UPSC Prelims 2020 question on Fertigation Advantages

Statement by statement

Statement 1 – CORRECT: A frequent supply of nutrients reduces fluctuation of nutrient concentration in soil. The pH of the irrigation water is of great importance. In fertigation, the alkalinity of a fertigation system can be controlled by adding Acid. Hence statement 1 is correct.

Statement 2 – INCORRECT: Rock Phosphate and some other mineral fertilizers containing phosphorus are insoluble in water as well as in citric acid. They are suitable in strongly acid soils or organic soils and given in green manured fields. The phosphorus is very slowly released by microbes at action and remains in soil for long time. Hence Rock Phosphate cannot be efficiently applied through fertigation. Statement 2 is not correct.

Statement 3 – CORRECT: There is efficient utilization and precise application of nutrients according to the nutritional requirements of the crop. Fertilizers are applied throughout the irrigated soil volume and are readily available to plants. Hence statement 3 is correct.

Statement 4 – CORRECT: Drip fertigation reduced dissolved inorganic and organic N leaching by 90%. Nutrients can be applied to the soil when soil or crop conditions would otherwise prohibit entry into the field with conventional equipment. Hence statement 4 is correct.