UC Cooperative Extension | Agricultural Experiment Station
Questions about water and fertilizer use efficiency are major economic and environmental issues for California agriculture. Excess nitrate is an important concern for San Joaquin Valley communities that depend on groundwater for drinking. Vegetable crops such as carrots, onions and potatoes typically require high amounts of nitrogen fertilizer and frequent irrigation, usually by sprinkler. Although sprinkler lateral spacings vary from 30 to 50 feet, no season-long field study had determined the impact of these different spacings on efficiency of water and nitrogen use.