Mycotoxins are secondary metabolites of microscopic fungi, which commonly contaminate cereal grains. Contamination of small-grain cereals and maize with toxic metabolites of fungi, both pathogenic and saprotrophic, is one of the particularly important problems in global agriculture. Fusarium species are among the dangerous cereal pathogens with a high toxicity potential. Secondary metabolites of these fungi, such as deoxynivalenol, zearalenone and fumonisin B1 are among five most important mycotoxins on a European and world scale. The use of various methods to limit the development of Fusarium cereal head diseases and grain contamination with mycotoxins, before and after harvest, is an important element of sustainable agriculture and production of safe food. The applied strategies utilize chemical and non-chemical methods, including agronomic, physical and biological treatments. Biological methods now occupy a special place in plant protection as an element of biocontrol of fungal pathogens by inhibiting their development and reducing mycotoxins in grain. According to the literature, Good Agricultural Practices are the best line of defense for controlling Fusarium toxin contamination of cereal and maize grains. However, fluctuations in weather conditions can significantly reduce the effectiveness of plants protection methods against infection with Fusarium spp. and grain accumulation of mycotoxins.

Arbuscular mycorrhizal fungi inhabiting soil play an important role for vascular plants. Interaction between arbuscular mycorrhizal fungi, plants and soil microorganisms leads to many mutual advantages. However, the effectiveness of mycorrhizal fungi depends not only on biotic, but also abiotic factors such as physico-chemical properties of the soil, availability of water and biogenic elements, agricultural practices, and climatic conditions. First of all, it is important to adapt the arbuscular mycorrhizal fungi species to changing environmental conditions. The compactness of the soil and its structure have a huge impact on its biological activity. Soil pH reaction has a substantial impact on the mobility of ions in soil dilutions and their uptake by plants and soil microflora. Water excess can be a factor negatively affecting arbuscular mycorrhizal fungi because these microorganisms are sensitive to a lower availability of oxygen. Mechanical cultivation of the soil has a marginal impact on the arbuscular mycorrhizal fungi spores. However, soil translocation can cause changes to the population of the arbuscular mycorrhizal fungi abundance in the soil profile. The geographical location and topographic differentiation of cultivated soils, as well as the variability of climatic factors affect the population of the arbuscular mycorrhizal fungi in the soils and their symbiotic activity.

The principles of good agricultural and horticultural practice, which consider both giving environmental protection and high yielding of plants, require modern cultivation methods. Modern cultivation of horticultural plants uses, for example, cover crops, living mulches, plant growth-promoting microorganisms (PGPMs), plant growth regulators (PGRs) and other biostimulants protecting the soil against degradation and plants against phytopathogens and stress. The purpose of field and laboratory studies was to determine the effect of Trianum P (containing Trichoderma harzianum Rifai T-22 spores), Beta-Chikol (a.s.—chitosan), Timorex Gold 24 EC (based on tea tree oil) and fungicide Zaprawa Nasienna T 75 DS/WS (a.s.—tiuram 75%) on the health of carrot (Daucus carota L.) plants and the microorganism population in the rhizosphere of this plant. Moreover, the antagonistic effect of rhizosphere fungi on selected carrot fungal pathogens was determined. Laboratory mycological analysis allowed one to determine the qualitative and quantitative composition of fungi colonizing the underground parts of carrot plants. In addition, the total population of fungi and bacteria was determined (including Bacillus sp. and Pseudomonas sp.) based on the microbiological analysis of the rhizosphere soil. The application of the plant growth-promoting fungus (Trichoderma harzianum T-22), chitosan and tea tree oil positively influenced the growth, development and health status of carrot plants. T. harzianum T-22, chitosan and fungicide most effectively protected carrots against infection by soil-borne fungi from the genus Alternaria, Fusarium, Haematonectria, Sclerotinia and Rhizoctonia. The rhizosphere population of Bacillus sp. and Pseudomonas sp. in the treatments with Trianum P or Zaprawa Nasienna T 75 DS/WS was bigger than in the other experimental treatments. A reverse relationship was observed in the population of rhizosphere fungi. T. harzianum T-22, chitosan and tea tree oil promoted the growth of antagonistic fungi (Albifimbria sp., Clonostachys sp., Penicillium sp., Talaromyces sp. and Trichoderma sp.) in the carrot rhizosphere. Antagonistic activity of these fungi towards Alternaria dauci, Alternaria radicina, Sclerotiniasclerotiorum and Rhizoctonia solani was higher after the application of the preparations compared to control. Consequently, Trianum P, Beta-Chikol and Timorex Gold 24 EC can be recommended as plant biostimulants in ecological agricultural production, including Daucus carota cultivation.

According to the assumptions of Organisation for Economic Co-operation and Development OECD, the share of biofuels in the global transport sector is estimated to reach 15–23% by 2050. The triticale can be used to produce bioethanol. The appropriate production process should generate as much renewable energy as possible per production unit. Plant production can be carried out in various tillage systems and using appropriate doses of nitrogen fertilization. The objective of this study is to compare the effect of traditional tillage system (TRD) and reduced (RED) tillage technology and nitrogen fertilizer (0, 40, 80, 120 kg N ha−1) on grain and bioethanol yield of spring triticale. The field experiment was performed in the south east of Poland (50°42′ N, 23°15′ E) on medium dystrophic typical brown soil. Based on research and calculations, the TRD system and between 40 and 80 kg ha−1 of N fertilizer are recommended for use in the cultivation of triticale for bioethanol production purposes. Such a variant will ensure a sufficient yield of grain (5.190 and 5.803 t ha−1), starch (3.462 and 3.871 t ha−1) and bioethanol (2487.3 and 2780.7 L ha−1) and good agronomic efficiency of N fertilizer (16.96 and 12.15 L of bioethanol per 1 kg of nitrogen (N) applied). The best ratio of energy efficiency of bioethanol production (EROI—Energy Return on (Energy) Investment or “net energy”) was recorded for the TRD system (1.138:1) and for the N fertilizer at 40 kg N ha−1 (1.144:1).

Iodine is indispensable in the diet of humans and other mammals and iodine deficiencies cause serious illnesses. The content of iodine in food (with the exception of marine foodstuffs) does not meet the nutritional needs of humans, and for this reason prophylactic iodination of salt is currently carried out in many countries. Biofortification of plants with iodine can become a widespread, alternative means of supplying iodine-rich foods. In the present study, we discuss the main issues related to the cultivation of plants enriched with iodine. We describe the effect of various forms of iodine fertilizer on crops, such as natural iodine sources, organic iodine, iodate and iodide salts, as well as ways of biofortifying crops: fertigation, foliar and soil application, and by hydroponics. Effective biofortification of plants with iodine increases its concentration to levels corresponding to human nutritional requirements whilst preserving the desirable eating qualities of the plants. Because each species reacts in a specific manner to a particular chemical form of iodine application, fertilization and cultivation methods, and other conditions, the development of proper cultivation technologies is essential to bring about widespread biofortification with iodine.