Soil Health Analysis, Set. Группа авторов

Soil Health Analysis, Set - Группа авторов


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habitat, curbing production of surplus commodities, and providing income support for farmers (Allen and Vandever, 2012; FAPRI, 2007; Follett et al., 2001; Li et al., 2017). In exchange for retiring HEL for 10 years, USDA paid CRP participants (farm owners or operators) an annual per‐acre rent and half of the cost of establishing a permanent land cover (Young and Osborn, 1990).

      Soil quality assessment thus emerged as an evaluation tool as many first‐round contracts began to expire (Karlen et al., 1998). Since then, a plethora of studies have evaluated the CRP effect on soil health (Baer et al., 2002; Knops and Tillman, 2000; Matamala et al., 2008; Mensah et al., 2003; Reeder et al., 1998; Rosenzweig et al., 2016; De et al., 2020). Most have focused on insensitive or slower changing soil health indicators (e.g., soil organic carbon [SOC] and N pools). Only a few have evaluated more management‐sensitive active carbon pools, such as potentially mineralizable carbon (PMC), potentially mineralizable nitrogen (PMN) microbial biomass carbon (MBC) and soil microbial communities (Baer et al., 2002; Matamala et al., 2008; Haney et al., 2015; Rosenzweig et al., 2016; Li et al., 2018; De et al., 2020).

      In New Zealand, soil quality/soil health assessment was also a rigorously studied topic with one example being “Visual Soil Assessment” (VSA) guidelines for areas characterized as “flat to rolling” or “hill country (Shepherd, 2000; Shepherd et al., 2000a; Shepherd and Janssen, 2000; Shepherd et al., 2000b). Those publications provided instructions, photographs, and scorecards for using VSA to assign scores of 0, 1, or 2 for poor, moderate, or good, respectively, for a variety of soil and plant indicators. Guidelines to help land managers respond if soil quality/soil health was deemed to be either moderate or poor were provided. Inherent site characteristics including land use, soil type, texture, moisture condition, and seasonal weather conditions are also recorded.

      Soil quality quickly became closely aligned with good soil management in New Zealand. Furthermore, because land‐based industries were the main generator of export income, the use of soil quality assessment as a sustainability indicator generated a substantial amount of research and technology transfer activities throughout that country (Beare et al., 1999). Increasing economic pressure to intensify land use, possibly beyond the margins of sustainability further increased farmer demand for more information, better monitoring tools, and improved soil management practices. Ultimately this led to development of a soil quality monitoring system (SQMS) by Crop & Food Research Ltd. and the Centre for Soil and Environmental Quality (Beare et al., 1999). Several soil quality web sites and other technology transfer activities also evolved during that era.

      Many other New Zealand‐based soil quality studies that contributed to the foundation upon which current soil health activities have evolved were conducted, but even listing them is beyond the scope of this chapter. One study (Reganold et al., 1993) does warrant discussion because it helps illustrate that soil quality evolution during the 1990s was not without conflict and strong differences in scientific opinion. Reganold et al. (1993) evaluated soil quality and financial performance of biodynamic and conventional farms in New Zealand. They concluded that per unit area, biodynamic farms had better soil quality and were as financially viable as neighboring conventional farms. Within a year a critique questioned the statistical analyses that had been used (Wardle, 1994), but a reanalysis of the data (Reganold, 1994) confirmed the original conclusions and added information indicating that measurements collected from two of the farm pairs had twelve times more earthworms (by number) with biodynamic management than their conventionally managed counterparts.

      In Australia, soil quality/health research during the 1990s was focused on issues similar to those in New Zealand or the northern hemisphere. For example, Aslam et al. (1999) used MBC, MBN, MBP, and earthworm (Apporrectodea caligninosa) populations as biological soil quality indicators to quantify effects of converting pastureland to cropland through either plowing or no‐tillage practices. They concluded that conversion using no‐till practices could protect soils from biological degradation and maintain better soil quality than with moldboard plowing.

      Europe and New Zealand were not the only locations where soil quality was intensively debated. In the United States, Sojka and Upchurch (1999) were fearful SQI and similar efforts could lead to premature conclusions advocating a value system as an end unto itself. They argued there was very little if any parallel between soil, air, and water quality, and that there were regional or taxonomic biases. Karlen et al. (2001) rebutted, emphasizing that advocates and early adopters of soil quality were in total agreement that “our children and grandchildren of 2030 will not care whether we crafted our definitions or diagnostics well. They will care if they are well fed, whether there are still woods to walk in and streams to splash in — in short, whether or not we helped solve their problems, especially given a 30‐yr warning.” That philosophical debate is mentioned simply to alert soil health advocates the road ahead may not always be smooth.


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