Use of Active Microrganisms in Crop Production - A Review

Abstract

Phosphorus, other elements and natural resources are scarce, and so it is necessary to find alternative strategy to increase availability of nutrients for plants. One possible way could be application of so-called bioeffectors (BE) which should improve the mobilisation of nutrients (especially phosphorus) from less available forms in soil, improve plant growth and contribute to mycorrhiza development. BEs are commercially supplied products which contain active substances (live microorganisms and active natural compounds). BEs can be used in organic agriculture, because their application represents no risk for the environment. Several studies and experiments are focused on impact of bioeffectors' application and their active compounds on plants. Experiments were performed under different conditions (field, pot, greenhouse), on various testing plants and on various bioeffectors. These BEs have been used as a fertilizer, fungicide or molluscicide and they were applied either to soil, seed or leaf. Application should increase growth of root system and above-ground part of plants and also nutrient uptake. These products are developed for a wide variety of crops (e.g. maize, wheat, tomatoes, rape, spinach, grass, ornamentals). This review summarizes the most recent knowledge in this scientific field. Mycorrhiza is highly effective in absorbing nutrients from the soil, especially for nitrogen and phosphorus. Nitrogen and phosphorus are often limited in supply and fungal hyphae are able to absorb these nutrients more efficiently and from greater area of soil than the roots, which leads to increased plant growth. This causes mutually beneficial linkage between plants and fungi, the sugars (organic carbon) formed during photosynthesis are transported to the roots and the fungi are taken and the nutrients are absorbed by fungal hyphae from the soil and are transported into plants [10,11]. Arbuscular mycorrhizal fungi colonise most agricultural species (exceptions include Brassica spp., and Lupinus spp.) and play an important role in the phosphorus nutrition of many farming systems worldwide, especially on soils with low available phosphorus [3]. Literature Review Examples of plant strategies for phosphorus obtaining: a) Growth of roots b) Root exudates (acidic phenolics) c) Mycorrhiza d) Cooperation with microorganisms (P-solubilization). One alternative strategy in plant production can be use of unmycorrhizal organism's P mobilizing nutrients, which should help to increased nutrient availability for plants. These substances are so-called bioeffectors.