Fertilizers in Relation to Irrigation Practices

This chapter discusses some of the special problems of nutrient movement arising from irrigation, some of the fertilizer problems posed by the choice of irrigation method, and the application of fertilizers in irrigation systems. Irrigation poses some special problems in the use of fertilizers and also provides some unique ways to supply nutrients not encountered in nonirrigated agriculture. Irrigation methods can be divided into three general classes: furrow, flood, and sprinkler. Redistribution of nutrients by movement of soil water has been studied more under furrow irrigation systems than under the others. In flood irrigation that covers the entire surface with water in level systems of irrigation and with drilled crops on gently sloping systems, water and soluble ions move down. Flooding is more effective than furrow irrigation in removing soluble salts from saline soils. Poor distribution of water in either sprinkler or furrow irrigation results in uneven application of fertilizer dissolved in the irrigation water.