Characterisation of soil and irrigation water of the sugarcane belt in Palaghat in relation to yield, nutrient uptake and quality of the cane

Abstract

The investigation undertaken, envisages the characterization of the soil and irrigation water of three sugarcane growing regions namely Vannamada, Meenakshipuram and Attapadi in Palghat district and their relation to the nutrient uptake, yield and quality of sugarcane. One hundred and ninety seven surface soil samples (0-15cm) from the three regions were characterized for the major physico- chemical properties. Twenty four farmer’s plots were identified as observation plots to assess the yield, dry matter production and quality parameters of sugarcane juice and the inter relations between these parameters. Samples of irrigation water from four commonly used sources namely bore well, open well, canal, and river water used for irrigating sugarcane plots were collected in the pre monsoon and monsoon periods for determination of quality parameters and to study their effects on the crops. The soils of the three regions were predominantly mildly alkaline in reaction. The EC of these soils were on par with each other and were with in safe limits. The major texture of soils of the area was sandy clay loam, followed immediately by sandy loam. The bulk density, particle density and pore space of the three region did not vary significantly. The water holding capacity and volume expansion of the soils were significantly higher in Vannamada and lowest in Attapadi regions. None of the physical properties had any adverse effect on the growth of sugarcane. Organic matter, total N, P and K recorded low values in soils of the three regions. The rating of available N was medium in all the three regions. For available P and K, the rating for Vannamada and Meenakshipuram regions was medium while for Attapadi it was high. Available S followed the same trend as that of the major nutrient elements and its status in the soils of the three regions was above the critical level. Exchangeable Ca and Mg dominated in all the three regions. Exchangeable Mg and Na were significantly higher in the soils of Vannamada. The levels of micro nutrients viz. Fe, Mn, Zn and Cu in the soils of the three regions were above the sufficiency limits. The quality parameters of irrigation waters such as pH, EC, CI- and SO4- -contents, RSC and SAR studied were within the safe limits for the irrigation of sugarcane. All the three regions recorded high values in yield and dry matter production. However, in comparison Attapadi registered lower values than the other regions. The uptake of N, P, K, Na, Ca and Mg were highest in soils of Meenakshipuram and lowest in Attapadi region. The yield and dry matter production exhibited a significant positive correlation with uptake of N, P, K and Na. The uptake values obtained for micro nutrients were low, which may be attributed to high pH of the soils. Soil of the three regions did not show any significant variation in juice quality parameters such as brix, pol value, purity and commercial cane sugar content. Juice quality parameters were significantly and positively correlated with N, P, K and Na.