Impact of multi-cropping on some soil physical properties, nutrient proportion and enzymatic activity

Crop growing with multifunctional companions can maintain soil fertility and agrotechnological inputs, but the combinations of multi-crops are still not sufficiently investigated. For this reason, in Lithuania (54°53′7.5′′ N, 23°50′18.11′′ E), in humid continental climate conditions (Dfb), maize, technical hemp and faba bean were grown as single, binary and ternary crops. The aim was to determine their effect on the variation of soil structural proportion, penetration resistance, macronutrient contents and enzymatic activity continuously over three years. In most multi-crops soil aggregates stability decreases by 16–23%, NPK levels by 1–20% and urease activity by 70–87%, compared to the initial conditions. In the ternary crop the amounts of the main macronutrients in the soil decreased the most (about 2.7 times), because its biomass was 2–2.5 times higher, compared to other diversified crops. The maize-faba bean binary crop had the lowest negative influence or sometimes positive change in the soil parameters studied. Results suggest the cultivation of multi-crops during a single vegetative period, by including them in existing crop rotations or growing them continuously with more frequent fertilisation.