Growth Response of Cucumber (Cucumis sativus) to Organic and Inorganic Fertilizers under Shade House Conditions

The importance of soil fertility to plant growth is widely studied and is one of the most important factors for crop production. Soil quality which is sometimes used interchangeably with soil fertility is defined as the capacity of the soil to function within the boundaries of ecosystems to sustain biological activity, maintain environmental quality and promote plant and animal health (Krishna, 2002). Where plant production is concerned, soil fertility is a combination of the chemical, physical, mechanical and biological aspects of the soil that contributes to agricultural yield (Krishna, 2002). According to Krishna (2002) Soil fertility and crop management are the two most important ingredients of modern agricultural activity, he defined soil as the medium for crop production where the texture, soil composition, and aggregation along with other factors such as aeration, are essential considerations. The inclusion of soil additives to support the cultivation of crops is often indispensable to farming and many farmers rely heavily on fertilizer or other enriched material to support the growth of their plants. Soil additives may be in the form of fertilizers or other soil-enhancing inputs that affect the various production aspects of plants. In addition to soil additives, microorganisms play an important role in crop production whether positively or negatively. Bacteria and fungi in the soil may act as great advantages or disadvantages to crop growth and yield.

Plants take up nutrients easily from fertile soils and where there is biological balance, productivity is high, this allows for healthy plants to grow in a healthy environment (Sari et al. 2007). Deficiency due to the scarcity of single or multiple nutrients occurs regularly in agricultural soils and is made worse by intensive cropping practices assoil fertility drives crop productivity and thus crop yields. The scarcity of essential nutrients limits crop yield if not replenished. Fertilizer utilization in agriculture has assisted in increased crop production and helped in spreading agricultural zones to once infertile lands (Krishna 2002). Plants need more than just inorganic fertilizers, as the soil is a living system it needs to have a balance of organic, inorganic, and microorganisms as well as other important structural components.

Many countries around the world (IFOAM Organics Europe 2020) are focusing on sustainable agriculture and food safety (FAO, IFAD, UNICEF, WFP and WHO. 2019). A major focus for many sustainability-conscious farmers is to reduce the number of inorganic fertilizers used on the farm. Commercial farmers are therefore looking at different ways of improving yield and balancing the fertility of the soil. Some amendments studied (Minu Singh 2014), (Sari 2007), (N. Karagiannidisa 2011), (Tarraf W 2017), (Abay Ayalew 2012) and used effectively in other countries include a mixture of NPK and other fertilizers, compost, raw animal manure, microorganisms (IFOAM Organics Europe 2020).

The use of inorganic fertilizers has been the norm for avery longtime and we seethe effects of the depleted soil fertility from the use of inorganic fertilizers on our sugarcane (Chi L. 2017) and banana (Zake Y.K. 2000) production. Alternate ways of nourishing the soil are therefore necessary, these alternatives must also be available and adaptable to local conditions. These ways must be proven, economical, and can support the long-term fertility of the soil. There is a need for formal research and adequate testing of locally available soil nutrient sources.

As the world battles the unpredictable climatic variations it has become increasingly obvious that each nation needs to ensure its adequate food security. Global impacts such as the sudden decline in global trade and the uncertainty in the continuation of the crisis brought on by this pandemic, many countries are using more of their resources internally as opposed to exporting them (The World Bank 2020). The need for sustainable agriculture and food security ties in well with the United Nation's Sustainable Developments goals number 2, 6, 12, 13, and 15 (FAO, IFAD, UNICEF, WFP and WHO. 2019); Sustainable development goals: # 2: Zero Hunger, # 6: Cleaner Water and Sanitation, # 12: Responsible Consumption and Production, # 13: Climate Action, # 15: Life on Land. And therefore augments the need for such a local assessment as is being proposed. In an FAO 2019 report on‚ the state of food security and nutrition in the world, safeguarding against economic slowdowns and downturns‘ the authors highlighted that there is a trend in severe food security in the world, this they say is an indication of increasing hunger (FAO, IFAD, UNICEF, WFP and WHO. 2019). This trend started before the current COVID19 pandemic and has thus been exacerbated. The report warned of; slowing and stalled economic growth in many countries, including emerging and developing economies; episodes of financial stress; elevated trade tensions, declining commodity prices, and tightening financial conditions. All these warnings are a reality in this current time, not only for Jamaica but for many countries of the world. To make recommendations, the FAO pointed to the need for individual countries to implement short-term measures such as strengthening savings capacity when the economy is growing, as well as implement longer-term measures to ‘invest wisely during periods of economic booms to reduce economic vulnerabilities and build capacity to withstand and quickly recover when economic turmoil erupts” (FAO, IFAD, UNICEF, WFP and WHO. 2019). The FAO called for the transformation of the agriculture and food systems to include the types and quality of food production. If this was necessary before December 2019, we are now in a serious state of urgency to consider our food systems.

We can no longer rely on food, fertilizers, and other recourses coming from the USA and China, these are restricted by the internal need of these countries, trade tensions, and poor purchasing power among other factors (The World Bank 2020). Besides, if the FAO'scall for the transformation of the agriculture and food system to include the 'quality of the food' (FAO, IFAD, UNICEF, WFP and WHO. 2019) is to be considered at all, we must improve our food production to ensure food security. We are already constrained by our low storage capacity and must therefore find ways of producing food year-round. Locally grown foods when consumed also contribute to sustainability.

This research aims to test and identify sustainable methods of increasing the crop yield of Cucumis sativus, through the use of organic fertilizer treatments.