Vegetable plants have very diverse nutrient requirements. The aim should be to alternate between species with different needs. Directly cultivating species with high nutrient demands following each other can lead to excessive depletion of mineral nutrients from the soil. Mineral deficiency may not affect the entire soil profile but only individual layers. Therefore, to prevent the leaching of minerals into the deeper soil layers and make rational use of mineral nutrients, plants with deep and shallow root systems should be grown alternately. Vegetables with deep root systems include root vegetables, cabbages, kale, and tomatoes. Typical plants with an external root system are radishes, spinach, cucumbers, kohlrabi.
Plants with high nutritional demands are required to be grown on land where manure, compost, or legumes have been ploughed in. This is all about vegetables with very high requirements to nitrogen, which is a component significantly affecting the yield and at the same time easily leached into the soil profile (Table 1a).
Fertilising vegetables in the field
The issue of nitrogen fertilisation assumes great importance in the cultivation of vegetables with high nitrogen fertilisers rates. Moreover, increasing the amount of available nitrogen can contribute to excessive nitrate accumulation in the plant. Standard nitrogen rates for field vegetable production are listed in Table 1.
Phosphorus fertilisation is adjusted in the fall or early spring by spreading fertilizer evenly over the crop surface and then mixing it into the soil. Phosphorus fertilisers should not be applied simultaneously as calcium fertilisers because the phosphorus will become depleted.
Potassium is taken up by the plant as K+ ions, mainly from the soil solution. An increased amount of potassium in the soil contributes to greater plant uptake and accumulation. Potassium is readily translocated within the plant. Standard soil potassium contents for different vegetable crops are shown in Table 1.
Note: Detailed rules for fertilising vegetables are given in the following study.
References: – “Zrównoważone nawożenie roślin ogrodniczych ” – A collective study edited by Dr. Paweł Wójcik – link to the publication – pdf