Carbon and phosphorus biogeochemical cycles in native forest and horticultural areas in the Metropolitan Region of Curitiba, Brazil

Abstract

This study was carried out to understand the dynamics of carbon and phosphorus biogeochemical cycles in native forest and horticultural areas. Soilsamples were collected from native forest and horticultural areas, in four municipalities in the Metropolitan Region of Curitiba, Brazil, and evaluated for: carbon, nitrogen and phosphorus of soil microbial biomass (MBC, MBN and MBP, respectively), total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), inorganic phosphorus (iP), organic phosphorus (oP) and available phosphorus (aP. Soil suspensions diluted at 10-4were spread on plates and phosphate solubilizing bacteria (PSB) were counted. The analyses showed that horticultural areas soils accumulated 43% more TP whereas they lost 23% of TOC and 19% of TN comparing to native areas. 69% of TP in the native areas was organic (oP) whereas 59% of TP in the horticultural areas was inorganic (iP). Horticultural areas had lower numbers of colony forming unities of PSB than native areas. PSB was positively correlated with the ratio of MBC to TOC (qMic), which in turn, was negatively correlated with TOC and TN. Changes in the soil P fractions suggested a shift inthe soil community bacterial structure and in the values of soil microbial biomass of the two different soil ecosystems. The excessive P addition may stimulate soil microbial attack to soil organic matter reserves, whichmay have consequences for maintenance of soil quality and agriculture sustainability

Physical, chemical and microbiological soil attributes influence soil greenhouse gases fluxes in Atlantic Forest and pine (Pinus taeda) plantations in Brazil

“…Meanwhile, the pine plantations produced organic residues that form more lignin‐rich SOM, which is more recalcitrant to microbial degradation; and pine plantations may also have exuded compounds such as terpenes that inhibited the activity of soil microorganisms (Bini et al, 2013; Dietz et al, 2020; Olsson et al, 2019; Veloso et al, 2018; Xu et al, 2020). For example, differences in SOM between native forests and pine plantations (in Telêmaco Borba; Table 2) may have contributed to increase the values of soil microbiological attributes, such as the qCO 2 , BR, and urease and β‐glucosidase activities in the native forest of Telêmaco Borba (Table 4) since C availability often limits soil micro‐organism's growth (Anzalone et al, 2020; Ferreira et al, 2021; Lazeris et al, 2021).…”

Repeated Manure Application for Eleven Years Stimulates Enzymatic Activities and Improves Soil Attributes in a Typic Hapludalf

“…Glucosidase and phosphatases are directly involved in the mineralization of soil organic matter, attacking C-compounds and organic P-compounds, respectively [11,22]. Since soil chemical analyses revealed that labile P was satisfactorily available in all fertilized plots (Table 2), it is possible that soil microorganisms were not aiming at P, but probably C. In another word, soil microorganisms may have adjusted their metabolism in order to acquire the most limiting nutrients and preserve their cell nutrient ratios [20,21]. Therefore, in this study, the addition of residues rich in organic-P compounds is possibly activating the recycling of soil organic matter, resulting in more qCO 2 (Table 3) but also, producing more mineralized nutrients (Table 2).…”

“…On the other hand, nutrients from organic sources are released slowly in the soil environment which makes them available for a longer period of time and helps to maintain soil nutrient status. However, animal manure is a source of C, which is a limited resource for soil microorganisms [9,20,21]. The addition of manure should stimulate soil microbial biomass and activity, and increase activities of the enzymes related to the biogeochemical cycles of nutrients [9,11,12,21,22].…”

“…However, animal manure is a source of C, which is a limited resource for soil microorganisms [9,20,21]. The addition of manure should stimulate soil microbial biomass and activity, and increase activities of the enzymes related to the biogeochemical cycles of nutrients [9,11,12,21,22]. While in the short term, the addition of manure could stimulate the degradation of soil organic matter and increase the depletion of soil organic C due to higher soil respiration [12,21], repeated applications should accumulate more soil organic matter in the long term, which would have a crucial role on the improvement of chemical and physical soil attributes [10,12,16,23].…”