Rice–wheat production in the Indo-gangetic plains (IGPs) of India faces major concerns such as depleting resources, rice residue burning, excessive fertilizer use, and decreasing nitrogen use efficiency. These issues threaten sustainable crop production in the future. Therefore, a field study was conducted during the winter seasons of 2020–21 and 2021–22 to evaluate the effect of combined conventional and nano fertilizers on nitrogen application just before or after irrigation to improve wheat productivity, profitability and NUE under conservation tillage. The study evaluated eight treatment combinations of nitrogen application through conventionally applied urea (46% N) and foliar applied nano urea (4% N) under zero tillage with rice residue retention. Results revealed that growth, physiological indices, yield, and quality parameters were enhanced with the application of 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation alone (T2) or along with a spray of nano urea (T5) compared to other treatments. T5 recorded 7.2%, 8.5%, and 7.8% more plant dry matter, number of tillers, and grain yield, respectively, over the conventional practice of applying 150 kg N/ha in three equal splits as basal and 7–10 days after 1st and 2nd irrigation (T3, farmers practice). Although, T2 showed similar results to T5, T5 recorded significantly higher gross ($2542/ha) and net returns ($1279/ha) than the other treatments. However, the benefit–cost ratio of T2 and T5 was same (2.01). A significant and positive correlation coefficient between grain yield and physiological parameters such as CCI and NDVI confirmed that increasing the nitrogen dose enhanced the chlorophyll content, greenness, and plant vigor. Based on the results, it can be concluded that applying 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation under conservation agriculture, along with a single spray of nano urea (4% N) at 60–65 days after sowing, can improve growth, yield attributes, wheat yield, and NUE compared to farmers practice (T3) in India.

The intercropping of legumes with cereals help to achieve sustainable intensification by their mutual complementarity at efficiently using radiation, nutrients, etc. Several studies indicated such beneficial effects on the other component crop however, little research has been conducted to quantify their effects on the subsequent crop in a cropping system. In this study, the effect of the legume intercropping on the entire cropping system, particularly the maize + legume-wheat system was studied. Four legumes intercropped to maize followed by wheat crop were studied for intensification measures such as wheat equivalent yield (WEY), land equivalent ratio (LER), sustainable value index (SVI), and economic returns. N saving effect of legumes on the subsequent wheat crop was quantified with two N levels. Maize + cowpea-wheat combination was the most productive and economic intercrop combination (LER = 1.71, SVI = 0.96) with an increase in net economic return (43.63%) with a B:C ratio of 1.94. An additional 25% N (37.5 kg ha⁻¹) was saved in the wheat crop when the legume intercropping was undertaken with maize. The results suggest that intercropping is the key to diversification and reduces the risk of crop failures by enhancing land-use efficiency, soil fertility, and economic returns under weather vagaries. This will be beneficial to small and marginal farmers of many countries.

The gradual increase in the consumption of mineral nitrogen is leading to heightened levels of harmful air pollutants, particularly N₂O emissions from the agriculture sector. A potential solution to address the issues arising from the excessive use of urea in wheat is the substitution of conventional urea with nano urea. This study aimed to quantify the effects of nano urea, both independently and in conjunction with prilled urea, under various agroclimatic and sowing conditions in India. To achieve this objective, a multi-location field experiment on nano and prilled urea was conducted under irrigated conditions across 21 locations with 13 different treatments during the agricultural seasons of 2021–2022 and 2022–2023. The experiments followed a randomized block design with three replications, covering diverse agro-climatic regions of India. Analysis of combined data from multiple years and locations revealed that applying the recommended dose of nitrogen (RDN), i.e., 150 kg/ha in NWPZ (North western plains zone) and NEPZ (North eastern plains zone), and 120 kg/ha in CZ (Central zone) and PZ (Peninsular zone), along with two sprays of nano urea, resulted in a significant increase in grain yield 7.6%, 8.0%, 5.5%, and 9.1% in NWPZ, NEPZ, CZ, and PZ, respectively, compared to RDN alone. Notably, using 75% RDN along with either two sprays of nano urea or 5% urea showed a non-significant (P ≥ 0.05) difference in grain yield compared to the full RDN. From the perspective of higher net benefits, the combination of RDN and two sprays of 5% urea emerged as the most favourable option. On the other hand, considering the higher marginal rate of return (MRR), the combination of 75% RDN and two sprays of 5% urea proved to be more advantageous for farmers across the zones. In conclusion, environmentally friendly practices such as two sprays of nano urea or 5% urea combined with 75% RDN present promising alternatives for Indian farmers seeking to enhance wheat grain yield. Thus, this practice can save 25% of nitrogen (1.02 billion kg) which can reduce 5.06 billion kg CO₂ equivalent emissions annually over recommended practice and can play a significant role in achieving the goal of net zero emissions by 2070 in India.

The rice–wheat cropping system being the backbone of food security in South-Asia has resulted in soil health deterioration, declining water table, and air pollution affecting livability index of the region. The effect of rice residue retention (RRR), irrigation levels and foliar application of K on wheat grain yield (GY), water use efficiency (WUE) and profitability was tested over three years. RRR increased wheat GY (5224 kg ha⁻¹), above-ground biomass (AGBM = 11.9 t ha⁻¹), tillers per square meter (TPM = 469) and grains per meter square (GrPMS = 13,917) significantly. Relative water content (RWC = 93.8) and WUE (2.45 k gm⁻³) were also increased significantly by RRR. Consequently, profitability (Net return = 624.4 $ and Benefit to cost (B:C) ratio) was enhanced. Foliar application of K enhanced GY (5151 kg ha⁻¹), AGBM (12 t ha⁻¹), RWC (94.1), SPAD (52.2), WUE (2.40 kg m⁻³), net returns (625.2 $) and BC ratio (1.62) significantly. RRR increased GY (15.66%) and WUE (17.39%) with additional revenue of 151 $ with only one irrigation at the CRI stage (ICS). RRR adopted over 10% of the area can earn 187 million-US$ annually. RRR if adopted over existing practice on a large area would reduce environmental degradation with an enhanced income to small and marginal farmers.

A field experiment was conducted for eight years at ICAR-Indian Institute of Wheat and Barley Research, Karnal, Haryana, India to study the skipping effect of P application on productivity, profitability and sustainability of rice-wheat cropping system. Rice yield and biomass were 8.35% and 6.6% higher where cowpea was grown after wheat compared to rice-vegetable pea-wheat crop sequence, respectively. Phosphorus application to rice or wheat or both crops exhibited at par rice grain yield, biomass, harvest index. Phosphorus application to both crops or only in rice crop produced maximum and significantly higher wheat yield (4.62 t ha⁻¹) as compared to P application only to wheat (4.48 t ha⁻¹). Eight years growing of green gram, cowpea and vegetable pea increased the organic carbon content 42.89, 16.38 and 4.57 %, respectively compared to the initial level. Skipping of P to either crop, by considering 13.5 million ha rice-wheat area, will save approximately Rs 40,500 million (Rs = Indian rupee) or US $ 623 million ($ = Rs 65) per year. Air pollution may be checked, due to saving on diesel in transportation of P fertilizer, to the tune of 60,383 tonnes of CO₂ per year by reducing emission of one of important global warming gas.