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

Reactive oxygen species (ROS) are excited or partially reduced forms of atmospheric oxygen, which are continuously produced during aerobic metabolism like many physiochemical processes operating throughout seed life. Previously, it was believed that ROS are merely cytotoxic molecules, however, now it has been established that they perform numerous beneficial functions in plants including many critical roles in seed physiology. ROS facilitate seed germination via cell wall loosening, endosperm weakening, signaling, and decreasing abscisic acid (ABA) levels. Most of the existing knowledge about ROS homeostasis and functions is based on the seeds of common plants or model ones. There is little information about the role of ROS in the germination process of halophyte seeds. There are several definitions for halophytic plants, however, we believed “halophytes are plants that can grow in very saline environment and complete their life cycle by adopting various phenological, morphological and physiological mechanisms at canopy, plant, organelle and molecular scales”. Furthermore, mechanisms underlying ROS functions such as downstream targets, cross-talk with other molecules, and alternative routes are still obscure. The primary objective of this review is to decipher the mechanisms of ROS homeostasis in halophytes and dry seeds, as well as ROS flux in germinating seeds of halophytes.

Salinity tolerance is presumed to be improved in the intercropping system, however, there has been inadequate evidence to scientifically prove this. In the current study, the effect of salinity was examined on forage yield and quality of sorghum and kochia in an intercropping system with different planting ratios in a two-year field trial at Shiraz University. The treatments included three salinity levels of irrigation water; 2 (non-saline as a control), 7 and 14 dS m⁻¹ in main plots and planting ratios; sole sorghum (SS), ⅔ sorghum-⅓ kochia (S₂K₁), ½ sorghum-½ kochia (SK), ⅓ sorghum-⅔ kochia (S₁K₂) and sole kochia in subplots. The results showed that salt stress decreased forage yield of both plants, especially of sorghum. Salt stress at 14 dS m⁻¹ reduced fresh and dry weights by 44.9% and 62.4% in sorghum, and 38.7% and 23.3% in kochia, respectively. Salinity also reduced forage quality assessed in terms of crude protein, ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), and total digestible nutrients (TDN). The optimum intercropping systems did not change forage yield, but it increased forage quality via reducing ash, ADF and NDF. The optimum planting ratio was S₂K₁ for both sorghum and kochia, while the SK ratio was suitable for kochia only. Under non-saline conditions, the sole crop cultivation was a better system, while under saline conditions intercropping with a low density of another plant led to higher dry and fresh weights, as well as lower ash, ADF and NDF for each plant. Since kochia performed as a dominant plant, sorghum growth was considerably suppressed under the high density of kochia (i.e., S₁K₂), especially at 14 dS m⁻¹ salinity level, which might have been due to high salt tolerance of kochia. Based on the findings of the current study, it could be inferred that in regions with limited freshwater, optimum planting ratio (SK in general for both plants) in an intercropping system could improve the quality of forage with no significant reduction in forage quantity.