Journal article

Publication year: 1978

Pages: 165-177

Journal: Zeitschrift für Acker- und Pflanzenbau

Volume number: 146

Issue number: 3

ISSN: 0044-2151

Publisher: Parey

Abstract: 
In submerged paddy soils ammonium and nitrate undergo different transformations. In the case of nitrate application higher N losses by leaching and denitrification can be noticed than in the case of ammonium. Ammonium containing and ammonium producing fertilizers are commonly used in rice growing. With the increased cultivation of high yielding varieties high N doses in split application and complex fertilizers with differing nitrate and ammonium content are used to a larger extent. The N form of fertilizers has become a question of great importance. Pot experiments were conducted at Rauischholzhausen (in controlled growth chambers) and at Penang/Malaysia (under natural tropical climatical conditions) using different N sources. The N fertilizers were labeled with 15N. The conditions of paddy soils were simulated by submerging the soil and periodical drainage for aeration. Rice elongation was promoted more by nitrate than ammonium N if applied in 1 dose at the beginning of the vegetation period. Ammonium had a better effect on the tillering rate of the rice plant. The higher tillering rate caused by ammonium N was effective in increasing the number of panicles per plant at maturity. The plants treated with nitrate N had a higher number of grains per panicle and a somewhat higher 1000 grain wt. Grain yields obtained with ammonium application were slightly higher than those of the nitrate treatments. The very high nitrate contents found in the young rice plants in case of nitrate application (about 10% of total N) suggested that a limited nitrate reduction is the reason for low tillering rates. In case of split N dressing the highest yields were obtained with the combination of ammonium at the beginning and nitrate at booting stage. The superiority of this variant is based on a high tillering rate (caused by the early NH4 application) on a high number of grains per panicle and a high 1000 grain wt (caused by top dressing with nitrate). The utilization of applied N by the plants obtained by 15N analysis was always higher in case of ammonium application as compared with nitrate fertilization. The combined application of ammonium at the beginning and nitrate as top dressing resulted in a high rate of fertilizer utilization by the rice plant. The losses of fertilizer N by denitrification (leaching was excluded in the pot experiments) amounted to about 20% of the applied ammonium, 30-40% of the nitrate and 22% in the case of the combination of ammonium (1st dressing) and nitrate (top dressing). In a pot experiment with a malaysian paddy soil (acid sulfate soil) a very good response to urea, but a low response to ammonium sulfate was noticed. This result is explainable by the high sulfate/sulfide content in this soil, the adverse effect of which was intensified by the usage of ammonium sulfate. For optimal N nutrition of rice ammonium containing or ammonium producing fertilizers should be applied at the beginning of the vegetation, but nitrate fertilizers should be used for top dressing. On soils containing higher amounts of sulfate for the basal dressing urea should be used in place of ammonium sulfate.

Harvard Citation style: ATANASIU, N., WESTPHAL, A. and SILVA, M. (1978) EFFECT OF DIFFERENT NITROGEN-SOURCES IN YIELD AND YIELD - FORMATION OF RICE, ZEITSCHRIFT FUR ACKER UND PFLANZENBAU-JOURNAL OF AGRONOMY AND CROP SCIENCE, 146(3), pp. 165-177

APA Citation style: ATANASIU, N., WESTPHAL, A., & SILVA, M. (1978). EFFECT OF DIFFERENT NITROGEN-SOURCES IN YIELD AND YIELD - FORMATION OF RICE. ZEITSCHRIFT FUR ACKER UND PFLANZENBAU-JOURNAL OF AGRONOMY AND CROP SCIENCE. 146(3), 165-177.