Tillage systems and fertilization on yield of forage maize

About 15% of the world surface is subjected to the effect of man activities. The main causes of land surface degradation are livestock production, deforestation and inadequate agricultural practices. In Mexico, little attention has been given to soil conservation as a non-renewable natural resource. This has been mainly degraded by excessive use of agricultural machinery. As a result, 64% of the national territory suffers some degree of deterioration. Comarca Lagunera, located between Coahuila and Durango states in Mexico, is the main milk production region. In this region, 900000 t of cow manure are produced annually. This amount of cow manure could be used in increasing soil fertility and biology studies (i.e., reduction of environmental contamination levels). Objectives of this study were to determine (1) the effects of conservation tillage, and (2) the use of cow manure amounts on (a) soil physical properties, and (b) corn forage production. During spring and summer 2007 two tillage systems were evaluated: conventional and conservation tillage, and four fertilization levels: 20, 40 or 60 t/ha of cow manure, and one chemical fertilizer. A split-plot, completely randomized block design was used with four replications. Results showed statistical differences in temperature, soil moisture and resistance to clipping associated with the type of fertilization. No differences in yield were determined associated with the type of fertilization. However, yields were different depending on the tillage system used. Treatments with conventional tillage systems had yields 16% higher than those using conservation tillage systems.