Fertilization management is one of the agricultural practices that demand high investment. Thus, the objective was to evaluate the economic viability of using combinations of fertilizers applied to soybean and corn cultivated in succession in Goiás Savanna soil. The experiment was carried out in the field, in randomized blocks. The fertilization management consisted of the combination of monoammonium phosphate fertilizers; urea; 08:40:00 +9.3%S and 3.2% Ca; simple superphosphate; potassium chloride; elemental sulfur; polyhalite (37% K2O + 9.2% S, 5.8% Ca and 1.7% Mg) and polyhalite S (14% K2O + 19.2% S, 12% Ca and 3.6% Mg) which were applied in soybean sowing and evaluated the residual effect on corn. The economic assessment took into account crop productivity and fertilizer prices in the 2018/2019 agricultural year. For each treatment, the operating cost (COi) and profitability indicators were calculated: gross revenue (GRi); net revenue (NRi); profitability index (PITi); equilibrium production (Yei) and equilibrium price (Pei). Crop productivity was not influenced by fertilizer management, showing that economic indicators can help producers choose the management with the best return and that adjusts to the financial situation of the rural company. Thus, it is concluded that the management of MAP + KCl fertilization was economically outstanding in soybean cultivation and the MAP/S + KCl applied to soybeans, associated with nitrogen fertilization in corn coverage was the most viable for off-season corn. The economic indicators showed that the MAP+KCl fertilization performed on soybean, associated with urea in corn coverage, is the most viable management system for the soybean-corn production system cultivated in succession.

The advance of intercropping has generated the need for studies that evaluate methods of suppression of forage grasses in order to not harm the development of the commercial culture. The aim of this study is to evaluate the sensitivity of forage grasses to post-emergence herbicide application. To this end, an experiment was carried out in a greenhouse using a randomized complete block design in a 4 x 9 factorial scheme with four replicates. The first factor consisted of the forage grasses Urochloa ruziziensis, Panicum maximum cv. BRS Tamani, P. maximum cv. BRS Quênia, and P. maximum cv. BRS Zuri. The second factor consisted of the combination of eight herbicide treatments applied at post-emergence in association with atrazine (1200 g a.i. ha -1 ), besides a control treatment, without application. P. maximum cv. BRS Quênia was the least sensitive to post-emergence herbicide application. Tembotrione (42 and 84 g a.i. ha -1 ) and mesotrione (48 and 96 g a.i. ha -1 ) have potential for suppression of U. ruziziensis. Tembotrione (84 g a.i. ha -1 ), glyphosate (200 g a.i. ha -1 ), and nicosulfuron (7.8 g a.i. ha -1 ) have potential for suppression of the cv. BRS Quênia, and tembotrione (42 g a.i. ha -1 ) and mesotrione (96 g a.i. ha -1 ) have potential for the suppression of BRS Tamani. The P. maximum cv. BRS Zuri presented a higher plant height, shoot dry matter, and root dry matter than the other forages evaluated. For this forage, the use of nicosulfuron herbicides at post-emergence, regardless of the dose, reduced the shoot dry matter by 70%.