05).Soil pH was recorded potentiometrically using 1n KCl extraction, mobile selleck chemical P2O5 and K2O (mgkg?1 of soil)��by the Egner-Riehm-Domingo (A�CL) method [48]. Soil gravimetric moisture was also continuously recorded using probe (HydroSense Campbell CS-620), and soil bulk density was measured with meter (Fieldscout SC900 Spectrum Technologies) [49].2.2. Experiment SetupField test area of each fertilizing treatment was 10m2 (2 �� 5m). The N (ammonium saltpeter 34.4% N) and NPK (ammonium saltpeter 34.4% N + granulated superphosphate 19% P2O5 + potassium chloride 60% K2O) application scheme of 9 treatments in 2 replications (n = 18) of semi-natural sward (>20yrs abandoned former sown sward): control (0); N60; N120; N180; N240; N180P120; N180K150; N60P40K50; N180P120K150.
Investigated cultural pasture (CP) was fertilized with N180P120K150 sum year rate. P and K were applied before plant vegetation in early spring, and N fertilizer was applied two times: end of April and after 1st cut (beginning of July) in all grasslands. Fresh mass (FM) weighting (g 0.2m?2 per treatment, n = 20) and drying (105��C) were used to determine grassland productivity (gm?2) and obtain dry materials (DM, %). Grassland botanical composition was determined on harvested vegetation.GHG (CO2, N2O, and CH4) emissions were monitored by the static chamber method [50] using opaque circular chambers (0.05m?3), with 6 replicates per treatment (n = 60). Cylindrical steel collar (20cm high and 43cm diameter) was inserted into the soil to a depth of 6cm. Two collars and chambers were placed in each treatment.
The collar frames remained in the soil and were open to the atmosphere between samplings, except when removed for tillage and sowing. During the measurements, the chambers were closed with an airtight lid simultaneously Cilengitide in all treatments. Chamber air was sampled 3 times in one-hour interval period. Gas fluxes were measured on 4 different dates in grasslands. The measurements were carried out 2 or 3 weeks after fertilizer application every month between June and September in the absence of frost stress. The gas samples were analyzed in the laboratory by nondispersive infrared gas analyzer (MGA3000; ISO 9001:2000) calibrated separately for each gas using ML-800 gas standard (2atm) in accordance with LST/ISO: 1401: 2005. Gas samples were analyzed on the same day evaluating volume concentrations (ppm) of trace gases. Daily net exchange (mgh?1m?2) of CO2, CH4, and N2O in agroecosystem was calculated by integrating the 60-minute fluxes determined by the meteorological measurements over each day.