Catch crop for corn

Catch crop waiting for corn

If the forecrop for corn is species that leave the field earlier, such as rapeseed or cereals, the site remains unproductive for several months. During this time, the soil is exposed to unfavorable external factors, which may lead to erosion. The ideal solution seems to be sowing catch crops, thanks to which the soil surface is covered with a layer of vegetation. An appropriate intercrop mixture will not only protect the soil against erosion in a critical period, but will also bring other benefits – it can improve the properties of the soil, loosen its deeper layers, provide organic matter, and constitute a reservoir of nutrients.

How to calculate sowing rates in your own intercrop mixture?

Catch crop for green manure for corn

The selection of possible species for the intercrop mixture for corn is very wide. Without any major restrictions, you can choose various popular species, such as phacelia, buckwheat, sunflower, Abyssinian oilwort, various cabbage plants and legumes. However, it is worth being careful when determining the share of individual plants in the mixture.

Of course, it is possible to use Poaceae species (e.g. oats, rye) and Brassicaceae species (e.g. mustard, radish) as a catch crop for corn. Poaceae can become a good source of organic carbon in the soil, and brassicaceae with tap root systems loosen the soil well, which favors the development of corn. These species develop quite quickly and cover the soil well, which is important for its protection in winter. However, it is not advisable for them to dominate the mixture. This is related to the exposure of corn to nitrogen deficiency, which is a species with high nutritional needs.

In the case of a catch crop mixture based mainly on cereal plants, there is a risk that the decomposition of their residues with a wide C:N ratio will lead to nitrogen immobilization. Moreover, corn and cereals have a similar range of pests that threaten them. Too high a share of cabbage plants in the catch crop for corn is not recommended for a similar reason as in the case of cereals. Plants such as mustard and radish produce biomass and accumulate large amounts of nitrogen. On the one hand, this is a beneficial property because it protects against washing out of this ingredient during winter. On the other hand, the remains of these plants do not decompose in the soil quickly enough to "give back" all the accumulated nitrogen to the corn.

Due to the high demand of corn for nutrients, including nitrogen, it is worth choosing a mixture with a high proportion of legumes, such as lupins, peas, field beans, vetches, and clover.

Examples of simple catch crop mixtures for corn include:

yellow lupine (80 kg/ha) + phacelia (4-6 kg/ha),
serradella + buckwheat (40 kg/ha + 40 kg/ha)
oil radish + lupine (15 kg/ha + 100 kg/ha)
field pea + sunflower (130 kg/ha + 15 kg/ha)
oil radish (10 kg/ha) + phacelia (5 kg/ha) + field pea (80 kg/ha)
oil flax (15 kg/ha) + sunflower (9 kg/ha) + blue lupine (60 kg/ha) + common vetch (40 kg/ha)
white mustard (5 kg/ha) + buckwheat (20 kg/ha) + oats (35 kg/ha) + red clover (8 kg/ha)

Rules for successful sowing of catch crops: date, sowing method, location

An opportunity for additional fodder

Many farms use the time between harvesting the forecrop and sowing corn to obtain an additional source of fodder. You can then sow rye, rye with vetch, a Gorzów, Poznań or Chodzież mixture in the winter catch crop. The winter catch crop can be used for pasture after the plants reach 15-25 cm in height, harvested for green fodder or ensiled. Such a catch crop usually disappears from the field by mid-May, so you can still successfully sow corn for silage or for grain of a variety with a lower FAO count. However, such cultivation may be burdened with the risk of failure. Dry May, which has become more and more common in recent years, may doom a corn plantation sown after harvesting the winter catch crop for fodder to failure.