Comparative investigation into the effect of fertigation and of broadcast fertilization on the yield and nitrate content of lettuce (Lactuca sativa L.).

Abstract

Three [unnamed] cultivars were grown successively during March to May, June to July, and July to August 1983 on a sandy soil. For each of these field experiments the treatments were: no N application, and fertilization with various amounts of ammonium nitrate, either as split applications via irrigation water or as a single broadcast application. Fertigation increased the availability and uptake of N and increased the nitrate content of the crop compared with broadcast fertilization. A second-degree polynomial model fitted the fertilization:NO₃-content data. In the first cropping, yield was significantly higher when N was applied by fertigation compared with broadcast application, but in the following croppings there was no significant difference. However, it is suggested that the yield difference in the first cropping may be related to the very wet spring conditions (a 56 mm rain surplus compared with 105 and 116 mm deficits in the following two experiments) when leaching of NO₃ from the upper soil layer would be expected. (Abstract retrieved from CAB Abstracts by CABI’s permission)