Correlation of Phosphorus Content of Alfalfa with pH and Forms of Soil Phosphorus

Abstract

AbstractA study was made of the availability to alfalfa of acid soluble and alkali soluble inorganic and organic soil phosphorus. Samples of both soil and alfalfa were taken from experimental plots and farm fields located on eight soil types.In the case of the plot samples, it was found that the content of acid soluble soil phosphorus in 1948 and soil pH in 1949 were the variables most closely related to the phosphorus content of the alfalfa. Out of 22 cases of significant correlations of the phosphorus, 2 were with soil pH, 8 each with the acid soluble and alkali soluble inorganic forms and 4 with the alkali soluble organic form.When the silt loam soils were divided into two pH groups, those below 7.0 and those of 7.0 and above, the contents of acid soluble and alkali soluble inorganic phosphorus were the forms most closely (and about equally) correlated with the phosphorus content of the alfalfa for both groups.