Vol. 11, Special Issue 9 (2022)

Author(s):
Dr. S Suganya, Dr. VR Senthamizhkumaran, G Dinesh, P Gowtham, S Indhumathi, M Deepha, N Divyavarshini and B Humera

Abstract:
Tapioca (Manihot esculenta Crantz) is an important food security crop (Karlstrom et al., 2016). It is very tolerant of drought and heat stress and produces well on marginal soils. This tuber crop is largely cultivated in Tamil Nadu (64%), Kerala (32%) parts of Andhra Pradesh (1.5%), Nagaland (1.2%) and Assam (0.5%). In Tamil Nadu, Namakkal (21%), Dharmapuri (19%), Salem (15%), Villupuram (14%), Trichy (9%), Erode (5%) and Thiruvannamalai (5%) in an area of 1.21 lakh hectare (Chennakrishnan and Thenmozhi, 2020). In Namakkal the major tapioca growing blocks are Paramathy, Mohanur and Namagiripettai. The cost of cultivation of tapioca is very low but it is considered as high revenue crop. Even though the area under cultivation increased from 1,99,000 ha to 2,10,000 ha, there was no hike in yield and this might be due to improper soil and crop management. Soil test was the only criteria to delineate the fertility status of different regions and sampling was done by random method. The present study was undertaken to delineate, the physicochemical properties in major tapioca growing blocks (Mohanur, Paramathy and Namagiripettai) of Namakkal district. Totally 540 geo-referenced soil samples (Both surface (270) and subsurface (270) covering the entire three blocks of tapioca growing tracts of Namakkal district were collected by along with latitude and longitude. The results showed that the pH value of Paramathy block ranged between 5.83 to 9.85 with a mean of 9.48, the EC values ranged between 0.02 - 1.31 dS m^-1 with a mean of 0.54 dS m^-1. In Mohanur block, the pH values found to be ranged from 7.00 – 10.78 with a mean of 10.31 and the EC values ranged from 0.02 – 0.85 dS m^-1 with a mean value of 0.39 dS m^-1. In Namagiripettai block, the pH values ranged from 7.03 to 8.84 with a mean of 8.57, the EC values ranged between 0.11 - 0.17 with a mean value of 0.15 dS m^-1. Based on the results, we concluded that either we use application of lime for acid soil; gypsum for alkaline soil can be recommended as a source of nutrient under north western agro climatic conditions under study.