The production of biomass by different management of grasslands without using for forage production

The consequences of non-management grasslands are not known because up till now it has not been necessary to study the problems. But the spontaneously production biomass influences botanical composition of grasslands, product ion and decomposition of biomass and bottom water quality - especially nitr ates concentration. This work is a part of the solved problem of a relative balance of forming plant biomass and its decomposition. Each plant materia l is partly mineralised and humificated (Dykyjova et al., 1989). We expect the amount of organic soil mass remains roughly constant year by year conse quently there is a balance between inputs and outputs of organic substance (Rychnovska et al., 1987). These results are to be completed and developed because they do not issue from grasslands studies whose system of use was o n principle changed. That is, why in the years 1997 to 1999 we evaluated th e influence of a different way of treatment on biomass formation of grassla nds. The results are compared with standard management, thus two-cut plant with removal of mass. The other variant is let without management - green f allow and in further variants the grassland of association Trifolio-Festuce tum,rubrae Oberdorfer 1957 are influenced by different frequency and times of cutting and mulching always with leaving mass on cut out. During a relat ively short period of three years there is a great variability of results ( Tab. I). As to the formation of the total biomass there is not a significan t difference between variants. The trend of development for three years can be defined with difficulty. However, we can make out the dependence of yie ld on the number of cutting out (mulching). It is conforming to harvested g rowths, thus the yield of the first cutting is going down with the number o f cutting during the year. But this is not valid more by the fraction of st ubble and litter. By underground biomass where a decisive part is formed wi th roots the dependence of production of biomass on frequency of cutting (m ulching) is also indicated. The trends are not unambiguous in such a short time period. Weight of total biomass ranged on average of three years betwe en 20.5 and 28 t dry matter.ha(-1), highest by once mulched treatments and least by twice managed plots. Rate of above-ground biomass in total biomass was by all treatments between 22 and 27% (Fig. 2). Amount of litter inclus ive mulched or cut biomass was found in spring 1999 and it was highest by t reatment once mulched in September (1.75 t.ha(-1)) and least by harvested t reatment (0.12 t.ha(-1)) (Fig. 1). Significant differences in litter inclus ive cut or mulched biomass between treatments are shown in Tab. II.