The influence of nitrogen and soil conditioners on root's development, root activity and yield of rice, 2; the effects of nitrogen fertilizers on activity and development of root and rice yield
1987
Kim, H.M. (Rural Development Administration, Suwon (Korea R.). Research Bureau) | Kim, J.G. | Park, K.H. (Rural Development Administration, Iri (Korea R.). Honam Crops Experiment Station)
The effects of nitrogen fertilizers (urea, ammonium sulfate, compound fertilizers) on the root activity and the root development were studied at the poorly drained soils (Jeonbug series). In case of nitrogen applied at the rate of 12kg/10a, ammonium sulfate greatly promoted the vegetative growth of rice plant at early stage, and increased the rates of ripened grains and utilization rate of applied nitrogen. Above effectiveness was lessened by compou1503nd fertilizers and urea. However application of ammonium sulfate at the rate of 20kg/10a showed the most active vegetative growth at early stage, but it greatly decreased nutrient absorption and the rates of ripened grain due to lowering root activity at ripening stage. Consequenty it caused lodging and decreased yield. The higher yield was obtained by application of compound fertilizers than that of ammonium sulfate or urea, because it seemed to be balanced growth between top and r
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