Grażyna Mastalerczuk

Soil degradation is largely caused by human activity, and its severity can be exacerbated by unfavourable weather conditions. Selected species form a durable, compact cover that improves soil physical properties and limits degradation. The study included four single-species sowings of forage grasses: Dactylis glomerata, Festuca arundinacea, Festulolium braunii, and Lolium perenne. A plant growth enhancer containing silicon nanoparticles was foliar-applied at two levels: no Si and Si. Soil water properties, plant cover, chlorophyll content, leaf area index (LAI), light transmittance (T), aboveground biomass, and weed infestation were measured to evaluate plant viability and durability from 2018 to 2023. The research showed that after six years of utilization by mowing, D. glomerata and F. arundinacea, due to the greater durability of the plant cover and a stable share in the sward, were better suited to cultivation on degraded soil than F. braunii and L. perenne. Silicon increased grass species yield, plant–soil cover, chlorophyll content, and LAI while it reduced T. The Si application had the strongest effect on the monocultures of F. arundinacea and D. glomerata, particularly for DM (increased by 17.5 and 19.1%, respectively) and LAI (increased by 24.4 and 19.8%, respectively). Given the benefits of using silicon in plant fertilisation, further research is recommended, particularly on grass species used to revitalise heavily transformed and degraded soils.

The efficiency and quality of meadows is affected by, among others, the botanical composition of the sward and the frequency of cutting. The research was conducted in 2023–2024 on the experiment established in 2014 on arable land, where 3-species mixtures of grasses and legumes were sown. During the next three years, the sward was fertilized and cut 3-times per year, and then, for five years, was mown twice a year, without fertilization. On the sward formed at that time, in 2023, an experiment was established to evaluate how management intensity (2- or 3-cuts and rate of fertilizer) and silicon application (Si or 0Si) affect botanical composition, yield, and nutrient content in perennial meadow swards under variable precipitation over two years. Species richness rose in the sward in the second year, especially under 3-cut management (from 15 to 21 species). The share of species sown earlier in the mixtures Dactylis glomerata, Festulolium braunii, and Medicago x varia was very high at both management intensities (66–87% DM). Yield and the content of crude protein and nutrients were higher in the 3-cut system in the second and third regrowths. Silicon supplementation increased plant diversity and yield resilience during drought, with more intensive management supporting sustainable forage production. Moreover, the sward contained more nutrients with 3-cuttings in the second and third regrowths. These findings indicate that intensive meadow management and silicon application enhance productivity, forage value, and biodiversity, providing valuable insights for sustainable meadow management strategies.

Limited water resources and natural drought may result in reduced water availability for the population’s needs and the maintenance of the proper vegetation condition. Understanding the impact of drought on turfgrass species is essential to developing strategies that enhance the adaptability of plants to drought stress. It is vital for maintaining green areas in cities under changing climatic conditions. Therefore, studies on the ability of turfgrasses to recover after periods of drought without irrigation are becoming increasingly essential. We conducted research to determine the possibility of reducing the negative impact of drought stress on the photosynthetic efficiency, the morphometric features of plant shoots and roots, and the distribution of biomass of Lolium perenne lawn cultivars in the initial period of growth by applying biostimulant with silicon. We also investigated how drought and silicon (Si) application affect the leaf and root anatomical structure of L. perenne plants. Studies on the influence of drought on the physiological, biometric parameters and anatomical characteristics of two L. perenne cultivars were carried out under two levels of soil moisture (well-watered plants—control and drought caused by the cessation of watering) and also two variants of Si application (with and without Si application). Plants were exposed to drought in the tillering phase for 21 days. After this time, all plants were provided with optimal soil moisture conditions for the next 14 days (recovery period). Measurements of physiological parameters and biometric features of plants were evaluated in four terms: after 7, 14 and 21 days of drought and after recovery. Drought stress in L. perenne cvs. resulted in decreasing values of physiological parameters, especially maximal fluorescence, the quantum efficiency of photosystem II and photosynthetic electron transport rate compared with the values of features in well-watered plants. These adverse impacts were reflected in decreased biomass-related traits: shoot number, shoots and roots biomass, as well as area and length of roots. The application of Si reduced the detrimental effects of drought by accelerating plant growth after stress and increasing the values of most of the investigated physiological parameters. Under drought stress conditions, Si application led to the development of two-cell-layer exodermis, which reduced the water losses in L. perenne roots and shoots and, as a result, improved the drought tolerance of plants.

Sugar beet is a critical crop for global sugar production, and optimizing its growth and yield requires a thorough understanding of the effects of agronomic practices such as sowing date and nitrogen fertilization. This study was conducted in the WULS-SGGW Experimental Field in Miedniewice, Poland, during two growing seasons. The aim of the research was to determine the impact of sowing dates and nitrogen fertilization on the morphometric features and photosynthetic performance of the Lubelska sugar beet variety grown in Luvisols soil. The experiments were arranged as split-plot designs (SPDs) with four replications. The factors of the experiment were the sowing date (optimal and delayed by two weeks) and nitrogen fertilization at doses of 0, 60, and 120 kg N·ha⁻¹. The photosynthetic activity of sugar beet plants was measured four times during the growing season using chlorophyll fluorescence (ChlF) parameters. Morphometric features were determined by collecting sugar beet plants after each chlorophyll fluorescence measurement. The obtained results demonstrate the significant effect of nitrogen doses on the morphometric parameters of aboveground biomass. Increasing nitrogen doses also differentiated chlorophyll fluorescence parameters, such as F_V/F₀, F_V/F_M, PI_ABS, ET₀/CS₀, and ET₀/CS_M. A two-week delay in sowing affected both the fluorescence parameters and morphometric features of sugar beet, highlighting the interaction between agronomic practices and plant physiology.

Drought significantly impacts the growth and yield of forage grasses, particularly its effect on Dactylis glomerata photosynthetic apparatus during the initial phase of development remains largely unknown. This study investigated the effects of drought on physiological parameters of various D. glomerata varieties. The seedlings obtained after seed germination under optimal and simulated drought conditions by PEG 6000 (three variants) were planted in small pots filled with garden substrate. Over a span of 42 days, the plants were initially kept well-watered (70% capillary water capacity, CWC), after which half of the seedlings from each variant were subjected to drought. This drought stress was applied during the tillering phase for 12 days. Subsequently, the plants were rehydrated (at 70% CWC) and allowed to recover for 14 days. Throughout both drought and recovery periods, measurements were taken. Leaf chlorophyll fluorescence parameters were assessed, and the JIP-test analysis was utilised to provide detailed insights into the functionality of D. glomerata photosynthetic apparatus under drought stress and post-recovery conditions. Several parameters were identified as indicative of the plants’ sensitivity to drought, such as performance indices PI ABS and PI tot, along with quantum yield parameters Ψ E0, φ E0, and φ P0. The results highlighted that var. Minora and Tukan exhibited greater tolerance to water deficit when compared to the other varieties studied. They showed a large increases in PIABS and PItot values after drought stress as well as after the re-watering (recovery period) compared to control plants. This suggests their potential for better adaptation to drought conditions.

Drought and allelopathic conditions impact the germination of seeds of grass and legume species used in mixtures on grassland. This study evaluated the effects of drought and Medicago sativa root extracts at different pH levels on the germination and characteristics of seedlings of Lolium perenne and selected Medicago species. Two experiments were carried out: the first explored the effects of drought induced by PEG solutions (0.0, −0.3, and −0.6 MPa) under silicon (Si) application; the second studied the influence of Medicago sativa root extracts (12 and 24 g/100 mL H₂O) and variable pH solutions (control, 5.0, and 6.5) on seed germination. Germination was carried out on Petri dishes for individual species and in two-species mixtures. The drought conditions did not affect the germination capacity of seeds, but it increased the dry weight of the seedlings of the tested species. The application of silicon decreased the root length of the seedlings of all species, independent of the germination conditions. The higher concentration of M. sativa root extract combined with the studied pH solutions had an inhibitive impact on the germination capacity of L. perenne. Our findings revealed that the lower concentration of M. sativa root extract had a beneficial effect on the morphological features (length of roots and leaves, fresh and dry weight) of the seedlings when germination was carried out separately for both species. In the mixture, the effect was especially marked for L. perenne (only in terms of the root length and fresh weight of seedlings). The applied root extracts in combination with the acidic pH conditions limited the germination capacity and growth of the seedlings of L. perenne the most when germination was performed separately. It was concluded from this study that silicon application did not improve the germination capacity of seeds under drought conditions, whereas the germination of L. perenne seeds in a mixture with M. sativa mitigated the negative allelopathic effects of M. sativa root extracts on the seed germination capacity and morphological features of seedlings of L. perenne.

Research on mitigating the effects of water scarcity by applying silicon to perennial grasses is still insufficient. This study was conducted to investigate the effect of spring and summer droughts and silicon applications on gas exchange parameters; the morphometric characteristics of root systems; and the biomass distribution of Festulolium braunii, Festuca arundinacea, and Lolium perenne cultivars. Plants were treated with a drought during the tillering phase once a year (during spring or summer regrowth) for 21 days. Foliar nutrition with silicon was applied twice under the drought conditions. Grasses in a pot experiment were cut three times during vegetation. The plants that were exposed to the drought had lower values of the gas exchange parameters than those that were well watered. The beneficial effect of silicon was related to the reduction of excessive water loss through transpiration during the spring drought. Under the drought and silicon applications, the water use efficiency, root dry mass, and length increased compared to the control. Moreover, silicon increased the proportion of both the finer and thicker roots in F. braunii and L. perenne, while the distribution of the root diameter changed least in the more resistant F. arundinacea. Silicon also reduced the carbon content in the roots and increased root carbon accumulation. Our results indicated that Si may help perennial forage grasses cope better with drought stress. This was due to the allocation of carbon to the roots to develop the fine root network, increasing the length and root biomass and improving the water use efficiency.

The study was conducted to evaluate the influence of silicon application on the botanical composition of grass–legume mixtures as well as the nutritional value of individual species and mixtures. The two-factor field experiment was established in a split-block arrangement. The two grass–legume mixtures, consisting of Dactylis glomerata, Festulolium braunii and Trifolium pratense or Medicago x varia and grass mixture—Dactylis glomerata, Festulolium braunii and Lolium perenne, were sown on arable land. Silicon foliar and mineral NPK fertilization was applied in three variants: NPK (non-Si-fertilized), NPK+Si (Herbagreen), NPK+Si (Optysil). Changes in the botanical composition in the sward of mixtures during the study period were influenced by the competitiveness of individual plants and weather conditions, whereas the effect of foliar fertilization with silicon was only slightly marked. The nutritional value of individual species of grasses and legumes varied over the years and also depended on the application of silicon. The greatest content of crude protein (CP), irrespective of the species and variant of silicon fertilization, was noticed in years with no drought. Our research confirmed the beneficial effect of silicon fertilization, independent of weather conditions, on the CP content and on the reduction of crude fibre (CF), neutral detergent fibre (NDF) and acid detergent fibre (ADF) in plants, especially when Herbagreen was applied. The nutritional value of the mixtures under applied silicon fertilization depended on botanical composition. In the conditions of low rainfall, a large share of F. braunii and an approximately 20% contribution of T. pratense resulted in a higher content of CP. These results may be used in the fertilization practices of temporary grassland for enhancing nutritional value, especially crude protein content, and on the reduction of fibre in the sward.

Periodic and repeated water scarcity has become an increasing concern on grasslands, causing not only to a reduction in productivity but also negative alterations in the carbon balance. The objective of this work was to comprehensively investigate some physiological performance traits of forage grasses, their roots morphometric features and distribution of biomass under simulated water deficit applied in different terms over a period of study. Plants were exposed to water shortage for 21 days, and then grown in optimal substrate moisture conditions. The gas exchange parameters and the main traits of root system architecture of three grass forage species and their cultivars were analyzed: Festulolium braunii (Richt.) A. Camus, cvs. Felopa and Sulino, Lolium perenne L., cvs. Bajka and Gagat and Festuca arundinacea Schreb. cvs. Odys and Rahela. Rapid decrease in the values of parameters related to the gas exchange process in grasses in the following days of water shortage was noticed. Water use efficiency (WUE) value was low in drought conditions due to increased transpiration of plants and was associated with a low C:N ratio in shoots. No obvious, positive effect of previously experienced drought stress on survival of tested grass species after another stress was observed. Cutting of plants after drought period most probably underlied the lack of memory and also additional factor weakened plant regrowth. When the drought was applied for the second time in spring during intensive plant growth, higher biomass allocation to the roots was observed. It was associated with the reduction of plant dry biomass, a decrease of carbon accumulation and the C:N ratio in the shoots. Due to the drought applied for the second time in summer, some biometric features of the roots were strongly and positively correlated with WUE, which is an important feature from the point of view of yield optimization and moisture use by plants.

Morphological traits of seeds of Festulolium braunii (K. Richt.) A. Camus cultivars were studied in relation to weather conditions. The obtained results show that morphological traits of seeds varied among cultivars and years of cultivation. T...