Global warming
Agriculture at risk
[ By Mir Salam Sirak ]
A few decades ago, many kinds of wild fruit grew in the area south of Harare, including African chewing gum, a juicy fruit which grows on trees, and the bitter-sweet matamba. Mary Guzha used to live there when she was young. “We collected those fruits and ate them,” recalls the 84 year old farmer who now lives in Seke. Today, it is almost impossible to find those fruits.
What is bothering the rural people even more, however, is that the start of the rainy season has changed. As the elderly lady explains, there used to be the “madzura chando” (the winter rains in June), followed by the “gukurahundi” (the rain in August) and the “bumharutsva” (the rain in September). She goes on: “The kutemera gwati in November indicated the start of the actual rainy season and farmers knew exactly when to till their fields. But now we are completely at a loss.”
Priscah Mugabe (unrelated to President Robert Mugabe) is the deputy director of the Institute for Environmental Studies at the University of Zimbabwe and has analysed climate data for her country from 1901 to 2005. Research data show that the onset of the rains is now earlier and there are more events of heavy rainfall and even tropical cyclones. On the other hand, dry spells occur with greater frequency and intensity than they used to. Data from Zimbabwe’s Ministry of Agriculture, moreover, show that the 2009 rains started as early as 30 October, whereas the average start used to be 13 November.
There was a nationwide dry spell from mid-December 2009 to February 2010. Plants are particularly sensitive to drought in the grain-filling period and, accordingly, yields fell by more than 60 % in the regions worst affected. Meteorological studies have shown that rain levels in Zimbabwe have decreased in recent years by five per cent and the mid-season dry spell has become longer.
Climate projections assume a temperature increase of 0.15 to 0.55 degrees every ten years. The temperature in Zimbabwe has increased over the last century by 0.4 degrees which is relatively moderate compared with the global increase of 0.74 degrees. Nonetheless, it has wreaked havoc. There has been a steady decline in all crops every year since 1990. Maize, the staple food of the local people, is particularly affected. In areas with low rainfall, the harvest after the start of 2010 was only about 40 % of the previous year’s level. Yields from cash crops (tobacco, cotton, sugar peas and peanuts) and grains (sorghum and millet) have also shown a steady decline. Yields per hectare of land have fallen dramatically for farmers, their land is depleted and they are unable to afford any more fertiliser.
Land for maize and grains
In their time of hardship, farmers are devoting more and more land to the cultivation of maize and grain, a total now of about 400,000 hectares. There has been large-scale clearing of forests to provide space for fields, but deforestation also contributes to soil erosion. There was an increase in cattle breeding in the summer of 2009/2010 compared with the previous year. However, the meat quality fell considerably because animal feed is becoming scarcer. Ranchers too are affected by climate change.
In this context, the trend towards monocropping is harmful. Its origins go back in Zimbabwe’s history. Rather than looking for alternatives, farmers are now simply planting more of the established varieties hoping to secure their total yield – and the survival of their families. There is a clear increase in the area used to cultivate sorghum and grain from 2000 to 2010.
The additional land was distributed to the farmers during Zimbabwe’s controversial “land reform”. For the purpose of redistribution, commercial farmers were dispossessed of their land which was then given to those without land. The new owners seldom had any farming experience. They knew nothing about crop rotation and instead undertook large-scale forest clearing.
One reason for choosing to cultivate grain and sorghum could simply be the availability of seed. Neither the government nor the private sector in Zimbabwe manage to deliver seed on time to remote areas, so farmers have probably used their seed reserves to prepare for the next year. However, the decision to cultivate sorghum and grain is certainly a response to climate change too. Both varieties are relatively drought-tolerant.
Illegal clearing of forests
Plants sequester about two million tonnes of CO2 annually from the earth’s atmosphere, thus slowing down climate change. Long periods of hot weather have a negative impact on this process.
Some people in Zimbabwe, however, do not consider climate change the consequence of more carbon in the atmosphere; they think the cause is cultural change. “We used to hold our annual spiritual rain-making ceremonies in September every year”, recall members of the Vapostori sect. “Then it rained and we had bumper crops. But today even the Holy Place has been eroded. The elders who had ceremonial knowledge have passed away and with them their spirit has also turned away from us. That is why we are experiencing climate change.”
Others put climate change down to a decline in social values and unrestricted tree felling. Elderly farmers point out that the people once valued their native fruit trees: “Young people today are greedy and destroy nature for the sake of cash. They are cutting down all kinds of trees and sell the wood. They do not know that they are destroying the planet.” Village leaders complain that fines are not high enough to deter people from illegal logging.
In 1990, forests covered 57.5 % of Zimbabwe’s land area; in 2001 the share was 49.2 %. As the Zimbabwe Conservation and Development Foundation discovered in 2005, even the country’s national parks are in danger of destruction. Subsistence farmers in the Communal Lands – less fertile agricultural areas in joint ownership – are also cutting down the bush to cultivate more maize.
Dramatic shift in climate zones
Zimbabwe is classified into five natural climate regions (I-V) in regard to precipitation levels. Region 1 has the most rain and region V has the least. Regions IV and V are predominantly remote areas which are suitable only for extensive cattle breeding (few animals on a large area). In the south-eastern province of Masvingo, for example, the landscape is dominated by grassland and bush savannah, but intensive agriculture is possible in the province’s lowlands, where sugar cane, tobacco and cotton are cultivated. Most of Masvingo, however, is only suitable for cattle breeding.
The landscape of these regions is sensitive to climate change. Temperatures tend to be high, rainfall low, but there is flooding after sudden torrential rains. The topsoil is only a few centimetres thick. Grass and boxwood trees shade the ground and protect it from erosive wind and water, but also from drying up and overheating in the sunlight. The vegetation provides protection for the micro flora and fauna in a uniquely beautiful and exciting landscape.
In recent times there has been an eastwards shift in the climate regions. Chinhoyi, Chibero and their surroundings, which formerly belonged to natural climate region II, now belong to region III, and Kwekwe in the midlands has changed from region III to region IV.
The changes are particularly dramatic for the grasslands, which are turning into shrubby savannah. On farms, plant yields are falling in all marginal areas of rain-fed agriculture. Environmental expert Priscah Mugabe believes that total yields will fall up to half of today’s levels by 2020. Statistics on the maize harvest for 2009/2010 already seem to confirm this trend. Yields fell drastically in all marginal areas. Masvingo was particularly heavily affected with a 60 % drop in yields.
Farmers need support
In view of these trends, Zimbabwe’s Agritex (short for Agricultural, Technical and Extension Services), which was once the best institution of its kind in Africa, needs support in terms of human resources, funds and know-how in order to provide better advice to farmers. Zimbabwe already has sustainable concepts for agriculture. ICRISAT, the International Crop Research Institute for the Semi-Arid Tropics, introduced “Conservation Agriculture” in late 2008. The UN Food and Agriculture Organisation (FAO) and the German Technical Cooperation (GTZ) have run tests in numerous villages. In my personal experience, there has been much talk of “Conservation Agriculture” at village meetings. In practice, however, it is rarely implemented properly. Farmers either misunderstand the concept or fail to follow up on initial measures.
In view of declining levels of precipitation, it would be necessary to subsidise farmers who irrigate fields with water-saving methods and to assist rain-fed farms to cope with droughts more effectively. Farmers should also be offered fertilisers and seed of varieties with shorter vegetation periods. This is vital for stemming the worst effects of climate change on Zimbabwean agriculture.