Biomass Productivity On Marginal Land Using Low Cost Fertilizer.

Perennial herbaceous crops grown on marginal lands and fertilized with low cost fertilizers could be the basis of sustainable biomass production systems. Our objective was to evaluate inexpensive and widely available organic fertilizers on a 7-yr old forage field for the production of biomass. A 5-ha site was chosen and characterized spatially for soil properties in 2008. During the following three years, treatments consisted of three N fertilization sources (pig manure: PM, municipal biosolid: MB, mineral fertilizer: MF) broadcasted in one spring application at 120 kg total N ha^-1 and a control treatment (C) with no N applied. Treatments were randomized in a complete block design with four replicates (16 plots, 10 m × 130 m). Two cuts per year were taken (end of June and August) at each of the 64 sampling points from a 0.92 × 5.7-m area to determine biomass yields. Immediately after the second cut, the soil (0-60 cm) was sampled at each sampling point to determine soil residual nitrate (SRN). Fertilization significantly increased biomass yields with a 3-yr average of 6.2, 5.9, 5.4, and 3.8 Mg DM ha^-1 with MF, PM, MB, and C, respectively. The SRN was not affected by the fertilization treatments. Our results indicate that utilization of inexpensive and widely available organic fertilizers represents an interesting opportunity for biomass production of perennial herbaceous species on marginal lands.