Economics of Alternative Fertilizer Supply Systems for Switchgrass Produced in Phosphorus-Deficient Soils for Bioenergy Feedstock

Mohua Haque,Maru K. Kering,John A. Guretzky,Jon T. Biermacher

doi:10.1007/s12155-012-9264-5

Mohua Haque, Maru K. Kering + Show 2 more

Open Access

https://doi.org/10.1007/s12155-012-9264-5

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Abstract

Limited information is available explaining the economics of supplying N and P fertilizers on established stands of switchgrass growing in phosphorus-deficient soils. The objective of this study was to determine the most economical fertilizer supply system for producing feedstock in phosphorus-deficient soil in the southern Great Plains. Data collected from field trials conducted at two locations in south-central Oklahoma along with prices quoted by local input suppliers and custom service providers and assumptions about the farm-gate price of feedstock were used to estimate expected values for production costs, gross revenue and net return to owner's labor, management, and overhead for eight fertilizer supply systems. The systems included a zero fertilizer check system (0/0), three P systems (0/34, 0/67, and 0/101), one N system (135/0), and three N and P systems (135/34, 135/67, and 135/101). Random-effects mixed ANOVA models were used to determine the effects of fertilizer system on the values of total cost and net return. For the base-case price scenario (feedstock, N and P prices of $110 Mg−1 and $1.28 and 1.17 kg−1, respectively), the 135/0 system was the most profitable system, producing 10.2 Mg of feedstock and $263 of net return per hectare. Economic results were most sensitive to the prices of feedstock, N and P. Net return was negative for all eight systems for the scenario where the farm-gate price of feedstock was relatively low ($55 Mg−1) and prices for N and P were relatively high ($2.20 kg−1).

Highlights

Native to the southern Great Plains, switchgrass (Panicum virgatum L.) has been classified by agricultural scientists and public decision makers as a leading source of cellulosic feedstock for the large-scale production of bioenergy fuels such as ethanol [1, 2]
There is a limited body of published research that evaluated switchgrass yield response to fertilizers in phosphorusdeficient soil, and the results are mixed
In 2007, Alamo switchgrass plants were established at two locations that were deemed to be deficient in phosphorus via intensive soil sampling and testing

Summary

Introduction

Native to the southern Great Plains, switchgrass (Panicum virgatum L.) has been classified by agricultural scientists and public decision makers as a leading source of cellulosic feedstock for the large-scale production of bioenergy fuels such as ethanol [1, 2]. Most of the published research regarding fertilizer management decisions associated with producing switchgrass feedstock has focused mainly on nitrogen (N) as the primary limiting nutrient [3,4,5,6]. The majority of these studies were conducted in conditions where soil phosphorus levels were determined to be adequate; that is, they were deemed to be non-yield limiting or prohibiting the economic potential of the crop. There is a limited body of published research that evaluated switchgrass yield response to fertilizers in phosphorusdeficient soil, and the results are mixed. Results from a switchgrass yield response to N and P study conducted in Iowa indicated no response to P application [8].

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