Soil Pollution In Africa

Words: 1273
Pages: 6

Introduction
Soil has been used for many years for cultivating crops for consumption, But in recent years there has been a decrease in the yield of crops due to soil related problems. There has been an increase in salinization of soil, nutrient depletion and soil erosion. Around 950 million hectares of salt-affected lands occur in arid and semi-arid regions, which is 33% of the world's potentially arable land. Nutrient depletion is also has a very severe effect on the economy of the world, specifically Sub-Saharan Africa. Depletion rates per annum were estimated at 22 kg of Nitrogen, 3 Kg of Phosphorous, and 15 Kg of Potassium, per hectare (Sanchez, 2002).
Kenya has been facing a reduction in the production of food and thus correlates to the

The plants which are in soil get their oxygen from the soil and they rely on the oxygen in the air to pass through the soil and then to the roots of the plant. This can sometimes result in lack of oxygen or low levels of oxygen. The plants in hydroponics get their oxygen from the air pump which delivers air to the reservoir, thus oxygen is constantly passed through the water and the plants would get more oxygen than when in soil, thus they would be able to utilize this more oxygen effectively.
The hydroponics system requires the purchase of an air pump and air stone, which require electricity to run. It also requires hydroponic liquid nutrient solution, and the constant change of water and reproducing the same blend of nutrient solution. This requires time, energy and it can be quite costly. Whiles soil based plants need good agriculture soil, fertilizer, a pot, and water. This requires less time, and less money than hydroponics. Thus it is more costly to use hydroponics even though the yield may be

Thus my research question is: What is the difference in the effect of using hydroponics compared to soil as a planting medium on the yield of B. Oleracea Acephala?
Equipment/ apparatus
Hypothesis
It is common knowledge that plants need water, sunshine and soil. This is only partially correct as plants can now grow without soil. This method is more effective than using soil for a variety of reasons, the main being the availability of nutrients. In soil, the nutrients are diluted and have a lower concentration and spread out. Thus the plants have to use more energy to obtain the nutrients when in soil. In hydroponics, the plants do not have to use as much energy to obtain the nutrients as they are concentrated in water, this also means that they do not have to have longer roots.
Variables
Independent Variable: Hydroponic method- Deep water culture (as explained in the introduction)
Dependent variable: length of plant, number of leaves, length of