This article provides a short note on the nutrient deficiency symptoms of soil.
In this technique plants act as integrators of all growth factors. The appearances of abnormalities in the growing plants are caused by a deficiency of one or more nutrient elements. The visual method of evaluating soil fertility is good because it involves no expenditure and no laboratory tests.
Nutrient deficiency symptoms may be classified as follows:
(i) Complete failure from the beginning of the crop growth i.e. at the seedling stage.
(ii) Stunting of crop growth.
(iii) Nutrient specific leaf symptoms.
(iv) Internal abnormalities within the plant body.
(v) Delayed or off time maturity.
(vi) Yield reduction without exhibiting deficiency symptoms on plants.
(vii) Poor quality of crops.
Hidden hunger may be defined as to a situation in which a crop requires more of a given nutrient element without exhibiting deficiency symptoms on plants. The concentration of an element is above the deficiency level but still considerably below that required to permit the most profitable crop performance (Fig 28.1).
There are two critical limitsâ€”lower critical limit and the upper critical limit. The lower critical limit is defined as that concentration of a nutrient element in plant or soil below which the plant cannot complete its life cycle (Fig. 28.2).
The upper critical limit refers to that concentration above which the sufficiency range sets in. Hidden hunger may be eliminated by performing plants and soil testing which are useful for planning or modifying plant nutrient programmes for the subsequent crops.
Deficiency of nutrients in soils also results due to variation in weather and climatic conditions. As for an example, in drought and excessive moisture or unusual temperature very frequently affect the uptake of nutrients adversely which in turn results deficiency of plants.