DROUGHT STRESS IMPACT ON VEGETABLE CROP YIELDS IN THE ELBE RIVER LOWLAND BETWEEN 1961 AND 2014

作者：Potopova V; Stepanek P; Farda A; Turkott L; Zahradnicek P; Soukup J

来源：Cuadernos de Investigacion Geografica, 2016, 42(1): 127-143.

DOI：10.18172/cig.2924

<jats:p>The study is focused on drought stress that is detrimental to yield formation of field-grown vegetables in the lowland regions of the Czech Republic. Extensive vegetable yield losses are attributed to drought, often in combination with heat or other stresses. The objective of this research was to investigate, under field conditions, the effect of drought stress quantified by the Standardized Precipitation Evapotranspiration Index (SPEI) on yield variability of key vegetable crops growing in the Elbe River lowland, representing central European agriculture conditions. Additionally, we also tried to determine the period of crop with the highest sensitivity to drought (PCSD) of vegetable crops over the Elbe River lowland. Historical climate datasets for a regular gridded network with a high horizontal resolution of 10 km (CZGRIDS) and 305 climatological stations from the Czech Hydrometeorological Institute were applied. The SPEI at 1-, 3-, and 6-month lags was calculated for the period 1961-2014 based on precipitation and input dataset for the reference evapotranspiration (ETr) by the Penman-Monteith (PM) method. Moreover, the difference between daily precipitation and crop evapotranspiration (ETc) has been used to calculate the mean crop water balance (D) per main growth stages, as an indicator of plant stress. This improvement increased the applicability of the SPEI in agriculture drought impact on rainfed and/or irrigated field crops grown under various agronomic management systems. To understand how the SPEI, over the period 1989-2014, controlled the yield variation, we calculated the percentage of yield losses and gains for each crop. When the value of SPEI at 3-month lag–as a measure of the balance between the water availability and the atmospheric water demand–for PCSD was between -1.49 and 0.99, the yield moderately increased for Fruiting vegetables (e.g. tomatoes, cucumber). Conversely, when the SPEI-3 in the key development stage dropped below -3.0, the yield losses were about -30% and a negative influence is apparent from threshold of the SPEI≤-1.5. The effect of the SPEI on yield formation of vegetable cultivars grown under filed conditions was achieved up to 62% in the study region.</jats:p>

• 出版日期2016