Talaj és N-adag hatása a repcemag nitrogén és foszfor arányára, termésére és olajtartalmára

Translated title of the contribution: Effect of soil and N rate on the nitrogen and phosphorus ratio, yield and oil content of rape seeds

MáthéNé Gáspár Gabriella, Radimszky László, Németh Tamás

Research output: Contribution to journalArticle

Abstract

The investigations were carried out in the rape plots of a long-term N fertilization experiment set up in 1985 in the Nagyhörcsök (NH) and Orbottyán (OB) Experimental Stations of RISSAC. Half (NH) or a third (OB) of the N rates (0, 150, 300 and 450 kg·ha-1) were applied as basic fertilizer prior to sowing, together with the P and K fertilizers (100 and 200 kg·ha-1), and the remainder in spring as top-dressing. In every 4th year of the experiment subplots were created in spring within each main plot. The autumn N rates on the main plots (designated 1-4) were 0, 75, 150 and 225 kg·ha-1 and the spring rates on the subplots (designated 1-5) were 0, 50, 100, 150 and 200 kg·ha -1, thus representing four N levels in the autumn treatment (including the control) and a total of 20 in spring. The experiment was set up in four replications, giving a total of 80 plots. The subplots had a gross area of 50 m2 and a net area of 32 m2. The two soils, a pseudomyceliar (calcareous) chernozem in Nagyhörcsök and a calcareous sandy soil in Orbottyán, had similar values of pH(H2O) (NH: 8.1; OB: 7.8) and CaCO3 content (NH: 9.5%; OB: 8.7%), but differed greatly in terms of humus content (NH: 2.95%; OB: 0.87%) and clay content (NH: 20-24%; OB: 4-5%). In response to annual applications of P fertilizer, the AL-P2O5 content of the ploughed layer was high on both soils, averaging 312 and 306 mg·kg-1, respectively, averaged over the main plots. The diverse nature of the soil texture and humus content resulted in considerable differences in the average AL-K2O contents (NH: 401 mg·kg-1; OB: 256 mg·kg-1) and in the KCl-soluble NO3 contents in the upper 1 m soil layer, which increased from 1.8 to 6.8, 30.2 and 39.2 mg·kg-1 at rising N application rates in Nagyhörcsök and from 1.3 to 1.9, 7.5 and 16.1 mg·kg-1 in Orbottyán. The forecrop of winter rape (Brassica napus ssp. napus cv. GK-Gabriella) was spring barley. Sowing, with a row distance of 24 cm and 90,000 seeds per hectare, took place in September 2007 and harvesting in July 2008. The study aimed to determine how the N/P ratio of the rapeseed changed on the two soils, and how it correlated with the N supplies, and with the quantity and oil content of the yield.The main results were as follows: - As the N rate increased, there was an increase in the N content and N/P ratio of the seed and a decline in the P and oil contents on both soils. The individual levels of the two nutrients in the seed were higher on sandy soil, but the average N/P ratio was higher on chernozem soil. - The N/P ratio of seed grown on the two soils had a similar range (4.1-4.2 and 5.3-5.4), with the same value on plots without N fertilizer (4.4). On both soils an increase in the ratio resulted in a decline in the seed oil content. There were characteristic differences between the seed and oil yields, in the correlation between N/P ratio and yield, and in the seed N/P ratio at maximum yield. As the N/P ratio increased, the seed yield rose on the sandy soil but decreased on the chernozem. There was also a difference in the characteristic N/P ratio of the maximum yield, indicative of optimum nutrient supplies, with values of 4.5-4.7 in Nagyhörcsök and 4.8-5.3 in Orbottyán. The maximum yield was thus achieved at a lower N/P ratio on chernozem soil than on sandy soil. - It can be seen from the results that although there were great similarities in the nitrogen and phosphorus contents and N/P ratios of rapeseed on the two types of soil, characteristic differences in the optimum levels and ratios of the nutrients can be expected due to the different nutrient uptake conditions. Table 1. Effect of N treatment on the yield, oil content and oil yield of rape on the main plots at the two experimental locations. (1) Main plots, code and N treatment. a) Mean; b) LSD5%. (2) Calcareous sandy soil, Orbottyán. (3) Yield. (4) Oil content. (5) Oil yield. (6) Pseudomyceliar chernozem, Nagyhörcsök. Table 2. Effect of N treatment on the N and P contents (%) and N/P ratio at harvest in the seed of winter rape grown on calcareous sandy soil in Orbottyán (OB) and on pseudomyceliar chernozem soil in Nagyhörcsök (NH). (1) Main plots. a) Mean; b) LSD 5%. (2) Subplots. Note: N treatment to the main plots in autumn; to the subplots in spring every 4th year of the experiment. Table 3. Correlation between the N/P ratio of rapeseed grown on pseudomyceliar chernozem soil in Nagyhörcsök (NH) and on calcareous sandy soil in Orbottyán (OB) and the N, P and oil contents (%) of the seeds and the seed yield (n = 20). Note: + Seed yield correlations only refer to N-treated plots; *** Significant at the P = 0.001 level of probability. Fig. 1. Changes in the N/P ratio of rapeseed grown on calcareous sandy soil in Orbottyán (OB) and on pseudomyceliar chernozem soil in Nagyhörcsök (NH) as a function of N rates. Fig. 2. Correlation between the N/P ratio of rapeseed grown on sandy soil in Orbottyán (OB) and on chernozem soil in Nagyhörcsök (NH) and the yield quantity.

Original languageHungarian
Pages (from-to)345-356
Number of pages12
JournalAgrokemia es Talajtan
Volume59
Issue number2
DOIs
Publication statusPublished - Dec 1 2010

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ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Soil Science

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