Zambia: Impact of climate change on agriculture
In the next few weeks, this column, Our Organic World will focus on climate change and how it impacts on agriculture and issues of household and national food security.
It is important to appreciate that the impact of climate change on agriculture is two-fold. This impact is ranked as primary and secondary and this column will try as much as possible to focus on both categories of impact. Primary impact is that, which has a potential of directly invoking the actual change in climate, while secondary impact is that which arises as a consequence of primary impact. In this regard, the impact on agricultural production is of primary nature, while the resultant effects on food security, income, mitigation and adaptation is of secondary nature.
A number of reliable studies have been conducted in the past to assess the impact that climate change continues to have on the environment and the welfare of the people at large. In Zambia, the studies have confirmed a positive correlation between climate change and the deterioration of living conditions particularly for small-scale farmers. Way back, from 1976, studies have indicated reduction in crop production in seasons of droughts and extreme wetness confirming a positive relationship between rainfall amount and crop production levels.
Some of the research considered in this article includes the Ministry of Tourism, Environment and Natural Resources research report, which confirmed loss of yield within the last 20 years due to prolonged dry spells and shorter rainfall seasons. The International Red Cross and Red Crescent societies also reported an 80 per cent crop failure during the 2004-05 season. One female farmer, Susan, of Petauke District suffered a 70p er cent loss in maize production during the 1994-95 agricultural season. The highest failure in maize production was in 1992 when 730,000 metric tonnes was harvested against the expected production of 1,200,000 tonnes. During this time, 660,000 hectares of land was planted. The loss was even heavier at 740,000 tonnes in 1995 considering that more land, with 850,000 hectares was committed to maize production.
Climate change affects crop production by compromising internal chemical processes that build the dry matter, which is stored as grain or tubers. Therefore, the stage in plant development at which departure from normal temperature and water supply occurs is crucial. A reduction in mean temperature from normal during the growth stage and reduction in soil water tend to slow down the processes that are essential for production of harvestable dry matter stored in the grain and tubers. Low dry matter production means low yields and harvests. Low harvest translates into low sales volumes, which in turn translate into low net incomes.
Maize is by far the most important crop grown by many small-scale farmers for food and income. Small-scale farmers produce the bulk of maize for national consumption and food reserves. In 2008-09 agricultural season, their contribution to the national food basket was above 80 per cent of the national food needs as noted by the Ministry of Agriculture and Cooperatives during the launch of Farmer Input Support Programme (FISP) in 2009. Any production slumps by small-scale farmers have telling effects on the national food security and the economy. The national food shortages experienced since the 1991-92 droughts are a result of a significant reduction in maize production by small-scale farmers, which can be attributed to drought and excessive rains.
Small-scale farmers in Zambia are vulnerable to climate change. Their production systems are wholly based on natural resources and rainfall. Development organisations and local civil society organisations have recorded food shortages arising from droughts and floods. Some of the impact of climate change that can have a direct impact on farmers and affect food production include; reduced crop production, loss of livestock, loss of income and an upsurge in environmental diseases such as cholera, malaria and dysentery, loss of property, shelter and extreme exhaustion as effects of climate change. It is also important to note that El Ni-o-related droughts exert a heavy toll on the inhabitants and economies of southern Africa resulting in significant decreases in agricultural production, which exacerbates food insecurity.
Without quantifications, the Ministry of Tourism, Environment and Natural Resources in its 2007 report stated that livestock numbers and fish populations decline when temperature increases and increases when temperature decreases. This phenomenon is attributed to the fact that food availability for both livestock and fish is in abundance in good rainy years, which are also years of temperatures lower than those of drier years. Veterinary experts have recorded higher rates of out break of diseases during the droughts and floods and livestock populations tend to significantly reduce as a result of diseases such as foot and mouth and corridor diseases.
These temperature variations result in widespread hunger being experienced by millions of people during and subsequent drought years. The major crop grown in specific areas also dictates regional variations in food production. Southern, Central and Eastern provinces, whose major crop is maize and occupy more than 70 per cent of the total area cultivated in these provinces are more vulnerable to food deficits. Maize yields in these areas show a very positive correlation with the total seasonal rainfall. In the Northern Province, where only about 18 per cent of the total cultivated area is planted with maize, yields does not indicate a correlation with the total seasonal rainfall. Sorghum, a drought-tolerant crop, which is widely grown throughout the country, does not have correlation with seasonal rainfall.
Changes on climate change have been found to lead to high poverty levels and it is estimated that the economic impact of climate change on net revenue for rain-fed agriculture in Zambia, shows that an increase in mean temperature in November and December and a reduction in mean precipitation in January and February have negative effects on net farm revenue. They respectively lead to a reduction in net income of 243 per cent and 253 per cent respectively. On the other hand, an increase in mean temperature in January and February led to 237 per cent increase in net farm revenue. Based on rainfall scenarios of 1991 - 92, 1994 - 95 and 2006 - 07, studies have shown a significant increase in poverty head counts at national level and respective agro ecological regions associated with severe droughts and floods. The national poverty rate has been said to rise by 7.5 per cent in a severe drought year and by 3.9 per cent in a modest drought year, while it rises by 2.4 per cent in a year with severe floods.
Researchers warn of extended negative impacts on fresh water resources and rangeland quality and rangeland areas. The quality of rangeland and rangeland areas will deteriorate as to decimate livestock production. The current water management resources may not be sufficient to cope with these impacts and many Zambians would be exposed to increased water stress. This is likely to adversely affect livelihoods and exacerbate water-related problems, which have a direct bearing on agriculture production.
Disclaimer: Opinions expressed in this article are those of the writer(s) and not do necessarily reflect the views of the AfricaFiles' editors and network members. They are included in our material as a reflection of a diversity of views and a variety of issues. Material written specifically for AfricaFiles may be edited for length, clarity or inaccuracies.