Effects of long-term fertilization on the yield of winter wheat and N forms on Luvic Phaeosem soil determined in 0.01 M CaCl 2

Autor: L. Blaskó, E. Bertáné Szabó, Gy. Zsigrai, Jakab Loch
Rok vydání: 2010
Předmět:
Zdroj: Agrokémia és Talajtan. 59:135-144
ISSN: 1588-2713
0002-1873
DOI: 10.1556/agrokem.59.2010.1.16
Popis: The effects of regular NPK fertilization on the amounts of winter wheat yield and the amounts and proportion of different N forms (NO3-N, NH4-N, Norg, Ntotal) of a Luvic Phaeosem soil determined in 0.01MCaCl2were studied in the B1740 variant of the National Long-Term Fertilization Experiment at Karcag. According to the yield data, N and P fertilization increased winter wheat yield significantly. When applying the 200 kg N·ha-1dose, P fertilization resulted in a more than 2 t·ha-1yield increase, as compared to the treatments without P fertilization. K fertilization had no effect on the yield, similarly to preceding years. These findings may be adapted to fields of the Middle-Tisza Region with similar conditions to the trial site. The N forms of the soil determined in CaCl2reflected fertilization well. All of the fractions, but especially NO3-N and Ntotal, increased significantly in response to N fertilization. Close relationships (r = 0.87–0.88) were found among the NO3-N and Ntotalfractions and the N balance, which means that the amounts of NO3-N and Ntotalare suitable for assessing both the N deficit and the N surplus. The strength of the correlation between the NH4-N content and N balance was moderate (r = 0.65). The Norgfraction increased significantly as a function of N and P fertilization. These results can be explained with the yield increase. A significant correlation (r = 0.55) was found between the Norgfraction and yield amounts. It can be established that organic residuals remaining on the site resulted in a significant increase in the Norgcontent of soils. The gained results confirm that the Norgfraction is suitable for the characterization of the readily mobilizable N reserves previously ignored in fertilization practice. On the basis of the presented results the CaCl2method is recommended for the precise estimation of nutrient requirements.
Databáze: OpenAIRE