Crop cultivation: soil, crops and crop rotation
The foundation for growing healthy crops with high and stable yields
Crop cultivation is about growing crops to give good yields without exhausting the soil. It requires knowledge of soil properties, crop requirements and the interaction between cultivation, fertilisation and plant protection. A skilled arable farmer thinks in whole rotations and whole seasons, not just in the individual field here and now.
§Soil as a growing medium
Soil texture – the ratio of sand, silt and clay – determines how well the soil retains water and nutrients. Clay soil holds nutrients well but can be heavy to work and poorly drained. Sandy soil is easy to work in and drains quickly but dries out easily and leaches nutrients. Most Danish fields fall somewhere in between.
The soil's content of organic material (humus) affects both fertility, structure and the ability to retain water. Good soil structure with stable aggregates provides room for air, water and roots and is a prerequisite for healthy plants.
§Crop rotation and its benefits
Crop rotation means changing between different crops on the same field from year to year. A well-thought-out crop rotation breaks disease and pest cycles because many pests are tied to specific crops. It also distributes nutrient requirements over time and can improve soil structure.
- 01Legumes (e.g. peas and clover) bind nitrogen from the air via root nodule bacteria and leave nitrogen for the following crop.
- 02Grain is the main crop in many crop rotations and places moderate demands on soil.
- 03Root vegetables and field crops loosen the soil and allow for mechanical weed control.
- 04Cover crops cover the ground in autumn, retain nutrients, and protect against erosion.
§The season's planning
Planning begins in autumn or winter with crop selection and field selection. This is followed by soil preparation, sowing, fertilisation and ongoing monitoring of crops throughout the growing season. Harvest and subsequent soil treatment complete the cycle and prepare the field for the next crop.
Field watering crop protection and fertilisation must be adapted to each crop and the current weather situation. Therefore regular field walks — where you walk through the field and assess the plants' condition — are a central part of the crop grower's work.