EFFECTS OF SULPHUR AND PHOSPHORUS FERTILIZATION ON THE YIELD AND QUALITY OF BARLEY ( Hordeum vulgare L.) IN THREE SOUTHWESTERN QUEBEC SOILS

Abstract

Field studies were conducted on three southwestern Quebec soils for 2 yr to provide information on effects of S fertilization on barley growth, to examine any S-P interaction, and to assess contributions of S from rain during the growing season. The treatments were arranged in a factorial combination of four levels of S (0, 15.6 or 31.2, 62.4 and 93.6 kg S/ha) with three levels of P (0, 117 and 234 kg P 2 O 5 /ha) added as gypsum and triple superphosphate, respectively. The results showed that added S either had an inconsistent effect or no effect on barley yield on the experimental soils. The lack of response was attributed to annual S additions from rain estimated to be in excess of 10 kg S∙ha −1 ∙yr −1 , as well as high levels of available S in the soils. No S-P interaction was observed, indicating that high P fertilization should not result in S deficiencies for barley in southwestern Quebec.