Caraway: Soil preparation, setting up of a plantation

2015

A field for caraway should be prepared with special care, considering deep penetration of its roots and also a period of 2 or even 3 years of its cultivation at the same place. Ploughing should be necessarily performed in autumn, since long-time observations provided evidently worse results if it was conducted in spring (). On deep soils there is recommendation to use standard plough provided with a chisel, or a special subsoil cultivator, working askew or across the direction of basic ploughing.

In spring, agricultural practices should be carried out as soon as possible to prevent clodding and drying out of the soil top layer, and they include dragging and multiple harrowing. Cultivator is recommended only for very heavy soils, strongly stale after winter. This operation should be immediately followed by harrowing. If the soil is too loose and uneven on the surface, the use of a flat roller is required for precise sowing and to enhance capillary rise of soil moisture, and finally to obtain uniform emergence of caraway seedlings.

Caraway sowing material are achenes, whose germination capacity should be at least 80%. This level can be maintained for 2–3 years, then rapidly declines (). The weight of 1000 achenes may reach 5g and according to commercial standards in Poland, it should not be below 2.6g. In spite of a high germination capacity in a laboratory, caraway seeds sown in the field may germinate unevenly, taking a long time. The research carried out during the 1950s and 1960s showed that the field germination capacity could be increased by a pre-sowing stimulating treatment. Vrzalova () achieved a better field emergence by soaking achenes in water (running in particular) and explained such an effect by washing out seed germination inhibitors. Chotin and Szulgina () obtained significantly advanced and more uniform emergence as a result of seed stratification at 0°C for 20–25 days and also by warming up the seeds just before sowing. A sufficient water supply during germination is required for uniform emergence. Optimum soil moisture for caraway germination is 80% ().

At present, caraway is grown only from direct sowing. In the moderate climate of Central Europe two cultivation methods are used: mixed or pure crop. Difference concern only the first growing season. Mixed cultivation with a cover crop is usually preferred by the owners of relatively smaller farms located under favourable soil and climatic conditions. Those growers are orientated towards intensive usage of arable land. Cover crops are cultivated together with caraway and yield in the first year, being mainly represented by garden poppy, pea, black cumin and spring oilseed rape. Moreover, coriander is also considered by Polish growers as a cover crop very suitable for caraway. In Hungary the most popular cover crops are dill and annual caraway (). However, Müller () is of a different opinion, regarding coriander as well as dill, marigold and spring barley grown for grain as the plants which have a negative effect on caraway performance. According to the same author, spring barely grown for green forage can be recommended as a suitable cover crop, likewise camomile, if sown together with caraway in previous autumn. Experiments carried out in Poland during the 1970s () pointed also to flax and spinach as potential cover crops for caraway.

According to some authors () pure sowing can be delayed to the end of May, and even to August. However according to Wêglarz () and over the years of practice the growers recorded the highest yields from crops sown as soon as possible. In mixed cultivation, possibly the earliest sowing (March, April) is just obligatory.

The sowing rate depends on both the cultivation method and soil type, ranging from 6– 8 kg to 8–10 kg per ha for mixed and pure crops, respectively. A lower sowing density is recommended for firm soils, maintained in a good culture. According to Nordesgaard (), the amount of 4 kg of seeds per ha is sufficient for pure sowing in a single-harvest biennial cultivation, while the required amount for a double-harvest three-year crop rises to 6–7 kg. The sowing is performed in rows at a 35–50 cm spacing (larger on heavy soils rich in humus). Sowing depth increase from 1.5 cm on heavy soils to 2–4 cm on relatively lighter soils, exposed to fast drying of the top layer.

In a mixed crop the sowing rate is 20–40% lower as compared to pure cultivation. Longtime practice proved that cover plants (excluding pea) should be sown together with caraway into the same rows. Pea, instead, is sown into rows at a distance of 8cm, followed by the sowing of caraway at a row spacing of 40–50 cm. In Hungary dill is sown in cross direction to the rows of the main crop, and before it ().

 

Selections from the book: “Caraway. The Genus Carum”. Edited by Éva Németh. Series: “Medicinal and Aromatic Plants — Industrial Profiles”. 1998.