Changes in macro‐ and micronutrient contents of grasses and forbs following Miscanthus x giganteus feedstock, hydrochar and biochar application to temperate grassland

Abstract

Biochar and hydrochar application to soil holds promise for climate change mitigation. This study provides first insights into the nutrient concentration and removal of grassland vegetation after addition of various carbon compounds together with pig slurry. Four treatments: control (no carbon application), feedstock, hydrochar and biochar from Miscanthus x giganteus were applied at a permanent grassland site near Giessen, Germany. Changes in plant functional groups, biomass production and nutrition status were monitored over 2 years. Total biomass production was not affected by the carbon amendments. However, biochar favoured growth of forbs over grasses, while legume growth was increased by all carbon amendments. The initial nutrient concentrations of the carbon compounds were enriched according to their degree of carbonization, potentially providing nutrients to plants. The plant biomass from hydro‐ and biochar amended plots, added up over 2 years, exhibited higher potassium concentrations compared to biomass from feedstock and control plots. All carbon amendments led to lower sodium concentrations in total biomass, compared to the control. Uncarbonized feedstock led to increased manganese concentrations in total biomass, while the concentrations of all other heavy metals were not influenced by any carbon amendment, compared to the control. From a plant and animal nutritional point of view, none of the carbon amendments reduced grassland yield or fodder quality. The study suggests that hydrochar and, even more so, biochar may provide a source of potassium to plants.

Effect of biochar application on the content of nutrients (Ca, Fe, K, Mg, Na, P) and amino acids in subsequently growing spinach and mustard

“…In all plants, Na content decreased in spring spinach (88% on average), mustard (64%) and autumn spinach (79% on average) by BC application. Decrease of sodium content was found in maize (Kim et al 2016) by BC treatment and in mixed biomass of grasses and forbs on temperate grassland (Schimmelpfennig et al 2015). The positive effect of BC application on plant accumulation of elements was observed only for K. Although this element was applied to the soil as a fertilizer at the beginning of the experiment, BC increased K availability and its accumulation in the tested plants during the whole experiment ( Figure 1, Table 2).…”

The potential of biochar for reducing the negative effects of soil contamination on the phytochemical properties and heavy metal accumulation in wheat grain

“…In the study by Ahmed and Schoenau (2015), biochar (1-2 t ha the availability of N and P, and its effects on soil pH, organic carbon and electrical conductivity were minor; it increased the yield of the crops studied only in some treatments. In the study by Schimmelpfennig et al (2015) interactions between the carbon amendments (uncarbonized feedstock, hydrochar, biochar from Miscanthus giganteus) with slurry did not occur, neither improving nor worsening the efficiency of nutrient use. The reasons for the changes in the yield structure can be sought not only in the properties of BC but also in the properties of macroand micronutrients, because complexation is an important mechanism controlling the mobility of cationic metals, whereas competition for available sites on soil minerals between metalloids and soil amendments could be a dominant factor involved in sorption/ desorption of metalloids (Violante et al 2010).…”

“…However, these processes are reversible under buffer acidic conditions . On the other hand, in the study by Schimmelpfennig et al (2015) the use of various forms of carbon (uncarbonized feedstock, hydrochar, biochar from Miscanthus giganteus) did not significantly change the concentration of heavy metals (Cu, Zn, Cl) in grass biomass.…”

“…Especially considering the varying properties of biochar and it's influence on plants. Biochar may significantly change both physico-chemical and biological properties of soil (Atkinson et al 2010, Schimmelpfennig et al 2015. The application of biochar to soil changes its structure as well as the distribution, size and density of pores; it changes soil aeration and water retention capacity.…”

“…This can lead to increased yield potential (with yield increases of 10-12%) (Biederman and Harpole 2013). Increased bioavailability of soil nutrients is mainly the result of direct or indirect change in soil pH after biochar application is made (Hossain et al 2011, Lehmann et al 2011, Schimmelpfennig et al 2015. major nutritional components, is a source of biologically active substances regulating physiological processes in the human organisms.…”