Effect of Sewage Sludge and Inorganic Fertilizers on Productivity and Micronutrients Accumulation by Palak (Beta vulgaris) and their Availability in a Typic Haplustept

Abstract

This study evaluated the effect of sewage sludge obtained from three locations in Delhi namely, Okhla,Keshopur and Pappankallan on crop productivity and accumulation of micronutrients and heavy metals inplant and soil. Palak (Beta vulgaris) was grown as a test crop for the present study because of its capabilityto accumulate large quantities of heavy metals and also that sewage sludge is mainly used as amendment orsource of nutrients for growing vegetables, especially in the peri-urban areas. Data revealed that biomassyield of Palak was significantly increased by application of sewage sludge, but the integrated managementof sewage sludge and inorganic fertilizers performed better over only sludge amendment. Similarly, themicronutrients and heavy metal accumulation by Palak were greater in the treatments receiving conjointuse of sewage sludge and inorganic fertilizers compared to sludge application alone. But the accumulationof micronutrients and heavy metal was within the permissible limits. Soil amended with sewage sludgealone resulted in significant build-up in DTPA-extractable micronutrient and heavy metal over control. Itwas observed that conjoint use of sewage sludge and 50% NPK fertilizers resulted in further build-up ofDTPA-extractable micronutrients and heavy metals over treatments receiving sewage sludge alone. Pearson’scorrelation matrix showed significant and positive relationships between biomass yield, accumulation ofmicronutrients and heavy metal by crop with DTPA-extractable micronutrients and heavy metal in soil.This study clearly shows the increased accumulation of micronutrients in foliage of Palak due to sludgeamendment from all the three sources. Thus, it can be concluded that use of sewage sludge can be followedas a good supplement of nutrients for crop production, but care should be taken for the presence of heavymetals and pollutants.