Organically fertilized plants can manage water-limited growth conditions better than minerally fertilized plants. Results from a multi-year experiment

Summary

Since 1980 a field trial is carried out on a sandy soil under dry-warm climate conditions (590 mm annual precipitation, 9.5°C annual mean air temperature) comparing farmyard manure with and without biodynamic preparations and mineral fertilizer, each treatment at three application rates between 60 and 140 kg total nitrogen per hectare. The amount of water available in June was a relevant yield determining factor (p<0.05) only for minerally fertilized wheat. During 13 years the manure fertilized wheat yielded between 30 and 50 dt ha-1, irrespective to water availability. Manure fertilization gave lower maximum yields but higher minimum yields showing a better yield stability. With manure fertilization the wheat plants realized a better harvest index of 45% compared to mineral fertilization (41%; p<0.05). Other studies in this experiment revealed an enhanced root growth with better root distribution, even in the sub-soil, with manure fertilization and biodynamic preparations. This may have enabled the organically fertilized cropping system to compensate better for restricted growth conditions.