use efficiency (NUE) of sunflower crop is low due to various nitrogen (N) losses. Therefore, it is necessary to evaluate the advanced strategies to minimize N losses and also improve sunflower productivity under arid climatic conditions. A field trial was conducted with four slow release nitrogenous fertilizers [SRNF (bacterial, neem, and sulfur-coated urea and N loaded biochar)] and three N levels (100% = 148 kg N ha−1, 80% = 118 kg N ha−1, and 60% = 89 kg N ha−1) of recommended application (100%) for sunflower crop under arid climatic conditions. Results showed that neem-coated urea at 148 kg N ha−1 significantly enhanced crop growth rate (CGR) (19.16 g m−2 d−1) at 60–75 days after sowing (DAS); leaf area index (2.12, 3.62, 5.97, and 3.00) at 45, 60, 75, and 90 DAS; and total dry matter (14.27, 26.29, 122.67, 410, and 604.33 g m−2) at 30, 45, 60, 75, and 90 DAS. Furthermore, higher values of net leaf photosynthetic rate (25.2 µmol m−2 s−1), transpiration rate (3.66 mmol s−1), and leaf stomatal conductance (0.39 mol m−2 s−1) were recorded for the same treatment. Similarly, neem-coated urea produced maximum achene yield (2322 kg ha−1), biological yield (9000 kg ha−1), and harvest index (25.8%) of the sunflower crop. Among various N fertilizers, neem-coated urea showed maximum NUE (20.20 kg achene yield kg−1 N applied) in comparison to other slow release N fertilizers. Similarly, nitrogen increment N60 showed maximum NUE (22.40 kg grain yield kg−1 N applied) in comparison to N80 and N100. In conclusion, neem-coated urea with 100% and 80% of recommended N would be recommended for farmers to get better sunflower productivity with sustainable production and to reduce the environmental nitrogen losses.

Evaluation of the Foliar Application of Nano Urea on the Performance of Rabi Sunflower (Helianthus annuus L.)

“…These findings were in close agreement with the findings of Adhikary et al [7], Siddiqui et al [8], Dambale et al [9]. This might be due to slow release nature of neem coated urea and plant assimilated more with the conventional urea Waqar et al [10]. This has led to more leaf area and drymatter.…”

Impact of weather parameters on maize agroecosystem and adaptation strategies under changing climatic conditions: A review: Sustainable and climate-resilient adaptation strategies in maize agroecosystem

“…The use of neem-coated urea showed the highest nutrient use efficiency i.e. 20 kg yield per kg nitrogen applied, and has resulted in an increase in the sunflower yield (2322 kg ha -1 ), biological yield (9000 kg ha -1 ), and harvest index of 25.8 % and for sustainable sunflower productivity, neem coated urea with 100 % and 80 % of recommended nitrogen helps to get higher productivity and reduces the environmental impact (48).…”

Amount and speciation of N leached from a sandy soil fertilized with urea, liquid digestate, struvite and NH4‐enriched chabazite zeolite‐tuff

“…Moreover, the relative concentration of NH 4 + ‐N in the leachates over the whole course of the experiment was nearly always less in N‐CHA than in STRV. This indicates that the release rate of this ion by CHA‐zeolite minerals through desorption processes (in this specific environment) is slower than the release rate of NH 4 + ‐N by STRV dissolution and much slower than from LD, suggesting that natural zeolites are more efficient in mitigating the N losses in this form and in improving the NH 4 + ‐N retention in sandy soils, which is essential for improving nitrogen use efficiency and crop yield (Geng et al, 2017; Ghafoor et al, 2021; Waqar et al, 2022).…”