Soil Acidification due to Point Application of Fertilizers through Drip Irrigation

An experiment was conducted to know about the effects of point application of fertilizers. Fertigation through drip irrigation was done to tomato and french bean grown under plastic house in two consecutive seasons. Fertilizers were applied at 100%, 75% and 50% of the recommended doses and compared with basal application. Fertigation was also done at three different intervals of application i.e. 2 days, 6 days and 10 days. Urea, Single Super Phosphate and KNO3 was used as source of NPK. The soil pH of polyhouse was 6.51. The irrigation water had the pH of 5.89. Fertilizer applied at the interval of two days at 100% of recommended dose (RD) and 75% of RD to tomato and french beans gives highest yield. After the first crop season of tomato, the pH was found to reduce by 1-1.5 points over the base value from 6.51 to 4.92 in 100 % of RD application irrespective of interval of fertigation. The pH before the 2nd crop was found to be slightly reduced (6.34) over the base value of 6.51. However, after the 2nd crop, the soil pH was found to be reduced and the values were from 5.16 to 5.29. The reduction of soil pH was not as high as in the case of tomato. It indicated that though soil acidity increased due to point application of fertilizers, the increment might have linked to the types of crops and french bean being a leguminous crop had a positive effect against soil acidification