Landscape Integrated Soil and Water Conservation (LISWC) System for Sloping Landscapes in Atlantic Canada

Abstract

Soil and water are fundamental and precious resources for agriculture. In Atlantic Canada (AC), intensive agricultural production systems have led to detrimental environmental effects such as soil erosion and the contamination of receiving waters, posing significant threats to the resilience and sustainability of the agro-ecosystem. Although many beneficial management practices (BMPs) have been developed, they all have their shortcomings and there are often trade-offs for each individual BMP. In this paper, a new paradigm is proposed for soil and water conservation—landscape integrated soil and water conservation (LISWC), a system designed to conserve and reuse soil and water within the landscape by integrating multiple BMPs based on an understanding of the landscape processes and knowledge about the BMPs. On a typical sloping field in AC, an LISWC system can be established by integrating BMPs such as diversion terraces and grassed waterways, tile drainage, water retention structures, supplemental irrigation, conservative tillage practices and soil–landscape restoration. Each individual BMP is designed to enhance one aspect of soil and water conservation but working on their own, they are all insufficient for the landscape as a whole and sometimes even have negative impacts. However, once integrated in the landscape, they complement each other: water erosion is reduced by diversion terraces and grassed waterway and conservative tillage, field drainage condition is enhanced by tile drainage, runoff and tile drained water is stored in the retention structure and reused for irrigation, and most eroded soil is returned to the soil loss area with soil–landscape restoration. This holistic landscape perspective can be used to develop LISWC systems for other landform types or applied at watershed or regional scales. Future studies are needed for the connections and interactions between individual BMPs, and analysis on the overall economic benefit of an LISWC system.

The Importance of Environmental Factors for the Development of Water Erosion of Soil in Agricultural Land: The Southern Part of Hronská Pahorkatina Hill Land, Slovakia

“…The mosaic of small fields has changed at the expense of large-scale arable land [38]. The soil cultivation system has changed, which contributes to the development of erosion processes [39]. This is also pointed out by the work of Solín and Cebecauer [40] who state that the collectivization process in Slovakia caused about a 40% increase in areas with a high or very high degree of susceptibility to soil erosion.…”

Short-term response of soil aggregate stability and labile carbon to contour tillage, diversion terrace, grassed waterway, and tile drainage implementation

“…As Li (2021) points out, past studies on BMPs such as DT and GW often suggest that they are effective in solving their targeted problems. However, there are often unexpected tradeoffs.…”

“…In 2017, the Landscape Integrated Soil and Water Conservation (LISWC) system was proposed by Dr. Sheng Li of the Fredericton Research and Development Centre (FRDC) as a new, holistic system designed to conserve soil and water on sloping landscapes by integrating multiple BMPs and studying their interactions (Li, 2021). Individual BMPs, included in the LISWC system, are diversion terraces (DT), grassed waterways (GW), tile drainage (TD), water retention structures, supplemental irrigation, contour tillage (CT), and soil-landscape restoration.…”

“…As a proof of concept, a field site was designed and constructed in 2018 to test the effects of the LISWC system on soil hydrology and physical, chemical, and biological properties, as well as on offsite water quality and greenhouse gas (GHG) emissions (Li et al, 2021). At present, only one study has been completed at the LISWC site; it focused on the removal of excess water from the tile-drained LISWC fields relative to fields without drainage that otherwise had the same combination of BMPs (Dobson, 2022).…”

“…While DT and GW have been extremely effective at reducing runoff and soil loss during a decade-long study in New Brunswick, just outside the city of Grand Falls, these conservation structures were not able to stop the decline of soil carbon (Rees et al 2008;Chow et al 2010). As Li (2021) points out, past studies on BMPs such as DT and GW often suggest that they are effective in solving their targeted problems. However, there are often unexpected tradeoffs.…”