Effects of biochar in combination with varied N inputs on grain yield, N uptake, NH3 volatilization, and N2O emission in paddy soil

Abstract

Biochar application can improve crop yield, reduce ammonia (NH3) volatilization and nitrous oxide (N2O) emission from farmland. We here conducted a pot experiment to compare the effects of biochar application on rice yield, nitrogen (N) uptake, NH3 and N2O losses in paddy soil with low, medium, and high N inputs at 160 kg/ha, 200 kg/ha and 240 kg/ha, respectively. The results showed that: (1) Biochar significantly increased the rice grain yield at medium (200 kg/ha) and high (240 kg/ha) N inputs by 56.4 and 70.5%, respectively. The way to increase yield was to increase the rice N uptake, rice panicle number per pot and 1,000 grain weight by 78.5–96.5%, 6–16% and 4.4–6.1%, respectively; (2) Under low (160 kg/ha) N input, adding biochar effectively reduced the NH3 volatilization by 31.6% in rice season. The decreases of pH value and NH4+-N content in surface water, and the increases of the abundance of NH4+-N oxidizing archaea and bacteria (AOA and AOB) communities contributed to the reduction of NH3 volatilization following the biochar application; (3) Under same N input levels, the total N2O emission in rice season decreased by 43.3–73.9% after biochar addition. The decreases of nirK and nirS gene abundances but the increases of nosZ gene abundance are the main mechanisms for biochar application to reduce N2O emissions. Based on the results of the current study, adding biochar at medium (200 kg/ha) N level (N200 + BC) is the best treatment to synchronically reduce NH3 and N2O losses, improve grain yield, and reduce fertilizer application in rice production system.

Biochar Production and Characteristics, Its Impacts on Soil Health, Crop Production, and Yield Enhancement: A Review

“…Several field studies have explored the impact of biochar on plant growth and the productivity of different crops ( Table 1 ). Its use involves plants with fewer nutrients in degraded soils than in healthy and productive soils [ 17 , 18 , 127 , 128 ]. Four-year field trials using rice husk biochar in dry, poor, non-acidic soils in the Philippines and Thailand (tropical climate) resulted in increased seed and water yields, improved K and P availability, and yields of 16–35% [ 129 ].…”

“…Depending on location, deployment is not expected to have the same impact on soil fertility and carbon stability. Numerous studies, even laboratory studies, have shown the beneficial effect of using biochar and organic amendments on yields [ 17 , 18 , 19 , 20 ]. Several studies conducted in temperate regions showed no negative effects of biochar on the yield of various crops [ 21 , 22 , 23 , 24 ].…”

Using the Conditional Process Analysis Model to Characterize the Evolution of Carbon Structure in Taxodium ascendens Biochar with Varied Pyrolysis Temperature and Holding Time

“…Besides, the leaf-based biochar had a higher nitrogen concentration. This finding suggests that the leaf-derived biochar has greater potential to raise the soil's total N content and improve plant uptake of N, both of which can increase the yields of crops such as wheat, rice, and grains [79][80][81].…”

Biochar and Dairy Manure Amendment Effects on Cynodon dactylon Performance and Soil Properties

“…Biochar as a soil amendment to improve soil fertility and row crop yields has been well documented as it improves soil moisture and nutrient retention as well as soil microbiome health [ 17 ]. Several studies, mainly in annual row crops, reported that biochar increases plant productivity, with an average yield increase of 10–42% [ 18 , 19 , 20 ]; however, short-term (first growing season) biochar amendment efficacy for ameliorating pasture soil characteristics and increasing forage yields and nutritive values in warm climates has not been widely tested and remains controversial. In temperate climates, research results indicate that initial soil fertility effects can be negative when they bind nutrients that then become unavailable to forage root uptake.…”