**4. Effective management of agricultural solid wastes**

There are options on how agricultural solid wastes could be handled. This chapter is necessary because of the need to focus people's attention on efficient ways of managing these wastes. Traditionally, shafts from palm oil processing could be used as fuel in fuel wood for cooking and heating. In the recent time, some of these wastes are put into better uses. Some of these agricultural solid wastes could be used as additives in cement mixes, water glass manufacturing, paper making, ethanol production, animal feed, electricity and biogas generation, heavy metal removal, mulching, organic fertilizers, and compost. An effective means of managing agricultural solid wastes is to recycle them to produce useful products. This can be achieved through:

	- 1.Compositing: Li et al. [26] recommended that kitchen wastes, largely agricultural solid waste from food wastage could be used as an animal feed via sterilization, fertilizer via composting and bioenergy via anaerobic digestion. These wastes are important candidates for compositing owing to their high organic matter content and nutrients, although their high salt, moisture content and oil may impair composting.
	- 2. Substrates for mushroom cultivation: mushroom has been grown on different agricultural solid wastes as substrates [32, 37]. Steps involved in mushroom cultivation and its benefits are highlighted by Olayiwola et al. [32].
	- 3.Nonconventional feed ingredient. Several attempts have been made to feed agricultural solid wastes to livestock as a means of recycling as well as a cheap source of feed for raising animal-source protein. A nonconventional feed ingredient, *mycomeat* has also been produced from agricultural solid wastes. The wastes served as substrate and a mixture of the substrates and the cultivated fungi (mushroom) was feed to broiler chicks, as a nonconventional feed ingredient, *mycomeat* [36–40] fed some agricultural solid wastes to albino rats and recommended processing of the wastes in order to obtain a better result. Adebiyi et al. [41] recommended the combination of 40% cassava peel +40% concentrate +20% watermelon wastes for feeding grower pigs. Poultry feathers could be used for several products instead of being indiscriminately discarded or burnt. Traditional, feathers are used for decoration, pillows and could be converted as nonconventional feed ingredients to feed livestock.

Feathers are a group of agricultural solid wastes that are generated in large quantities annually as a by-product of poultry processing [42].

It may account for about 6% of the total live weight of a mature chicken. They are rich in a keratinous protein, which is a fibrous and insoluble protein [43]. Adejumo et al. [44] reported protein content of between 84 and 87% for feather meal, hence, effective use of feather meal as livestock feed ingredient may payoff than its use as other produce. Feathers can be used in erosion control, for diaper filling, as biodegradable composites, in the greenhouse industry, animal feeds, upholstery, artwork, paper alternatives, light-weight structural materials, water filtration fibers, fabric, aircraft, and automotive industries and thermal insulation [45, 46]. The major limitation to the use of feathers as a livestock feed ingredient is the insoluble keratinous protein, but recent studies are suggesting ways of overcoming the limitation [38, 44, 47]. It has been documented that about 80% of kitchen wastes, largely food wastage are fed to pigs in China, although direct feeding of kitchen waste has not been without restriction in China, arising from the concern of foot and mouth disease [48] Processing of agricultural solid wastes could enhance their value for feeding pigs [49, 50]. The effect of dried sweet orange (*Citrus sinensis*) peel has been tested on humoral immune response of broiler chickens [51] as well as maize replacement and its effect evaluated on growth performance and carcass qualities of broiler chickens [52], instead of allowing them to accumulate and constitute a nuisance as agricultural solid wastes.


arising from open-field agricultural solid wastes burning or dumping but to improve energy production and reduce economic losses of waste disposal as well.

6.Production of silica: Production of silica: Silicon, the 2nd most abundant nonmetallic element in the earth crust with an atomic weight of 28 [61, 62] forms silica and silicates. It is rarely found in its elemental state owing to its affinity for oxygen [63]. It has been reported as a beneficial trace element, widely distributed in foods. Its health benefits include improvement of the structural integrity of nail, hair, skin, immunity, bone mineralization, bone calcification and reduces the occurrence of atherosclerosis [64–66]. In the presence of hydrochloric acid and other gastric fluids in the GIT, silicon compounds are degraded into bioavailable forms of silicic acid (ortho, meta, di, and tri-silicates) [67] and are diffused into different organs of the body [68, 69]. Silicon quantity decreases with age and tends to be more in plants than animal-sources, although dietary sources are low in silicon and may need to be supplemented in diets through other means [65, 70–72]. It does not bond with plasma proteins, hence, about 75% of plasma silicon is excreted within a few hours after ingestion [68, 73]. Agricultural solid wastes are potential sources of silica. Silica has been produced from agricultural solid wastes such as corn cob, rice husk, bagasse and rice straw using chemical, thermal, and microbial methods [74–79].

### **5. Conclusion**

Food wastage is an important source of agricultural solid wastes. Hence, the prevention of food wastage at all levels before they are created will salvage some of these wastes and prevent unnecessary ill-health and environmental disadvantages as well as huge economic losses. This can be achieved through proper education and awareness of those involved with agricultural activities at all levels as well as being a little more generous by feeding hungry people with fresh food instead of keeping them till they are spoilt. There are hungry people everywhere in the world. Feeding animals saves food scraps and bioconversion of agricultural by-products, which may turn to agricultural solid wastes if their values are not enhanced and will go a long way in preventing such wastes as well. Composting and conversion of agricultural solid wastes to a renewable energy source is another effective way of managing agricultural solid wastes. It is high time attention is focused on turning these huge potential agricultural solid wastes to wealth, particularly in developing countries. To make our world safer for us to live, all hands must be on deck. Research activities should be geared toward commercial scaling of some productive findings made toward the efficient recycling of agricultural wastes.

Proper awareness should be made to everyone involved in agricultural activities whether at a middleman or woman, farmer, or consumer on the effects of indiscriminate disposal of agricultural solid wastes and benefits of efficient management of agricultural solid wastes. Political leaders, particularly in developing countries should be open-minded and formulate policies that ensure the efficient recycling of agricultural solid wastes and appropriate funds should be earmarked to achieving this. Attention should be focused on minimizing wastage by creating a more efficient sustainable agricultural supply chain through the development of sustainable durable markets and improving rural infrastructures such as electrification, roads, and storage [34].

#### *Agricultural Solid Wastes: Causes, Effects, and Effective Management DOI: http://dx.doi.org/10.5772/intechopen.93601*

It should also be noted that huge revenue could be generated from the conversion of agricultural solid wastes into useful products, as it has the potential of employing people if well-harnessed. Hence, its importance goes beyond the health implication but includes income generation for individual and governments which receive tax from companies and individual working in such establishments involved in the conversion of wastes to useful products. Also, it could contribute significantly to minimizing civil unrest plaguing some villages in developing countries. Some idle youths used to foment trouble could be scarce to find if they are gainfully employed, and that gainful employment could be companies or individuals who are efficiently engaging in turning agricultural solid wastes to wealth. Recycling of agricultural solid wastes into useful products could generate other sets of agricultural solid wastes, which may serve as raw materials for another useful products, thereby necessitating the continuous recycling of agricultural solid wastes until every potential waste is converted into wealth.
