There are different types of nitrogen fertilizers and the most famous are ammonium nitrate, carbamide (Urea), ammonia water and ammonium sulfate. Ammonium nitrate is high-speed and universal feeding containing about 35% nitrogen. It is white, slightly pink crystals. Nitrate is hygroscopic and therefore quickly caked. Keep it in a waterproof package in a dry place. Each gardener, at the question of which fertilizer to make when planting, first of all, he will tell you ammonium nitrate: in the spring it is fed at the rate of 25-30 g / sq.m. Ammonium nitrate slightly acidifies the soil, which is favorable for black soil. Top dressing is carried out by its aqueous solution (20 g per bucket of water).
Ammonium sulphate is a salt in the form of white crystals, contains 20-21% nitrogen. This fertilizer is used both in the spring and in the autumn, as it is poorly washed out of the soil, lingering in it. This substance even more acidifies the soil. At the basic fertilizing, up to 50 g of ammonium sulphate per square meter is applied, and with feeding – twice less.
Urea (Carbamide) is a white crystalline substance, especially rich in nitrogen (46%). It is digested gradually, so gardeners make it in the spring as the main fertilizer, and in heavy soils also add 20-25 g / m2. in the autumn. Can serve as additional fertilizer for irrigation of soil (10 g / m2) Or as foliar dressing, when fruit and berry crops are sprayed with a concentrated solution (30-40 g of carbamide per bucket of water).