The effect of various N, P and K supply levels and their combinations on the development, yield and quality of fibre hemp (variety Kompolti) was investigated in the 16th year of a long-term mineral fertilisation experiment on loamy chernozem soil with lime deposits. The soil of the growing site contained 3% humus, 5% CaCO3 and 20% clay in the ploughed layer, and was classified as poorly supplied with P and Zn and moderately well with N and K. The experiment was set up with 4N×4P×4K=64 treatments in 2 replications, giving a total of 128 plots. The mineral fertilisers were applied in the form of calcium ammonium nitrate containing 25% N, 18% superphosphate and 50% potassium chloride. The groundwatcr was at a depth of 13-15 m and the area was prone to drought. The main results were as follows: 1. The N×P interactions were dominant during the first two months of fibre hemp development and the N×K interactions during the second half of the vegetation period. Growth maxima were observed between May 30th and June 13 th, when the height of the plant stand increased by 78 cm in the course of 14 days, i.e. by 5.6 cm a day, as the result of plentiful NPK supplies. 2. The air-dry shoot mass was 0.6-1.3 t at the end of May, 3.5-8.0 t on June 26th and 7-12 t at stem harvest on August 11th, while the fresh mass of the green stems was 25-41 t per hectare, depending on the treatment. Optimum supply levels were found to be 100 kg/ha/year N, 150 mg/kg ammonium lactatc (AL)-soluble P2O5 and 250-300 mg · kg-1 AL-K2O. These data could serve as guidelines for the Hungarian fertiliser extension service. 3. N fertilisation reduced the plant number, increased the length, thickness and fibre yield of the stems and led to a deterioration in fibre quality. Good quality was obtained on plots given no N for 16 years and satisfactory quality in treatments given 100-200 kg · ha-1 · year-1 N, while on plots fertilised with 300 kg · ha-1 · year-1 the quality was not suitable for use by the textile industry. After P fertilisation there was a drastic decline of almost 20% in the plant number and in the % of crush, and a rise of 2% in the fibre content of the crude stems. K fertilisation had a positive effect on this soil, which was only moderately supplied with K: there was an increase in the length and thickness of the stems, and a 0.4 t · ha-1 increase in the fibre yield. 4. Among the treatment combinations, the following minimum-maximum values were recorded in the experiment: plant density 160-261 plants · m-2, technical length of the stem 180-250 cm, stem thickness 4-8 mm, fibre yield 2.0-3.0 t · ha-1.
|Translated title of the contribution||Effect of mineral fertilisation on the yield of fibre hemp (Cannabis sativa L.)|
|Number of pages||12|
|Publication status||Published - Apr 1 2003|
ASJC Scopus subject areas
- Agronomy and Crop Science