**Abstract**

In this chapter, agricultural waste residue management by bio-organisms is discussed along with different types of decomposition processes. Tons of agricultural wastes are produced every year. These agricultural wastes create major environmental problems without effective means of management methods. There are many technologies being used for the decomposition, which mainly include anaerobic decomposition, compositing, fermentation, etc. All these decomposition processes depend upon the different soil-inhabiting microbes. These microbes are the key components of agri-residue decomposition process. Every step of decomposition requires different microbes. Various sets of catalytical enzymes are involved for the catabolic procedures of organic matter. By successive catabolic reactions, all the organic matters are mineralized into soil essential constituents, which will be the most effective sources of macro- and micronutrients for the soil fertility. Working efficiency of these microbes depends upon different parameters like moisture, temperature, pH, etc. The vitality and efficiency of microbes can be enhanced by using various inert carriers. If the efficiency of these soil microbes enhances by various factors, then the rate of decomposition could be enhanced to handle this ever-increasing problem of agriculture residue in near future.

**Keywords:** agri-waste, pollution, decomposition, mineralization, microbes

#### **1. Introduction**

Agricultural waste is produced by various agricultural operations, and it contains sugarcane baggage, paddy and wheat straw and husk, waste of vegetables, food products, jute fibers, crop stalks, etc. About 998 million tons of agri-residue waste is produced every year [1]. The abundance of agricultural waste production causes a lot of environmental pollution and generates many environmental contamination problems. During certain periods of time, characteristics of waste materials have changed and cause harmful and toxic effects toward human beings. Approximately, 2 tons per day agri-waste is produced in rural areas. Besides this, cow houses and sugar industry produced an average 20 million tons of waste, which is a rich source of nutrients and manures. Conventionally, farmers burnt up or left the agricultural waste in the field, but this causes lots of air pollution and soil pollution. Various techniques have been utilized for agri-residue disposal.

Agricultural waste mainly consists of crop residues which have lots of organic carbon content and a supply of plant nutrients. Crop residues' retention after

harvesting reduces soil erosion [2]. Combine harvester machines contributes 75% residue after harvesting but due to high silica content animals are not likely to feed these residues. Then farmers start to burn the residues, but burning emits 8.77 Mt. of CO, 141.15 Mt. CO2, 0.23 Mt. of NO, and 0.12 Mt. of NH3 [3], which causes air pollution and loss of organic content of approximately 80–90% N, 25% of P, 20% of K, and 50% of Singh et al. [4]. So, the rice straw management is a challenging task in rice-producing regions. So, there is a need for an effective waste disposal technology for converting this waste into some valuable form. Physical, chemical, and biological decompositions break the lingo-cellulose bonds in crop residues and result in the enhancing of the nutrient content of soil [5]. Biological decomposition is the main and efficient decomposition method in which bacterial and fungal spores speed up the decomposition of waste under aerobic and anaerobic conditions. Microbial decomposition enhances nutrient content by nitrogen fixing, phosposorous solublization, and cellulose decomposition of decomposed final product [6]. There are a variety of bio-decomposers such as bacteria, fungi, protozoa, etc. and they are capable to degrade cellulose by depolymerizing cellulases which hydrolyze lignocelluloses. Most commonly known bio-decomposers are fungi which include *Humicola*,*Trichoderma*, and *Penicillium aspergillus* [7]. The market sale value of soil microbes are increasing nowadays [8]. Indian government is working for food selfsufficiency and environmental sustainability. Due to the high market value, the production of soil microbial-based decomposer product would be expected to increase in coming years. Researchers have been able to identify and isolate multiple types of bio-decomposers, but still no formulation is available for the efficient use of these microbes. Researchers are working to improve the efficiency and storage of multiple types of microbes in an effective formulation product in one package which would have a high commercial value.

products. The leafy vegetables, fruits, and cereal crops residues are an efficient source of basic nutrients such as nitrogen, phosphorus, and potassium as well as secondary and micronutrients such as calcium, boron, magnesium, and manganese.

1.**Livestock manure**: The agricultural land is generally devoted to three farm animals: cattle, pig, and poultry, and lands used for the farms are about 15.3, 0.10, and 1.3 million hectares, respectively [15]. Around 120 million tons of

2.**Postharvest agricultural waste:** These wastes are in the category of primary agricultural residue. It mainly includes straw, husk, and stalks of planted crop,

decomposed by different waste decomposers or burnt. These residues are rich

which are left after harvest. These can be used in fodder and rest is

The bio-decomposer enhances the soil fertility and soil texture (**Figure 1**).

There are three major types of agricultural waste (**Figure 2**):

manure are produced from these livestock sectors per year.

**3. Types of agricultural waste**

*Agriculture waste percentage from different sources.*

*Role of Decomposers in Agricultural Waste Management DOI: http://dx.doi.org/10.5772/intechopen.93816*

**Figure 1.**

**Figure 2.**

**527**

*Types of agricultural waste.*

in cellulosic fibers [16].
