Növénytermelés / Volume 62 / Issue 2 (June 2013) / pp. 29-50
Izsáki Z; Némethné Kádi G
Fertilisation of Jerusalem artichoke (Helianthus tuberosus L.) I. The impact of nutrient supply on the dynamics of biomass accumulation and biomass yield
The effect of NPK fertilisation on the dynamics of biomass accumulation and the leafy stem and tuber yield was examined in the case of two Jerusalem artichoke cultivars (Tápió early and Tápió normal) in a fertilisation field experiment.
The fertilisation experiment was established in 2002 on deeply calcareous chernozem meadow soil with two cultivars and 13 fertilisation treatments in a split-plot design with four replications. The main soil characteristics of the experimental area are as follows: pH(KCl): 5.8, no CaCO3 content, clayey adobe, humus content: 2.65 %, AL-P2O5: 121 mg kg-1, AL-K2O: 278 mg kg-1. During the growing season, we took samples on five occasions and measured plant height, the green mass and dry matter weight of the leafy stem, as well as the tuber yield.
The main findings and conclusions of the fertilisation experiment are summarised below:
1. The growth characteristics, biomass accumulation and tuber formation dynamics of the short growing season Tápió early and the long growing season Tápió normal cultivars significantly differ from each other. The most intensive period of the shoot growth of Tápió early is between the 85th-115th day of the growing season, while it is between days 115-155 in the case of the Tápió normal cultivar. Averaged over the fertilisation treatments, both cultivars reached the maximum of their total biomass yield on the 155th day of the vegetation period, but there is significant difference in the share of the leafy stem and tuber yield in the total biomass. In this period, the tuber yield of Tápió early was 56% of the total biomass, while that of Tápió normal was 4%. At the time of harvesting, these values were 87% and 40%, respectively.
2. The separately applied N fertilisation increased the height of the Tápió early crop stand, while excessive N supply reduced the length of the main shoot in the case of the Tápió normal cultivar. The highest K supply resulted in a more moderate main shoot growth in the case of both cultivars.
3. In the period of forming the maximum above-ground biomass, the highes leafy stem yield (38.34 t ha-1) was obtained as a result of the 100 kg ha-1 N and P fertilisation in the case of the Tápió early cultivar. As regards the Tápió neutral cultivar which forms signifantly more leafy stem yield, the highest above-ground biomass (78–80 t ha-1) was achieved by applying 200 kg ha-1 N, P and K fertilisation.
4. Excessive N fertilisation without P and K fertilisation decreased the tuber yield of the Tápió early cultivar. As regards both Jerusalem artichoke cultivars, the most favourable tuber yield was achieved with the 200 kg ha-1 N dose, supplemented with P and K fertilisation.
Keywords: Jerusalem artichoke, fertilisation, biomass accumulation, yield