Effects of biochar and nitrogen fertilizer on soil physicochemical properties, nitrogen use efficiency and upland rice (Oryza sativa) yield grown on an Alfisol in Southwestern Nigeria

Abstract

Purpose Biochar and inorganic fertilizer when co-applied have been reported to increase crop yield and enhance soil fertility. However, studies on this complementary effect on soil properties and rain-fed upland rice performance in Sub-Saharan Africa are still scanty. Methods Field factorial studies conducted over 2 years was set up to investigate the interactions between rice husk biochar and inorganic nitrogen (N) fertilizer on a sandy clay loam Alfisol. A two-factor (4 × 4) in RCBD where rice husk biochar was incorporated at four doses, 0, 3, 6, and 12 t/ha −1 , inorganic N fertilizer (urea) at four rates, 0, 30, 60 and 90 N kg/ha −1 , and their combinations was adopted. Results Results showed that combination of biochar and N fertilizer exerted significant (P > 0.05) interactive effect on rice harvest index, grain and straw yield and N-use efficiency. Interaction between biochar and N fertilizer increased agronomic efficiency by 140% and grain nutrient recovery by 191% over 2 years. Combination of biochar and N fertilizer reduced soil bulk density, increased water holding capacity and soil chemical status such as pH, N, P, K, Corg, Ca, ECEC and base saturation, all within the top 10 cm depth of the soil. Conclusions Overall, the results established that rice husk biochar can be used as a soil conditioner to enhance upland rice yield on an Alfisol. The combined dose of 3-6 t/ha −1 biochar and 30 kg/ha −1 of N fertilizer is thus recommended for upland rice farmers in the study area.

Different rates of biochar application change 15N retention in soil and 15N utilization by maize

“…Our results showed that when biochar application rate was too high as the case with P48 treatment, the 15 N uptake in most organs (Figure 4a) and the overall 15 N utilization efficiency of maize (Figure 4b) were markedly lower than that in P12 and P24, which is in accordance with the results obtained by Oladele et al. (2019). This is because higher biochar application rates markedly improve SOC content in a short period of time (Section 3.1), as also reported in Zhang, et al (2020).…”

“…This is because biochar application improved soil physical conditions (Figure 1), availability of soil nutrient (Table 1) and N uptake by maize plant (Figures 3 and 4). Improvement of soil properties and nutrient uptake by plants after biochar application has been shown to increase crop yield (Mandal et al., 2016; Oladele et al., 2019; Wang et al., 2020). However, excessive biochar application (P48 treatment) appeared to slightly reduce the N uptake and absorption by maize plant parts (Figure 4), resulting in the slight decline in crop yield and biomass in each plant parts (Figure 5).…”

“…Biochar is a C‐rich substance that stores C in a stable form (Zhang, et al, 2020) and is essential to conserve soil moisture by modifying the soil pore size distribution, soil aggregates and water storage in pores (Kammann et al., 2011; Ma et al., 2016). It improves the fertility of agricultural soils (Hagemann et al., 2017; Oladele et al., 2019) and enhances crop yield (Hagemann et al., 2016; Liao et al., 2020) by reducing nutrient losses caused by volatilization or leaching (Gul et al., 2015; Hagemann et al., 2016). Moreover, biochar application also improves soil aggregate stability (Burrell et al., 2016), minimizes soil erosion (Ajayi et al., 2016; Baiamonte et al., 2015) and reduces soil bulk density (Burrell et al., 2016), as well as improves microbial activities (Abujabhah et al., 2018).…”

Integrated Nutrient Management Enhances Productivity and Nitrogen Use Efficiency of Crops in Acidic and Charland Soils

“…The results revealed that IPNS treatments had no significant effect on soil bulk density in acidic soil, although IPNS treatments significantly decreased soil bulk density in charland soil. Many studies have shown that including organic material in the soil reduces its bulk density [75,76]. The reason for the decreased soil bulk density is the addition of organic materials, which increases soil organic matter content, resulting in soils that are more friable, porous, and chemically active, reducing soil bulk density [77].…”

Effectiveness of Melaleuca cajuputi Biochar as a Leaching Loss for Nitrogen Fertilizer and Intercropping in Maize

“…The interaction between biochar and N has shown to increased plant growth. It attributed that biochar can increase the availability of nutrients, especially N for plants (Oladele et al, 2019). N was released slowly, so that is utilized by the plants (Haider et al, 2016).…”