Abstract
Positive effects of a biochar–compost mix on soil nutrient status in infertile soil have been reported, but the potential effect of biochar amendments in excessive compost-fertilized soils has not been extensively studied. Excessive application of compost can result in the accumulation of nutrients and heavy metals (Cu and Zn). Thus, the objective of this study is to investigate the effect of biochar–excessive compost co-application on soil nutrient status. We hypothesized that biochar co-application could have positive effects on the absorption of excessive nutrients of Cu and Zn. A 371-day laboratory incubation study was conducted to evaluate the effects of the lead tree (Leucaena leucocephala (Lam.) de. Wit) biochar produced at 750 °C on the dynamics of the soil nutrients. Three Taiwan rural soils were selected, including slightly acidic Oxisols (SAO), mildly alkaline Inceptisols (MAI), and slightly acid Inceptisols (SAI). The biochar treatments include control (0%) and 0.5%, 1.0%, and 2.0% (w/w). In each treatment, 5% (w/w) poultry-livestock manure compost was added to test excessive application. The results indicated that the biochar treatments had a significant increase effect on soil pH, total carbon (TC), total nitrogen (TN), C:N ratio, and available K concentration. The effect of biochar on electrical conductivity (EC) and available P, Ca, Mg, Fe, Mn, Cu, Pb, and Zn was insignificant. The effect of biochar, with relatively low application rates (<2% by wt), low surface area, and less surface function group, was eliminated by excessive compost (5% by wt). In addition to carbon sequestration and nitrogen conservation, biochar addition has no effect on the absorption of the excessive nutrients Cu and Zn in three studied soils.
Highlights
IntroductionPoor fertility of highly weathered soils raises concerns about the sustainability of agriculture and has motivated the development of management practices to restore or improve fertility [1]
Poor fertility of highly weathered soils raises concerns about the sustainability of agriculture and has motivated the development of management practices to restore or improve fertility [1].the use of biochar has attracted increasing interest as a sustainable means of improving highly weathered or degraded tropical soils [2]
We examined the effects of biochar-excessive co-application on soil nutrient status and evaluated the regulation or enhancement role of biochar application rates in three rural soils over time
Summary
Poor fertility of highly weathered soils raises concerns about the sustainability of agriculture and has motivated the development of management practices to restore or improve fertility [1]. The use of biochar has attracted increasing interest as a sustainable means of improving highly weathered or degraded tropical soils [2]. The application of charcoal to degraded agricultural soils has been found to improve soil fertility in the USA [3], but no change was observed in extractable soil nutrients of Aridisols in Australia [4]. A more prominent improvement in soil fertility can be achieved by biochar application to the sandy soil having low clay, nutrient, and organic matter contents [10]. Biochar co-application with manure to calcareous soil had several beneficial effects on soil properties [11], including improving the soil water status, which would be considered beneficial in areas where irrigation or rainfall is limited;
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
