What are the advantages of fertigation in agriculture? 1. Controlling the alkalinity of irrigation water is possible. 2. Efficient application of Rock Phosph

1. A. 1, 2 and 3 only
2. B. 1, 2 and 4 only
3. C. 1,3 and 4 only
4. D. 2, 3 and 4 only

Answer: C

Explanation

Fertigation has some specific advantages over broadcast and band fertilization: (1) A frequent supply of nutrients reduces fluctuation of nutrient concentration in soil. (2) There is efficient utilization and precise application of nutrients according to the nutritional requirements of the crop. (3) Fertilizers are applied throughout the irrigated soil volume and are readily available to plants. (4) Nutrients can be applied to the soil when soil or crop conditions would otherwise prohibit entry into the field with conventional equipment. The pH of the irrigation water is of great importance, as it affects many chemical reactions. In fertigation, the reasons for adjusting the pH to an optimal range are: 1. To allow optimal uptake of nutrients, especially micronutrients; 2. To keep the irrigation system free from clogging. Alkalinity of a fertigation system can be controlled by adding Acid. The injection of acid to the irrigation water should be, as much as possible, uniform and continuous, throughout the entire duration of the irrigation. Drip fertigation increases water and nitrogen use efficiency. Drip fertigation reduced dissolved inorganic and organic N leaching by 90%. Soluble fertilizers like urea, potash and a wide variety of fertilizer mixtures available in the market could be well mixed with irrigation water, filtered and then passed through the irrigation unit. 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. These fertilizers are given in green manured fields. The phosphorus is very slowly released by microbes at action and remains in soil for long time. Hence option (c) is the correct answer.