Nutritional Evaluation of Millet Plants Grown in Soils Fertilized With Organic Wastes From Different Sources

Wilker A Morais,Igor O F Silva,Vitória R De C Martins,Frederico A L Soares,Leandro S Pereira,Gustavo Da S Vieira,Marconi B Teixeira,Cicero T S Costa,Vinícius De O Marques,Fernando R Cabral Filho,Aurélio F Melo,Fernando N Cunha,Giovani S Moraes

doi:10.5539/jas.v11n4p325

Abstract

The losses of essential elements to crops make necessary to correct soil fertility to meet the nutritional requirements of plants, which can be achieved by increasing soil organic matter. The objective of this work was to evaluate the leaf nutritional conditions of millet plants grown in soils fertilized with organic wastes from different sources at different rates. Organic matter can make the soil more productive and suitable to agricultural crops. A randomized block experimental design with a 4 &times; 2 factorial arrangement was used with four replications, consisting of 32 experimental units. The treatments consisted of four organic matter sources (swine manure, sewage sludge, bovine manure, and poultry litter), and two organic matter rates (20% and 40% of the pot volume). Boron extraction was performed by dry digestion&mdash;the organic matter of the plant tissue was incinerated in an electric muffle furnace at 450-550 &ordm;C, and the inorganic residue (ash) was dissolved in a dilute acid solution. N, K, Ca, Mg, S, Fe, Cu, Mn, and Zn was extracted through wet digestion&mdash;the organic matter of the leaf tissue was oxidized by concentrated mineral acids and by heat. N, P, S, B, Ca, Mg, Cu, Fe, Mn, and Zn was determined by spectrophotometry. K was determined by flame photometry. All macro and micronutrient contents in the millet leaves, and biometric parameters of the millet panicle were affected by the organic matter sources, organic matter rates, and the interaction between them.

Highlights

The use of lands for agricultural purposes contributes to soil nutrient loss due to crop harvest (Galvão et al, 2008; Santos et al, 2010)
The interaction between the organic matter sources (OMS) and rates (OMR), and the isolated effects of OMS and organic matter rate (OMR) were significant for all macronutrient contents (N, P, K, Ca, Mg, and S) (Table 2), except the effect of OMR on N and K
All macro and micronutrient contents in the millet leaves, and biometric parameters of the millet panicle were affected by the organic matter sources, organic matter rates, and the interaction between them

Summary

Introduction

The use of lands for agricultural purposes contributes to soil nutrient loss due to crop harvest (Galvão et al, 2008; Santos et al, 2010). Organic matter can make the soil more productive and suitable to agricultural crops. The most used organic fertilizers for supplying organic matter to soils are bovine manure, chicken litter, swine manure, and more recently, sewage sludge (Morais, 2016). Bovine manure and poultry litter are low moisture residues and are, known as solid wastes. Effluent or sewage sludge are residues with plenty moisture. All residues must undergo a previous treatment of composting before incorporated into the soil to avoid damage to crops by phytotoxicity. Organic fertilization is important for agriculture, especially for millet crops

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Methods

Conclusion