Micronutrient malnutrition is a global health challenge affecting almost half of the global population, causing poor physical and mental development of children and a wide range of illnesses. It is most prevalent in young girls, women, and pre-school children who are suffering particularly from the low consumption of vitamins and micronutrients. Given this global challenge, biofortification has proven to be a promising and economical approach to increase the concentration of essential micronutrients in edible portions of staple crops. Produce quality and micronutrient content can be further enhanced with the use of micronutrient fertilizers. Especially developing countries with a high percentage of malnourished populations are attracted to this integrated biofortification, combining modern agronomic interventions and genetic improvement of food crops. Consequently, maize, rice, wheat, beans, pearl millet, sweet potato, and cassava have all been biofortified with increased concentrations of Fe, Zn, or provitamin A in various developing countries. Today, there are several large-scale success stories in Africa and Asia that support the research and development of biofortified crops. In this review, we summarized what has been achieved to date and how edible crops can be further improved by integrating agronomic and genetic strategies to upgrade the nutritional status of children and adults around the world.
Exhaustive crops such as cotton require potassium (K) in copious amounts as compared to other crops. High yielding cultivars in cotton-wheat cropping system, have further increased its demand in cotton growing areas of Pakistan. As cotton is grown in arid and semiarid areas, therefore often prone to water deficiency. The reproductive growth particularly flowering and boll setting are highly sensitive to low soil water potentials, where enough K supply can play a vital role. In this two-year field studies, three cultivars (early, mid and late maturing) were cultivated at two K fertilizer levels 100, 200 kg K ha−1 along with control with no K fertilizer application at two irrigation levels. In first irrigation level, water was applied as per full irrigation schedule, while in water deficit irrigation water was applied at deficit irrigation schedule started after flowering till harvesting. It has been revealed that K application has impact on boll setting as well as seed cotton yield, however early and mid-maturing cultivars are more responsive to K fertilization. Furthermore, irrigation level had significant impact against K fertilization and relatively better response was observed in deficit irrigation as compared to full irrigation. Nevertheless, fiber quality parameters were unaffected by K fertilization. Considering the best benefit cost ratio under water deficiency, it is concluded that 100 kg K2O ha−1 should be applied at the time of seed bed preparation for economical seed-cotton yield of early maturing Bt cotton.
Excess nitrogen is a pollutant and global problem that harms ecosystems and can severely affect human health. Pollutant nitrogen is becoming more widespread and intensifying in the tropics. There is thus a requirement to develop nitrogen biomonitoring for spatial mapping and trend analysis of tropical biodiversity and ecosystems. In temperate and boreal zones, multiple bioindicators for nitrogen pollution have been developed, with lichen epiphytes among the most sensitive and widely applied. However, the state of our current knowledge on bioindicators is geographically biased, with extensive research effort focused on bioindicators in the temperate and boreal zones. The development of lichen bioindicators in the tropics is further weakened by incomplete taxonomic and ecological knowledge. In this study we performed a literature review and meta-analysis, attempting to identify characteristics of lichens that offer transferability of bioindication into tropical regions. This transferability must overcome the different species pools between source information - drawing on extensive research effort in the temperate and boreal zone - and tropical ecosystems. Focussing on ammonia concentration as the nitrogen pollutant, we identify a set of morphological traits and taxonomic relationships that cause lichen epiphytes to be more sensitive, or more resistant to this excess nitrogen. We perform an independent test of our bioindicator scheme and offer recommendations for its application and future research in the tropics.
26 March 2021 in Bulletin of Environmental Contamination and Toxicology