Quality Assessment Of Soils Under Irrigation Along The Jakara Stream In Metropolitan Kano, Nigeria

Paper produced for the Department of Geography, Bayero University, Kano, Nigeria (4731 words)
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“— a system of land use that is being practiced in metropolitan Kano will be considered. This system of land use that has been going on for centuries involves the use of stream water to irrigate land at the banks. Principal of these streams are Challawa, Getsi, Jakara and Salanta. The main objective is to produce fruits and vegetables for the consumption of the city dwellers. This system of land use has been called by Binns et al (2003), by the name urban and peri-urban agriculture (UPA).”

Complete paper can be read here.

Conclusions and Recommendations

The results have indicated that the quality of the soil for cultivation is only marginal in terms of fertility, largely caused by cultural practices that result in over utilization of the land transiting from rain-fed to irrigation agriculture.

The findings in this research have also shown that the levels of these metals in the soil has not reach a level that could cause any immediate threat as all the mean values have been found to be significantly lower than the internationally recommended values. There may however be a long term risk of concentrations rising to unwanted levels. Water quality is a major factor in determining success and safety of irrigation agriculture, and pollution of irrigated soils with heavy metals is a possibility when polluted water is being used for irrigation. Studies have already established high concentrations of many of such metals in the waters being used for irrigation in the area, which probably is a major source for the small concentrations detected in the soils, along with other sources such as fertilizer, chemicals and vehicular discharges. If current land use practices are maintained the soil could be at higher risk because of the tendency of metals to accumulate in the soil as they are hardly detoxified and they form complexes with various
substances in the soil.

Based on the findings therefore, the following recommendations are suggested;

1. Incorporation of higher levels of organic matter. The textural nature of the soil shows it to be predominantly sandy, which makes the soil susceptible to water loss. Incorporation of higher levels of organic matter may help to improve the water holding capacity of the soil, thereby reducing the need for frequent irrigation, which will further reduce the exposure of the soils to pollution source. Preferably, the organic matter to be used should be composted, which will rule out the need for decomposition within the soil environment, thereby
enhancing utilization of the minerals released by the organic matter, and helping to reduce the chances of the metals forming complexes with the organic matter.

2. Continuous monitoring of fertility situation in the soil with the aim of evaluating its quality for the land use.

3. Diversification of income generating activities. This will go along way in shedding off some of the pressure on the land. These activities could be farm or non-farm based. For example, commercial composting may be encouraged as an avenue to supply some of the farmers with alternative safe and cheap farm inputs. Other activities may include apiculture, renewable energy generation etc.

4. Re-planned farming system. This may involve a change in the crops being grown, such that high income generating crops may be incorporated in one round of farming so as to reduce the necessity of having to go for second round within the same season.