Smuts finger grass (&lt;i&gt;Digitaria eriantha&lt;/i&gt; Cv Irene) root growth assessment and some physicochemical characteristics on coal mined land compacted soil

P.E Mosebi,I.C Madakadze,W.F Truter

doi:10.4314/jasem.v22i8.24

Abstract

The coal mine soil layers contained high values of bulk density of 1.80gcm -3 and 1.90gcm -3 at depths of 0-20 and 20-40 cm respectively, low contents of organic matter, soil pH and soil nutrients concentration. A field trial was conducted to investigate root growth responses of Smuts Finger grass ( Digitaria eriantha cv Irene) to compacted mine soil layers. It was revealed that the greatest root masses were noted in the upper horizons with progressively significantly less in the deeper horizons. Roots of this species penetrated compacted soil layers and decreased soil bulk density. The highest soil pH values were found in the upper layers with greatest root biomass. Soil nutrients (P, Mg, Ca, Na and K) status was also better in the upper layers. Smuts Finger grass could be used as an alternative method for rehabilitation of compacted mine soil layers. Keywords: Coal mine soil; Smuts Finger grass; Soil bulk density; Soil pH; Soil nutrients

Highlights

Returning mined land to productivity through reclamation activities requires more time than other stages of site construction and mining (Adiansyah et al, 2015)
Morphological characteristics of Smuts Finger grass (Digitaria eriantha cv Irene) makes it suitable to grow on extreme soils and climatic conditions
This study was conducted to assess root growth of Smuts Finger grass on compacted soil and to see their potential for improved bulk density in order to have a better understanding of soil compaction tolerance

Summary

Introduction

Returning mined land to productivity through reclamation activities requires more time than other stages of site construction and mining (Adiansyah et al, 2015). Using self-sustaining plant cover which includes grass species that vary in rooting depth and type help to minimize soil compaction impacts (Kaliyan, et al, 2013). Plant cover improves soil structure, water infiltration by creating root channels and penetration into soil (Wick et al, 2017). The root penetration is mainly vertical and grows up to 2 m deep depending on the soil conditions (Alcantara et al, 2015) Based on these characteristics Smuts Finger grass is being used in a range of disturbed areas. This study was conducted to assess root growth of Smuts Finger grass on compacted soil and to see their potential for improved bulk density in order to have a better understanding of soil compaction tolerance. Soil samples at 0-20 and 20-40 cm were collected during each growing season to analyse for pH (H2O) and nutrient concentrations (P, Ca, K, Mg and Na mgkg-1) using an ammonium acetate extraction method

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Results

Conclusion