Sunflower (Helianthus annuus L.) is an important oilseed crop in India popularly known as "Surakanthi flower" It belongs to the family Asteraceae. The global challenge for the coming decades is to increase the food production with utilization of less water. It can be partially achieved by increasing crop water use efficiency (WUE). Improving the water and nutrient use efficiency has become imperative in present day's Agriculture. A field trial was conducted at Water Technology Center, College farm, College of Agriculture, Professor Jayashankar Telangana State Agricultural University (PJTSAU), Rajendranagar, during rabi season (2018-19) to study the effect of different levels of drip irrigation regimes and fertigation on rabi sunflower. The experiment was carried out under split plot design with three main plot treatments (Irrigation regimes) and four sub-plot treatments (Fertigation levels) and replicated thrice. In irrigation levels sunflower performed better under 1.2 and 1.0 Epan in growth parameters followed by 0.8 Epan. The growth parameters, viz., plant height (214.4 & 214.6 cm), Number of leaves per plant (24.7 & 24.6), LAI (5.63 & 5.27), dry matter accumulation (6041kg ha^-1& 5683 kg ha^-1), Root depth (17.2 cm & 17.4 cm) and Root volume (91.5 cm³& 101.0 cm³) were found significantly higher at 1.2 Epan and 1.0 Epan. Among fertigation levels, fertigation with120% RD N & K₂O reported higer plant height (216.8 cm), Number of leaves per plant (25.5), LAI (5.96), dry matter accumulation (5950kg ha^-1),Root depth (18.6 cm) and Root volume (103.2 cm³) followed by 80% RD N & K₂O and 60% RD N & K₂O. The economic yield reported higher at 1.0 Epan (2082 kg ha^-1) and 100% RD N& K₂O (2162 kg ha^-1) in main and sub plot treatments than other treatments. The benefit-cost ratio was reported highest for Drip irrigation scheduled at 1.0 Epan (2.52) and fertigation with 100% RD N& K₂O (2.59) among the Irrigation and fertigation levels and concluded that drip irrigation scheduled at 1.0 Epan with 100% RD N & K₂O showed the best results.

Energy use efficiency is a key indicator of sustainability in pulse-based agricultural systems. This study evaluated the energy input–output performance of five major pulse crops of India—chickpea, redgram, lentil, greengram, and blackgram-across representative pulse-growing districts using standard energy equivalents and APSIM simulations. Total energy input ranged from 4579 MJ ha ⁻¹ in greengram to 10,048 MJ ha ⁻¹ in lentil, while energy output varied considerably across crops and regions. Redgram recorded the highest mean total energy output (110,346 MJ ha ⁻¹ ), net energy (101,868 MJ ha ⁻¹ ), and energy use efficiency (13.02). Lentil showed the lowest efficiency (5.02) and the highest specific energy (8.30 MJ kg ⁻¹ ). Chickpea exhibited relatively low specific energy (3.93 MJ kg ⁻¹ ) and stable performance under semi-arid conditions. Significant spatial variability in energy indicators reflected regional differences in climate and management practices. Overall, redgram and chickpea emerged as energetically superior pulse crops under Indian conditions. Quadratic regression analysis of the water use-yield relationship revealed crop-specific optima, with redgram requiring 600–900 mm seasonal water use for maximum yield, whereas chickpea, greengram, lentil, and blackgram showed optima between 100 and 550 mm. These findings highlight the importance of region-specific crop and water management strategies to improve productivity, energy efficiency, and sustainability in pulse-based cropping systems.

India faces large, persistent yield gaps across eight major crops—wheat, rice, maize, soybean, pulses, mustard, cotton, and sugarcane—that collectively limit food security and rural income. This review synthesises evidence from over 100 peer-reviewed studies (1990–2024) to provide the first comprehensive, multi-crop, agro-climatically resolved yield gap analysis for India. Applying the three-tier framework of potential yield ($Y_p$), attainable yield ($Y_a$), and farmer yield ($Y_f$), exploitable yield gaps are quantified at national and agro-climatic zone level, ranked limiting factors are identified, and projected climate change impacts are assessed. Yield gaps range from 20 to 35% in irrigated rice of the north-western Indo-Gangetic Plain to 60–75% in rainfed cotton and pulses of the semi-arid tropics. Yield gaps of blackgram across 20 major districts average 515 kg ha⁻¹, driven by moisture stress, biotic pressure, and management constraints. Nitrogen management, irrigation access, variety adoption, and sowing-date optimisation collectively explain 80–85% of exploitable gaps, while nitrogen and irrigation alone account for 40–58%. Closing 50% of exploitable yield gaps could add approximately 100 million tonnes of food grain annually without expanding cultivated area, directly supporting Sustainable Development Goal (SDG 2). However, climate change is projected to widen yield gaps of rainfed rice by 15–30% by the 2040s under Representative Concentration Pathway (RCP) 8.5. Beyond this crop-by-crop synthesis, the review proposes a constraint-transition framework in which the dominant type of limiting factor shifts predictably from biophysical (water, climate) in the largest-gap rainfed systems to agronomic management (nitrogen, sowing date, variety) at intermediate gap levels and to institutional and socioeconomic constraints (credit, extension, land tenure, gender) as gaps narrow in the best-resourced irrigated systems, thus offering a conceptual lens for prioritising interventions by development stage rather than by crop alone.