Effect of sources and doses of sulfate on soybean crop1

ABSTRACT Crop demands for the macronutrient sulfur (S) are similar or greater than those for phosphorous. However, S is often overlooked in the management of crop fertilization. This study aimed to evaluate the effect of sources and doses of S on soybean cultivation under field conditions. A randomized block design, with 4 replications, was used. The treatments were arranged in a factorial scheme with one additional treatment (3 x 5 + 1), totaling 64 experimental units. Sources (elemental sulfur, single superphosphate and agricultural gypsum) and doses (20 kg ha-1, 40 kg ha-1, 60 kg ha-1, 80 kg ha-1 and 100 kg ha-1) of S were used, in addition to one control (without fertilizer). The following parameters were assessed: plant height at flowering, 1,000-seed weight, yield and agronomic efficiency, which were affected by the doses and sources of S; number of pods per plant, only affected by the sources of S; and number of pods with 3 seeds, with no statistical difference for any of the treatments. The highest yield recorded was 1,927 kg ha-1, at the dose of 80 kg ha-1 of S for gypsum, and the greatest agronomic efficiency was observed for the single superphosphate, at the dose of 20 kg ha-1 of S.

摘要：作物对大量营养素硫（sulfur, S）的需求与磷相当甚至更高。然而在作物施肥管理实践中，硫肥常被忽视。本研究旨在探究田间条件下，不同来源与施用量的硫肥对大豆栽培的影响。试验采用随机区组设计，设置4次重复。处理方案采用析因设计外加1个对照处理（3×5+1），共计64个试验单元。试验设置3种硫肥来源（单质硫（elemental sulfur）、过磷酸钙（single superphosphate）、农用石膏（agricultural gypsum））与5种施用量（20 kg·ha⁻¹、40 kg·ha⁻¹、60 kg·ha⁻¹、80 kg·ha⁻¹、100 kg·ha⁻¹），另设1个无肥对照。本试验测定了以下指标：开花期株高、千粒重、籽粒产量及农艺效率，上述指标均受硫肥施用量与来源的影响；单株荚数仅受硫肥来源的影响；而三粒荚数在各处理间均无统计学差异。试验测得的最高籽粒产量为1927 kg·ha⁻¹，对应施用农用石膏且施用量为80 kg·ha⁻¹时；而过磷酸钙在施用量为20 kg·ha⁻¹时展现出最高的农艺效率。