**Abstract**

The role of the agricultural sector in human development and economic development cannot be overemphasized. Awareness for increased agricultural production is on the increase, arising from the need to feed the ever-increasing human population. Interestingly, almost all agricultural activities generate wastes, which are generated in large quantities in many countries. However, these wastes may constitute a serious threat to human health through environmental pollution and handling them may result in huge economic loss. Unfortunately, in many developing countries where large quantities of these wastes are generated, they are not properly managed because little is known about their potential risks and benefits if properly managed. There are studies that address some of the challenges of agricultural solid wastes as well as suggestions on how they can be properly managed. In this chapter, we intend to explore the major sources of agricultural solid wastes, their potential risks, and how they can be properly managed.

**Keywords:** agricultural solid waste, animal feed, composting, environmental safety, recycling

#### **1. Introduction**

Increasing growth in human population has necessitated increased agricultural production. Agricultural production in the last five decades has been said to increase more than three times. Other factors responsible for increased agricultural production include technological advancement toward green revolution and expansion of soil for agricultural production [1, 2]. It has been estimated that agricultural sector provides about 24 million tons of food globally [1] with accompanying health risks and threat on ecosystems [3]. We cannot do without agriculture because food is a necessity across the globe, but the impact of agriculture on the environment is also evident. For example, it has been documented that about 21% of greenhouse gas emission comes from agriculture. The negative influence of agriculture on the environment, aquatic lives and human health have necessitated improvement in agricultural production, involving effective and efficient ways of handling agricultural solid wastes [4].

The global leaders have been mandated to prioritize production of more food and energy for increasing human population which is estimated to exceed 10 billion by 2050 as well as to tackle the impacts already caused. However, this mandate is expected to be achieved with lower emissions of pollutants, zero solid waste and

less fossil fuel [5, 6]. The future prediction for increased agricultural production involves food production for human population, industrial needs, and animal feed [7]. However, every step of agricultural production, processing and consumption generates quantities of agricultural solid wastes, depending on the type of agricultural produce or product, processing techniques and purpose of use.

The agricultural sector is one of the main sectors generating the largest quantities of agricultural solid wastes, which may be allowed to accumulate indiscriminately and constitute nuisance to global health and threat to food security or used as raw materials for bio-economy [8, 9]. The benefits of recycling of agricultural solid wastes include reduction of greenhouse gas emissions and use as fossil fuel as well as contributing significantly to the development of new green markets, creation of jobs, production of bio-energy and bio-conversion of agricultural solid wastes to animal feed [10, 11].

The emphasis on the management of agricultural solid wastes cannot be overemphasis. Agricultural solid wastes are generated from many sources. One of such sources are pesticides, including herbicides and insecticides. It has been estimated that the global food production would fall by an estimate of about 42% if the use of pesticide is completely stopped [12]. The influence of agricultural solid wastes on human health, animal health, and the environment is significant and all hands must be on deck to tackle the menace posed by mismanagement of agricultural solid wastes. Agricultural solid wastes are mismanaged largely owing to ignorance. Many of the farmers and household managers who generate these wastes do not know how to effectively manage them. Many of them do not know the health implications of what they toy with, while some who know are 'handicapped'. Year after year, large tons of agricultural solid wastes are being produced, with an annual increase of about 7.5% [13, 14]. In many parts in developing countries, agricultural solid wastes are indiscriminately dumped or burnt in public places, thereby resulting in the generation of air pollution, soil contamination, a harmful gas, smoke and dust and the residue may be channeled into a water source thereby polluting the water and aquatic environment [15–17].

### **2. Classification and causes/sources of agricultural solid wastes**

Agricultural solid wastes are produced mainly from farming activities. However, it is not limited to the production but other activities associated with farming and food chain. Every stage and phase of the agricultural-food chain can generate significant agricultural solid wastes. The broad classification of agricultural solid wastes includes the following:


Agricultural solid wastes are usually generated through agricultural activities involving preparation, production, storage, processing and consumption of agricultural produce, livestock and their products. Agricultural solid wastes are produced via:

	- 1.Farming activities—the main source of agricultural solid waste generation is agriculture. Beginning from land clearing till harvest, every phase of farming activities results in the generation of agricultural waste. From preparing the pen for the arrival of the animals to the farm, preparation of pasture/paddock till the animals are slaughtered and sold, solid wastes are generated.
	- 2.Poor road network for transporting harvested produce from the farm to the market or storage is another avenue of generating large quantities of agricultural solid wastes. This happens largely as a result of the bad road network in some developing countries, which may result in a road accident or delay of agricultural produce from farms to markets. When road accident occurs, perishable agricultural produce result easily in wastage, and when delayed, the same result may occur. The spoilt produce is either thrown away on the road or separated to be discarded once the farmer gets to the market. **Figure 1** shows agricultural produce being transported in a city in Nigeria.
	- 3.Poor electricity or lack of rural electrification—the epileptic power supply and lack of rural electrification in some parts of developing countries with significant agricultural activities are contributing in no small measure to the generation of agricultural solid wastes. Stable electricity could have facilitated the cold storage of the harvested produce and thereby reduce spoilage and consequently agricultural solid wastes.
	- 4.Inadequate drying technique and storage facilities—spoilage of much agricultural produce could be prevented with adequate drying techniques. If farmers have access to adequate drying technique or moisture monitor, it would have gone a long way in militating against food spoilage and agricultural solid waste, thereby enhancing food security and reducing the impact of agricultural solid waste on human health and the environment. Many of the farmers depend largely on the unpredictable solar system to dry their produce before they are stored, as well as rely on the conventional method of moisture monitoring which is neither effective nor accurate. Inadequate monitoring of moisture content in grain before storage has been reported to result in aflatoxin infestation. Aflatoxin is produced by *Aspergillus flavus*. Aflatoxin infestation is both a cause and a product of food spoilage [23] and its contamination of food and livestock feed can lead to significant annual crop losses globally [24].

It has been estimated that about 10% of global crop harvest is destroyed by filamentous fungi through contamination of food and feed with mycotoxins. Aflatoxins have been reported to produce liver carcinogens, impair human health in *Agricultural Solid Wastes: Causes, Effects, and Effective Management DOI: http://dx.doi.org/10.5772/intechopen.93601*

**Figure 1.** *Transportation of agricultural produce in Nigeria. Source: Vanguard Newspaper [22].*

developing countries, and result in the huge economic losses, in the U.S. corn alone amounting to about \$280 million annually. The economic losses could be as high as 1 billion dollars if other crop-infestation such as cotton, peanuts and tree nuts are included. Aflatoxins B1 and B2 which cause preharvest and postharvest crop infestation are produced by *Aspergillus flavus* [23].


#### **Figure 2.**

*Home-generated agricultural solid wastes.*


*Source: Li et al. [26].*

#### **Table 1.**

*Composition of kitchen wastes in Chinese cities (unit: %).*


#### **Table 2.**

*Nutritional characteristics of kitchen wastes in Chinese cities (unit: %).*
