Soil preparation or tillage

Hemp requires well-structured soil to achieve high yields. Creating optimal growing conditions is essential, including site-adapted soil cultivation. The goal is to prepare the soil in a way that effectively incorporates harvest residues from the previous crop, retains moisture from precipitation, and ensures adequate aeration. According to Bouloc et al. (2013), preventing soil compaction during tillage and seedbed preparation is particularly important. (TFZ, 2020)

For the seedbed preparation, a fine top layer of soil is required to ensure good contact for germination. The soil structure should strike a balance between not being too coarse or too fine to prevent wind erosion of fine sand. A tailored preparation is needed depending on the local conditions (van den Oever et al., 2023). For example, for soils with a high sand content, this tillage measure can be postponed until spring. After tillage, the soil should be recompacted with a roller to close the soil and allow capillary water to rise (TFZ, 2020).

The fertiliser requirements of hemp are mainly dependent on the native soil fertility and the end use of the crop. In general, hemp is not responsive to phosphorus or sulphur fertiliser if the soil is already adequately supplied (Fike, J., 2016; Government of Alberta – Agriculture and Forestry, 2020). However, this is not the case for nitrogen fertiliser as hemp is a heavy nitrogen user (Fike, J., 2016).

When cultivating the crop for grain harvest, increasing amounts of fertiliser result in higher biomass and grain yields, reaching maximum values of 150 kg of fertiliser per hectare (Fike, J., 2016; GA – Agriculture and Forestry, 2020).

To supply the soil with nutrients and especially nitrogen, organic producers often cultivate perennial alfalfa prior to hemp, which is then plowed back into the soil while it is still green.

As the plants decay, the nitrogen and other nutrients are released slowly, which possibly even improves nutrient retention and nitrogen uptake efficiency, while reducing leaching losses. The plants used for this process are often referred to as green manure (GA – Agriculture and Forestry, 2020; Cherr, C. M., et al., 2006).