Slovenian Agronomy Research
Herein I present a brief abstract of my graduate research project investigating the effects of irrigation, soil nutrients and crop density on the growth of hemp crops of the cultivar ‘Kompolti Hibrid TC’.
The experiment began in 1995, and although the results were not encouraging (due to destruction by birds, unhomogenous soil, extended rainy season, and interference by police) the potential of further research seemed promising. The problems confronted the first year can be explained by the long absence of hemp crops in Slovenia and the resultant misunderstanding by government officials who do not recognize the difference between industrial hemp and marijuana plants.
The second phase of the experiment was carried out in 1996 in structures providing protection from uncontrolled rain. The seeds were sown on July 6 at two different densities (227 and 682 plants/m2 ). Four levels of soil moisture (10, 30, 60 and 90% dryness) were maintained and three levels of nitrogen fertilization (0, 85 and 170 kg/ha) were tested. Measurements were made of the number of male and female plants, as well as the dry yield of whole plants, stalks and seeds.
The crop density had no significant effect on the yield or the sexual ratio of the crop. Increased yield resulted from increased irrigation and fertilizer application. Sexual ratio was not affected by soil water or nutrient levels.
This experiment shows that late high-density sowings of hemp can be utilized as a cash-crop after the Spring harvest of cereals.
In 1996, I grew a crop of the two monoecious Spanish hemp cultivars, ‘Delta-405’ and ‘Delta-Llosa’, at the Superior Polytechnic School of Santiago de Compostela University in the Galician province of Lugo in northern coastal Spain, where hemp is not presently grown commercially. Sixty plants of each variety were grown in a 22.4 m2 plot, protected from thieves by a greenhouse. Plots were sown on April 26. Plants developed normally, growing rapidly in June and flowering in August. Plants were irrigated every two or three days until flowering, when irrigation was reduced by half. The crops were affected by spider mites and white flies which caused no economic damage. Birds ate 30-40% of the seeds. The crops were harvested during the second week of September and no apparent differences between the two varieties were noticed. Seed viability was 80-99%. Initial analyses indicate that leaf protein levels may be quite high, even in excess of cereals and legumes. However, toxicity to livestock must be tested.
Estimates based on experimental yields of stalks and seed indicate that hemp could possibly be grown profitably in Galiza under field conditions. However, considerable additional research must be performed and local markets for hemp products developed.