Author(s)

Xinhua Yin^1*, Nacer Bellaloui², Angela M. McClure¹, Don D. Tyler³, Alemu Mengistu⁴

¹Department of Plant Sciences, The University of Tennessee, Jackson, TN, USA.
²Crop Genetics Research Unit, USDA-ARS, Stoneville, MS, USA.
³Crop Genetics Research Unit, USDA-ARS, Jackson, TN, USA.
⁴Department of Biosystems Engineering and Soil Science, The University of Tennessee, Jackson, TN, USA.

Information is limited about phosphorus (P) fertilization effects on soybean seed composition. A field experiment was conducted to investigate the effects of P application rates on the concentrations of various fatty acids, protein, and oil in soybean under no-tillage on low and high testing P soils at Jackson and Milan, Tennessee from 2008 through 2011. Five P rates 0, 10, 20, 30, and 40 kg·P·ha^-1 plus the recommended P fertilizer rate based on soil P testing results were arranged in a randomized complete block design with four replicates. Protein, oil, and fatty acid concentrations in seed responded differently to P fertilization. In general, protein concentrations were enhanced but oil levels decreased with increased P application rate. Palmitic and oleic concentrations responded positively to P application rate up to a certain level. However, the response of linolenic acid concentration was inconsistent (negative or positive). Stearic concentration was not influenced by P fertilization. Application of 10 kg·P·ha^-1 resulted in higher production of protein and palmitic, oleic, and linolenic acids than zero P and the higher P application rates as well on the P deficient soil. Excessive P application rates could lower seed yield and the quality of some attributes in seed. In conclusion, linoleic acid concentration, a key quality attribute in soybean seed for human and animal consumption, can sometimes be enhanced by P fertilization; the indigenous soil P level and P application rate should be taken into account in breeding soybean cultivars with low linolenic acid level.

Phosphorus, Fatty Acids, Protein, Oil, Yield, Soybean

Yin, X. , Bellaloui, N. , McClure, A. , Tyler, D. and Mengistu, A. (2016) Phosphorus Fertilization Differentially Influences Fatty Acids, Protein, and Oil in Soybean. American Journal of Plant Sciences, 7, 1975-1992. doi: 10.4236/ajps.2016.714180.