Published online by Cambridge University Press: 27 March 2009
A nutrient indexing survey of the soils and rice crop was conducted on 300 fields of four villages in some floodplain areas of Ludhiana. The soils are, in general, alkaline in reaction, highly calcareous, medium in organic matter and mostly heavy in texture. Soil analysis (DTPA extraction) indicated that about 27% are deficient in available zinc. Leaf analysis indicated the concentration of N, Zn, Cu, Fe and B to be below their critical levels in 27, 25, 93, 39 and 6% of the samples respectively: the low levels of Cu(l–3 μg/g) are considered as a ‘hidden hunger’ as the crop lacked any visual Cudeficiency symptoms.
Correlation studies indicated the absence of any relationship between the micronutrient status of the soils, assessed by DTPA extraction, and leaf content. Consequently leaf analysis is recommended for evaluating the nutritional disorders of lowland rice.