Biochar (BC) applications have multiple impacts on crops’ nutrient availability, growth and yield depending on the feedstock type and pyrolysis conditions. Pot and field experiments were conducted to examine the effects of biochars (BCs) prepared from three different feedstocks, Acacia modesta wood biochar (AWB), Dalbergia sissoo wood biochar (DWB) and poultry litter biochar (PLB), on soil’s nutrient availability, uptake by wheat (Triticum aestivum) and sunflower (Helianthus annuus) crops and their yield attributes. All BCs were applied at the rate of 10t ha⁻¹ in each treatment in both experiments, and pot and field trials were designed according to a two-factor factorial completely randomized design (CRD) and two-factor factorial randomized complete block design (RCBD), respectively. The concentration of soil NO₃-N, NH₄-N, Olsen P and extractable K increased by 98.5, 296, 228 and 47%, respectively, in the pot experiment with the application of PLB+polyhalite (PH) treatments. Similarly, in field experiments, NO₃-N, NH₄-N and Olsen P contents increased by 91, 268 and 156% under the PLB+PH treatment, respectively. However, in both experiments, soil’s microbial biomass phosphorus (MBP) was significantly higher after AWB+PH treatment, and the increments were 127 and 109% while microbial biomass nitrogen (MBN) contents were 16 and 14% higher than the control under DWB+PH and AWB+PH treatments, respectively, in the field experiment. Similarly, combined PLB+PH increased the total organic carbon (TOC) of soil by 193%. Moreover, PLB+PH co-applications with PH significantly increased sunflower grain yields by up to 58% and the harvest index by 45%. Overall, no negative impact with respect to BCs was observed on the soil’s nutrient content and plant growth. Hence, for immediate crop benefits and soil health, using nutrient biochar (PLB) alone or in combination with chemical fertilizers is recommended.

Currently, the global agriculture productivity is heavily relied on the use of chemical fertilizers. However, the low nutrient utilization efficiency (NUE) is the main obstacle for attaining higher crop productivity and reducing nutrients losses from these fertilizers to the environment. Coating fertilizer with micronutrients and biopolymer can offer an opportunity to overcome these fertilizers associated problems. Here, we coated urea with zinc sulphate (ZnS) and ZnS plus molasses (ZnSM) to control its N release, decrease the ammonia (NH₃) volatilization and improve N utilization efficiency by sunflower. Morphological analysis confirmed a uniform coating layer formation of both formulations on urea granules. A slow release of N from ZnS and ZnSM was observed in water. After soil application, ZnSM decreased the NH₃ emission by 38% compared to uncoated urea. Most of the soil parameters did not differ between ZnS and uncoated urea treatment. Microbial biomass N and Zn in ZnSM were 125 and 107% higher than uncoated urea, respectively. Soil mineral N in ZnSM was 21% higher than uncoated urea. Such controlled nutrient availability in the soil resulted in higher sunflower grain yield (53%), N (80%) and Zn (126%) uptakes from ZnSM than uncoated fertilizer. Hence, coating biopolymer with Zn on urea did not only increase the sunflower yield and N utilization efficiency but also meet the micronutrient Zn demand of sunflower. Therefore, coating urea with Zn plus biopolymer is recommended to fertilizer production companies for improving NUE, crop yield and reducing urea N losses to the environment in addition to fulfil crop micronutrient demand.

The low nitrogen utilization efficiency (NUE) of commercial fertilizers is one of the main hurdles in higher crop production and reduction of fertilizer N losses to the environment. However, interactions between most the macronutrients could have synergistic outcomes that affect crop NUE. The coating of urea with macronutrients and biopolymers may control N release and synergistically impact its crop NUE. In this study, urea was coated with 3% of different polymers, combined with 5% potassium iodide (KI) (i) Gum Arabica (GA + KI), (ii) polyvinyl alcohol (PVA + KI), and (iii) gelatin (Gelatin + KI) to control its N release, leaching, and increase of wheat NUE. Scanning electron microscopy, Fourier Transform Infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses confirmed the successful coating of all KI and biopolymer combinations on urea granules. All coating combinations slowed down urea release in water and reduced its leaching from the soil, but the highest reduction in both parameters was observed with the GA + KI treatment, compared to the uncoated urea. After soil application, GA + KI decreased urea leaching by 26% than the uncoated urea in lysimeter. In the field, soil mineral N remained significantly high with the GA + KI and PVA + KI treatments at the wheat tillering, booting, grain filling and maturity stages, compared to the uncoated urea. However, K content was only high (28%) with the GA + KI treatment at final harvest. Likewise, microbial biomass N was only high with GA + KI at grain filling (20%) and maturity stages (24%) than the uncoated urea. Such synchronized N availability led to high wheat grain yield (28%), N (56%) uptake, and apparent N recovery (130%) with the GA + KI treatment, compared to the uncoated fertilizer. The increment in NUE with GA + KI could be due to the synergistic effect of K on N availability; therefore, we observed higher wheat yield and N utilization efficiency with this treatment. Hence, urea coated with macronutrient (K) plus biopolymer is recommended to improve wheat yield, NUE, and for reduction of environmental N losses.

Wheat recalcitrance to in vitro culture is one of the most important and crucial steps for its genetic transformation, regenerate, composition of the media and genotype. Callus induction and regeneration potential of various explants, viz, mature embryo, immature embryo, endosperm supported (ES) mature embryo and shoot apical meristem, taken from the same investigated using Murashige and Skoog (MS) basal callus 2,4-dichlorophenoxyacetic acid (2,4-D) and regeneration media comprising various combinations of auxins and cytokinins. In vitro culture response of the explants taken from the same and media composition. Immature embryo culture of genotype AS-2002 exhibited the highest callusing ability (84.75 %) (78.50 %). Similarly, immature embryos cultured on MS basal exhibited the highest callusing ability of 90.83 and 88.33 %, regeneration medium comprising 0.4 mg/L 2,4-D, 1.0 mg/L potentials of 59.67 and 59.0 %, respectively. Appraisal of the supported mature embryo is the most suitable explant for plant .

Nitrogen is the major yield-limiting factor for Brassica napus but is often deficient in soils. Excessive and inefficient nitrogen application can lead to lodging, reduced nitrogen use efficiency, and increased shattering losses during mechanical harvesting. However, co-application of mepiquat chloride and nitrogen can be a viable agronomic intervention to alleviate these challenges. A two-year field study (2022-23 and 2023-24) with factorial randomized complete block design (RCBD) was conducted to unravel effects of nitrogen (0, 85, 170, 255 kg ha⁻¹) conjugated with foliar application of mepiquat chloride (0, 50, 100 mg L⁻¹) on shattering, lodging and nitrogen use efficiency (NUE) of B. napus . Increasing nitrogen from 0 to 255 kg ha⁻¹ significantly increased plant height, biological yield, lodging and shattering; however, integration of nitrogen with mepiquat chloride (MC) abridged these traits. In both years (2022-23 and 2023-24), 170 kg ha ^–1 nitrogen combined with 50 mg L ^–1 MC resulted in significantly higher number of pods plant ^-1 (375.88, 356.13), seeds pod ^-1 (24.30, 21.83), 1000-seed weight (3.84 g, 3.65 g), chlorophyll content (8.84 mg g ^–1 , 8.49 mg g ^–1 ), seed yield (2362 kg ha ^–1 , 2260 kg ha ^–1 ), NUE matrixes viz.; apparent recovery (53.68%, 51.57%), agronomic efficiency (6.36 kg kg ^–1 , 5.73 kg kg ^–1 ), utilization efficiency (13.64 kg kg ^–1 , 13.45 kg kg ^–1 ), agro-physiological efficiency (11.83 kg kg ^–1 , 11.14 kg kg ^–1 ), and antioxidant activity, but lower lipid peroxidation (MAD). Lodging was positively correlated with plant height ( r = 0.85, 0.71), biological yield ( r = 0.94, 0.89) and nitrogen uptake efficiency ( r = 0.75, 0.75), while seed yield was negatively correlated with shattering ( r = – 0.74, – 0.64) and malondialdehyde (MDA) content ( r = – 0.72, – 0.86). This is the first report demonstrating that combined nitrogen and MC application reduces shattering and lodging in B. napus , while improving yield. Applying 170 kg ha⁻¹ nitrogen and 50 mg L⁻¹ MC at rosette and silique formation stages is recommended for higher seed yield in water-deficient environments.