Distribution Characteristics and Source Analysis of Nitrogen and Phosphorus in Different Rivers in Two Water Period: A Case Study of Pi River and Shiting River in the Upper Reaches of Tuo River in China

Abstract

In this paper, the distribution characteristics of total nitrogen (TN), total phosphorus (TP) and fractions of nitrogen and phosphorus in water and surface sediments of the Pi and Shiting rivers in the dry and wet seasons were studied by molybdenum blue/ascorbic acid spectrophotometry and Standard Measurements and Testing (SMT). Correlation analysis, cluster analysis and principal component analysis were used to identified nitrogen and phosphorus pollution sources. The results showed that: (1) nitrogen and phosphorus in water and surface sediments in the study area were at different levels. (2) In the Pi river, the decomposition of animal and plant residues, the leachate from the accumulation of aquaculture wastewater and urban domestic sewage were the main sources of nitrogen and phosphorus pollution, while in the Shiting river, the unreasonable application of pesticides and fertilizers, the degradation of animal and plant residues, agricultural wastewater from agricultural drainage channels, industrial production wastewater and the weathering of agricultural wastes had a great impact on the nitrogen and phosphorus pollution. The results in this study provide reliable experimental data and a reference to local relevant departments for the implementation of effective control measures for the reduction of the nitrogen and phosphorus pollution load in the river basin.

Effects of drought and salt stress on seed germination and seedling growth of Elymus nutans

“…The total root length, surface area, volume and number of root tips were determined by EPSON GT-X980 root scanner; plant height and root length were determined by straightedge. After measuring the morphological indicators, Elymus nutans was dried in a 65 °C oven for 48 h, and total nitrogen content was determined by the Kjeldahl method ( Singh et al, 2020 ); total phosphorus content was determined by molybdenum blue ascorbic acid method ( Li et al, 2022 ); determination of organic carbon content was made by Elementar vario TOC elemental analysis ( Wolski et al, 2022 ).…”

Impact of Intercropping on Nitrogen and Phosphorus Nutrient Loss in Camellia oleifera Forests on Entisol Soil

“…This study also revealed that intercropping cultivation did not significantly alter the N loss pattern. Generally, N loss primarily consists of soluble N, with distinct proportions of NO 3 − -N and NH 4 + -N losses [42]. The loss of NO 3 − -N in surface runoff constituted 4.1% to 7.8% of TN loss, while the loss of NH 4 + -N constituted 14.3% to 28.4% of TN loss.…”