Changes in Labile Fractions of Soil Organic Matter During the Conversion to Organic Farming

Abstract

Organic farming can overcome the environmental consequences of intensive conventional farming. The objective of the work was to investigate the changes in labile soil organic matter (SOM) fractions during the conversion from conventional to organic farming in two Italian sites, namely Foggia (FG) and Metaponto (MT), which differed mainly in initial soil organic carbon (SOC) content. Fields were cultivated with lentil and wheat in rotation and treated with either compost or nitrogen or phosphorus (N/P) fertilizers in three field replicates. The SOM was sequentially fractionated into light fraction (LF), particulate organic matter (POM), and mobile humic acid (MHA) fraction. Isolated fractions were quantified and analyzed for C and N contents. Although total SOC responded to the fertilization treatments, the LF and POM fractions were yet more responsive. The MHA represented on average of 15% of SOC at both sites; however, the LF represented only 5-6% of the total SOC but was the most responsive to changes in soil management. Compost application contributed significantly greater quantities of LF, POM, and MHA than did the N/P fertilizers application. The initial SOC content can play an important role in determining the impacts of introducing organic farming practices on SOM fractions. Although both sites had an initial low SOC content, the MT site, with a lower SOC content, showed a substantial fractional C increment as compared to the FG site.

Organic Farming Enhances the Diversity and Community Structure of Endophytic Archaea and Fungi in Maize Plant: a Shotgun Approach

“…5). The abundance of endophytic fungi in the FK site agrees with an earlier study in which endophytic fungi are reported to thrive well through organic farming (Xia et al 2019;Yang et al 2019). The position retained by each endophytic fungi class indicates the sequences linked to its makeup, while the vector arrows revealed the genus most affected by the distribution.…”

“…In the last two decades, organic farming has gain prominence all over the world because of the low chemical input it required alongside their immense benefits to the environment, crop growth, and health (Van Bruggen and Finckh 2016; Reganold and Wachter 2016;Abdelrahman et al 2020). Consequently, these farming practices have a direct impact on the diversity, functions, and abundance of soil microbial communities and hence can be linked to crop yield and growth improvement, enhancement of crop to abiotic, and biotic stress alongside improved soil health (Kniss et al 2016;Gamboa et al 2020;Flores-Rentería et al 2020).…”

“…Previous studies have revealed that the abundance and diversity of soil and plant microbiomes are greatly influenced by different farming practices; one reason attributed to this is that the difference in water use can influence the interaction of the soil environment across the farming types (Lori et al 2017;Hartmann et al 2015). For instance, the growth and survival of microorganisms in soil can be directly influenced by the water content in the soil, which significantly affects the access of microorganisms to the essential nutrient which are critical for their survival (García-Orenes et al 2013;Lienhard et al 2013;Abdelrahman et al 2020).…”

“…Fertilizer application has been reported as one of the major factors that affects soil microbial diversity (Leskovar and Othman 2018;Abdelrahman et al 2020). For instance, the quality and quantity of organic fertilizers have been reported to perform major roles in the diversity of soil microbes (Hartmann et al 2015;Leskovar and Othman 2018).…”

Chemical and Spectroscopic Investigation of Different Soil Fractions as Affected by Soil Management

“…In addition, the main OM input, which is the above-ground crop residues, has been removed from the field at the end of the crop cycles in all treatments. With regard to the latter topic, it has been demonstrated that the aboveground crop residues are important for building up soil fertility not only as input of OM, but also because they cover the soil during the hot weather, which conserves SOM [35]. Lastly, the fractional OC content did not differ between fertilized and not fertilized plots since the adopted fertilization was only inorganic and rather low.…”