Availability of Nitrogen, Phosphorus and Potassium from Poultry Litter and Conventional Fertilizers in a Volcanic Soil Cultivated with Silage Corn
Poultry litter (PL) is an organic matter source used as soil amendment. Besides its important nutrient content, it is a cheap alternative to conventional fertilizers in crop production. The efficient use of PL also helps reduce the environmental problems normally associated with its disposal near poultry production farms. This article reports the relative effects of PL and conventional fertilizers on the availability of soil N, P and K, dry matter (DM) production and total nutrient content in silage corn (Zea mays L.). The field experiment was carried out in a soil derived from volcanic ash (Tipic Melanoxerands) of Central South Chile. Corn was grown for three seasons (2002-2005) and PL and conventional fertilizers were applied in the first two years. The residual effect of the added fertilizer sources was evaluated in the third year. DM production in the fertilized treatments was similar and fluctuated between 30.6 and 37.1 Mg ha-1 for the two years of fertilization, and between 18.9 and 20.4 Mg ha-1 for the year without addition of nutrients. The plant nutrient concentrations were similar between fertilized treatments, except for the second year, in which N and P concentrations were higher with PL. During the third year (without fertilization), N decreased in the whole plant. Soil nutrient availability was similar between fertilization sources for the three years evaluated, the higher concentration being presented in the first two years (with fertilization). These results suggest that PL is an alternative fertilizer source to conventional fertilizers.