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In water scarce regions of South Asia, diversification of rice with maize is being advocated towards sustainability of cereal-based cropping systems. Adoption of innovative agronomic management practices, i.e., conservation agriculture (CA) and sub-surface drip irrigation (SSDI) are considered as key strategies for much needed interventions to address the challenges of water scarcity under projected climate change. Benefits from CA and SSDI concerning water economy are well-established, however, information about their complementarity and water budgeting in cereal-based systems are lacking. A field study was conducted with process-based model (HYDRUS-2D) to understand water transport, root water uptake and components of soil water balance in maize grown in rotation with wheat after five years of continuous adoption of conservation agriculture. In this study, altogether eight treatments comprising of 6 CA+ treatments (CA coupled with SSDI); permanent beds using sub-surface drip (PB-SSD) with (WR) and without (WOR) crop residue at different N rates, 0, 120 and 150 kg N ha −1 were compared with CA (PB using furrow irrigation-FI with crop residue-120 kg N ha −1 ) and conventional tillage practices (CT) (CT using FI without crop residue-120 kg N ha −1 ). Results showed that the model could simulate the daily changes in profile soil water content with reasonable accuracy in all the treatments. Simulated soil water balance indicated higher cumulative root water uptake (CRWU), lower cumulative evaporation (CE) and higher soil water retention in CA+ (PB-SSD+ crop residue at 150 and 120 kg N ha −1 ) than CA and CT plots. Hydrus-2D model efficiency > 0, RMSE between 0.009–0.026 and R 2 value between 0.80–0.92 at P  < 0.01 indicates that the model is performing efficiently. The mean evaporation from CA+ treatments was 10 and 36% less than CA and CT treatments, respectively. On average, CRWU under CA+ treatments were 14–48% higher than FI treatments. The mean cumulative deep drainage in CA+ plots was 80–100 mm less than CA and CT plots. In CA+ based plots significantly higher biomass production and radiation use efficiency were observed with reduced water use than CA and CT. Therefore, the study justifies the water-saving nature of CA+, while maintaining higher productivity and meeting the transpiration demand of crops and halting unnecessary evaporation and deep drainage losses.

India faces significant air quality challenges, contributing to local health and global climate concerns. Despite a national ban on agricultural residue burning and various incentive schemes, farmers in northern India continue to face difficulties in curbing open-field burning. Using data from 1021 farming households in rural Punjab in India, we examine the patterns and drivers of the adoption of no-burn agriculture, particularly for farmers who mulch instead of burning crop residue. We find a growing trend in no-burn farming practices among farmers between 2015 and 2017, with the highest adoption rates among large farmers compared to medium and small farmers. Our findings suggest that access to equipment and learning opportunities may increase the likelihood of farmers using straw as mulch instead of burning it. Specifically, social learning appears to increase the likelihood of farmers embracing no-burn practices relative to learning from extension agencies. Furthermore, the form of learning depends on farm size. While large and medium farmers exhibit a variety of learning strategies, small farmers primarily self-learn. These results underscore the importance of a multiprong policy that provides sufficient access to equipment and a combination of learning platforms that enabling farmers from different land classes to adopt no-burn technologies.

Development of a sustainable and environment friendly crop production system depends on identifying effective strategies for the management of tillage and postharvest crop residues. Three-year (2004-2007) field study was initiated on two soil types to evaluate the effect of straw management (burning, incorporation and surface mulch) and tillage (conventional tillage and zero tillage) before sowing wheat and four nitrogen rates (0, 90, 120 and 150 kg N ha⁻¹) on crop yields, N use efficiency, and soil fertility in the northwestern India. Effect of tillage and straw management on nitrogen transformation in soils was investigated in a laboratory incubation study. In sandy loam, grain yield of wheat with straw mulch-zero-till (ZT) was 7% higher compared to when residues were burnt-ZT but it was similar to straw burnt-conventional till (CT), averaged across 3 years. In silt loam, grain yield of wheat with straw mulch-ZT was 4.4% higher compared to straw incorporated-CT, but it was similar to straw burnt-CT. Response to N application was generally observed up to 150 kg N ha⁻¹ except in 2004-2005 on sandy loam where N response was observed up to 120 kg N ha⁻¹, irrespective of straw and tillage treatments. In sandy loam, RE was lower (49%) for straw burnt-ZT than in other treatments (54-56%). In silt loam, RE was higher in straw mulch-ZT compared with straw incorporation-CT (65 vs. 58%). In sandy loam, AE was higher in straw burnt-CT and straw mulch-ZT compared with the other treatments (19.2 vs. 16.9 kg grain kg⁻¹ N applied). In silt loam, AE was lower in straw incorporation-CT than in other treatments (16.0 vs. 17.6 kg grain kg⁻¹ N applied). Rice yield and N uptake were not influenced by straw and tillage management treatments applied to the preceding wheat. Recycling of rice residue (incorporation and surface mulch) compared with straw burning increased soil organic carbon and the availability of soil P and K. There was more carbon sequestration in rice straw mulch with zero tillage (25%) than in straw incorporation with conventional tillage (17%). Soil N mineralization at 45 days after incubation was 15-25% higher in straw retention plots compared with on straw burnt plots.

Farmer profit can be increased and air quality improved Although intentional use of fires to transform land has decreased globally ( 1 , 2 ), particularly among highly capitalized countries through regulatory and market-oriented approaches and moral suasion, regulatory strategies have been less effective in southern and eastern Asia (see table S21). Some densely populated agricultural regions in China and India buck the global trend, showing increases in agricultural fires ( 2 ). This is particularly true in northwestern India, where rice residue burning makes a substantial contribution to air pollution and short-lived climate pollutants ( 3 , 4 ). Regulations are in place to reduce agricultural fires, but burning continues because of uncertainty regarding policy implementation and regarding access and returns to alternative technologies. With the field burning season soon upon us, we synthesize emerging evidence on alternatives to burning, clarify the business case for alternative practices, identify remaining uncertainties, and discuss approaches to increase their widespread adoption. Often, there are difficult trade-offs between environmental improvement and profitable economic opportunities. The case of crop residue management in northwestern India does not appear to fit this pattern and provides lessons that may be useful elsewhere.

The environmental carrying capacity is usually assumed to be fixed quantity in the classical predator–prey population growth models. However, this assumption is not realistic as the environment generally varies with time. In a bid for greater realism, functional forms of carrying capacities have been widely applied to describe varying environments. Modelling carrying capacity as a state variable serves as another approach to capture the dynamical behavior between population and its environment. The proposed modified predator–prey model is based on the ratio-dependent models that have been utilized in the study of food chains. Using a simple non-linear system, the proposed model can be linked to an intra-guild predation model in which predator and prey share the same resource. Distinct from other models, we formulate the carrying capacity proportional to a biotic resource and both predator and prey species can directly alter the amount of resource available by interacting with it. Bifurcation and numerical analyses are presented to illustrate the system’s dynamical behavior. Taking the enrichment parameter of the resource as the bifurcation parameter, a Hopf bifurcation is found for some parameter ranges, which generate solutions that posses limit cycle behavior.

We study the properties of travelling combustion waves in a diffusional thermal model with a two-step competitive exothermic-exothermic reaction mechanism. This investigation considers the system in one spatial dimension under adiabatic conditions. Based on the notion of the crossover temperature, the model is examined analytically using the activation energy asymptotic method to predict travelling combustion wave behaviour in the limit of large activation energies. The model is then studied numerically using a shooting-relaxation method over a wide range of parameter values, such as those describing the ratios of enthalpies, pre-exponential factors and activation energies. It is demonstrated that the flame speed as a function of these parameters is a single-valued monotonic function and there are two flame regimes identified—each region representing parameter values when one reaction dominates the other.

The rice–wheat system (RWS) practiced in northwestern parts of the Indo-Gangetic plains of India is highly productive, but conventional practices are resource (water, labour and energy) and cost intensive. A 4-year field study evaluated the effects of green manure (GM), crop residue and tillage on crop yields, economic profitability and soil fertility in a RWS. Four main plot treatments in rice included combinations of wheat stubble and Sesbania aculeata GM management: (1) puddled transplanted rice (PTR) with no wheat stubble, (2) PTR with 25% wheat stubbles (15–20 cm high) retained, (3) PTR with no wheat stubble plus GM, and (4) PTR with wheat stubble splus GM. Three sub-plots treatments in subsequent wheat included (1) conventional till wheat with rice straw removed (CTW R0 ), (2) zero till wheat with rice straw removed (ZTW R0 ) and (3) zero till wheat with 100% rice straw retained as surface mulch (ZTW R100 ). The results showed that main rice yield was significantly higher (8.0%) with 50% less fertilizer N application in GM compared with conventional PTR with no GM. Rice treatments did not affect the grain yield of subsequent wheat. ZTW R100 produced significantly higher mean wheat grain yield by 7.3% and 17.5% compared with CTW R0 and ZTW R0 , respectively. System productivity was 11.5% higher in PTR with wheat stubble + GM followed by ZTW R100 compared with the conventional RWS and resulted in Rs 24,075 ha −1 more net returns. Significant increases in soil organic carbon, available P and available K contents were recorded in ZTW R100 over CTW R0 . Recycling rice and wheat stubble in the field in RWS is also environment friendly as it avoids ill effects of straw burning.

Firefighting is a hazardous occupation that requires the wearing of appropriate protective clothing which must be designed to be flame- and heat-resistant while also allowing for a firefighter’s ease of movement. To increase the thermal protection provided by a firefighting suit and decrease the likelihood of the firefighter receiving skin burns, we propose incorporating a layer of a phase-change material (PCM) as well as air gaps in its structure. We investigate the distribution of heat through the layers of a firefighting suit and skin to determine whether this approach will be successful when different suit configurations are exposed to a range of fire scenarios with external heat fluxes between \\[5\\, kWm^-2\\] and \\[84\\, kWm^-2\\]. We use a one-dimensional model of heat transfer which we solve numerically to determine the length of time each suit configuration allows a firefighter to be exposed to heated conditions before suffering irreversible thermal skin damage. Thermal damage to the skin is known to occur when the temperature in the basal layer exceeds \\[44\\]°C. Our earlier research indicated that the combination of air gaps and a PCM layer reduces the likelihood of skin burns, and that the most effective position of a PCM in a suit is near the outer layer.This current work considers a number of different PCM compounds for providing additional thermal protection while ensuring that the extra weight required is feasible for a firefighting suit. We found that of the PCMs studied, \\[ MgCl_2 6H_2O\\] with an overall thickness of 0.17 mm gave the best improvement in the time until thermal skin damage (of between \\[13\\%\\] and \\[19\\%\\]), depending on the fire scenario.

The self-heating and spontaneous ignition process pose a fire risk for industrial biomass piles during storage. Most studies, from theoretical to numerical, pay more attention on the effect of pile size on self-heating and self-ignition, which in essence is due to chemical reactions. However, the effect of ambient humidity on the self-heating and spontaneous ignition process, which is due to physical process of water evaporation and vapor condensation, is not well understood. In fact, fire accidents and the related experimental studies have shown that the sudden increase of ambient humidity would cause the rapid increase of biomass pile temperature, leading to spontaneous ignition. In order to fill this knowledge gap, this work proposed a computational self-heating model, coupling heat and mass transfer process and both the microbial and chemical reactions. The processes of moisture evaporation, transportation and convective exchange of vapor were considered in this model to study the effect of humidity on self-heating process. The model was validated against the full-scale experiments of Zhanjiang Biomass Power Plant firstly. The numerical results show that the sudden increase of ambient humidity can lead to a quick increase of pile temperature due to the condensation process. Spontaneous ignition is highly dependent upon the heat generation evolution of the chemical reaction within the pile. The sudden increase of humidity could speed up the chemical reaction process, leading to a fire. This study helps understand the role of humidity on self-heating process during biomass storage.Graphic Abstract

Cr3C2-NiCr, NiCr, WC-Co and Stellite-6 alloy coatings were sprayed on ASTM SA213-T11 steel using the HVOF process. Liquid petroleum gas was used as the fuel gas. Hot corrosion studies were conducted on the uncoated as well as HVOF sprayed specimens after exposure to molten salt at 900 °C under cyclic conditions. The thermo-gravimetric technique was used to establish the kinetics of corrosion. XRD, SEM/EDAX and EPMA techniques were used to analyze the corrosion products. All these overlay coatings showed a better resistance to hot corrosion as compared to that of uncoated steel. NiCr Coating was found to be most protective followed by the Cr3C2-NiCr coating. WC-Co coating was least effective to protect the substrate steel. It is concluded that the formation of Cr2O3, NiO, NiCr2O4, and CoO in the coatings may contribute to the development of a better hot-corrosion resistance. The uncoated steel suffered corrosion in the form of intense spalling and peeling of the scale, which may be due to the formation of unprotective Fe2O3 oxide scale.