摘要
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 < 0.01);particularly, the PARP and SSP were significantly higher than the both control and the GRP. A comparison of PARP and SSP within each soil based on both biomass yield and P uptake showed no significant difference between them. Despite the fact that the RAE values based on biomass yield were in most cases higher than those base on the P uptake, the trend was the same. On average the PARP was >90% effective within and across the four soils indicating that the PARP is reactive and suitable for direct application for crop production.
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 < 0.01);particularly, the PARP and SSP were significantly higher than the both control and the GRP. A comparison of PARP and SSP within each soil based on both biomass yield and P uptake showed no significant difference between them. Despite the fact that the RAE values based on biomass yield were in most cases higher than those base on the P uptake, the trend was the same. On average the PARP was >90% effective within and across the four soils indicating that the PARP is reactive and suitable for direct application for crop production.
作者
Simfukwe Paul
Bilima Tukuza Bester
Simfukwe Paul;Bilima Tukuza Bester(School of Agriculture and Natural Resources, Mulungushi University, Kabwe, Zambia;Zambia Agricultural Research Institute, Chilanga, Zambia)
