No abstract

To investigate the environmental advantages of using grass-clover binary mixtures over pure stands as winter cover crops, a serial of five field experiments (each designed as randomized complete blocks with four replicates) was carried out in eastern Slovenia. Trifolium incarnatum L. and Lolium multiflorum Lam. were sown in late summer as pure stands and binary mixtures. Pooled data calculated from all the experiments revealed that the soil mineral N in spring and accumulation of N by plants decreased with decreasing proportion of T. incarnatum in the binary mixtures, while the C:N ratio of cover crop organic matter increased. C accumulation was the highest when the seeding ratio of the binary mixture of T. incarnatum and L. multiflorum was 50:50. In the C and N environmentally sustainable management efficiency coefficients, three important traits of winter cover crops for environmental protection were given equal importance (low soil mineral N content in spring, high C accumulation in plants, and high N accumulation in plants). The coefficient was higher for binary mixtures of T. incarnatum and L. multiflorum than for pure stands of these crops, proving the complex environmental advantages of binary mixtures over pure stands.

No abstract

Climatic changes have led to extreme weather events, with longer dry periods affecting forage production in mesic grasslands. The effects of grassland management and years with periods of low precipitation on herbage dry matter (DM) yield were studied in two-long term grassland experiments with different cutting and fertilization regimes for the period 2000-2012. In both experiments, the annual herbage DM yields had high correlations with the amount of precipitation. The correlation was stronger in frequent cuttings regimes. The management type and the year significantly affected the herbage DM yield in both experiments. There was also a significant management × year interaction. On average, over the whole observation period, the herbage DM yield of equally fertilized treatments in experiment I was higher in treatments with two cuts per season than in treatments with more cuts. Furthermore, longer periods of low precipitation exerted fewer effects on the DM yield of the two cuts treatments compared to higher cutting frequencies. However, the increase in herbage productivity in years following seasons with low precipitation was higher in the treatments with higher cutting frequencies than in those with two cuts per season. When the treatment, cut four times per year, received a higher amount of fertilizer than the treatment, cut twice per year (experiment II), the long-term average annual herbage DM yield was higher and the yield was less decreased by longer periods of low precipitation than the two cuts per year treatment. Despite the fact that the effects of different treatments were proved in both experiments, the differences in the DM yields among the treatments in low precipitation years were not high enough to recommend best-management practices for forage production on mesic grasslands in areas subject to increasing periods of low precipitation.

Povečane koncentracije toplogrednih plinov v atmosferi vodijo v segrevanje planeta. Z gospodarjenjem na travinju lahko vplivamo na vezavo ogljika v organsko snov travniških tal in s tem zmanjšujemo koncentracije toplogrednega CO2 v ozračju. Po uvodnih poglavjih so v znanstveni monografiji analizirani vplivi gnojenja, kjer je poseben poudarek na učinkoviti rabi N iz gnojevke. Opisani so sodobni načini obnove travinja in za pridelovanje krme najpomembnejše rastline, ki tvorijo rušo. Delo zaključujejo načini rabe ruše, ki omogočajo ohranjanje ali povečevanje organskega ogljika v travniških tleh.