text: As of 2017 there are no peer-reviewed scientific studies available regarding the efficacy of the technique. A few university student projects investigate Hügelkultur but have not been published in scientific journals.
  One small scale and short term student project investigated the Hügelkultur method as a potential use for yard trimmings waste, and also if lima beans, kale and okra planted on a Hügelkultur mound showed any signs of nutrient deficiency compared to a non-raised control bed. It was found that over 11 tons of yard trimmings were used in the mound, and no evidence of macronutrient deficiency could be detected in the crops in the short term. Indeed, despite concerns that incorporation of large quantities of high carbon woody matter would lead to nitrogen immobilization and hence nitrogen deficiency in the crop, a higher level of nitrogen was found in the raised bed. However, the micronutrient iron was lower relative to the control bed. The author speculated that no nitrogen deficiency occurred since the roots of the plants did not penetrate past the superficial layers of the mound into the deeper wood-containing region.
  A student thesis investigated the water holding capacity of Hügelkultur beds and whether the technique could be useful to prevent karst rocky desertification in China. Over 3 months of measurements, water concentration in hügel mounds remained high. Samples from hügel sites contained almost twice as much water as those from flat control plots. It was suggested that  of hügels has 3-10 times more water than a flat plot affected by karst rocky desertification.