The worldwide agricultural enterprise is facing immense pressure to intensify to feed the world’s increasing population while the resources are dwindling. Fertilizers which are deemed as indispensable inputs for food, fodder, and fuel production now also represent the dark side of the intensive food production system. With most crop production systems focused on increasing the quantity of produce, indiscriminate use of fertilizers has created havoc for the environment and damaged the fiber of the biogeosphere. Deteriorated nutritional quality of food and contribution to impaired ecosystem services are the major limiting factors in the further growth of the fertilizer sector. Nanotechnology in agriculture has come up as a better and seemingly sustainable solution to meet production targets as well as maintaining the environmental quality by use of less quantity of raw materials and active ingredients, increased nutrient use-efficiency by plants, and decreased environmental losses of nutrients. However, the use of nanofertilizers has so far been limited largely to controlled environments of laboratories, greenhouses, and institutional research experiments; production and availability on large scale are still lagging yet catching up fast. Despite perceivable advantages, the use of nanofertilizers is many times debated for adoption at a large scale. The scenario is gradually changing, worldwide, towards the use of nanofertilizers, especially macronutrients like nitrogen (e.g. market release of nano-urea to replace conventional urea in South Asia), to arrest environmental degradation and uphold vital ecosystem services which are in critical condition. This review offers a discussion on the purpose with which the nanofertilizers took shape, the benefits which can be achieved, and the challenges which nanofertilizers face for further development and real-world use, substantiated with the significant pieces of scientific evidence available so far.Graphical Abstract

Climate change and extreme weather events are threatening agricultural production worldwide. The anticipated increase in atmospheric temperature may reduce the potential yield of cultivated crops. Agroforestry is regarded as a climate-resilient system that is profitable, sustainable, and adaptable, and has strong potential to sequester atmospheric carbon. Agroforestry practices enhance agroecosystems’ resilience against adverse weather conditions via moderating extreme temperature fluctuations, provisioning buffers during heavy rainfall events, mitigating drought periods, and safeguarding land resources from cyclones and tsunamis-type events. Therefore, it was essential to comprehensively analyze and discuss the role of agroforestry in providing resilience during extreme weather situations. We hypothesized that integrating trees in to the agro-ecosystems could increase the resilience of crops against extreme weather events. The available literature showed that the over-story tree shade moderates the severe temperature (2–4°C) effects on understory crops, particularly in the wheat and coffee-based agroforestry as well as in the forage and livestock-based silvipasture systems. Studies have shown that intense rainstorms can harm agricultural production (40–70%) and cause waterlogging. The farmlands with agroforestry have been reported to be more resilient to heavy rainfall because of the decrease in runoff (20–50%) and increase in soil water infiltration. Studies have also suggested that drought-induced low rainfall damages many crops, but integrating trees can improve microclimate and maintain crop yield by providing shade, windshield, and prolonged soil moisture retention. The meta-analysis revealed that tree shelterbelts could mitigate the effects of high water and wind speeds associated with cyclones and tsunamis by creating a vegetation bio-shield along the coastlines. In general, existing literature indicates that implementing and designing agroforestry practices increases resilience of agronomic crops to extreme weather conditions increasing crop yield by 5–15%. Moreover, despite its widely recognized advantages in terms of resilience to extreme weather, the systematic documentation of agroforestry advantages is currently insufficient on a global scale. Consequently, we provide a synthesis of the existing data and its analysis to draw reasonable conclusions that can aid in the development of suitable strategies to achieve the worldwide goal of adapting to and mitigating the adverse impacts of climate change.

Pinus gerardiana Wall. is an important nut-producing pine having restricted distribution in the world. It has been observed that natural regeneration in the species is extremely poor or entirely lacking. The species has erratic and infrequent seed years, dormancy-related problems, and slow growth of seedling, which reduces its regeneration process in natural habitats. Therefore, we investigated the effect of growing medium and seed size on germination and seedling growth of the Pinus gerardiana. The seeds were categorized into two sizes, viz, small (2.35 cm) and five growing medium treatments were used, viz, Soil:Sand:FYM; Soil:Sand:Moss:FYM; Soil:Moss:Vermicompost; Soil:Sand:Vermicompost; and Soil:Sand:Moss:Vermicompost, for assessing their impact on germination and seedling growth. It was observed that, among different growing medium treatments, higher germination and seedling growth parameters were recorded, when Soil:Sand:Moss:Vermicompost was used for the study. Between different seed sizes, higher germination and seedling growth were recorded when seed size was large.