Luo Laichao, Hui Xiaoli, He Gang, Wang Sen, Wang Zhaohui, Siddique Kadambot H M
State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China.
Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, School of Resources and Environment, Anhui Agricultural University, Hefei, China.
Front Plant Sci. 2022 Feb 22;13:799093. doi: 10.3389/fpls.2022.799093. eCollection 2022.
Plastic mulching (PM) is widely used to improve crop water use efficiency and grain yield, but few studies have reported the effects of PM on cereal crop quality, especially sulfur (S) nutrition of wheat, which has significant effects on grain protein content, dough rheology, baking quality and human health. To fill this knowledge gap, we conducted a multi-site field experiment on the Loess Plateau from 2014 to 2016 to study the effects of PM combined with nitrogen (N) fertilizer on grain yield, shoot S accumulation, and grain S concentration of winter wheat in dryland. Compared with no mulching (NM), PM increased grain yield by 13.7% but decreased grain S concentration, S requirement for 1,000 kg grain, soil available S concentration, and post-anthesis S uptake by 9.0, 9.7, 24.4, and 51.8%, respectively. Plastic mulching significantly increased shoot S accumulation at anthesis by 19.2%, but there was no significant difference at maturity. Additionally, grain S concentration and S requirement had a linear-plateau relationship with N fertilization amount, reaching maximum values at 110 and 127 kg N ha under PM, 37.5 and 27.0% higher than those under NM. Furthermore, shoot S accumulation and N application rates well-fitted the linear-plateau model at anthesis and maturity. At maturity, straw, grain, and shoots accumulated the most S at threshold N rates of 120, 85 and 110 kg N ha, respectively. Crucially, stem + leaf S concentration at anthesis had a significant linear relationship with grain S concentration under PM; a 1 g kg increase in stem leaf concentration corresponded with a 0.24 g kg increase in grain S concentration. This study's findings suggest that combining soil S supplementation with optimal N fertilizer under PM in northwest China and other regions with similar cropping systems increases grain S concentration and improves nutritional and processing qualities.
地膜覆盖（PM）被广泛用于提高作物水分利用效率和粮食产量，但很少有研究报道地膜覆盖对谷类作物品质的影响，尤其是对小麦硫（S）营养的影响，而硫营养对籽粒蛋白质含量、面团流变学、烘焙品质和人体健康有显著影响。为填补这一知识空白，我们于2014年至2016年在黄土高原进行了一项多地点田间试验，以研究地膜覆盖与氮肥配施对旱地冬小麦籽粒产量、地上部硫积累和籽粒硫浓度的影响。与不覆盖（NM）相比，地膜覆盖使籽粒产量提高了13.7%，但籽粒硫浓度、每1000 kg籽粒硫需求量、土壤有效硫浓度和花后硫吸收量分别降低了9.0%、9.7%、24.4%和51.8%。地膜覆盖显著提高了花期地上部硫积累量19.2%，但成熟期无显著差异。此外，籽粒硫浓度和硫需求量与施氮量呈线性-平台关系，在地膜覆盖下，施氮量分别为110和127 kg N·ha时达到最大值，比不覆盖处理分别高37.5%和27.0%。此外，花期和成熟期地上部硫积累量与施氮量很好地拟合了线性-平台模型。成熟期，秸秆、籽粒和地上部在施氮阈值分别为120、85和110 kg N·ha时积累的硫最多。至关重要的是，花期茎+叶硫浓度与地膜覆盖下的籽粒硫浓度呈显著线性关系；茎叶硫浓度每增加1 g·kg，籽粒硫浓度相应增加0.24 g·kg。本研究结果表明，在中国西北及其他种植制度相似的地区，地膜覆盖下结合土壤补硫和优化氮肥施用可提高籽粒硫浓度，改善营养和加工品质。
