ISSN:
1573-5036
Keywords:
Buffering capacity
;
EUF extracted phosphorus
;
Readily available phosphorus
;
Reserve phosphorus
;
Seed cotton yield
;
Slowly available phosphorus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Preliminary investigations were carried out on calcareous silty loam (clay content 25%, pH 8.0) at the Cotton Research Institute, Multan to determine the solubility and desorption rates of phosphorus at various soil depths throughout the cotton growing season using the EUF technique. The treatments included two applications of single superphosphate, equivalent to 0, 75, 150, 250 and 350 kg P2O5/ha. There was no significant difference in seed cotton yield between the five treatments. EUF-extracted phosphorus decreased with depth in all samples. There was an increase in phosphorus concentration during the growing season, but most of the increase was noted in the slowly available phosphorus fraction (10–30 minutes EUF aliquots). This was attributed to continuous transformation of phosphorus into less soluble calcium phosphate forms. The available phosphorus fraction (0–10 minute EUF aliquots) remained small throughout the growing season. It was concluded that this fraction was in equilibrium with the slowly available phosphorus fraction and was continually being replenished as crop uptake continued. A high level of effectively available phosphorus (0–30 minute EUF aliquots) was recovered in all five treatments and was above the sufficiency level of 12 ppm phosphorus reported by Nemeth and Makhdam7. There was therefore no difference between treatments in phosporus concentration nor in phosphorus uptake by plants.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02375161
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