| 摘要 |
PROBLEM TO BE SOLVED: To obtain a mixed fertilizer contg. a coated nitrification suppressing material which is low in the rate of conversion of ammonium nitrogen to nitrate nitrogen in soil and is capable of maintaining the ammonium nitrogen over a long period and reducing the adverse effect of the nitrification suppressor on crops. SOLUTION: The production of this mixed fertilizer comprises mixing 3 to 45 wt.% of a coated nitrification suppressing material formed by coating a nitrification suppressor with a coating material with 55 wt.% to 97 wt.% of a fertilizer contg. ammonium nitrogen and/or urea nitrogen. In particular, the mixed fertilizer is appropriately used as a fertilizer for a tea field in which it is desired to maintain ammonium nitrogen over a long period. Further, by utilizing such properties of this fertilizer that the ratio of the amount of the coating component to the amount of the coated fertilizer is comparatively low and the runoff of ammonium nitrogen in soil from the soil is hardly caused, the mixed fertilizer is also useful as an inexpensive fertilizer for field crops. |
