[Effects of irrigation with treated wastewater on nutrient distribution in cucumber and tomato plants and their fruit quality].

A field experiment was conducted to investigate the effects of irrigation with treated wastewater on the nutrient distribution in cucumber and tomato plants and their fruit quality. Irrigation with treated wastewater promoted tomato growth significantly, but had definite inhibition effect on cucumber growth. After the irrigation with treated wastewater, the nitrogen in plants had the characteristics of upward translocation, potassium was easily to be accumulated in cucumber leaf but not accumulated in tomato root, and sodium was mostly accumulated in root but less enriched in leaf, not giving damage to the plants. No significant effects were observed on the distribution of calcium, magnesium, and chlorine in plants. Under the irrigation with treated wastewater, the overall quality of cucumber and tomato fruits was less affected. The nitrate concentration in cucumber and tomato fruits was increased by 5.3% and 32.9%, respectively, but still lower than the state food safety standard of China.

[Effects of canal-lining project on groundwater and ecological environment in Hetao Irrigation District of Inner Mongolia].

The canal-lining project in Hetao Irrigation District (HID) for water-saving irrigation has been implemented for many years. By using statistical method, ordinary Kriging, and software ArcGIS 9.0, this paper analyzed the spatiotemporal variation of groundwater table depth and salinity in HID in September, 2001 and 2009. In the meantime, the vegetation distribution on the both shores of the lining part and non-lining part of Yangjiahe channel was also investigated. After the many years implementation of the project, the water diversion amount in HID in 2009 was reduced to 44.5 x 10(8) m3. The region area of groundwater table with a depth of 2.5-3.0 m was increased from 1.2 x 10(4) hm2 in 2001 to 9.11 x 10(4) hm2 in 2009. The region area of groundwater table with a depth of 2.0-2.5 m in 2009 took 80% of the total area of HID. In the northwestern region of HID, the groundwater salinity had reduced from 5000-10000 mg x L(-1) to 3000-5000 mg x L(-1). In Wulate irrigation region, the areas of salt water belt and half-salt water belt were increasing. After the canal-lining of Yangjiahe channel, the plant species and diversity index on both shores reduced, and some herbaceous plants with shallow roots showed degradation signs. The implementation of the project and the reduction of water diversion for irrigation did not exert negative effects on the maintenance of water surface area of Wuliangsuhai Lake.

[Coupling effect of two drought-resistant agents on photosynthetic characteristics of Euonymus japonicus].

A field study on the coupling effect of new drought-resistant agents FA Handilong (FA HDL) and Beijing Green Angel (BGA) on the photosynthetic characteristics of Euonymus japonicus showed that these two agents could all decrease the stomatal conductance (gs) and transpiration rate (Tr) , and increase the net photosynthesis rate (Pn) and Pn/Tr of E. japonicus leaves. The inhibitory effect of FA HDL on gs and Tr was more significant when BGA was not applied. FA HDL inhibited the Pn and Pn/Tr when applied with BGA, but stimulated them when BGA was not applied. Applying BGA could obviously shorten the action period of FA HDL on E. japonicus. The fact that BGA could influence the effect of FA HDL was attributed to the properties of BGA and the photosynthetic characteristics of E. japonicus. The appropriate concentration of FA HDL to the E. japonicus without BGA application was 2 g x L(-1), and FA HDL was not appropriate to the E. japonicus applied with BGA.