Cereal/legume rotation effects on cereal growth in Sudano-Sahelian West Africa: soil mineral nitrogen, mycorrhizae and nematodes

• Published in: Plant and soil Vol. 218; no. 1/2; pp. 103 - 116
• Main Authors: Bagayoko, M, Buerkert, A, Lung, G, Bationo, A, Romheld, V
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer Academic Publishers 2000; Springer; Springer Nature B.V
• Subjects: Africa; Agricultural practices; Agricultural soils; Agronomy. Soil science and plant productions; Arachis hypogaea; Biological and medical sciences; Cereal crops; Cereal grains; colonization; Crop rotation; crop yield; Cropping systems; Cropping systems. Cultivation. Soil tillage; Cultivation; Dry matter; dry matter accumulation; field experimentation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Cropping systems and patterns; Grain cultivation; growth; Infections; Legumes; Millet; mineralization; Nematoda; Nematodes; Nitrogen; nutrient availability; Pennisetum glaucum; plant parasitic nematodes; population density; Rotation; soil fauna; soil fertility; Soil nematodes; Sorghum; Sorghum bicolor; Topsoil; vesicular arbuscular mycorrhizae; Vigna unguiculata; Niger; Burkina Faso; West Africa; Sub-Saharan Africa; Sahel; Africa; Sudan; Monocotyledones; Growth; Soil fertility; Pennisetum glaucum; Vigna unguiculata; Cereal crop; Fungi; Sorghum bicolor; Pest; Gramineae; Dicotyledones; Angiospermae; Nematoda; Thallophyta; Symbiosis; Symbionte; Treatment efficiency; Cropping system; Arachis hypogaea; Nitrogen; Oil plant(vegetal); Grain legume; Endomycorrhiza; Leguminosae; Crop rotation; Mycorrhiza; Helmintha; Nutrient; Nemathelminthia; Spermatophyta; Invertebrata; Infestation
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1023/A:1014957605852

Yield increases of cereals following legumes in rotation have been previously reported for West Africa, but little progress has been made to explain the mechanisms involved. At four sites in Niger and Burkina Faso, field trials with pearl millet (Pennisetum glaucum (L.) R. Br.), cowpea (Vigna unguiculata (L.) Walp), sorghum (Sorghum bicolor (L.) Moench) and groundnut (Arachis hypogaea L.) were conducted from 1996 to 1998 to investigate the role of soil mineral nitrogen (Nmin), native arbuscular mycorrhizae (AM) and nematodes in cereal/legume rotations. Grain and total dry matter yields of cereals at harvest were increased by legume/cereal rotations at all sites. Soil Nmin levels in the topsoil were consistently higher in cereal plots previously sown with legumes (rotation cereals) compared with plots under continuous cereal cultivation. However, these rotation effects on Nmin were much larger with groundnut than with cowpea. Roots of rotation cereals also had higher early AM infection rates compared to continuous cereals. The dominant plant-parasitic nematodes found in all experiment fields were Helicotylenchus sp., Rotylenchus sp. and Pratylenchus sp. In sorghum/groundnut cropping systems, nematode densities were consistently lower in rotation sorghum compared to continuous sorghum. Continuous groundnut had the lowest nematode densities indicating that groundnut was a poor host for the three nematode groups. In millet/cowpea cropping systems with inherently high nematode densities, crop rotations barely affected nematode densities indicating that both crops were good hosts. These results suggest that on the nutrient poor Sudano-Sahelian soils of our study, total dry matter increases of rotation cereals compared with continuous cereals can be explained by higher Nmin and AM infection levels early in the season. The site-specific magnitude of these effects may be related to the efficiency of the legume species to suppress nematode populations and increase plant available N through N₂-fixation.