Sulfur in Non-Irrigated and Irrigated Chestnut Soils and Evaluation of Application of Increasing Doses of Sulfur Fertilizers (with NPK) for Potatoes

Abstract

It was found that due to the low humus content and low biological activity of virgin chestnut soils of Western Transbaikalia, the gross amount of sulfur is low. The distribution of sulfur along the profile is gradually decreasing with some accumulation of it in the carbonate horizon. Prolonged irrigation due to an increase in humus content and biological activity contributed to an increase in the amount of sulfur, which practically increases with the depth of the profile. When irrigated in a layer of 0-20 cm, the stock of mobile sulfates was 3 times larger than in virgin soil (7.3 and 2.4 kg/ha, respectively); in the 0-50 cm layer - 1.3 times, in the 0100 cm layer - 2.9 times. According to the content and reserves of mobile sulfur, chestnut soils in a layer of 0-20 cm are classified as low-income. After 3 years of using increasing doses of sulfur fertilizers (against the background of NPK) for irrigated potatoes, the content of all forms of sulfur in the soil increased depending on the dose size. The following pattern was revealed: with an increase in the dose, the amount of Sorg in the soil and the enrichment of humus with it increased, the ratio C : Sorg narrowed. A negative sulfur balance was established in the control and in the background version. The introduction of the lowest dose of S15 has already formed a positive balance, but given that chestnut soils are depleted of mobile sulfur, it is necessary to apply a dose of S30 (against the background of NPK) in compliance with irrigation standards.