Geographical Distribution of Atmospheric Nitrogen Deposition in China and Its Response to Emission Control Policy

Atmospheric nitrogen(N)deposition has experienced significant change because of anthropogenic emissions,thereby exerting a pronounced impact on global ecosystem services.With the rapid development of industry and agriculture and the swift expansion of urban areas in China since the 1980s,reactive nitrogen(Nr)emissions and N deposition have substantially increased.In pursuit of im-proving air quality,China has implemented a series of environmental protection policies and undertaken diverse measures to reduce pol-lutant emissions.This paper is a review of multivariate data sources of atmospheric N deposition based on the results of literature from 1980 to 2023,and the original data from 1980 to 2020 are summarized,counted and calculated.The main findings are as follows:1)the annual average atmospheric N deposition ranged from approximately 20-40 kg/(ha·yr),with the variability primarily linked to different assessment methods;2)regional disparities were evident in the spatial distribution of N deposition,with elevated values concentrated in areas with intense Nr emissions;3)atmospheric N deposition significantly declined after 2010,particularly the deposition of oxidized N,while reduced N deposition remained stable.These results reflect the effects of China's serious control policies on nitrogen oxide(NO.)emissions and strengthen the importance of agricultural NH3 emission mitigation.This study contributes to a comprehensive understanding of the N dynamics in the emission-deposition process,and provides a scientific foundation for the research of environmental protection,climate change,and sustainable development.

不同施肥模式对芒果产量、品质的影响

探讨不同施肥模式对芒果产量、品质的影响,为芒果园科学合理的施肥方式提供依据。以‘台农’为研究对象,在海南芒果主产区的乐东县红泰农场芒果园进行大田试验,共设置7个处理:不施肥(CK)、化肥20 cm浅施(H2)、化肥40 cm深施(H4)、生物有机肥替代20%N 20 cm浅施(T2)、生物有机肥替代20%N 40 cm深施(T4)、水肥一体化20 cm浅施(SH2)、水肥一体化40 cm深施(SH4)。结果表明:化肥、有机肥替代、水肥一体化处理产量与经济效益均显著高于CK,其中SH4处理产量与经济效益较CK增产203.64%,增益266.87%;T2、T4、SH4处理的产量、经济效益显著高于H2处理,其中SH4处理较H2处理增产23.25%,增益31.28%。施肥处理的果长、果横径、果厚均显著高于不施肥处理,SH4处理果型指数显著高于CK处理。施肥处理的可溶性固形物、糖酸比与固酸比均显著高于CK处理,其中SH4处理可溶性固形物含量较CK处理增加14.45%。CK的总酸含量显著高于施肥处理,H2处理总酸含量显著高于化肥深施、有机肥替代、水肥一体化处理,其中,SH4处理总酸含量较CK减少78.79%,较H2减少48.98%。各处理果实Vc与可溶性糖差异不显著。通过对果实产量以及品质的主成分评价,果实各指标的主成分打分由高到低排列依次为:SH4>T4>SH2>T2>H4>H2>CK。在本试验条件下,水肥一体化40 cm深施是提高芒果产量、品质和经济效益的最佳模式。

台农杧果干物质及养分积累研究

通过枝解法采集台农一号杧高产树和低产树不同生育期不同器官干物质并进行分析,研究海南台农一号杧果年周期干物质积累量和养分积累量,为平衡施肥提供参考。结果表明,营养生长期、花期、果期3个阶段干物质积累量之比约为3∶2∶5,不同器官干物质积累量从大到小依次为果>叶>枝>落花≈落枝≈落果。生产1000kg鲜果所需N、P、K、Ca、Mg纯养分量分别为2.86~2.95、0.43~0.49、3.21~3.60、2.30~2.77、0.27~0.42kg。叶片N、P养分积累量与果实养分积累量有较强相关性,且果实N、P、K养分之间两两显著相关,存在协同作用。

海南‘红金龙’芒果叶片矿质养分特征与诊断指标

在海南的岛东林场、乐东阳光、陵水福田、陵水六合、乐东千家基地5个具有代表性的芒果种植区,选择长势正常的果树随机进行样品采集,分析第一、二蓬叶中N、P、K、Ca、Mg、S 6种矿质养分含量,对‘红金龙’芒果叶片进行矿质养分的变化规律分析,确定进行叶片养分诊断的适宜采样时间和适宜采样指标,为确定‘红金龙’芒果营养诊断指标提供参考依据。研究红金龙第一、二蓬叶片的N、P、K、Ca、Mg、S 6种矿质营养元素在不同月份的变异系数和平均值。结果表明:12月份第二蓬叶N、P、K、Ca、Mg、S 6种矿质元素变异系数小,且叶片矿质元素含量稳定能代表全年树体营养状况。故‘红金龙’叶片营养诊断在12月采集第二蓬叶作为测定N、P、K、Ca、Mg、S6种矿质养分较为适宜,营养诊断指标值:氮14.74～18.28 g/kg,磷0.99～1.33 g/kg,钾8.98～12.1 g/kg,钙21.91～30.03 g/kg,镁1.77～1.89 g/kg,硫1.25～1.51 g/kg。