Effect of phosphate rock placement methods and incorporation of organic residues on phosphorus availability and maize yields in two soils with different phosphorus fixing capacities
| dc.contributor.author | Merumba, Mgeta Steven | |
| dc.date.accessioned | 2025-08-28T05:15:24Z | |
| dc.date.available | 2025-08-28T05:15:24Z | |
| dc.date.issued | 2004 | |
| dc.description | Dissertation | |
| dc.description.abstract | A study was conducted under pot and field conditions to evaluate the effects of Minjingu phosphate rock (MPR) placement methods and organic residues on MPR dissolution, P availability and maize yields in two soils with different P fixing capacities. Observations from two field experiments, one at Sasanda, Mbeya and another at Magadu, Morogoro were continued to evaluate the effect of continued addition of organic materials (OM) banded with MPR on MPR dissolution, P availability and maize yields. One field experiment was carried out at Sasanda to evaluate the effects of different rates of OM applied together with MPR on MPR dissolution, P availability and maize yields. For the continued experiments, the treatments tested were control, broadcasted MPR, 2 to 5 cm width strip banded MPR, 20-cm wide MPR band incorporated to 10 or 20 cm depth, and 20-cm MPR band + O.M incorporated down to 10 or 20 cm depth. These were tested only in the field. For the new experiment the treatments tested were control, broadcasted MPR, 2 to 5 cm width strip banded MPR, 20-cm wide MPR band incorporated to 20 cm, and 20- cm band MPR + OM applied together at 2, 4, 6 and 8 t/ha and incorporated down to 20cm depth. Field experiments were laid using Randomized Complete Block Design (RCBD) with four replications while pot experiment was laid using Complete Randomized Design (CRD) with three replications. Dry matter yields (DM) yields, P uptake, P concentrations, extractable P and grain yields were used to assess the effects of these treatments. The results showed that continued incorporation of OM banded together with MPR significantly (P=0.05) improved MPR dissolution, P availability, and increased grain yields. This was supported by highest maize grain yield (3.01 t/ha) obtained from these continued observations, which was higher than the maximum (2.27 t/ha) obtained in the previous study from the MPR + OM incorporated down to 20 cm depth. The results of the new experiment showed that banding of MPR together with OM at the rates of 2, 4 6 and 8 t/ha significantly (P=0.05) increased MPR dissolution, P availability, and maize grain/ dry matter yields. The increase was in proportion to the increased rates of OM. For example, in the pot experiment, MPR + OM increased DM yields from 14.14 to 76.17 g/pot and 4.10 to 70.87 g/pot in Magadu and Sasanda soils, respectively. In the field experiment, MPR + OM at 2, 4 and 6 t/ha increased extractable P in the soil from 0.18 to 0.47 mg/kg and maize grain yields from 0.36 to 3.38 t/ha. The increase was also proportional to the increased rates of OM. The highest extractable P (0.47 mg/kg) and grain yields (3.38 t/ha) were observed from MPR + 6 ton OM/ha. | |
| dc.description.sponsorship | Minjingu rock phosphate utilization project-DANIDA | |
| dc.identifier.uri | https://www.suaire.sua.ac.tz/handle/123456789/6946 | |
| dc.language.iso | en | |
| dc.publisher | Sokoine University of Agriculture | |
| dc.subject | Phosphate rock | |
| dc.subject | Phosphorus | |
| dc.subject | Maize yields | |
| dc.subject | Minjingu phosphate rock (MPR) | |
| dc.title | Effect of phosphate rock placement methods and incorporation of organic residues on phosphorus availability and maize yields in two soils with different phosphorus fixing capacities | |
| dc.type | Thesis |