ABSTRACT

Maize (Zea mays L.) yield increases from sulfur (S) fertilizer have recently been documented in Iowa, but responses have not been consistent. The objective for this study was to evaluate the response of juvenile maize to S applied as ammonium sulfate (AMS), ammonium thiosulfate (ATS), and S-enhanced mono-ammonium phosphate (MAPS). Clarion loam (Typic Haplaquolls), Fayette silt loam (Typic Hapludalfs), and Muscatine silt loam (Aquic Hapludolls) were collected from eroded hillslopes in Iowa, and amended with 0, 22, 34, and 45 kg S ha⁻¹. Maize (Pioneer 36N71) seedlings were planted in pots, placed in a controlled-climate chamber, and harvested after 21 days. Fertilizer S increased maize shoot dry matter (DM) when AMS was applied to Clarion loam, and when S from any source was applied to Muscatine silt loam. Sulfur fertilizer had no effect on DM accumulation in Fayette silt loam. Whole-plant S concentrations were generally higher than the control for all S sources. The agronomic efficiency of S (DM yield per unit applied) was greatest for the Muscatine soil, and was not related to S source or application rate. Early season growth of maize in Iowa may benefit from S fertilizer application, but the response may be site-specific.

摘要

衣阿华州最近记录了从硫（S）肥料中获得的玉米（Zea mays L.）单产增加，但反应却不一致。这项研究的目的是评估少年玉米对作为硫酸铵（AMS），硫代硫酸铵（ATS）和S增强磷酸一铵（MAPS）施用的S的响应。从爱荷华州受侵蚀的山坡上收集了Clarion壤土（典型的Haplaquolls），Fayette泥质壤土（典型的Hapludalfs）和Muscatine泥质壤土（Aquic Hapludolls），并分别用0、22、34和45 kg S ha ^-1进行了修正。。将玉米（Pioneer 36N71）幼苗种植在盆中，置于气候受控的室内，并在21天后收获。当将AMS应用于Clarion壤土时，以及将来自任何来源的S应用于Muscatine淤泥质壤土时，肥料S都会增加玉米芽的干物质（DM）。硫肥对费耶特粉质壤土中的干物质积累没有影响。对于所有S源，整株植物的S浓度通常都高于对照。麝香碱土壤上的S的农艺效率（每单位施用的DM产量）最大，与S的来源或施用量无关。爱荷华州玉米的早季生长可能受益于施S肥，但响应可能是针对特定地点的。