**2. Literature review**

#### **2.1 Sustainable agricultural practices**

The green revolution as it was called brought with it increased productivity enabling the world to meet its food needs. As of the mid-1960s, Asia was faced with a food crisis that threatened millions. This situation was salvaged by the green revolution, which made Asia self-sufficient with essential food products within 20 years [6]. This self-sufficiency that was the trend during the green revolution can be said to be coming to an unfortunate end given the looming food crisis and the prediction by the World Bank that the world will need to feed 8.9 million persons by 2050 (which has been reiterated by many researchers)**.** The agricultural practices that characterized the green revolution can be described as a quick fix that came at a very high cost. The positive effects of high yield were doused by negative impacts on the environment, such as erosion, water pollution, eutrophication of water bodies, water wastage, and the growth of resistant varieties of weeds and pests [7].

The transition from traditional agricultural practices to modern agricultural practices characterized by the use of machines, inorganic fertilizers, pesticides, and herbicides among others can be linked first to the Industrial Revolution in the eighteenthcentury discovery of fossil fuels in the twentieth century, which made the industrial production of agrochemicals possible [8]. Consequent to the green revolution, crops

### *Sustainable Agricultural Practices: Value Chain of Egusi, A Local Soup Condiment… DOI: http://dx.doi.org/10.5772/intechopen.109854*

were cultivated with little or no consideration for the depleting nutrients and the destruction of the soil structure. This, however, has polluted the entire agricultural value chain [9]. The use of pesticides destroys both pest and useful soil organisms, inorganic fertilizers cause water pollution when washed into water bodies, monocropping depletes soil nutrients without replenishing them, and heavy ridging destroys the soil structure making it more susceptible to erosion among others remain the major non-sustainable agricultural practices. Consequently, the need for sustainable agricultural practices cannot be overstated.

One of the earliest definitions of sustainable agricultural practices states that it is a set of management strategies that address the concerns of society about the quality of food or the protection of the environment [10]. Later, the focus was on the ability of agricultural practices to productivity over a long period and the capacity to adapt to changes in future. Currently, the criteria for sustainable agricultural practices are economic viability, environmental protection, and social consideration.

Franklin King [11] in his publication titled Farmers of Forty Centuries: Permanent Agriculture in China, Korea, and Japan brought to light how farmers in some parts of East Asia cultivated their fields for four centuries without depleting the soil. It was around the same time that industrialization was emerging. With machines, more efficiency and effective use of resources could be guaranteed. This led to higher productivity and profitability; hence, the long-term effect was not considered.

By adopting sustainable agricultural practices, it is not implied that farmers should return to pre-Industrial Revolution practices. Sustainable agricultural practices involve adopting a system of crop cultivation with the use of fertilizers, pesticides, and herbicides among others. Emphasis is rather placed on combining traditional methods and modern innovations that are sustainability-centric. These practices include crop rotation, water and soil conservation, use of organic fertilization methods, little or zero tilling, cover cropping, and many other practices that put into consideration the long-term implication of their application.

The International Federation of Agricultural Movement (IFOMA) opined that organic agriculture, which is sometimes used as a synonym for sustainable agricultural practices, is a method of production that can preserve the soil nutrients, ecosystem, and health of the members of the value chain. Such practices could be said to be the best agricultural system to adopt given the challenges of the present day [12]. Sustainable agricultural practices are been promoted because of their ability to enrich environmental biodiversity through the use of animal manure, compost manure, organic waste materials, crop rotation, mixed cropping, and biological pests and weed control methods.

Sustainable agricultural practices have a positive impact on the environment as well as the farm. These practices help soil microorganisms thrive. Soil microorganisms such as rhizobacteria produce bioactive substances, which in turn enhance plant growth and offer protection against pathogens [13]. The presence of soil microorganisms also promotes the aeration of the soil. Another noteworthy action of soil microorganisms is the replenishing of soil nitrogen through their action on the roots of legumes. Given this myriad of benefits offered to the soil by microorganisms, it is in place to protect and promote their existence in the soil. The consequence of the neglect is the increasing use of harmful chemicals in farming systems. In the bid to safeguard and enhance the existence of soil microorganisms, the use of eco-friendly agricultural chemicals, which contains effective microorganisms, has proven to enhance plant growth and environmental sustainability [13].

In 2012, a research by Chhetry and Mangang, the French Bean Rust was studied for 3 years. During the course of the study, farmers who adopted sustainable agricultural practices and those who adopted intensive methods were understudied. Their research revealed that intercropping beans with maize lessened the occurrence of beans rust as the maize served as a sort of barrier between the spores that cause beans rust and the leaves of the beans plant. Indications were also made that maize plants could have a negative effect on rust pathogens. The application of plant extract was found to be beneficial as it reduces the severity of bean rust although it did not reduce the occurrence of the disease. These findings led to the conclusion that sustainable agricultural practices are more effective in reducing bean rust compared to inorganic methods.

#### **2.2 Dimensions of sustainable agriculture**

The misconception would be to think that sustainable agricultural practices are targeted just to conserve the environment while negating the advantages of machinery, pesticides, and herbicides to improve yield and profitability for the farmer. In some corners, it is discussed as an ineffectual method of food production [14]. Contrary to the foregoing, it is a blend of science, traditional agricultural methods, and innovation [15] while putting into consideration the relationship between the environment and quality of life. Agricultural practices can be described as sustainable if they maintain productivity and profitability over a long period of time without compromising the ability of future generations to do the same. Simply put, the farm has to be viable economically, ensure environmental protection, and be socially fair [7]. Sustainability in agriculture has dimensions that encompass all areas of concern to the stakeholders in the agricultural value chain. These dimensions are economic, social, and ecological.

#### **2.3 Economic dimension**

Considering the overall economic viability of a farm is key to promoting sustainable agricultural practices. A farm can be said to be sustainable if it can cater to the financial needs of the farm and create value and profit throughout the value chain among other criteria. This brings to light the fact that sustainable agriculture is not just about environmental protection. It is pertinent that the farm is profitable. To incur a loss on account of the use of sustainable agricultural practices would be a contradiction and a poor application of sustainable practices. Economic profitability is a key criterion in ascertaining a farm practice of sustainable agriculture [15]. Economic sustainability can be achieved through the use of fewer inputs without putting productivity at risk.

When a farm decides to adopt sustainable practices, its dependence on input relating to intensive agriculture is reduced if not eradicated completely. Consequently, the production cost is reduced [16]. The argument is that shifting to sustainable agricultural practices will result in poor yield. However, it has been brought to light in practice that relying on crop rotation, mixed cropping, minerals-carrying rocks, planting cover crops, and biological means of pest control among other methods could result in high yield while maintaining soil fertility and productivity [17]. It is common for farmers to adopt cropping systems that enhance output, profitability, and sustainability [18]. Therefore, bringing to light the benefits of sustainable agricultural

*Sustainable Agricultural Practices: Value Chain of Egusi, A Local Soup Condiment… DOI: http://dx.doi.org/10.5772/intechopen.109854*

practices will serve to the advantage of ecological sustainability given the high level of ignorance among farmers in developing countries like Nigeria.

Intercropping has been considered a practice that is low input and energy-efficient [19]. Intercropping is an agricultural practice where two or more crops are grown together. These crops could be planted at different times and in most cases harvested at different times resulting in efficient use of resources, enhancing productivity and income as well as giving support to each other. Cultivating two or more crops simultaneously promotes the existence of insect pollinators, which in turn improves yield and also suppresses the growth of weeds because of plant population [19]. Leguminous plants have the ability to host predators, which results in a simpler pest management practice [20].

#### **2.4 Social dimension**

The social dimension of sustainable agriculture advocates for the welfare and safety of the players in the value chain. The prevailing practices in the past years have failed to meet the aspirations of a large part of society who seek good working conditions and dignified lives (www.ilo.org). This has led to the advocacy for practices that puts the welfare of people and the environment at the heart of its affairs. The employment relationship in the agricultural value chain has proved to be complicated. This is due to the nature of the contract, which is wage-based. This complicated relationship gives little or no room for proper benefits that ensures welfare. This is because the contract ends with the completion of each task with no guarantee of renewal.

This unclear relationship thrives because the employers hide the true legal status of engagement. The resulting effect denies the worker labor protection and other benefits. Sustainable agriculture promotes the proper treatment of employees and a better relationship among all members of the value chain, a relationship where trust and respect are evident. The adoption of sustainable agricultural practices results in increased labor demand, improved productivity, and higher reverse migration.

#### **2.5 Ecological dimension**

This dimension of sustainable agricultural practices stems from the rising cases of the pollution of both surface and groundwater, which is caused by the heavy application of chemical fertilizers, and pesticides and also the erosion of surface soil due to repeated tilling, which poses a great environmental challenge [21]. Agricultural practices and the environment are so closely linked in such a way that for agriculture to thrive, environmental processes need to be functioning properly, and the health of the environment depends on a balanced agricultural system [22]. From this closely knitted relationship, intensive agricultural practices can be referred to as self-sabotage.

The environmental degradation caused by intensive agricultural practices needs to be critically analyzed [23] and its long-term effect needs to be brought to the knowledge of the stakeholders in the agricultural value chain. Realizing that environmental pollution caused by intensive agricultural practices threatens the livelihood of millions could lead to the modification of agricultural systems that promotes both environmental sustainability and economic sustainability [24]. Putting the harmful effect of intensive agriculture in the open is not enough, innovative, and sustainable practices should be promoted. The importance of promoting sustainable agricultural practices goes without saying considering the harmful effect of chemicals on beneficial

microorganisms, which are responsible for fixing soil nitrogen and decomposition of organic wastes suppressing plant diseases among others. From the perspective of environmental protection and the vitality of soil microorganisms (which further impacts the overall health of the soil), intensive agricultural practices can be said to be a menace.

Such practices are mixed cropping, crop rotation, zero-till practice, use of compost, green manure and biopesticides, planting of cover crops, and effective water management among others. Intensive agricultural practices, such as mechanization use of chemicals, monoculture, and intensive tilling, led to the simplification of the different parts interacting in the agricultural systems. This has led to erosion, making the agricultural system prone to abiotic stress and thus, putting the agricultural system at risk of being unsustainable. In order to safeguard the sustainability of the cropping system, restoration of the biodiversity of farms is integral. This restoration can be achieved through the adoption of mixed cropping and other farming systems that guarantee sustainability [25].

The success of sustainable agricultural practices in promoting biodiversity and environmental production hinges on the effectiveness of the diversification of crops, the inclusion of leguminous crops in the cropping system, organic restoration of soil fertility, and the no-till practice. Notable among the benefits of mixed cropping to the environment is its ability to reduce runoff water because the crops tend to cover more ground. As insignificant as this may seem, less run-off water means less soil erosion and nutrient loss [26].

#### **2.6 Strategies for sustainable agricultural practices**

As earlier seen, the practice of sustainable agriculture has been heavily debated. Hence, in order to fully achieve sustainability, it is necessary for a workable framework to be followed. Mac Rea et al. [27] suggested substitution and agroecological and global strategies.

In substitution, the farming practices are not fundamentally altered but are slightly modified. The use of toxic pesticides, herbicides, and fertilizers is replaced with less toxic chemical compounds and the cultivation of genetically modified plants [7]. An agroecological strategy is a holistic approach. Here, ecological principles and concepts are applied to the planning and execution of all farm practices. Practices such as mixed cropping, crop rotation, and the use of compost manure are used to foster biodiversity [7].

The global strategy as the name implies seeks to find solutions to the adoption and application of sustainable agricultural practices at a global scale. In the global strategy, an interdisciplinary effort involving scientists, economists, politicians, and agriculturists is called for in order to fine-tune the current rough edges of sustainable agricultural practices, economic growth, and food security. The global strategy, therefore, implies that in order to achieve sustainability, the relationship between the players in the agricultural value chain has to be cemented as farm systems without the collaboration of the food systems cannot achieve sustainability [28].
