[Impact of Exogenous Nitrogen Import on Sediment Denitrification and NO Emissions in Ditches Under Different Land Uses].

Farmland drainage ditch soil can consume part of the agricultural non-point nitrogen through nitrification-denitrification processes. Paddy fields, vegetable land, and orchards are the main types of land uses in the Taihu Lake region, and many drainage ditches are distributed across these lands. The way exogenous nitrogen is imported to drain ditches under different land uses differs significantly, which can directly affect the nitrogen consumption ability of the channels.

Mechanisms of enhanced inorganic phosphorus accumulation by periphyton in paddy fields as affected by calcium and ferrous ions.

The effect of periphyton propagation in paddy fields on phosphorus biogeochemical cycling has received little attention. In this phytotron study, inorganic phosphorus (P) accumulation by periphyton was investigated for varying inputs of calcium [Ca(II)] or ferrous‑iron [Fe(II)], and lighting conditions. Results indicated that additions of Ca(II) or Fe(II) enhanced abiotic accumulation of P by up to 16 times, and decreased solution P concentration by up to 50%, especially under light condition.

[Effects of Biochar Amendment and Irrigation on Denitrification Losses in Greenhouse Tomato Fields].

Biochar addition and irrigation are normal farm practices for tomatoes management, while their impacts on denitrification are less known. In this study, three irrigation treatments(hereafter main plots)were set as 50% (W50%), 75% (W75%) and 100% (W100%) of reference evapotranspiration (ET), and the subplots coupled three biochar treatments at the rates of 0 (B0), 25 t·hm (B25) and 50 t·hm (B50). Typical soil samples in each plot were collected when tomatoes were harvested in 2014 and 2015.

[Denitrification Loss and NO Emission from Different Carbon Inputs in Orchard Drains Sediments].

The orchard is an important economic crop in Taihu Lake region. Heavy nitrogen application in orchard results in great nitrogen loss to drainage ditch, and unbalanced carbon nitrogen ratio. Therefore, carbon might be an important limiting factor for sediment nitrification and denitrification.

[Temporal and spatial variations of total nitrogen and total phosphorus in the typical reaches of Qinhuai River].

The year-round concentrations of total nitrogen (TN) and total phosphorus (TP) were monitored from June 2010 to May 2011 in the typical reaches of the Qinhuai River. The spatial and temporal variations in TN and TP concentrations and the pollution status of the river water were investigated using typical statistics analysis. Results showed that the river water was seriously polluted in terms of TN and TP, and that the concentrations of both TN and TP showed high spatial and temporal variations.

[Effects of applying nitrogen fertilizer and fertilizer additive on rice yield and rice plant nitrogen uptake, translocation, and utilization].

A field experiment was conducted in the Taihu Lake region of southern Jiangsu to study the effects of applying nitrogen (N) fertilizer and fertilizer additive on the rice yield and the rice plant N uptake, translocation, and utilization. Applying N fertilizer had significant positive effects on the rice yield, accumulative absorbed N at all growth stages and at each growth stage, and N translocation rate after anthesis (P < 0.01).