4. A new maize modernizes savanna farming.
In: IITA 1990; Publ. of the Int.Inst. of Trop. Agriculture, (IITA), Nigeria, 1990, pp. 5-8
A new maize has broken the mode of agriculture in northern Nigeria, enabling farmers to begin modernizing their age-old practices with intensified farming.
Agricultural procutivity has improved markedly in the most savanna zone of northern Nigeria. Recent surveys there by IITA and the Institute for Agricultural Research (IAR) have shown increases in use of improved maize, fertilizer, and improved management practices, such as animal traction and effective weeding, as fallow periods have become abbreviated.
IITA has developed a high-yielding maize variety, TZB, by building on two composite breeding lines of Nigeria's Federal Department of Agricultural Research. In experimental trials the new variety yielded consistently one-and-a-half to two times as much as local varieties.
Also, it was resistant to the fungal diseases of rust, blight, and ear rot, and highly adapted to growing conditions in the savanna.
The agricultural development projects introduced TZB to northern farmers and demonstrated how to obtain high yields.
Maize has become a major food crop in virtually all villages, and a major cash crop in more than two-thirds of them.
Sorghum, traditionally the favorite food crop, is still planted over a greater area than maize. However, since TZB outyields local varieties of sorghum and millet, the other staple cereals in the region, TZB can reduce the land requirement for feeding farmers' families. Many farmers have found that, by growing TZB for household consumption, they can free additional land for cash crops. With the surplus over food needs being marketed, farmers have increased their cash income which they can use to reinvest in cash crop production.
The characteristics which enabled TZB to make farming so commercially viable are its high yields and attractive appearance. Experiments on farmers' fields show that TZB, with moderate levels of fertilizer, yields 21-115% more than local maize. Its grain quality, with a white color and resistance to the ear rot, make it compatible with local food preferences.
The question of sustaining intensification, moreover, spotlights two distinct and critical issues: economic sustainability, in terms of the profitability of maize production; and environmental sustainability, in keeping up soil fertility and keeping down pests and diseases.
Environmental sustainability becomes a problem when cereals dominate the cropping regime, as sorghum and maize do in the savanna. Cereal dominance drains the soil of nutrients, because cereals demand a high level of soil fertility to be productive. And cereal dominance leads to a build-up of specific pests - insects, fungal diseases, nematodes, the parasitic weed striga, among others - because a similar pest and disease complex preys on all cereals. An ominous threat lies in the proximity of sorghum, historically striga's main host, with maize, also highly susceptible. The combination appears to be hastening the spread of the pest.
Several research institutes have joined to explore ways to help promote sustainability by expanding the role of nitrogen-fixing legumes in the cropping system. Legumes restore soil fertility with nitrogen from their residues or direct deposits.
1094 92 - 4/137
Asia, Thailand, study, field trials, environmental effects, crop adaptation, genotype component, soybean varieties, yield evaluation
IVORY, D.A. et al.
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