Yield and Quality of Maize Grain Depending on Soil Fertilization Technology and the Foliar Application of Silicon

Climate change is forcing the search for innovative solutions to effectively reduce its harmful effects on food production. In addition, increasingly stringent regulations are being introduced in the European Union (The European Green Deal), mandating reductions in mineral fertiliser doses, which can reduce crop yields. One innovative technology could be the soil fertilisation and dolsit application of silicon (Si). In 2023–2024, in commercial crop conditions in Kraski (52°2’42” N, 18°54’6” E), in Central Poland the effect of differentiated soil fertilization and the foliar application of silicon products on the yield and quality of maize grain at two levels of nitrogen/phosphorus/potassium (NPK) fertilization (100% and 50%) was studied. The soil fertilizer SiGS® (Si – 200 g kg-1, Ca – 181 g kg-1, Mg – 46 g kg-1, Mn – 45 g kg-1) was applied to the soil at doses of 100, 300, and 500 kg ha–1, alone or with Barrier Si-Ca® (Si – 336 g dm-3; Ca – 207 g dm-3) foliar fertilizer (1 dm3 ha–1). The number of combinations assessed is 16. The effects were compared against a control treatment. The experiment evaluated plant physiological parameters, grain and dry matter yield, grain moisture content and quality (protein, fat and starch content) and grain yield components. The highest grain yields were obtained with soil fertilization at a dose of 500 kg ha–1 (giving an increase of 17.5%), at a dose of 300 kg ha–1 plus foliar application (+16.4%), and at a dose of 500 kg ha–1 plus foliar application (+17.8%). The increase in grain yield in treatments with a half-rate of NPK was of a similar magnitude (on average, +11.9%) to the full rate (+12.6%) compared to the control treatments. Doubling the NPK rate contributed to an increase in grain yield of 7.8%. The applied silicon fertilization treatments had a significant effect on the protein, fat, and starch contents of the grain, and, in most treatments, increased the protein and fat contents and reduced the content of starch.