Pearl millet (Pennisetum Glaucum L.) response after ferti-irrigation with sugar mill effluent in two seasons

Background The disposal of sugar mill effluent has become a major problem in India due to generation of huge volume of effluent. The value of wastewater for crop production has been recognized in many countries, including India. The effluents not only contain nutrients that stimulate growth of many crops, but also may have various toxic chemicals, metals, metallic oxides along with nitrogenous and phosphate compounds, which may affect various agronomical characteristics of crop plants. The present investigation was conducted to asses the agro-potentiality of agro-based sugar mill effluent as ferti-irrigant, and an alternative of irrigation water. Six plots were selected for six treatments of sugar mill effluent viz. 0 % (control), 20, 40, 60, 80, and 100 % for the fertigation of Pennisetum glaucum L., cv. Nandi 35. P. glaucum was grown, fertigated with effluent till harvest and effect of effluent fertigation on the soil and agronomical characteristics of P. glaucum were analyzed. Results The fertigant concentration produced changes in electrical conductivity (EC), pH, organic carbon (OC), sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), total Kjeldahl nitrogen (TKN), phosphate (PO4 3−), sulfate (SO4 2−), iron (Fe), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), and zinc (Zn) of the soil in both seasons. The agronomic performance of P. glaucum increased from 20 to 40 % in both seasons compared to controls. The accumulation of heavy metals increased in soil and P. glaucum from 20 to 100 % sugar mill effluent concentrations in both seasons. Biochemical components like crude proteins, crude fiber, and crude carbohydrates were found maximum with 40 % sugar mill effluent in both seasons. The contamination factor (Cf) of various metals were in the order of Mn > Zn > Cu > Cd > Cr for soil and Mn > Zn > Cu > Cr > Cd for P. glaucum in both seasons after fertigation with sugar mill effluent. Sugar mill effluent irrigation increased nutrients in the soil and affected the growth of P. glaucum in both seasons. Conclusions It appears that sugar mill effluent can be used as a biofertigant after appropriate dilution to improve yield of P. glaucum.