Agricultural system diversity is frequently touted as having advantages for a variety of goals, such as ensuring food and nutrition security in low- and middle-income countries. Based on a thorough search in Web of Science, our review aims to provide an overview of the strength and direction of the diversity-food security relationship as presented in research published since 2010.

The four dimensions of food security-availability, access, stability, and utilization-as well as different spatial scales and units of observation-from the individual to the global-are presented in an overview and their respective results are synthesized. Eighty-eight of the 924 publications surveyed meet the criteria for inclusion and provide information on the strength and direction of 314 distinct relationships between diversity and food security. Agricultural diversity increased food security in almost two thirds of all cases.

Agricultural diversity had no effect on food security in about one-third of the relationships or the results were inconsistent. Food security can be influenced by diversity, but the extent of this influence depends on the local farming system's more general socio-economic and biophysical characteristics. We come to known that diversification is a potential tactic for enhancing food and nutrition security.

We offer a number of suggestions for improving future research that can show the relationship between agricultural diversity and food security. Additionally, extensive discussion has been had regarding the buildup of heavy metals and pesticide residues in soils and plants. Additionally, a review of plant physiological parameters and characteristics of contaminated soil has been conducted.

Additionally, reports of human illnesses brought on by pesticides and heavy metal exposure were made. Both heavy metals and pesticides bioaccumulation mechanisms of action, and transmission pathways are highlighted. These contaminants' bioavailability in soil and plant uptake have also been taken into account. Meanwhile, it has been discussed how heavy metals and pesticides interact both positively and negatively, as well as the toxicity of these interactions alone. To fully address all facets of this review, earlier pertinent studies are included. The information in this review offers profound insights into our comprehension of environmental toxins and the dangers they pose.

The environment is becoming more polluted as a result of tremendous economic development and rapid growth in many sectors, including agriculture and industry. Environmental pollutants are poisonous substances that come from both anthropogenic and natural sources into the environment. Some environmental processes, such as burning waste, converting coal, and synthetic industries, have a negative impact on both biotic and abiotic (animals, plants, and people) communities. Environmental toxicants typically include pesticides and heavy metals and pose a serious threat to the ecosystem as a whole, seriously impairing both its structure and function.

Heavy metal sources were split into two main categories by scientists: anthropogenic and natural sources. Sedimentary rocks, volcanic eruptions, soil formation, and rock weathering are examples of natural sources, whereas domestic effluents, industry, agriculture, and mining are examples of anthropogenic sources. However, using pollution indicators is a useful way to distinguish between anthropogenic and geogenic soil pollution. Despite the use of sophisticated research techniques, it should be noted that source apportionment may be challenging in many instances. Alloway talked about the various heavy metal sources and how they vary, including the sedimentation of aerosol particles, heavy metal-containing raindrops, and agrochemicals. In general, this review covers the sources of heavy metals, the classification of pesticides, and the types of both toxicants in light of the aforementioned ecological risks.

The characteristics of agricultural soils that alter as a result of heavy metal and pesticide contamination are also covered. Additionally, various plant species negative effects, which can range from infection to death, have been discussed. The unique aspect of this study is that it offers an integrated synthesis of knowledge on the full pathway by which both heavy metals and pesticides enter the environment, accumulate in soil and plants, and eventually reach people. Additionally, reports on the combined toxicity of heavy metals and pesticides in soil, plants, and people as well as their synergistic and antagonistic interactions have been made.