Plant ecology a single growth-limiting resource, perhaps for light in agricultural systems with sufficient water and nutrients, or in dense stands of marsh vegetation, but in many natural ecosystems plants may be colimited by several resources, e.g. light, phosphorus and nitrogen at the same time. Therefore, there are many details that remain to be uncovered, particularly the kinds of competition that arise in natural plant communities, the specific resource(s), the relative importance of different resources, and the role of other factors like stress or disturbance in regulating the importance of competition. Mutualism is defined as an interaction "between two species or individuals
Natural growth promoter Natural growth promoter Natural growth promoters (NGPs) are feed additives for farm animals. Different categories of feed additives for farm animals are referred to as natural growth promoters (NGPs) or non-antibiotic growth promoters. They are commonly regarded as favorable alternatives to antibiotic growth promoters (AGPs) in livestock production. NGPs include predominantly organic acids, probiotics, prebiotics, synbiotics, phytogenics, tannins, feed enzymes and immune stimulants., an ongoing search for alternatives has created a large variety of NGPs for pigs, poultry, ruminants and aquatic species. The main advantage of NGPs over AGPs is that they do usually not bear any risk regarding bacterial