Mixed seeds
In agriculture and horticulture, seed that contains more than one type of seed is called batch seed . Often species or varieties are mixed. They can be made by the farmer or the gardener himself. There are also commercially available seed crops. The proportions of the plant species are given in percent.
purpose
Batch seeds serve various purposes in agriculture. On the one hand, the different types of plants make different demands on soil properties and nutrients and can complement each other. They are suitable as catch crops . They can also be used for a balanced harvest, for example when feed is required for animal husbandry. Then the seeds are put together so that the harvested yields correspond to the desired composition (proteins, carbohydrates).
In horticulture, crop seeds are used to cultivate flower fields across the board.
When growing, it is important to ensure that certain weather and soil influences affect the fruits involved differently. Fruits can fail selectively due to ground frost or rainy days. When harvesting, a precise point in time must often be observed, as the plants reach their optimum at different times. Mixed seeds are therefore often not suitable for a longer harvest. In horticulture, however, they can change the appearance of the fields when the flowering periods follow one another. They are then often the only way to change the appearance of the fields without re-ordering.
advantages
- The joint cultivation of grain types such as rye and oats that are at risk of storage, together with stable types such as barley and wheat, can reduce the risk of storage .
- Cultivation of legumes (nitrogen collectors, nodule bacteria ) together with fruits that require nitrogen. This is mainly done in organic farming , since the use of artificial fertilizers is not allowed there.
- Increased yields because the species use different resources ( light , water ) or these resources at different times.
- A plant with a fast early development can suppress the weeds for plants with a late development ( potato and sunflower ).
- Better yield stability, as one fruit can compensate for the poor yield of the other. This is the case, for example, when one resource is too little and the second type can handle it better.
- In some combinations (for example, carrot and onion ), one species repels the pest of the other.
- Loss of nutrients can be avoided because the roots of the plants retain nutrients and soil ( erosion ).
disadvantage
- The harvest is not varietal. This makes marketing more difficult, as the mixing ratios are difficult to determine and mainly single-variety products ( wheat flour , oat flakes ) are offered in stores
- It is difficult to determine when to harvest as the fruits are not always ripe at the same time.
Manufacturing
Today, mixed seeds are produced by mixing pure seeds. Production from cultivated crops is only possible if the plant species ripen at the same time and can be harvested in the same way, which is possible with some grasses. As a rule, the seeds are mixed again before each order, which also reduces the stocking . Successive sowing and harvesting, as was common in the past, is no longer common today because the percentages of the seeds change as a result of different growth and ripening times. A subsequent admixture of pure seeds does not lead to constant quality, but this can also be desirable in the ecological cultivation of pasture areas.
The quality of seed crops is more difficult to assess than that of pure seeds. Germination tests and test seeds are essential for a reliable judgment.