Agricultural production is a crucial part of policy issue in preventing depopulation of mountainous areas across Europe. However, soil and climate conditions are limiting yields and profitability of crop production in these regions. The European Union (EU) subsidizes agriculture in mountains by special payments (Less Favoured Area (LFA) subsidy) when areas match law-specified natural handicaps. This study aims to assess whether LFA subsidy in Poland is sufficient to cover losses caused by lower yields of crops cultivated in a mountainous region of Poland (Low Beskid Mountains in Carpathians) compared to lowland regions (non-LFA areas). The results indicated that LFA subsidy was adequate for crops (facultative wheat, winter wheat, field bean and spring barley) grown in the years 2015–2018.

Natural products have always enjoyed great popularity among consumers. Wild tea is an interesting alternative to tea from intensive plantations. The term “wild tea” is applied to many different varieties of tea, the most desirable and valued of which are native or indigenous tea plants. Special pro-health properties of wild tea are attributed to the natural conditions in which it grows. However, there are no complex studies that describe quality and health indicators of wild tea. The aim of this research was to evaluate the quality of wild and cultivated green tea from different regions of China: Wuzhishan, Baisha, Kunlushan, and Pu’Er. The assessment was carried out by verifying the concentration of selected chemical components in tea and relating it to the health risks they may pose, as well as to the nutritional requirements of adults. Wild tea was characterized by higher micronutrient concentration. The analyzed teas can constitute a valuable source of Mn in the diet. A higher concentration of nitrates and oxalates in cultivated tea can be associated with fertilizer use. The analyzed cultivated tea was a better source of antioxidants with a higher concentration of caffeine. There were no indications of health risks for wild or cultivated teas.

Cultivation of spring cereal mixtures (SCMs) is one of the ways to increase the yield of crops in mountainous areas of Poland. There are only a few current long-term studies on this topic. Our study aimed at analyzing yield and competitiveness as well as the economic indicators of spring cereals in pure or mixed sowings in integrated or organic crop rotations over nine years. A field experiment including pure sowings of oats, spring barley, or spring triticale and their two-component SCMs, each in two systems, organic and integrated crop rotation, was carried out in the Mountainous Experimental Station in Czyrna, Poland, in the years 2011–2019. On average, cereals in the pure sowings and mixtures yielded 18% lower in the organic rotations compared with the integrated ones. However, SCMs yielded higher than the pure sowings, and displayed a higher leaf area index and land equivalent ratio. The average gross margin without subsidies was almost two times higher in the organic crop rotations than in the integrated ones, which was influenced mainly by the cultivation of barley in pure sowing. Summing up, the cultivation of SCMs in the mountainous areas of southern Poland is advised because of both productive and economic factors.

The yield and quality of crop mixtures depend on natural and agrotechnical factors and their relationships. This research aimed to analyze the grain yield, its components and total protein content of the organically grown oat–vetch mixture on two different soils and depending on the oat cultivar. The three-year field experiment with two crop rotations was carried out. The experiment was set up in the southern Poland on two soils: Stagnic Luvisol (S.L.) and Haplic Cambisol (H.C.). One of four oat cultivars (‘Celer’, ‘Furman’, ‘Grajcar’ and ‘Kasztan’) was grown with the common vetch cv. ‘Hanka’. The results showed that the grain yield of mixtures was affected mainly by weather conditions. During the dry season, the share of vetch in the grain yield was 46% lower than in the season of regular rainfall. The share of vetch seeds in the mixture’s yield was ca. 21% higher when the mixtures were grown on the S.L. than the H.C. soil. The selection of oats’ cultivar for the mixture with vetch affected significantly the thousand seed mass and protein content in the vetch seeds, 46.2–50.4 g and 270–280 g kg⁻¹, respectively. The mixture with Kasztan cultivar yielded the best and this oat cultivar seemed to be the most appropriate for organic conditions; however, in years with high variability of rainfall distribution its usefulness was less.

Oilseed rape (Brassica napus L.) reacts differently to foliar application of sulfur (S) and boron (B), and for that reason it is important to find an early indicator that would inform about the direction of this reaction. This study aimed at evaluating the early response of two double-low cultivars of winter oilseed rape: hybrid (Nelson) and open pollinated (Digger) on the foliar fertilization with S and B in two terms: fall and spring, based on the rate of leaf greenness index (SPAD) and seven indicators of chlorophyll a fluorescence (FL). On 7th or 9th day after the application of liquid fertilizers, the selected parameters of FL and SPAD were determined on the leaves of rape. As a result, a significant effect of foliar B and S supplementation on the yield of oilseed rape was found. Principal component analysis (PCA) allowed for a separation for each of the cultivars the two parameters of FL, namely Tfm and Fv/F0, which are sensitive indicators of a physiological state of the rape plants shortly after foliar S and B dressing.

The research aimed to compare the yields and yield components of mixtures of oats with common vetch grown for seeds in organic and conventional farming systems. Moreover, the selection of oat cultivars for the mixture and its performance in a crop rotation experiment in different growing years was analyzed. Additionally, the leaf area index (LAI) and the relative content of chlorophyll (SPAD) of the mixtures were assessed. The field experiment with four-field crop rotation in organic or conventional farming systems was carried out in 2012–2014 in southern Poland. Common vetch (Vicia sativa L., cv. ‘Hanka’) was mixed with one of two oat (Avena sativa L.) cultivars, ‘Celer’ or ‘Grajcar.’ The effects of all of the factors on the mixtures’ canopy indices and yield were found. The canonical analysis revealed that the weather course, especially drought, had the largest effect on the oat-vetch mixtures’ performance. Moreover, the mixtures developed the highest LAI (5.28 m²∙m⁻²) and seed yield (4.57 t ha⁻¹) in the conventional farming system. On the contrary, the share of vetch seeds in the mixtures was 24% higher in the organic system than in the conventional one. The selection of cv. ‘Grajcar’ oats for the mixture with vetch increased the share of vetch seeds in the yield by 16.5%. In summary, a balanced share of oat-vetch mixture components depends on the proper selection of the oat cultivar, especially for organic farming systems.