**1. Introduction**

Agro waste is called undesirable material that is generated from agriculture farming practices and includes crop residues, leaf litter, livestock waste, sawdust, weeds, and forest waste. Agro waste is misled or discarded in most part of this earth due to either unawareness or proper route to transfer and its utilization. These agro wastes can create a great constraint, if proper measures will not be taken off for its proper discard, as it can lead to a clearly impact on the environment issue. In addition to the hazards of burning and land filling, the synthetic chemicals adopted during farming and agriculture are able to instigate pollution if these wastes wind up in the undesirable places. Agriculture sector is the major backbone of the developing nations, and it is one of the greatest contributors to the GDP. Millions of people are adopting agriculture as their primary occupation in this earth. With the ever-increasing of the world

population, there is an escalation in the demand for food and food product supplies, so nowadays many people make use of modern agriculture to encounter the need. Modern agriculture uses the up-to-date cultivation technique along with synthetic fertilizers. Urban people are also adopting garden farming using modern methods. The demand for animal products such as milk products, poultry, and meat is also high, and producers have been developing new strategy to enhance the productivity and lower the unit cost of production. Chemicals such as fossil fuels, inorganic fertilizers, and organic pesticides improved genetics of production species and are enhancing the increase in the generation. The agro waste and its processing are a universal issue, as its major part is going for burning or to be buried in soil, which is responsible for pollution of air, water, and soil, a general loss of aesthesis. The degradation of water quality can affect adjoining water bodies and groundwater both on-site and off-site. Such kind of degradation in the water quality reduces the ability of water resource to support aquatic life and water consumption for humans and animals. Unplanned burying of agro waste leads to greenhouse emission and a major concern for climatic change. Conventionally, a large volume of agro waste is utilized as animal fodder, domestic combustion fuel, composting, roof thatching, etc. The management of agro waste and the reformation of its transition into a fit for use product through the utilization of biotechnology in agriculture are getting a lot of recognition nowadays [1]. Solid state fermentation can be considered as the better process for transition of agro waste into usable bioproducts. Different agro wastes such as wheat straw [2], barley straw [3], cotton stalks [4], sunflower stacks [5], etc., from abundant agriculture goods, as well as significant horticulture wastes such as apple [6], mango [7], orange peels [8], and potato [9] were used to create beneficial products in this review. Agro wastes can be used for contributing to guaranteeing resource efficiency, sustainable production and consumption, and the reduction of negative environmental impact on adopting recent and superior scientific methods in disposal of it [10]. The main objective of this chapter is to emphasize on the use of agro waste as a source for generating ecofriendly material such as (i) compost to enhance soil productivity, biodiversity, and sustainable environment; (ii) activated carbon, which can be used as adsorbent for removal of heavy metals from drinking and industrial wastewater; (iii) nanocellulose, which is widely applicable as membrane in water purification; (iv) the agro waste containing lignocellulosic residues can be used to produce different bioproducts including biofuel, biofertilizer, bioplastic, organic acid, etc. Furthermore, these value-added products can enhance the bioeconomy without affecting the environment.
