The influence of different nitrogen and potassium fertilizer rates on seed yield and quality of spring oilseed rape
2005
Borovko, L., Latvia University of Agriculture, Skriveri, Aizkraukle reg. (Latvia). Agency Research Institute of Agriculture
It was for the first time under soil and climatic conditions of Latvia when the Research institute of Agriculture in Skriveri carried out field trials with spring oilseed rape 'Olga' on optimization of nitrogen and potassium nutrition in 2001-2003. The influence of nitrogen (N) and potassium (K) fertilizer rates 60, 80 (60+20), 100(60+40), 120 (60+60), and 140(60+80) kg haE-1 on the formation of spring oilseed rape yield and quality of seed was tested on phosphorus fertilizer background P70. The fertilizer was split into two applications. The first dose of fertilizer N60K60 kg haE-1 was applied before sowing while the second - as additional NK fertilizer 20-80 kg haE-1 at the stage of stem formation. The results of 2001-2003 show that nitrogen and potassium fertilizers on background P70 provided seed yields 2.06-3.15 t haE-1. Introduction of nitrogen 60-100 kg haE-1 and potassium 60-100 kg haE-1 resulted in yield increase 0.75-1.09 t haE-1 (LSD0,05=0.22 t haE-1). The increase of seed yields is significant in comparison with the control. The highest increase of the seed yield - 1.09 t haE-1 was obtained in treatment N100K100. The seed yields showed tendency to decrease when increasing NK fertilizer rates to 120-140 kg haE-1. The highest seed yield increase with 1 kg of applied NK fertilizers (6.25, 6.0 kg) was observed in treatments N60K60 and N80K80 kg haE-1, but the lowest (3.36 kg) - in treatment N140K140 kg haE-1. The use of NK fertilizers promoted the accumulation of crude protein (22.12- 24.13%) but decreased the content of oil (47.06-43.72%) in the seeds. The economic optimal rate of nitrogen and potassium in the sowings of spring oilseed rape 'Olga' was N88K88 kg haE-1, providing the highest seed yield 3.07 t haE-1 and yields of oil 1286 kg haE-1.
اظهر المزيد [+] اقل [-]