Yield and quality of maize following the foliar application of a fertilizer based on the byproduct “shale water”

Rafael Da Silva Messias,Cesar Valmor Rombaldi,Manoel Artigas Schirmer,Vanessa Galli,Clenio Nailto Pillon,Sérgio Delmar Dos Anjos E Silva,Carlos Augusto Posser Silveira

doi:10.4236/as.2013.412a006

Abstract

The water extracted from the shale rock (shale water) through the pyrolysis process to obtain fuel oil and other products shows a composition based on organic compounds and a wide range of minerals and trace elements with an important role in plant nutrition, suggesting its use as a fertilizer. Thus, the influence of foliar application of shale water (SW), with or without the micronutrients zinc (Zn), manganese (Mn), copper (Cu), boro (B) and molybdenum (Mo), was evaluated regarding yield and quality of maize grains. The yield, the total antioxidant activity, and the content of starch, phenolic compounds and carotenoids were improved in maize grains following the application of three doses of 7 L/ha of SW, which indicates that SW may influence the primary and secondary metabolisms. The application of SW with micronutrients resulted in the increase of grain yield; however, did not result in the improvement of grain quality. The foliar fertilizer formulations also had an influence in the content of minerals and aminoacids of the grain. The results indicate that SW has potential to be used in agriculture to improve yield and quality of maize.

Highlights

Nowadays, the search for food with nutritional and functional quality, free of toxic residues, as well as environmental friendly produced, is a worldwide tendency.Major cereal crops are staple foods that have the role to provide great amount of dietary macronutrients such as carbohydrates, lipids and proteins, micronutrients such as minerals and vitamins, as well as functional compounds, which can improve human health [1,2]
The yield of maize following the application of three doses of 7 L/ha of shale water (SW) (SW-2) was statistically higher than the control and similar to the yield of maize following the application of micronutrients (DW-M), suggesting that the SW may be used as an alternative
The SW with micronutrients (SW-M) treatment showed similar yield as SW-2 treatment; the application of SW-M represents an alternative strategy instead of SW-2, if yield is the parameter of interest, because the treatment SW-M has a lower dose of SW than SW-2 treatment

Summary

Introduction

The search for food with nutritional and functional quality, free of toxic residues, as well as environmental friendly produced, is a worldwide tendency.Major cereal crops are staple foods that have the role to provide great amount of dietary macronutrients such as carbohydrates, lipids and proteins, micronutrients such as minerals and vitamins, as well as functional compounds, which can improve human health [1,2]. Maize grains are a considerable source of poliphenol antioxidants, especially phenolic acids such as ferulic, caffeic and ρ-cumaric acids [5] This cereal displays great natural variation for carotenoid composition, including the xanthophylls lutein and zeaxanthin and vitamin A precursor’s α-carotene, β-carotene, and β-cryptoxanthin [2,6]. Most of these compounds have an important role as antioxidants and regulators of the human immune system, resulting in the prevention of cardiovascular diseases, as well as several types of cancer and other age-related diseases [4,7]. Phenolic compounds and carotenoids are important targets for biofortification efforts, especially vitamin A precursors, because the dietary deficiency of vitamin A is related to eye diseases in many developing countries that have maize as their major dietary source [8]

Methods

Results

Discussion

Conclusion