Influence of different forms and rates of mineral nitrogen fertilizers on tomato productivity in open field conditions

Abstract

Tomato is one of the major vegetable crops valued for its high content of various vitamins, organic acids, antioxidants, essential macro- and microelements, and other substances necessary for maintaining normal body functions. Due to its characteristics, tomatoes are widely grown, but there are still "blank spots" in their production technology, especially in fertiliser application. This article presents the experience of using different rates of liquid (KAS-32) and solid (ammonium nitrate) mineral nitrogen fertilisers on the author's tomato varieties in open field conditions. The authors found a significant effect of nitrogen fertilisers on the duration of the main phases of the growing season and the entire period of tomato growth. Specifically, using ammonium nitrate for up to 15 days and KAS-32 for up to 17 days increases the vegetation period. Fertiliser application substantially improves crop structure and increases crop productivity. The difference compared to the control is over 150%, with the maximum effect achieved at increased doses of KAS-32. The maximum yield increase is 45 t/ha in variants with ammonium nitrate and up to 62 t/ha in variants with KAS-32. Under the influence of nitrogen fertiliser application, the content of dry matter increases by 15–20%, total sugar by 76%, and vitamin C by 38%. The most significant effect is achieved using KAS-32, where all quality indicators are 5–10% higher than ammonium nitrate.