Vol. 12, Issue 7 (2023)

Author(s):
Anjali Bhadra Vijay, Dr. Mini V and Dr. Rani B

Abstract:
The acid-saline soils of Kerala are unique in their origin and existence. These soils are known for the special saline farming practices or the varieties followed locally as Pokkali, a geographically indicated acid and saline-tolerant rice cultivar and Kaipad, which is a saline-prone and naturally organic tract of northern Kerala. Orumundakan soils constitute acid saline soils of agroecological unit 3 of the state, unlike the similar acid saline soils found in the southern and northern districts, these soils are nutrient-poor and lack water and nutrient retention. A semi-detailed soil survey was conducted to characterise the 200 geo-referenced soil samples in the pre-growing season (September) and soil was analysed for its major primary, secondary, micro and beneficial nutrients. The mean nutrient status of blocks was determined considering the area thus deriving the nutrient status of this special agroecological Unit by the weighted average method. It can be more meaningful and reasonable at arriving the formulation composition recommendation for rice fields in this AEU. Based on the weighted average data of 17 panchayaths spanning in 6 blocks of AEU revealed that the soils of AEU had a soil reaction of 5.05, soluble salt content expressed as the electrical conductivity of 1.39 dS m^-1, OC- 0.69, soil available nitrogen- 251.64 kg ha^-1, Phosphorus and potassium content of 40.93 and 194.72 kg ha^-1, secondary nutrients of Ca-163.64 ppm, Mg and S of 50.24 and 72.98 ppm. Available micronutrients – Fe- 622.88 ppm, Mn- 10.19 ppm, Cu-0.19 ppm, Zn-0.25 ppm and B-0.27 ppm. Beneficial elements of silicon, sodium, Aluminium and chlorine were recorded at 31.45, 674.07, 107.49 and 169.91 ppm respectively. Based on results obtained revealed that soils were deficient in major nutrients except for phosphorus, iron, manganese and sulphur. The nutrient mixture was formulated with the composition of N- 1.60%, K-12.5%, Ca- 1.88%, Mg- 5.05%, Mn- 0.16%, Cu- 0.70%, Zn- 1.20%, and B- 2.31% specific for rice growing acid saline soils of AEU 3.