Response of hemp (Cannabis sativa L.) to integrated application of chemical and manure fertilizers

Abstract

The investigation of various nutrition systems in hemp plays an influential role in improving its production. An experiment was conducted in University of Birjand, Iran, during 2013-2014, in which manure (0, 10, 20, and 30 t.ha-1 of cow manure) was considered as the main plot and the combination of nitrogen (0, 50, and 100 kg N ha-1 as urea) with phosphorus (0 and 80 kg P ha-1 as triple superphosphate) fertilizers was considered as factorial in subplots. The type of soil fertility management had no significant effect on the percentage of female plants. Applying 20 t.ha-1 of manure plus 100 kg N ha-1 produced the highest biological yield, seed, and leaf extract. The highest oil content was obtained by applying a maximum of 50 kg N ha-1 without the use of phosphorus. The 30 t ha-1 manure plus 100 kg N ha-1 increased the leaf harvest index and decreased seed harvest index. Nitrogen consumption also increased the seed oil content and yield. Phosphorus increased the biomass and extracts of seed and leaves, also biological, seeds and oil yield. It seems hemp responds well to the combined application of nitrogen fertilizer and animal manure, while its response to P fertilization was limited.