Biochars from local agricultural waste residues contribute to soil quality and plant growth in a Cerrado region (Brazil) Arenosol

Abstract

Arenosols (sandy soils) in the Cerrado region of Mato Grosso, Brazil, are increasingly used for maize production, the second most important crop in the region after soybean. Yet, these soils are typically nutrient poor with low soil water retention, requiring high fertilizer inputs that are often lost in surface runoff or leached. The addition of biochar, a more recalcitrant organic amendment, may therefore be beneficial in Cerrado Arenosols, contributing to sustainable crop production in the region. To examine biochar contribution to soil nutrient levels and maize growth in a Cerrado Arenosol, we conducted a greenhouse experiment using biochars made from local agricultural waste feedstocks. These were cotton husks, swine manure, eucalyptus sawmill residue, and sugarcane filtercake, pyrolyzed at 400 °C, and applied to soil at five rates: 0%, 1%, 2%, 3%, and 4% by weight. Maize plants were grown under unstressed conditions (e.g., no nutrient or water limitations) to highlight any possible negative effects of the biochars. After 42 days, soils were analyzed for nutrient levels, and plant physical and physiological measurements were taken. Filtercake biochar had the highest plant biomass and physiological properties (e.g., photosynthesis, respiration, nitrogen use efficiency), while cotton biochar had the lowest. Importantly, maize biomass decreased with increasing application rates of cotton and swine manure biochars, while biomass did not vary in response to biochar application rate for filtercake and eucalyptus biochars. In this study, we found that while each biochar exhibited potential for improving chemical and physical properties of Cerrado Arenosols, filtercake biochar stood out as most promising. Biochar application rate was identified a key factor in ensuring crop productivity. Transforming these agricultural residues readily available in the region into more stable biochar can thus contribute to sustainable crop management and soil conservation, providing an alternative form of waste disposal for these residual materials.

Influence of Pyrolyzed Grape-Seeds/Sewage Sludge Blends on the Availability of P, Fe, Cu, As and Cd to Maize

“…In our study, the application of pyrolyzed materials did not increase maize yield compared to the control treatment. This might be due to their low N availability, since maize is known to be a crop with high N demand [68,69]. On the contrary, we observed an increase in plant growth-meaning the aerial part-of 60% for the Incubated mixture (Figure 1).…”

“…Some studies did not find differences in Fe availability in soil after amendment with biochars from different wastes [72]. Whereas others, such as Speratti et al, (2017) [69], found that Fe availability doubled after the application of sugarcane filtercake biochar in a tropical arenosol.…”

Correction of Acidity of a Brazilian Cerrado Oxisol with Limestone and Wood Ash on the Initial Growth of Cowpea

“…These soils are known as acid soils. These soils contain high concentration of aluminum and manganese, being necessary the use of liming to increase crop production [1] [2].…”

Growth and development of cowpea under wood ash doses and liming

“…The production areas are in a Cerrado region with soils that have low natural fertility and high soil acidity, the costs with correction and fertilization contribute to the increase in production expenditures. These soils contain a high concentration of aluminum and manganese, and it is necessary to perform the liming to increase the agricultural production (SANTOS et al, 2018;SPERATTI et al, 2018).…”