How & When Urea Will Be Taken Up By Plants | Farming Inspirations

The conversion of urea into plant consumable forms as ammonium or nitrate in soil is a complex process and can take anywhere from a few days to several weeks, depending on several factors. Of those several factors, 4 key factors majorly influence in conversion of urea into plant available form, 1. Soil conditions 2. Environmental factors 3. Method of application 4. Plant species & crop uptake Urea, which contains N in amide form is not directly taken up by plants as it has to undergo several process to become available to plants. Plants can absorb the N in urea in the form of ammonium and nitrate. Ammonium is more readily taken up by plants than nitrate, but nitrate is the main form of nitrogen used by most crops. Urea is a highly soluble fertilizer that dissolves easily in soil water. Whenever urea is applied to the soil, urea undergoes hydrolysis followed by nitrification, a process in which the urea is converted to ammonium by urease enzymes and then to nitrate by nitrifying soil microorganisms. The rate at which urea is converted into nitrate for plant uptake in soil depends on soil conditions, environmental factors, method of application and plant species. Soil condition is mainly influenced by a combination of physical, chemical and biological elements. Soil’s physical conditions mainly include soil moisture and soil aeration. 1. Soil moisture: It should be needed enough to improve the growth & activity of nitrifying bacteria (nitrosomonas & nitrobacter) that convert urea to nitrate. 2. Soil aeration: Nitrifying bacteria need oxygen to carry out the conversion of urea to nitrate. Therefore, good aeration is important for the activity of these bacteria. Soil’s chemical conditions comprises its pH and nutrient availability. Nitrification is an important process in the nitrogen cycle and requires optimal soil pH between 6.5 and 7.5 for the activity of nitrifying bacteria to be successful. If the soil’s pH is either extremely acidic or extremely alkaline, the activity of nitrifying bacteria is inhibited and nitrification slows down or stops completely. Nitrifying bacteria also need other essential nutrients, such as phosphorus, sulfur, and micronutrients, in order to carry out their metabolic processes. Biological conditions such as presence of nitrifying bacteria and competition from other microorganisms play a role in the rate of conversion. The presence of nitrifying bacteria is essential for the conversion of urea to nitrate in soil. However, these bacteria may face competition from other microorganisms in the soil for resources, such as nutrients and space, which can affect their activity and thus the conversion of urea to nitrate. Environmental factors: 1. Temperature: Nitrification is a biological process that is temperature-sensitive. The optimum temperature range for nitrification is between 25°C and 30°C. At temperatures above 35°C, nitrification is inhibited, while at temperatures below 5°C, nitrification is slowed down.