Higher Biochar Rate Can Be Efficient in Reducing Nitrogen Mineralization and Nitrification in the Excessive Compost-Fertilized Soils

Abstract

The effects of a high biochar rate on soil carbon mineralization, when co-applied with excessive compost, have been reported in previous studies, but there is a dearth of studies focusing on soil nitrogen. In order to ascertain the positive or snegative effects of a higher biochar rate on excessive compost, compost (5 wt. %) and three slow pyrolysis (>700 °C) biochars (formosan ash (Fraxinus formosana Hayata), ash biochar; makino bamboo (Phyllostachys makino Hayata), bamboo biochar; and lead tree (Leucaena leucocephala (Lam.) de. Wit), lead tree biochar) were applied (0, 2 and 5 wt. %) to three soils (one Oxisols and two Inceptisols). Destructive sampling occurred at 1, 3, 7, 28, 56, 84, 140, 196, 294, and 400 days to monitor for changes in soil chemistry. The overall results showed that, compared to the other rates, the 5% biochar application rate significantly reduced the concentrations of inorganic N (NO3−-N + NH4+-N) in the following, decreasing order: lead tree biochar > bamboo biochar > ash biochar. The soil response in terms of ammonium and nitrate followed a similar declining trend in the three soils throughout the incubation periods, with this effect increasing in tandem with the biochar application rate. Over time, the soil NO3−-N increased, probably due to the excessive compost N mineralization; however, the levels of soil NO3−-N in the sample undergoing the 5% biochar application rate remained the lowest, to a significant degree. The soils’ original properties determined the degree of ammonium and nitrate reduction after biochar addition. To reduce soil NO3−-N pollution and increase the efficiency of compost fertilizer use, a high rate of biochar application (especially with that pyrolyzed at high temperatures (>700 °C)) to excessively compost-fertilized soils is highly recommended.

Quality Evaluation of Poultry Litter Biochar Produced at Different Pyrolysis Temperatures as a Sustainable Management Approach and Its Impact on Soil Carbon Mineralization

“…3 ) is negligible for all the PLBs, but the cumulative content of the total water-extractable inorganic N (NH + 4 -N) of P2, P3, P4, P5, and P6, as compared to total N, was about 8.4, 7.0, 2.2, 0.12, and 0.10%, respectively. The results of the cumulative NH + 4 -N of the five studied PLBs were much higher than the reports concerning lignocellulosic biochar [19,21]. In addition to the enhancement of more available N in P2, P3, and P4 biochar, the higher water-extractable N could also enhance the C mineralization rate.…”

“…Additionally, extraction of water-soluble biochar C and N was also conducted. This extraction process, which involved gentle shaking with deionized water (water/biochar ratio 10:1) for 30 min, was repeated 5 times for each biochar sample with three replicates [19][20][21]. Water extracts were filtered through 0.45 mm pore-size nylon membrane filters (Whatman ® , Maidstone, UK) and were collected.…”

“…Water extracts were filtered through 0.45 mm pore-size nylon membrane filters (Whatman ® , Maidstone, UK) and were collected. The pH and EC of the extraction, in addition to water-extractable organic C (WEOC), water-extractable NO − 3 -N and NH + 4 -N concentrations, were determined using the analysis methods described in previous studies [20,21].…”

“…Soil and biochar were added to each jar and a spoon was used to thoroughly mix the samples. In a similar way to a previous study [17,18,20,21], 25 g of the mixed soil sample was incubated in a 30 mL plastic container inside a 500 mL plastic jar, with 10 mL of 1 M NaOH and 10 mL of water in a vial added separately. Three blanks consisting of jars with only water and NaOH, as described above, were also included.…”

Influence of differentiation of nitrogen fertilization of dark chestnut alkaline soil on its agrochemical indicators and yield of crops.

“…Значну кількість сучасних публікацій присвячено азотному живленню та удобренню рослин. Зокрема, досліджували вплив тривалого азотного удобрення на агрохімічний стан чорнозему вилугуваного і врожайність пшениці озимої [5,6], питання мінералізації та нітрифікації азоту за високих рівнів унесення добрив [7], азотного живлення зрошуваного рису [8], отримання високих урожаїв за низьких рівнів унесення азоту [9].…”