Agronomic Suitability of Biologically Produced PARP as a Source of Phosphorus for Maize Production

Simfukwe Paul,Bilima Tukuza Bester

doi:10.4236/as.2020.1111067

Abstract

Phosphorus (P) and Nitrogen (N) deficiencies are recognized as the major constraint of agricultural productivity in developing countries including Zambia. While N deficits can be restored at least in part through the application of crop residues and manure, the restoration of soil P can only be achieved by use of phosphate fertilizers which are unaffordable by the small scale farmers. The aim of the study was to assess the availability of P for crop use from rock phosphate (RP), partially acidulated by acid produced by sulfur oxidizing bacteria. The RP was obtained from Keren Mining Limited at Sinda district, Zambia; the Pyrite rock (iron sulfur) and bacteria culture were obtained Nampundwe mine dump. The pyrite and PR were ground and mixed with the bacterial culture to produce the Partially Acidulated Rock Phosphate (PARP). A pot experiment was set up in a CRB design in a greenhouse on four soil types with four treatments of: soil alone (control), soil with GRP, soil with PARP and soil with super single phosphate (SSP) replicated four times. The results showed that the plant height, biomass yield and P uptake across the different P sources showed significant differences (p 90% effective within and across the four soils indicating that the PARP is reactive and suitable for direct application for crop production.

Highlights

Most soils in Zambia are inherently low in P (3 - 12 ppm) [1] and this seriously limits the productivity of maize which is the staple food crop
The results showed that the plant height, biomass yield and P uptake across the different P sources showed significant differences (p < 0.01); the Partially Acidulated Rock Phosphate (PARP) and single phosphate (SSP) were significantly higher than the both control and the ground rock phosphate (GRP)
This study shows the importance of the local rock phosphate as a source of phosphorus in maize plant in acidic soils

Summary

Introduction

Most soils in Zambia are inherently low in P (3 - 12 ppm) [1] and this seriously limits the productivity of maize which is the staple food crop. Application of farm yard manures and crop residues does add some limited quantities at farm level [4] [5] due to their low P content. For this reason, organic matter has been used mainly as sources of N, while inorganic fertilizers are used to supply P. The Kaluwe PR 0.5% - 8.5% P2O5 grade but the Niobium in these PRs as pyrochlore makes it technically and economically not suitable for phosphate extraction for agricultural purposes [10] [11]

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Methods

Results

Discussion

Conclusion