Browsing by Author "Pennala, Tuomas"

Wheat is one of the world's three most important arable crops among rice and maize. Therefore, the study of fertilization is important, especially in the long run, to provide reliable information on the impact on potassium fertilization to farming land, spring wheat growth and its yield. The aim of this study is to find out how potassium fertilization affects spring wheat yield and soil properties, as well as straw yield in long-term field experiment. I wanted to find out whether the current recommendations for potassium fertilization are sufficient to spring wheat varieties on sandy loam and which factors are most affected wheat grain and straw yield. The experiment was conducted on sandy loam in Hausjärvi as field experiment, in which four fertilization treatments were used, two of which contained the same amount of potassium and two were left without potassium. Wheat grain and straw yields were sampled and analyzed. In addition, the wheat crop samples were taken during the summers. Wheat straw was collected each year from the field, except in 1978, when they were plowed in the field. According to the results of spring wheat grain and straw yield year affect both fertilization and year. Year explained the differences in yields better than fertilization. Potassium fertilization levels significantly affected the straw yield. Most fertilized wheat took the most soluble and reserve potassium. The amount of soluble potassium in topsoil decreased in all treatments, but reserve potassium remained almost unchanged. The study shows that the current recommendations for potassium fertilization of fields potassium balance fall in the long run. Also, wheat other macronutrient intake significantly affect potassium commissioning. The amount of potassium in topsoil decreased during the experiment and some of potassium probably leached from the field. The test use 60 kg of K / ha are sufficient for current wheat varieties. Without potassium fertilization may occur potassium deficiency after decades, especially if the natural potassium resources are small. In the future, therefore, should pay attention to improving the use of potassium and to prevent potassium leaching.