Some effects of thallium sulfate upon soils

Abstract does not appear. First page follows.

Introduction

With the increasing use of poisons for pest control in agriculture, new and little-known chemicals are frequently introduced. The ultimate effects of these reagents upon soils and crops may present serious problems, and the continued use of certain of them cannot be safely recommended until their long-time behavior is understood.

Brooks ⁽¹⁾4 has warned of the possible sterilization effects of thallium sulfate used in rodent control, and McCool ⁽⁴⁾ has confirmed the highly toxic nature of this chemical in soils.

In pest control, toxicity is of eminent importance; and in weed work, soil effects are of special interest. Although thallium compounds are too expensive to be practical in weed control, their behavior in soils characterizes a certain type of toxic materials. A study of their reactions should contribute to our general information.

A preliminary report on work done on the problem of thallium toxicity in California soils has been published ⁽²⁾. The method used in toxicity studies, as already described by the author ⁽³⁾ in.a previous paper, consists principally in pot-culture tests using 500-gram lots of soils in No. 2 cans as the culture media. The chemicals to be tested are applied to the soils in various ways, and their effects upon indicator plants (Kanota oats) are measured by recording height and fresh weight of the latter after a 30-day growth period. The details of the individual tests with thallium will become apparent in the following pages.