engleski

Yield response and element content of grass in a fertilization experiment

The effects of four different N, P and K supply levels and their combinations on the yield and element content of an established all-grass sward were examined in the 28-31st year of a long-term fertilization experiment set up on a calcareous chernozem soil. During the four years the N alone gave 4.8 t/ha, while the K gave 0.5 t/ha hay surplus. N-fertilization lifted the hay mass 4-5 times compared to the N-control. The rising N, P and K supply together increased the hay yield of the control to its 7-fold. The 2nd cuts yielded less hay with higher element concentrations. The N, P, Cu content increased by 30-50% and Mo content by 200-500% in some cases. The phosphate / molibdenate and nitrate / molibdenate anion antagonism had negative effect on Mo uptake. The Cu/Mo ratio showed great variability according to the NxP interactions and cuts. Long-term fertilization can drastically modify the element composition of the fodder, so its regular control by hay analysis seems to be reasonable.

all-grass ; NPK fertilization ; hay yield ; mineral elements ; diagnostic criteria

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