The combination of two scion-one rootstock was used for two apple cultivars, ‘Pink Lady’ and ‘Qinguan’, budded on the same, one-year-old Malus hupehensis (Pamp.) Rehd. to reduce the impact of root and pot size and in order to understand the growth, water-use efficiency (WUE), and chlorophyll fluorescence characteristics. The two-scion grafted trees were planted in plastic pots under two water regimes, i.e. 70% field capacity (FC) and 55% FC. Results indicated that different scions were affected differently by drought stress. ‘Pink Lady’ had higher net photosynthetic rate (PN), stomatal conductance (gs), and transpiration rate (E) compared with ‘Qinguan’ under both water treatments. However, ‘Qinguan’ had lower minimal fluorescence (F0), higher maximum fluorescence (Fm), and higher maximum photochemical efficiency of photosystem II (Fv/Fm) than ‘Pink Lady’ at 55% FC. Moreover, ‘Qinguan’ had larger shoot dry mass (ShDM) and higher intrinsic WUEI than ‘Pink Lady’ under both water status. Gas-exchange and growth parameters, except for PN and scion diameter, were significantly affected by the cultivar and water treatment. At 70% FC, ShDM was significantly correlated with WUEI. Moreover, WUEI was negatively linearly correlated with g s at either 70 or 55% FC. These results might indicate that ‘Pink Lady’ was more sensitive to drought than ‘Qinguan’. ‘Qinguan’ apple was able to improve WUE more than ‘Pink Lady’ under both well-watered and drought conditions. The growth parameters and photosynthetic capacity of two different scions showed that the combination of double
scion-one rootstock might eliminate the influences of the rootstock and pot size. and X. P. Sun ... [et al.].
Serious attention is paid today to the problems of landscape regionalization with respect to its hydrological response. The quantification and the spatial pattern of soil drought indicators (SDI) are considered crucial for a correct hydrological zonation of agricultural lands with regard to water-related phenomena of practical importance, such as drought risk, runoff generation and soil erosion. The paper deals with regional estimation of hydrolimits (field capacity, point of limited availability, wilting point) and water storage capacity (expressed as the difference between the field capacity and the wilting point) of the root zone of agricultural landscape and their interpretation as potential soil drought indicators (SDI). A spatial and pedotransfer approach was applied to the region of the Záhorská nížina Lowland. Relevant outputs (parameters of soil water retention curves) were derived from the data of the Comprehensive Agricultural Soil Survey digital database (KPP DB) using pedotransfer functions (Rosetta model). A spatial processing of model outputs to the form of the regional maps of SDI was performed using GIS tools. SDI were then quantitatively evaluated for (i) individual textural soil units and (ii) individual pedo-ecological regions of Záhorská nížina Lowland respectively. Water storage capacity of soil represents the maximum volume of long-term available water in the effective root zone of cultural crops. To be used as soil-drought indicator, the water storage capacity data should always be interpreted in combination with information about the water contents related to the field capacity and the wilting point. Generally, it is assumed that spatial pattern of SDI is closely related to the soil textural units, while in the case of Záhorská nížina Lowland the segmentation of the landscape to pedo-ecological regions is considered inadequate from hydrological point of view. and V súčasnosti je v kruhoch hydrológov venovaná veľká pozornosť problematike regionalizácie krajiny z hľadiska jej hydrologickej odozvy. Kvantifikácia indikátorov pôdneho sucha (SDI) a poznanie ich priestorovej variability sú kľúčové pre korektné delenie poľnohospodársky využívaných pôd na zóny vo vzťahu k hydrologickým javom s praktickým významom, ako sú sucho, tvorba odtoku a pôdna erózia. Príspevok sa v regionálnej mierke zaoberá odhadom hydrolimitov (poľnej vodnej kapacity, bodu zníženej dostupnosti, bodu vädnutia) a vododržnej kapacity (ako rozdielu v obsahu vody medzi poľnou vodnou kapacitou a bodom vädnutia) koreňovej vrstvy pôd v poľnohospodárskej krajine a ich interpretáciou ako potenciálnych indikátorov pôdneho sucha. Pedotransférový prístup bol využitý pre priestorové spracovanie SDI v rámci regiónu Záhorskej nížiny. Relevantné výstupy (parametre vlhkostných retenčných kriviek) boli odvodené z údajov digitálnej databázy Komplexného prieskumu poľnohospodárskych pôd (KPP DB) využitím pedotransférového modelu Rosetta. Výstupy z modelu boli priestorovo spracované do podoby regionálnych máp indikátorov pôdneho sucha s využitím nástrojov GIS a následne kvantitatívne zhodnotené pre (i) jednotlivé pôdne druhy a (ii) jednotlivé pedo-ekologické regióny Záhorskej nížiny. Vododržná kapacita pôdy reprezentuje maximálny objem vody v koreňovej vrstve pôdy dlhodobo prístupnej pre kultúrne plodiny. Údaje o vododržnej kapacite pôd musia byť pre účel stanovenia potenciálu pôdy z hľadiska jej ohrozenosti suchom (teda ako indikátor pôdneho sucha) interpretované vždy v kombinácii s informáciou o obsahoch vody zodpovedajúcich poľnej vodnej kapacite a bodu vädnutia. Všeobecne možno konštatovať, že priestorová distribúcia indikátorov pôdneho sucha je úzko zviazaná s prirodzenou variabilitou pôdnych druhov, kým segmentácia územia podľa pedo-ekologických regiónov je v prípade regiónu Záhorskej nížiny z hydrologického hľadiska nedostačujúca.