This research was llev6 out during the period January 2003 to March 2004, at the Experimental Station of Tropical Crops Institute, located 2.5 km. From Tarapoto, district Shilcayo province and department of San Martin; in order to determine the effect of chicken manure and chemical formulation (NPK) on yield banana variety "lnguiri" and "Vellaco" and its cost / benefit ratio in acid soils of San Martin. The experimental soil at the beginning the experiment presented extremely acidic reaction (pH = 4.0}, texture class! sandy clay loam, low levels of nitrogen, phosphorus and potassium. The factors studied were composed of varieties of banana (a1 = Bellaco and 32 = lnguiri) and levels of chicken manure (b1 = O th / a, b2 = 5 t / ha, b3 = 10 t / ha and b4 = 15 t /he has). The experimental design used was Randomized complete block factorial arrangement 2A x 48, plus two additional witnesses (...