Copper and Zinc in Rhizosphere Soil and Toxicity Potential in White Oats (Avena sativa) Grown in Soil with Long-Term Pig Manure Application

Use of Swine Manure in Agriculture in Southern Brazil: Fertility or Potential Contamination?

“…With the increase in Cu and Zn saturation and availability in the soil promoted by SM, consequently, there is an increase in the concentration of these metals in the soil solution, which potentiates their toxic effects on plants and organisms and their movement in the soil profile [7,16,17,20,63,64]. The increase in the concentration of these metals in the soil solution after continuous applications of PS was demonstrated by De Conti et al [65] in soil samples obtained in Santa Maria, RS.…”

“…The increase in SOM contents in soils fertilized by SM is a factor of great importance in increasing soil fertility, contributing to its CEC, microbiological activity, and soil structure, also is an attribute associated with soil quality [11,12]. However, it is important to notice that some studies have also shown the null effect of SM application on SOM contents [7,16,33]. In samples of Entisol, Inceptisol, and Oxisol, obtained from rural units in Western Santa Catarina under a no-tillage system, Scherer et al [37] observed that SOM contents were similar between areas with PS application and with mineral fertilization, submitted to both managements for 15 and 20-25 years.…”

“…In a parallel study, evaluating the maize cultivation in a soil (obtained from Braço do Norte, SC) submitted to nine years of PS and DL applications with doses based on the recommendation of N (90 and 180 kg N ha −1 ), Benedet et al [7] observed an increase in Zn concentration in the aerial part and small changes in stomatal density, chlorophyll content and APX and CAT activity in maize grown in the soil with PS 180 kg N ha −1 , but this did not affect the crop development. With soil samples obtained in the same area (but with 10 years of application), Benedet et al [16] observed that black oat plants showed an accumulation of Cu and Zn in the aerial part and Cu in the roots, especially when grown in the treatment with DL 180 kg N ha −1 . Additionally, at the beginning of crop development, leaves with chlorosis in DL 180 kg N ha −1 were observed.…”

“…However, SM also has factors limiting its use, such as its variable concentration of nutrients and unbalanced to the needs of the plants, which can compromise the quality and functionality of the environment when excessive and/or continuous fertilization is carried out in the same areas [13][14][15][16][17]. The main concerns raised by researchers, and according to the publications of international academic society, are related to the phosphorus (P) and heavy metals, such as copper (Cu) and zinc (Zn), accumulation, availability, and losses in areas submitted a long history of applications [3,[18][19][20][21][22][23].…”

Pig Slurry Improves the Productive Performance of Eucalypt and Exceeds the Mineral Fertilization

“…The soil quality reference standard values (Cetesb, 2016) establish the concentration of substances in the soil that defi nes it as clean or uncontaminated. One of the major concerns of the re-use of pig slurry in the soil is related to Cu and Zn contamination that can occur at high concentrations in PS (Legros et al, 2013;Benedet et al, 2019).…”