One of the biggest challenges to be addressed in world agriculture is low nitrogen (N) use efficiency (<40%). To address this issue, researchers have repeatedly underlined the need for greater emphasis on the development and promotion of energy efficient, and environmentally sound novel fertilizers, in addition to improved agronomic management to augment nutrient use efficiency for restoring soil fertility and increasing farm profit. Hence, a fixed plot field experiment was conducted to assess the economic and environmental competency of conventional fertilizers with and without nano-urea (novel fertilizer) in two predominant cropping systemsviz., maize-wheat and pearl millet-mustard under semi-arid regions of India. Result indicates that the supply of 75% recommended N with conventional fertilizer along with nano-urea spray (N₇₅PK+nano-urea) reduced the energy requirement by ~8–11% and increased energy use efficiency by ~6–9% over 100% nitrogen through prilled urea fertilizer (business as usual). Furthermore, the application of N₇₅PK+ nano-urea exhibited ~14% higher economic yields in all the crops compared with N₅₀PK+ nano-urea. Application of N₇₅PK+nano-urea registered comparable soil N and dehydrogenase activities (35.8 μg TPF g^-124 hrs^-1across all crops) over the conventional fertilization (N₁₀₀PK). This indicates that application of foliar spray of nano-urea with 75% N is a soil supportive production approach. More interestingly, two foliar sprays of nano-urea curtailed nitrogen load by 25% without any yield penalty, besides reducing the greenhouse gases (GHG) emission from 164.2 to 416.5 kg CO₂-eq ha^-1under different crops. Therefore, the application of nano-urea along with 75% N through prilled urea is an energy efficient, environmentally robust and economically feasible nutrient management approach for sustainable crop production.

The energy consumption pattern and greenhouse gas (GHG) emission of any rice production system is important to know the sustainability of varied cultivation and establishment technique. This study was conducted to determine the energy use pattern, GHG emission and efficiency of rice farms in puddled transplanted (PTR, rainfed) and direct-seeded rice (DSR, irrigated) production systems in Karnataka, India. The energy indices and GHG emission of different input and output in a rice production system were assessed by using energy and carbon equivalence. The efficiency of PTR and DSR farms were identified using data envelopment analysis (DEA) and energy optimization was ascertained. The key finding was excessive use of non-renewable energy inputs was observed for the PTR (92.4%) compare to DSR (60.3%) methods. The higher energy use efficiency (7.3), energy productivity (0.3 kg MJ⁻¹) and energy profitability (6.3) were mainly attributed to the large decrease in energy inputs under DSR. The DEA showed efficiency for 26 PTR farms in comparison for 87 DSR farms. The mean technical efficiency value highlighted the scope for saving energy by 6% and 2% in PTR and DSR, respectively and showed an economic reduction of $405.5/ha with PTR versus $163.3/ha with the DSR method if these inefficient farms perform efficiently. The GHG emissions revealed that the total emissions for PTR versus DSR production caused by on-farm emissions were 86% and 65%, respectively. The DSR method also had a higher carbon efficiency ratio and carbon sustainability index (10.1 and 9.1, respectively). Thus, adoption of DSR method is imperative for reduction of energy consumption and GHG emissions to achieve the carbon sustainability.

It is widely accepted that deficiency of macro (nitrogen) and micronutrients (zinc, copper etc.) affects the plant growth and development which cause a significant threat to crop production and food security. The Indian Farmers Fertilizer Cooperative (IFFCO) developed nano-urea (nano-N), nano-zinc (nano-Zn), and nano-copper (nano-Cu) liquid fertilizer formulations to enhance the crop yields, simultaneously addressing the nutrient deficiency, without causing toxicity. Therefore, this study was formulated to evaluate the effectiveness of nano-N (nano-urea), nano-Zn, and nano-Cu at varying N levels [0, 50, 75, and 100% of the recommended rates of nitrogen (RRN)] on maize-wheat and pearl millet-mustard systems during 2019–20 and 2020–21. The results exhibited that the application of nano-N + nano-Zn with 100% RRN exhibited significantly higher grain yields in maize (66.2–68.8%), wheat (62.6–61.9%), pearl millet (57.1–65.4%), and mustard (47.2–69.0%), respectively, over absolute control plots and combinations of three nano-fertilizers like nano-N + nano-Zn + nano-Cu applied plots. This was mainly attributed to the higher N and Zn uptake by the crops. However, 75% RRN with nano-N + nano-Zn also produced comparable yields. Thus, applying nano-N and nano-Zn via foliar applications, in conjunction with conventional urea, has the potential to reduce the required nitrogen fertilizer amount by up to 25%, while simultaneously maintaining equivalent yield levels. Similarly, 100% RRN and 75% RRN + nano-N + nano-Zn registered comparable profitability, soil mineral N, dehydrogenase activity (DHA), and soil microbial biomass carbon (SMBC), during both the study years. However, further research and field trials on nano fertilizers alone or in combination with conventional fertilizers are essential to fully unlock its benefits and ascertain its long-term effects which may offer a pathway to more efficient and eco-friendly crop nourishment.

Environmental crises, declining factor productivity, and shrinking natural resource is a threat to global agricultural sustainability. The task is much more daunting in the Indo-Gangetic northern plains of India, where depletion of the underground water table and erratic rains due to the changing climate pose a major challenge to agriculture. To address these challenges a field investigation was carried out during 2016–2018 to test the efficacy of biopolymeric superabsorbent hydrogels namely Pusa Hydrogel (P-hydrogel: a semi-synthetic cellulose derivative-based product) and kaolin derivative of Pusa Hydrogel (K-hydrogel: semi-synthetic cellulose derivative) to assess their effect on crop and water productivity, soil moisture, root dynamics, and economics of soybean (Glycine max L.)–wheat (Triticum aestivum L.) system under three irrigation regimes namely full irrigation, limited irrigation and rainfed. The results revealed that the full irrigation along with P-hydrogel led to enhanced grain yield, biomass yield, and water productivity (WP) of soybean (1.61–10.5%, 2.2–9.5%, and 2.15–21.8%, respectively) and wheat (11.1–18.3%, 12–54% and 11.1–13.1%, respectively) over control plots. Likewise, under water stressed plots of rainfed conditions with P-hydrogel exhibited 52.7 and 20.6% higher system yields (in terms of wheat equivalent yield) over control and other combinations during the respective study years. Whereas the magnitude of increase in system yield under limited irrigation with P-hydrogel was ~ 15.1% and under full irrigation with P-hydrogel was 8.0–19.4%. Plots treated with P-hydrogel retained 3.0–5.0% higher soil moisture compared to no-hydrogel plots, while K-hydrogel treated plots held the lower moisture (4.0–6.0%) than the control. In terms of profitability, full irrigation along with P-hydrogel plots registered 12.97% higher economic returns over control. The results suggested that P-hydrogel (2.5 kg ha⁻¹) reduces runoff water loss in full irrigation applied plots and retained more water, where loss of water is more thus reduces number of irrigations. Hence P-hydrogel with irrigation water is a viable option for sustainable production of soybean-wheat systems in the Indo-Gangetic plains of India and other similar eco-regions of the world.

Residue management has become a new challenge for Indian agriculture and agricultural growth, as well as environmental preservation. The rice-wheat cropping system (RWCS) is predominantly followed cropping system in the Indo-Gangetic plain (IGP), resulting in generating a large volume of agricultural residue. Annually, India produces 620 MT of crop residue, with rice and wheat accounting for 234 MT of the surplus and 30% of the total. Farmers are resorting to burning crop residue due to the short window between paddy harvest and seeding of rabi season crops, namely wheat, potato, and vegetables, for speedy field preparation. Burning of residues pollutes the environment, thus having adverse effects on human and animal health, as well as resulted in a loss of plant important elements. This problem is particularly prevalent in rice-wheat-dominant states such as Punjab, Haryana, Uttarakhand, and Uttar Pradesh. If we may use in situ management as residue retention after chopper and spreader, sowing wheat with Happy seeder/zero drill/special drill with full residue load, full residue, or full residue load incorporation with conventional tillage, burning is not the sole approach for residue management. In addition, off-farm residues generated are being utilized for animal feed and raw materials for industries. While there are regional variations in many mechanization drivers and needs, a wide range of mechanization components can be transported to new places to fit local conditions. This article focuses on innovations, methods, and tactics that are relevant to various mechanization systems in particular geographical areas. This article also stresses the need for a thorough analysis of the amount of residue generated, residue utilization using modern mechanical equipment, and their positive and negative effects on crop yield and yield attributes, weed diversity, soil physic-chemical, biological properties, beneficial, and harmful nematode populations in the IGP, which will aid researchers and policymakers in farming research priorities and policy for ensuring sustainability in RWCS.

‘Participatory-mode’ adaptive research was conducted in wheat in north-western Himalayas (NWH) during 2008–2014 to develop an improved chemical weed management (ICWM) technology. First of all, two years ‘on-farm experimentation’ was performed in a randomized block design at 10 locations in NWH using seven treatments (Clodinafop @ 60 g a.i./ha (Clod); Clod followed by 2,4-D (Na-salt) @ 1.0 kg a.i./ha (Clod-fb-D); Isoproturon 75 WP @ 1.0 kg a.i./ha (Iso); Iso + D; Sulfosulfuron 75% WG @ 25 g a.i./ha + Metsulfuron 5% WG @ 2 g a.i./ha (Sulf + Met); weed-free-check; and un-weeded-check). In this study, the post-emergence application of Sulf + Met reported the lowest weed-index and NPK depletion by weeds with higher weed control efficiency (86.4%), weed control index (81.1%) and herbicide efficiency index (2.62) over other herbicides. Sulf + Met exhibited significantly higher wheat productivity (3.57 t/ha), protein yield, net-returns and water-productivity, which was followed by Iso + D and Clod-fb-D, all of which remained statistically at par with each other. An impact assessment of intensive technology-transfer programme (2008–2014) revealed a higher technology adoption rate (71–98%) of ICWM leading to higher wheat productivity (~22%) and net income gains (2.8–26.4%) in NWH. Overall, Sulf + Met proved highly effective against mixed weed flora in wheat to boost wheat productivity, profitability, quality and water productivity in addition to a higher technology adoption rate and NIGs to transform rural livelihoods in NWH.