دانلود رایگان مقاله لاتین تنوع میکروبی خاک مربوط به عملکرد محصول از سایت الزویر
عنوان فارسی مقاله:
فعالیت و تنوع میکروبی خاک مربوط به عملکرد و کیفیت محصول در سیستم تولید گندم آلی دیم
عنوان انگلیسی مقاله:
Soil microbial diversity and activity linked to crop yield and quality in a dryland organic wheat production system
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
A central tenet of the organic agriculture philosophy revolves around improving soil quality through building soil organic matter (SOM), enhancing biodiversity, and increasing soil biological activity (Lotter, 2003). Greater soil microbial diversity has been considered an indicator of greater overall ecosystem diversity and function, and is considered a sign of a “healthy” organic soil. Organic agriculture emphasizes the use of animal and green manures and composts to enhance soil fertility, as these materials have been shown to increase SOM (Fliessbach et al., 2007; Haynes and Naidu, 1998; Ros et al., 2006). The precise character of fertility amendments used in organic versus conventional agriculture exert a large effect on soil microbial populations, in the same way that the amount and type of organic matter inputs strongly affect soil microbial status (Shannon et al., 2002). As SOM accumulates, ecosystem productivity can often become limited by the mineralization rate of soil humic materials (Parfitt et al., 2005), which is determined by the amount and activity of extracellular enzymes produced by soil microorganisms that break down complex organic molecules (Allison and Vitousek, 2005; Sinsabaugh, 1994). Extracellular enzyme production depends on bacterial and fungal biomass, physiological state, and species composition of the community, as well as a variety of environmental factors (Allison et al., 2007). Organic producers have reported that they struggle to maintain adequate soil inorganic N to achieve levels of production equal to those of conventional systems (Tautges and Goldberger, 2015; Walz, 2004). However,several studies report finding similar or greater total N levels in organic versus conventional soils (Gosling and Shepherd, 2005; Marinari et al., 2006; Marriott and Wander, 2006). While total soil N may be greater in organic than conventional soils, N is usually the most limiting nutrient for crops in organic systems because much of the N is tied up in organic matter (Badgley et al., 2007; Seufert et al., 2012). Greater partitioning of N to the organic fraction may be favorable for soil health; however, a high organic to inorganic N ratio in soils often results in insufficient levels of available N for crop plants and consequently low grain yields. Mader et al. (2002) found that the soluble fraction of N was lower in organic than in conventional soils, but that extracellular enzyme activity and microbial diversity was greater in organic soils. Further, they observed more complete decay of particulate organic matter and greater microbial biomass in organic systems, indicating greater turnover of SOM but not necessarily a surplus of soluble forms of nutrients. Instead, N released through mineralization is likely being immobilized via assimilation into microbial biomass (Burger and Jackson, 2003; Willson et al., 2001). For example, yield benefits are observed in grain crops when legumes are added into the crop rotation to increase soil N with additional N fertilizer. Additional soil available N observed following the legume crop has been attributed to turnover of microbial biomass N, rather than the release of N from the legume tissues or roots (Bremer and van Kessel, 1992; Peoples et al., 2009). Some studies have found that, over time, organic systems that return large amounts of organic matter to the soil accumulate enough SOM that mineralization of SOM results in sufficient quantities of inorganic N that can support high-yielding grain crops (Mason and Spaner, 2006). For example, Zentner et al. (2004) found in years 5 through 12 of a long-term study that an organic spring wheat-legume green manure rotation achieved yields similar to that of a conventional spring wheat-fallow rotation. They also observed a significant increase over time in grain protein and N mineralization, indirectly indicating that microbial mineralization of accrued SOM can reach levels sufficient to support high-yielding organic crops. Therefore, soil microbial diversity and activity is of greatinterest in evaluating the outcomes of organic management practices on soil fertility, especially as compared to conventional management. Perhaps not surprisingly, important biological indicators of soil health, including microbial biomass (Birkhofer et al., 2008; Fliessbach et al., 2007; Tu et al., 2006), microbial abundance (Shannon et al., 2002), enzyme activity (Marinari et al., 2006; Tu et al., 2006), microbial diversity (Mader et al., 2002; Shannon et al., 2002), and C substrate utilization (Ros et al., 2006) have all been found to be greater in organically-managed soils than in conventionally-managed soils. Fungal biomass has also been consistently found to be greater in organic systems, compared to conventional systems (Birkhofer et al., 2008; Gunapala and Scow, 1998; Shannon et al., 2002; Yeates et al., 1997). While some studies have reported bacterial abundance to be higher in organically-managed soils (Mulder et al., 2003; Van Diepeningen et al., 2006), others have found bacterial abundance to be less sensitive to management practices than fungal abundance (Yeates et al., 1997). Activity and diversity of soil microbes is, at least in part, a function of the availability, variety, and recalcitrance of C substrates and, as organic systems generally receive greater organic matter inputs than conventional systems (Burger and Jackson, 2003; Tu et al., 2006; Yeates et al., 1997), soils under organic management generally have a higher C content than those under conventional management. Greater soil C content does not necessarily imply greater microbial utilization of C, however. Birkhofer et al. (2008) found that soil C in a conventional system was more labile and therefore more easily accessible to microbes than in an organic system.
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کلمات کلیدی:
Impacts of Cropping Systems and Long-Term Tillage on Soil Microbial ... https://www.hindawi.com/journals/isrn/2012/487370/ by JP Ng - 2012 - Cited by 12 - Related articles Oct 18, 2011 - We hypothesized that a combination of no-tillage and crop-rotation practices ... The soil samples used in this study were collected from a dryland farming .... The 16S sequences were quality-checked and edited using .... including pH, organic C (OC), total N (TN), and microbial biomass C, N, and P (Table 3). Tarah S. Sullivan | Dept. of Crop and Soil Sciences | Washington State ... css.wsu.edu/tarah-s-sullivan/ Soil Microbial Diversity and Activity Linked to Crop Yield and Quality in Dryland Organic Wheat Production System. Applied Soil Ecology 108:258-268. Sullivan ... [PDF]Sustainable dryland organic cropping systems for eastern Washington www.tfrec.wsu.edu/pdfs/P1867.pdf Wheat, nutrition, wheat quality, crop rotation, organic, no-till, sustainable. ... effects of environmental conditions on grain yield and quality, we ... are absent in white flour), which in turn are associated with reduced glycemic index and ... of organic, no-till, and conventional wheat, including total dietary fiber, antioxidant activity,. Soil Quality and Soil Erosion - Page 324 - Google Books Result https://books.google.com/books?isbn=1574441000 Raj Ratta, R. Lal - 1998 - Technology & Engineering ... 47 in dryland, 163 microbial activity and, 68 pH and, 44 winter cover crops and. ... 244, 245, 265 Organic carbon, 97, 103, 1 12, 264, 277-278 crop yields and, ... Article metrics for: Comparing the yields of organic and conventional ... www.nature.com/nature/journal/v485/n7397/nature11069/metrics/citations?page=14 May 10, 2012 - To establish organic agriculture as an important tool in sustainable ... and activity linked to crop yield and quality in a dryland organic wheat ... Searches related to activity linked to crop yield and quality in a dryland organic why are worms important to agriculture economic importance of termite in agriculture why are birds important to agriculture why are ladybugs important to agriculture uses of termite termite control in agriculture why are termites important in ecosystems ants
