Site-Specific Effects of Organic Amendments on Parameters of Tropical Agricultural Soil and Yield: A Field Experiment in Three Countries in Southeast Asia

Abstract

Organic amendments may improve the quality of acidic tropical agricultural soils with low organic carbon contents under conventional management (mineral fertilization and irrigation) in Southeast Asia. We investigated the effect of biochar, compost and their combination on maize growth and yield, soil physical, biological and chemical properties at harvesting time at four sites in three countries: Thailand, Vietnam and Laos. Treatments consisted of 10 t·ha−1 cow manure compost and 7 t·ha−1 of Bamboo biochar and their combination. Maize biomass production and cop yields were recorded for two seasons. Elemental content, pH and nutrient availability of soils were analyzed after the first growing season. We also characterized macrofauna abundance and water infiltration. Few changes were noted for maize biomass production and maize cop yield. Soil chemical parameters showed contrasting, site-specific results. Compost and biochar amendments increased soil organic carbon, pH, total K and N, P and K availability especially for sandy soils in Thailand. The combination of both amendments could reduce nutrient availability as compared to compost only treatments. Physical and biological parameters showed no treatment response. We conclude that the addition of compost, biochar and their mixture to tropical soils have site-specific short-term effects on chemical soil parameters. Their short-term effect on plants is thus mainly related to nutrient input. The site-dependent results despite similar crops, fertilization and irrigation practices suggest that inherent soil parameters and optimization of organic amendment application to specific pedoclimatic conditions need future attention.

Using Morpho-Anatomical Traits to Predict the Effect of Earthworms on Soil Water Infiltration

“…The Ultisol is characterized in 0-10 cm depth by a soil organic carbon content of 1.7 %, a clayey texture (58 % clay, 25 % silt and 17 % sand) and a pH Kcl of 4.6 (Doan et al, 2021). The Fluvisol is characterized in 0-10 cm depth by a soil organic carbon content of 2.4 %, a loamy texture (13 % clay, 50 % silt and 37 % sand) and a pH Kcl of 7.1 (Bottinelli et al, 2010).…”

Effects of Organic Amendments Produced from Agro-Wastes on Sandy Soil Properties and Black Pepper Morpho-Physiology and Yield

“…To overcome this problem, the use of organic fertilizers or amendments produced from agricultural wastes has been advocated, as they are less of a danger compared with chemical fertilizers due to their slow release characteristics, less losses to the environment if managed well, and improvements in soil life. Various studies have shown that organic amendments, when applied to sandy and other textured soils, significantly improve soil fertility, crop performance, and yields [7,8,16,20,21].…”