A field experiment was conducted in two seasons (2019–2020 and 2020–2021) at three locations in Slovenia (Rogoza, Fala, and Brežice) to evaluate the yield and silage quality of winter cover crops (WCCs). The experiment included Italian ryegrass (IR) in pure stands, fertilized with nitrogen in spring, and mixtures of crimson clover (CRC), red clover (RC), and IR+CRC+RC without nitrogen fertilization in spring. The highest dry matter yield (DMY) was observed in IR+CRC+RC (4.98 t ha⁻¹). For fresh feed, the CRC+RC treatment had significantly higher (p < 0.05) crude protein (208 g kg⁻¹ DM), nitrate nitrogen (116.7 mg kg⁻¹ DM), and buffering capacity (1290 mmol kg⁻¹ DM) but significantly lower (p < 0.05) dry matter (128 g kg⁻¹) and water-soluble carbohydrates (121 g kg⁻¹ DM). For silage, the CRC+RC treatment had significantly lower (p < 0.05) dry matter (476 g kg⁻¹ silage), metabolic energy (9.65 MJ kg⁻¹ DM), net energy of lactation (5.77 MJ kg⁻¹ DM), and neutral detergent fiber (375 g kg⁻¹ DM) but higher ammonia nitrogen (66.5 g kg⁻¹ of total nitrogen), crude protein (158 g kg⁻¹ DM), and acid detergent fiber (279 g kg⁻¹ DM). No significant differences (p > 0.05) were found among treatments for acetic, lactic, and butyric acid, crude fat, pH, and soil mineral nitrogen (N_min). The results of the study show that the same or higher DMY and a comparable quality of highly wilted silage can be produced with mixed Italian ryegrass and clovers compared with those of Italian ryegrass in pure stands. The experiment aimed to determine whether clover-based mixtures can achieve comparable silage quality and dry matter yield without spring N fertilizers compared with those of pure stands of Italian ryegrass fertilized in spring.

Summary: Grassland ecosystems are key biodiversity reservoirs, especially for the soil fauna. Among them, nematodes have been widely used as bioindicators to assess soil conditions and health in grasslands. However, their interactions with plant functional types, particularly in hot and dry climates like the Mediterranean region, remain poorly understood. The development of management strategies to optimise the resilience and productivity of grassland requires a better understanding of these biotic relationships. To address this, nematode communities were examined in grassland monocultures of three plant functional groups (grasses, legumes, forbs) in the Mediterranean. In France, Slovenia, Spain, Jordan and Lebanon, grasslands differing in soil properties and climate were investigated in autumn and spring in consecutive seasons. The genus composition of nematode assemblages was assessed, and their ecological indices and metabolic footprints were related to site characteristics and plant functional type. The Renkonen and Sörensen Index revealed that nematode communities differed greatly among regions. The western Mediterranean grasslands were dominated by bacterial feeders like Rhabditis and Eucephalobus , resulting in a low Channel Index and high Enrichment Index. The eastern Mediterranean sites showed higher proportions of fungal and plant feeders like Aphelenchus and Geocenamus and a higher Channel Index but lower Enrichment Index. Due to prolonged drought, the Spanish soils were infested by plant feeders such as Scutylenchus and Pratylenchus . The forage plant had only a minor impact, with legumes enhancing certain bacterial-feeding genera and grasses fostering some plant-parasitic nematodes. Overall, regional factors shape the nematode community more than forage plant cover. The dry conditions in the eastern Mediterranean, as well as the drought in Spain, increased herbivores and decreased top-down control, which is relevant in the light of future climate change.

One hundred and fifty-eight hay samples with known chemical composition and in vitro determined concentration of net energy for lactation (NEL) were scanned over the wavelength range from 1100 to 2500 nm at 8 nm intervals. Calibration equations for the prediction of dry matter (DM), crude protein (CP), crude fibre (CF), crude fat, ash and NEL were developed by the use of principal component analysis. NIRS demonstrated high predictive ability for CP (R² = 0.98), CF (R² = 0.95) and ash (R² = 0.94). Only moderate accuracy was characteristic for DM (0.87) and crude fat (R² = 0.75). With exception of ash deviations from reference methods are comparable to those which are expected by the use of the same reference methods in different laboratories. NIRS has a high ability to predict in vitro assessed NEL concentration (R² = 0.89). More than 95% of samples lied within acceptable limits of ± 0.3 MJ NEL kg^–1 dry matter (DM). Despite suboptimal sample distribution, i.e. small number of samples in classes below 4.4 and above 5.6 MJ NEL kg^–1 DM, the deviations of NIRS predicted values from reference values were not related to concentration of NEL. It was concluded that NIRS is rapid and reliable technique for determination of chemical composition and energy value of hay.

A field experiment was conducted in 2019–2020 and 2020–2021 at Rogoza, Fala, and Brežice in Slovenia to examine the biological viability of a mixed intercropping system and the effect of winter catch crops (WCCs) on maize growth parameters. The experiment included Italian ryegrass (IR) in pure stands, fertilized with nitrogen (N) in spring (70 kg N ha⁻¹), mixtures of crimson clover and red clover 50:50 (C), and intercropping between IR and C (IR+C). Neither mixture was fertilized with N in spring. We evaluated different competition indices and biological efficiency. Relative crowding coefficient (RCC) and actual yield loss (AYL) exceeded 1, indicating a benefit of IR+C intercropping. The IR in intercropping was more aggressive, as indicated by positive aggressivity (A) and a competitive ratio (CR) > 1, and it dominated over C in IR+C (that had negative A values and CR < 1). The competitive balance index (Cb) differed from zero, the relative yield total (RYT) was 2.24, the land equivalent coefficient (LEC) exceeded 0.25, the area–time equivalent ratio (ATER) exceeded 1, and land use efficiency (LUE) exceeded 100%. IR+C exhibited the highest total aboveground dry matter yield of maize (29.22 t ha⁻¹), the highest nitrogen content in dry matter grain yield of maize (206.35 kg ha⁻¹), the highest nitrogen and potassium content in maize stover (105.7 and 105.7 kg ha⁻¹, respectively), and the highest nitrogen and potassium content in the total aboveground dry matter of maize (312 and 267.3 kg ha⁻¹, respectively). The C/N ratio in dry matter yield of IR was 45.35, and in IR+C it was 33.43, which means that the mixture had a positive effect on nutrient release in maize. The ryegrass–clover mixture, according to the calculated biological indices, had advantages over pure stands and had a positive effect on maize yield.

Pridelava in konzerviranje krme v obdobjih, ko ni pomanjkanja vode za rast rastlin in pridelava proti suši odpornih rastlin sta ključna elementa prilagajanja živinoreje klimatskim spremembam. V Eip- Agri projektu 'Izboljšane tehnologije pridelave in konzerviranja z beljakovinami bogate krme - metuljnice in njihove mešanice za prilagajanje podnebnim spremembam' smo primerjali pridelavo in konzerviranje metuljnic v čisti setvi ter mešanice metuljnic in trav (oboje brez gnojenja z dušikom) s pridelavo z dušikom gnojenih trav v čisti setvi. Rezultati kažejo, da je uporaba metuljnic v čisti setvi in mešanic metuljnic s travami primerna za pridelavo in konzerviranje s proteini bogate krme. Pridelava mešanic z visokim deležem metuljnic je zanesljivejša. Te mešanice dajejo primerljive pridelke z metuljnicami v čisti setvi in silaže visoke kakovosti.