Untitled - MendelNet 2013 - Mendelova zemědělská a lesnická ...

MENDELNET 2013a)2days with rain9b)1.8 2013one day after rain81.62 or more days after rain 71.4running mean61.25140.830.60.42Crop coefficientc)Soil moisture (%)0.206-May 26-May 15-Jun 5-Jul 25-Jul80706050403020100.10 m0.25 m0.50 mEvapotranspiration (mm)d)Bowen ratio106-May 26-May 15-Jun 5-Jul 25-Jul1412108642ET barleyET0 grassET0 alfalfa06-May 26-May 15-Jun 5-Jul 25-Jul06-May 26-May 15-Jun 5-Jul 25-Jule)30Rain - daily sumsf)5.0Rain (mm)252015105Plant Area Index (m 2 /m 2 )4.03.02.01.006-May 26-May 15-Jun 5-Jul 25-Jul0.06-May 26-May 15-Jun 5-Jul 25-Julvalues dramatically increased. Subsequently, it dropped again after increased soil moisture.Fig 1 Results of the survey: a) crop coefficient (Kc) calculated from ETo of grass; b) actual ET ofspring barley and reference ETo for both grass (dashed line) and alfalfa (solid gray line); c) soilmoisture in three depths under spring barley; d) Bowen ratio calculated for spring barley; e) dailysums of precipitation during whole growing season; f) Plant Area Index of spring barley.Further, ET rate (mm/hour) for particular months was quantified and is shown in Fig 2. Due to wetbeginning of the growing season the difference between actual and reference ET in May and June isnot so pronounced. However, ETo calculated for alfalfa shows systematically higher values.In contrast to this, in July the ET for barley is significantly lower than ETo. Our assumption that ETwill correlate better with ETo of alfalfa was not confirmed. Values of Kc for individual months canbe seen in Tab 1. However, the hypothesis was possibly not confirmed due to relatively low vapourpressure deficit (VPD) at our site (in average 0.75 kPa during daytime).360 | P age