P. RAGALYI, I. KADAR and P. CSONTOS
Hungarian Academy of Sciences, Institute for Soil Science and Agricultural Chemistry, Centre for Agricultural Research, Budapest, H-1022, Hungary
RAGALYI, P., I. KADAR and P. CSONTOS, 2014. Effect of precipitation on the yield of hay meadows with contrasting nutrient supply. Bulg. J. Agric. Sci., 20: 779-785
Available nutrients and water are known as major factors influencing the production of grasslands. In the present paper effects of precipitation on hay production was studied on nutrient-rich (NR) and nutrient-poor (NP) soils, in a long-term field experiment from 2002 to 2012. The most effective period of precipitation was also investigated. Using a mixture of 8 grass species, we established a grassland (near to Sárbogárd, Hungary) where 16 permanent quadrates each 6 m by 6 m in area were marked out, of which 8 were abundantly and other 8 were poorly supplied with N, P and K nutrients. Quadrates were harvested in early June, and air dried hay production were measured. Precipitation was recorded by a Hellmann rain meter established in the experimental area. Air dried hay production was 92 g m-2 for the NP and 572 g m-2 for the NR treatments as the average of eleven years. Winter season precipitation showed no effect on biomass production. Increasing rainfall of the spring season significantly raised the air-dried hay biomass on NR treatments. Focusing the monthly precipitations of spring, rainfall in March increased considerably the biomass only on NR plots. Precipitation in April had significant effect on both NR and NP quadrates. Rainfall of May had no significant positive effect on the hay production. The most effective period on the increment of hay production was the total precipitation of March and April which had significantly positive effect on the production of both NP and NR quadrates; moreover the coefficients were statistically different from each other with a steeper slope for the NR quadrates. It seems that there is a critical amount of nutrient supply above which precipitation becomes increasingly effective on elevating hay production of mixed grass meadows.