ABSTRACT This study aimed to determine the chemical, physical-chemical properties and agronomic efficiency of fermented composts formulated with agro-industrial wastes and tephrosia (Tephrosia sinapou) phytomass (TS) in arugula fertilization. The experiment was carried out in two phases, using wheat bran (FT), sugarcane bagasse (BC), TS phytomass and malt bagasse (BM) in the compound formulations. The first stage consisted of evaluating the chemical and physical-chemical properties in a completely randomized experimental design with 9 treatments (60TS+30FT+10BC; 60TS+30BM+10BC; 60TS+20FT+20BC; 60TS+20BM+20BC; 60TS+ 10FT+30BC; 60TS+10BM+30BC; 60TS+40FT; 60TS+40BM; 60TS+40BC) and four replicates. The second stage consisted of evaluating the agronomic efficiency of the formulations 60TS+40FT, 60TS+10FT+30BC, 60TS+40BM, 60TS+10BM+30BC and 60TS+40BC in arugula crop and a control treatment (without fertilizer). The fermented composts showed suitable chemical and physical-chemical properties for being used as fertilizers. Tephrosia phytomass has the potential for producing fermented composts, whose combination with 40% FT or BM, respectively, provided increases in N, P, K, Ca and Mg uptake, and in arugula productivity of 129,14% and 127.32% higher than the control (without any organic fertilizer)

RESUMO Objetivou-se determinar as características químicas, físico-químicas e a eficiência agronômica de compostos fermentados formulados com resíduos agroindustriais e fitomassa de tefrósia (Tephrosia sinapou) (TS) na fertilização da rúcula. O trabalho experimental foi conduzido em duas etapas, utilizando-se o farelo de trigo (FT), o bagaço de cana-de-açúcar (BC), a fitomassa de TS e o bagaço de malte (BM) nas formulações dos compostos. A primeira etapa consistiu da avaliação das características químicas e físico-químicas, cujo delineamento experimental foi inteiramente casualizado com 9 formulações (60TS+30FT+10BC; 60TS+30BM+10BC; 60TS+20FT+20BC; 60TS+20BM+20BC; 60TS+10FT+30BC; 60TS+10BM+30BC; 60TS+40FT; 60TS+40BM; 60TS+40BC) e quatro repetições. A segunda etapa constou da avaliação da eficiência agronômica das formulações 60TS+40FT, 60TS+10FT+30BC, 60TS+40BM, 60TS+10BM+30BC e 60TS+40BC no cultivo de rúcula, acrescido de um tratamento controle (sem adubação). Constatou-se que os compostos fermentados apresentam características químicas e físico-químicas que permitem a utilização como fertilizantes. A fitomassa de tefrósia tem potencial para a produção de compostos fermentados, cuja combinação com 40% de FT ou de BM, respectivamente, proporcionou aumentos nas quantidades acumuladas de N, P, K, Ca e Mg, e produtividades de rúcula na ordem de 129,14% e 127,32% superior ao tratamento controle, sem adubação orgânica.

ABSTRACT: A reliable quantification of nitrogen (N) losses by ammonia (NH3) volatilization can contribute to identifying optimized strategies of fertilizer management. The objective of this study was to quantify ammonia volatilization from several organic N sources incorporated into or applied onto the soil surface. Two cultivation areas, under snap bean and corn, were evaluated at Embrapa Agrobiology, Seropédica, Rio de Janeiro (RJ). Both experiments used a randomized complete block design in split-plots, with four replications. The main plots consisted of four organic fertilizers (castor bean cake, bokashi, legume fertilizers, cattle manure), at rates of 200 kg ha-1 N, and a control treatment (without fertilization), and the subplots corresponded to the management forms (incorporated or surface-applied) of the fertilizers. In the first experiment, snap bean cv. Novirex was grown in winter/spring and in the second, corn cv. Catingueiro in summer/autumn. In each subplot, static semi-open NH3 collectors were installed. We conclude that surface-applied castor cake was the organic fertilizer with highest N loss by NH3 volatilization. A comparison of the management systems (incorporated or surface-applied) showed that volatilization from organic fertilizers incorporated into the soil was significantly lower, with a reduction of 80 % for castor cake, of 78 % for bokashi and 67 % for legume fertilizer. Nitrogen loss through ammonia volatilization varied, from rates of 3 to 25 % in winter/spring and from 2 to 38 % in summer/autumn, according to the organic fertilizer applied. The period required to recover 95 % of the N lost by NH3-N volatilization was between 13 to 18 days for castor cake; 14 to 43 days for bokashi; 17 to 49 days for legume fertilizer and more than 43 days for cattle manure.