dc.description.abstract |
Pakistan is a subtropical, semiarid country of 79.61 M ha area, which relies heavily on
agricultural production to supply food for its rapidly increasing population of over 135
million. The country is divided into four regions, two of which contain the majority of the flat
topographic plains having the bulk of 21 M ha of cultivated land. There are two general
cropping seasons in tropical flat plains of Pakistan i.e. Rabi (winter) and Kharif (summer)
season. Cotton, maize, rice and wheat are the main crops of Pakistan. Majority of Pakistani
soils are calcareous and alkaline with pH in the range 7.5 to 9.5. These soils reduce the
availability of P considerably as P is converted to insoluble forms at this pH. Overall, P
fertilizer application to Pakistani soils is inadequate. Energy crisis, high prices of phosphatic
fertilizers and their shortage at peak crop requirement has become a serious issue in Pakistan.
Rock phosphate (RP) has low bio-solubility of about 0.1 % under alkaline conditions if
applied directly. Therefore, bio-solubilization RP to release P needs to be boosted up using
some innovative approaches. Pakistan by default contains considerable quantity of
economical reasonable quality RP in Abbottabad and Haripur districts. However, extensive
scientific work is needed so that local rock phosphate may be used for P nutrition. Under this
research plan four consecutive experimental units were performed to enhance total and water
soluble P content in RP. In the first study, local and imported rock phosphates in combination
with different materials of organic nature were applied. The purpose of above research
proposal was to explore role of organic materials for P release from local & imported RP and
P uptake by maize crop. Maximum solubilization of P was achieved when filter cake press
mud (FCP) was applied in combination with rock phosphate. The 2nd study comprised of 7
treatments with three replications. Use of dewaxed filter cake press mud was evaluated as
most suitable source of local rock phosphate. Third study of this research proposal comprised
of 7 treatments which were replicated thrice. Combined use of FCP with RPR and TSP
performed better than their individual use. Use of organic amendment improved soil organic
carbon fraction of soil compared to control. The 4th study was conducted in the field using
RCBD with five treatments. Exogenous application of FCP along with indigenous Hazara
rock phosphate RPR and NK proved as better nutritional source compared to control. Further,
application of selected organic manure (dewaxed filter cake press mud) improved soil organic
carbon fraction in similar environment condition. |
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