Influence of Ca and Sr Amendments on Sr96 Uptake by Ladino Clover Upon Prolonged Cropping

Abstract

AbstractProlonged cropping experiments showed that a single application of CaCO3 in the amount recommended to produce better crop growth (2 to 5 tons an acre) continued to suppress Sr90 uptake from an acidic soil that initially was deficient in plant‐available Ca. This effect of treatment is attributable to the complementary ion influence of Ca on Sr. The cumulative amount of Sr90 removed by 15 successive cuttings of ladino clover was 29.38, 15.71 and 11.61% of the dose from Sassafras sandy loam treated with CaCO3 at levels of 1, 5 and 10 me. Ca per 100 g. soil (equivalent to 0.5, 2.5 and 10 tons CaCO3 an acre, respectively). The greatest amount of the Sr90 dose removed from the soil by a single clover cutting was 6.38% at the 1 me. Ca treatment.A single application of Sr(NO3)2 amendment at levels of 0.05, 1 and 2 me. Sr per 100 g. soil (equivalent to 0.05, 1 and 2 tons Sr(NO3)2 an acre) initially increased plant uptake of Sr90 from Hanford sandy loam as a result of the displacement of Sr90 from the exchange complex by stable Sr into the soil solution where it was more readily available to the plant. This enhancing effect of low levels of Sr amendment on Sr90 uptake became less apparent as time progressed. The carrier‐dilution effect of reducing plant uptake of Sr90 from Hanford sandy loam was achieved by applying Sr(NO3)2 at a level of 10 me. Sr per 100 g. soil (equivalent to 10 tons Sr(NO3)2 an acre).