Phosphorus Needs of Small Grains on a Moderately Saline Soil1
- Lawrence O. Fine and
- P. L. Carson2
An exploratory study was started in 1950 to evaluate soil amendatory practices which might be used to increase the yield of small grain on mildly saline intrazonal soils of the Chernozem area. Symptoms presently regarded as salt injury are widely observed on barley and oats and are associated with rather striking phosphate responses on the Maple soils. Application of large amounts of phosphate fertilizers, or manure and phosphate, in both the greenhouse and the field increased yields remarkably and alleviated symptoms on oats and barley. Phosphate application with the seed proved to be approximately twice as effective as broadcast applications.
Investigation of the soils revealed a higher total phosphorus content in the saline soil than in surrounding non-saline soils. However, smaller percentages and absolute amounts of phosphorus were soluble in sulfuric acid extractions of the saline than of the normal soil. In a greenhouse experiment using P32 on the saline and a normal upland soil, it was found that added sodium salts sharply depressed the yield, phosphorus uptake and percent plant phosphorus derived from the fertilizer, whereas added calcium salts only slightly depressed these. These observations appear to the authors to discount the theory that formation of salts of the nature of tricalcium phosphate is responsible for the low phosphorus availability in this soil.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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