Biochar Blended with Nitrogen Fertilizer Promotes Maize Yield by Altering Soil Enzyme Activities and Organic Carbon Content in Black Soil

Abstract

Biochar and nitrogen fertilizers are known to increase soil carbon storage and reduce soil nitrogen loss as amendments, suggesting a promising strategy for highly effectively increasing soil productivity. However, few studies have explored the mechanisms of their effects on crop yield in terms of active carbon fraction and enzyme activity, which ultimately limits the potential for the application of biochar in combination with nitrogen fertilizers. To evaluate the effect of biochar and nitrogen fertilizer on the improvement of black soils in northeast China, a field experiment was conducted in the black soil to compare and analyze the application methods on total organic carbon (TOC), total nitrogen (TN), enzyme activities, and maize yields. Biochar rates: CK, C1, C2, and C3 (0, 9.8, 19.6, and 29.4 Mg·ha−1); N fertilizer rates: N1/2 and N (30 and 60 kg·ha−1). Results indicated that biochar and N fertilizer amendments significantly ameliorated soil fertility, such as TOC and TN, compared to the unamended soil. The TOC levels in the C3 treatment increased by 35.18% and the TN levels by 23.95%. The improvement in TN is more significant when biochar is blended with N fertilizer. Biochar blended with N fertilizer increased maize cellulase, urease, and invertase activities by an average of 53.12%, 58.13%, and 16.54%, respectively. Redundancy analysis showed that TOC, TN, and MBN contributed 42%, 16.2%, and 22.2%, respectively, to the maize yield indicator. Principal component analysis showed that reduced N fertilizer was more effective in improving yields, with a maximum yield increase of 50.74%. Biochar blended with N fertilizer is an effective strategy to improve the fertility and productivity of black soils in northeast China, while nitrogen fertilizer reduction is feasible and necessary for maintaining grain yield.

Response of Cellulose Decomposition and Nodulation in Soils Amended with Biochar for Peri-Urban Agriculture

“…Cellulase and β-glucosidase activation percentages for clay and sandy soil exceeded 60% when employing the maximum rate of biochar (B4). This agrees with Sun et al [53], who found that biochar addition to soil increased urease, cellulase, and invertase activity by an average of 58.13%, 53.12%, and 16.54%, respectively. Improvements in soil physicochemical characteristics due to biochar addition may have boosted soil microbial and enzymatic activity and particularly cellulase functional groups that may also have contributed to soil fertility.…”

Effect of the application of peanut shell, bamboo, and maize straw biochars on the bioavailability of Cd and growth of maize in Cd-contaminated soil

“…Biochar application can increase soil nutrient cycling, improve soil physicochemical properties, and increase soil N content, all of which positively affect plant growth (Jin et al, 2019;Yu et al, 2019;Ángela et al, 2022). Sun et al (2023) found that N increased by 23.95% under 29.4 mg ha -1 biochar application, which substantially improved soil fertility. Higher levels of biochar application contribute to N retention in the soil and promote plant growth (Chan et al, 2007;Guerena et al, 2013).…”

“…Crop straw is rich in organic carbon (OC), phosphorus (P), nitrogen (N), trace elements, and potassium (K) (Cui et al, 2019). In recent years, biochar prepared by straw pyrolysis has been widely used for agricultural carbon sequestration and soil fertility improvement (Holatko et al, 2022;Yang et al, 2022;Sun et al, 2023). In addition to remediating heavy metal and organic compound-contaminated soils, biochar also acts as a catalyst, positively influencing crop growth and enhancing yield (Xu et al, 2019;Zha et al, 2022).…”