Eastern China coastal mudflats: Salt‐soil amendment with sewage sludge

Abstract

The mudflats developed along the east coast of China can be important alternative land sources for agricultural purpose after amending with organic fertilizers in large amounts. Abundant in quality organic matter and other plant nutrients, municipal sewage sludge has great potential to be used in mudflat amendment. However, the conflict between agricultural benefits from soil fertility elevation and environmental risks from hazard substances existing in sewage sludge is the critical issue to be resolved before large‐scale application of sewage suldge into salt‐affected degradaed mudflats. In compliance with the national standard for land application in China, raw sewage sludge and its compost can be used to amend mudflat salt‐soil by one‐time or multiple‐time application. One‐time input of sewage sludge followed by planting and tilling green manure has proved to be an optimal way for rapidly improving salt‐affected soil degradation with sustaining fertility benefits and minimal environmental risks. In salt‐soil amended with sludge, soil organic matter content was significantly elevated, and soil physicochemical properties were subsequently improved due to the increase of soil porosity, available nitrogen and phosphorus, and the decrease in bulk density, salinity, and pH in salt‐soil. Application of sewage sludge to mudflat soils increases soil total and bioavailable heavy metals derived from sludge application and thus increases risk of metal uptake by plants grown in mudflat salt‐soil. Environmental risks still represent a major issue in mudflat salt‐soil amendment by sewage sludge. Future holistic environmental risk assessment is warranted before using sewage sludge to amend mudflat salt‐affected degradated soil in China.

Cut Flower Characteristics and Growth Traits under Salt Stress in Lily Cultivars

“…This problem significantly reduces the value and yield of the crop. Strategies to avoid this problem are flesh water input [ 13 ]; the application of soil amendment such as biochar, organic matter, and mineral matter [ 41 , 42 ]; and admixture of the soil [ 20 ]; these are still prohibitively costly and require much effort on a large scale. Therefore, one of the most effective and feasible ways to sustain crop production under salt is to develop new cultivars and genotypes by enhancing their salt tolerance [ 13 , 43 ].…”

Towards sustainable agriculture for the salt‐affected soil

“…It is a general fact that the viability to use sewage sludge as organic amendment is conditioning with its content of heavy metals or other contaminants, and both of them strongly link with the origin of sewage sludge: industrial or residential cities. Bai, Zou, et al () also responded to these related environmental issues for sustainably applying sewage sludge under the China's State Standard for Agricultural Application of Sewage Sludge (GB/T 24600‐2009). In the case of alkaline soils, the potential immobilization of heavy metals could be treated with green manures in combination with biochar (Kripal, ; Luo et al, ; Srivastava et al, ).…”

“…Different types of organic amendments such as green manures, farmyard and poultry manures, compost, food‐processing wastes, and biochar have been applied to soils for enhancing soil quality (Bhaduri et al, ; Liu et al, ; Xu, Zhang, Shao, & Sun, ; Yang, Bian, Tang, Zhou, & Li, ). Among these, green manure is a promising way with long‐term effects and low cost (Bai et al, ; Bai, Xu, et al, ; Bai, Yan, et al, ; Bai, Zou, et al, ; Li et al, ; Maltas, Kebli, Oberholzer, Weisskopf, & Sinaj, ; Meier et al, ; Xu et al, ; Yang et al, ).…”

Structural and Predicted Functional Diversities of Bacterial Microbiome in Response to Sewage Sludge Amendment in Coastal Mudflat Soil

“…As a result of rapid population growth and urban sprawl, sustainable development of agriculture is facing serious challenges from decreasing available farmland [ 1 , 2 ]. The coastal mudflat, which is widely distributed worldwide, has been considered a promising alternative reserve for cultivated land resources to mitigate the issue described above [ 3 , 4 , 5 ].…”