The use of biochar-urea pellet formulations to reduced nitrogen losses

Abstract

This study aimed to evaluate the effects of soil texture, fertilizer formulation and nitrogen dose on the characteristics of upland rice production, and to compare the Agronomic Efficiency Index (AEI) of formulations of biochar-urea pellets (BUPs). The treatments comprised four fertilizers (three formulations of BUP and urea) and five nitrogen doses (0, 75, 150, 300 and 600 mg dm-3), analyzed in two soil (sandy and clay). For each soil texture, a greenhouse experiment was established as a randomized block design with a 5 x 4 factorial arrangement and four replicates. Chlorophyll index, plant height, number of tillers and panicles, dry mass of aerial parts and of grains were all affected significantly by soil texture, fertilizer formulation and nitrogen dose and/or by the interactions between these sources of variation. The results demonstrated that the performances of BUPs are highly dependent on soil texture. Under sandy soil, application of BUP-based fertilizers contributed to the increase or maintenance of grain production compared to that of urea alone. Whereas under clayey soil the performance of BUPs exceeded that of urea only at low nitrogen doses. Compared to urea, BUPs were more efficient under sandy soil, with potential to increase AEI.