Effect of Different Sources and Rates of Application of Fertilizer Materials on the pH and N, P, K, and Mg Content of the Soil to Which They Were Applied
1952
Vittum, M. T. | Lathwell, D. J. | Stanford, G.
A fertilizer experiment comparing the effects of different sources of N, P, and K, and different rates of application of complete fertilizer on the yield of beets, cabbage, peas, sweet corn, and tomatoes was conducted on a soil which, for the preceding 20 years, had been fertilized according to good commercial practice with a “complete” fertilizer high in phosphorus. After 5 years of consecutive application of the differential treatments, soil analyses showed the following results: (1) No significant difference in soil pH, ammonium N, nitrate N, P, K, or Mg from inorganic sources of N versus 40% of organic N; ordinary superphosphate versus “double” superphosphate; or muriate of potash versus 50% of the potash in the form of sulfate of potashmagnesia; (2) Significant decrease in pH and Mg and significant increase in nitrate N, P, and K with increasing rates of application of complete fertilizer; (3) No interaction between sources of fertilizer nutrients and rates of application; and (4) After 5 years of intensive vegetable cropping without addition of any fertilizer, available P, K, and Mg in the soil were 28, 86, and 557 pounds per acre, respectively. According to present New York standards, these values are classified as “very high,” “medium,” and “very high,” respectively.
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