| Sumario: | Within the range between macrovariability of soil and localized transient heterogeneity of, for instance, available nutrients in the surface soil, the term ‘soil microvariability’ has an intermediate position. The effect of microvariability on the growth and performance of upland food crops is generally very pronounced in the intertropical areas, leading to uneven stands of crops over short distances. The presence of soft and hardened plinthite (laterite) over wide areas in the subhumid tropics of West Africa is a common source of microvariability in view of the uneven depth and variable distribution of these formations. Conducting agricultural experiments, including testing of breeding lines in lands with considerable microvariability, is most commonly a cause for frustration of agricultural workers. The methodology of sequential testing, i.e. monitoring crop performance and laying out agronomic experiments across well‐defined and monitored intrafield variations of soils, appears very promising, especially in view of the evaluation of agronomic properties of different soils.
|
|---|