在波兰1975年7月的一个田间处理中,用尿素或者硝酸铵的颗粒和非颗粒态氮肥每公顷施入210公斤。两者均于早春单独施入,或者分三次等份施入。磷和钾则以140公斤 P_2O_5+240公斤 K_2O(公斤/公顷)施入。结果,在整三年中,施用颗粒态尿素(11.8～13.9吨/公顷)比施用非颗粒态尿素(11.4～12.4吨/公顷)的干草产量要高得多;在一年中,颗粒态氮肥在单独施用 In a field trial in Poland in July 1975, 210 kg per hectare were applied using urea or ammonium nitrate and non-particulate nitrogen fertilizers. Both are administered separately in early spring, or in three equal doses. Phosphorus and potassium were applied at 140 kg P 2 O 5 + 240 kg K 2 O (kg / ha). As a result, application of particulate urea (11.8-13.9 t / ha) was much higher than that of non-particulate urea (11.4-12.4 t / ha) throughout the three years; in one year, particulate nitrogen It is administered alone