Chemical properties of volcanic soil affected by seven-year rotations

Juan Hirzel1*, Pablo Undurraga1, and Jorge González1

Long-term crop rotation systems can benefit soil chemical-physical properties and crop productivity. The lack of information on the effect of long-term crop rotations on soil chemical-physical properties for volcanic soils in Chile could restrict reaping real benefits, and make it difficult to take agricultural management decisions, which could lead to possible negative consequences on some soil chemical-physical properties and the environment. The development of information associated with the effect on soil chemical-physical properties with respect to long-term rotation systems and their fertilization management contribute to improving agronomic management decisions for these soils. A study was carried out to assess the effect of six rotation systems replicating fertilization management used by farmers, especially N and P application, and eventually low rates of K, Ca and Mg on soil chemical properties in a volcanic soil after 7 yr in Central South Chile. Affected chemical properties were pH, inorganic N, and available K, along with a general decrease of pH related to fertilization used, which was insufficient in Ca, K, and Mg. Moreover, this soil exhibited high P adsorption capacity (90.2 to 97.5%). Hence, crop rotations that included pasture legumes and crops with high nutrient inputs such as sugar beet (Beta vulgaris L.) generated a less negative effect on soil chemical properties. This study indicates that fertilization management in crop rotation systems must consider the input and output nutrient balances to prevent the negative effect on some soil chemical properties.

Keywords: crop rotation, Andisol, nutrient management, soil fertility.
1Instituto de Investigaciones Agropecuarias INIA, Avenida Vicente Méndez 515, Chillán, Chile. *Corresponding author (jhirzel@inia.cl).