Vermicompost to recover the fertility of sandy loam soil and the yield of peanut (Arachis hypogaea L.).

Peanut production is a signif icant source of economic income for Chiapas, holding the second place at the national level as a producer. Jiquipilas is one of the producing municipalities of the state; however, its yield has decreased in the last four years (from 2.4 to 1.45 Mg ha-1) probably due to the intensive management, propitiating the gradual deterioration of the physical, chemical and biological properties of the soil (loss of fertility). In sandy loam soils, the changes in said properties were evaluated from the addition of vermicompost and how these, in turn, influence crop yield. The study was conducted in a single cycle (2016), in a plot traditionally planted with peanuts (Arachis hypogaea L.) in the ejido of Jose Maria Pino Suarez, Jiquipilas, Chiapas. The vermicompost was elaborated with agricultural residues of the region (manure, corn and peanut waste). We experimented with four different doses of vermicompost (300, 225, 150, and 75 g), which were complemented with agroecological management (without chemical inputs, and incorporation of manual weeding between rows as dead cover). Soil with intensive management (application of fertilizers, insecticides, synthetic herbicides) and soil with agroecological management were considered as controls. The addition of vermicompost to the soil had positive effect on physical properties (f ield capacity, real density and in porous spaces); in terms of chemical properties, there were positive results in the availability of phosphorus, potassium, iron and manganese, as well as in the pH. Higher CO2 emissions were also obtained due to microbial activity. The emergence of plants and their flowering occurred in less time with vermicompost. Although there is a clear trend in high crop yield with the addition of vermicompost, there were no statistically signif icant differences.