Results 11 to 20 of about 2,102 (132)

DNDC模型和TOPSIS法联合确定生物降解地膜覆盖农田合理施氮量

open access: greenShuitu Baochi Xuebao, 2022
为明确干旱区最优覆盖地膜类型和施氮制度,于内蒙古河套灌区木垒滩节水试验站进行为期2年的不同类型地膜覆盖农田不同施氮量试验。在高氮水平(传统施氮336 kg/hm2)下设置3种覆膜处理,包括塑料地膜(PFM3)、生物降解地膜(BFM3)和无膜覆盖处理(NFM3);同时在生物降解地膜覆盖下设立3个施氮水平,包括中氮(BFM2,276 kg/hm2)、低氮(BFM1,216 kg/hm2)和不施氮(BFM0,0 kg/hm2),共6个处理。利用2年观测的产量、吸氮量和氮淋失量对DNDC模型进行率定和验证 ...
冷旭, 李仙岳, 郭宇, 丁宗江
doaj   +1 more source

氮肥对节水栽培冬小麦产量、土壤硝态氮残留的影响

open access: yesShuitu Baochi Xuebao, 2006
在节水栽培条件下,研究了不同施氮量及氮肥运筹对冬小麦产量、氮肥利用率及生育期间土壤硝态氮的时空变化特征。同时计算了成熟期土壤硝态氮残留量。结果表明。节水栽培条件下冬小麦产量对氮肥反应不明显。氮肥利用率则随施氮量增加而显著降低。同时氮肥用量的增加显著增加了成熟期土壤硝态氮残留量。不同生育期0~60cm土层硝态氮含量均随施氮量增加而增加,开花期表现为施氮量157.5kg/hm^2或226.5kg/hm^2时氮肥一次性底施处理硝态氮含量均低于分次施用处理,成熟期表现为施氮量157.5kg/hm ...
张霞   +6 more
doaj   +2 more sources

氮磷肥对黑土玉米农田生态系统土壤微生物量碳、氮的影响

open access: yesShuitu Baochi Xuebao, 2004
通过田间氮磷肥配施试验研究了氮磷配施对黑土玉米农田生态系统玉米不同生育时期微生物量碳、氮的影响。微生物量随玉米不同生育期的动态变化表明,氮磷肥对微生物量碳和微生物量氮的动态影响并不同步,微生物量碳和微生物量氮变化最显著的时期均是授粉期,但此时微生物量碳是最低的谷值,而微生物量氮是最高的峰值。不同氮磷配比对微生物量碳影响的回归分析表明,氮肥是影响微生物量碳的主导因素,无论是适量施用还是过量施用都是氮肥对微生物量碳的影响较大。不同氮磷配比对微生物量氮影响的回归分析表明 ...
王继红 刘景双 于君宝 王金达
doaj   +2 more sources

Nitrogen deposition does not exacerbate phosphorus limitation of rhizosphere microbes in subalpine forests

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The stoichiometric imbalance caused by nitrogen (N) deposition typically exacerbates phosphorus (P) limitation in plants. However, it remains unclear whether this effect extends to soil microbes, particularly those in the rhizosphere.
Jipeng Wang   +5 more
wiley   +1 more source

Dutch landscapes have lost insect‐pollinated plants over the past 87 years

open access: yesJournal of Applied Ecology, Volume 61, Issue 6, Page 1323-1333, June 2024.
This study implies that Dutch landscapes are losing insect‐pollinated plant species, which is likely due, at least in part, to the decline in pollination services. Our results of quantifying the decline in insect‐pollinated plants support the necessity and urgency of taking conservation initiatives.
Kaixuan Pan   +3 more
wiley   +1 more source

不同氮肥运筹模式对稻田田面水氮浓度和水稻产量的影响

open access: yesShuitu Baochi Xuebao, 2020
通过构建包括不同氮肥类型、氮肥用量、施肥方式和施肥次数的6种氮肥运筹模式,分析了不同氮肥运筹模式对稻田田面水各形态氮浓度变化和水稻产量的影响。结果表明:不同时期施用缓控释肥和尿素后,总氮和铵态氮浓度均在1天达到峰值,硝态氮浓度在2~3天达到峰值,之后逐渐下降趋于稳定。铵态氮为各处理施肥后初期的主要氮形态,1天时铵态氮占总氮比例达50.6%~92.8%,而硝态氮仅占3.8%~22.6%。田面水总氮和铵态氮峰值浓度大小与氮肥类型、施用用量和施肥方式均存在相关性,等氮量施用条件下 ...
金树权   +4 more
doaj  

Trade‐off between soil carbon sequestration and net ecosystem economic benefits for paddy fields under long‐term application of biochar

open access: yesGCB Bioenergy, Volume 16, Issue 1, January 2024.
The use of biochar increased greenhouse gas (GHG) emissions but countered the harm caused by GHG emissions by considerable soil carbon sequestration resulting in a negative carbon footprint. Furthermore, the use of biochar lowered the proportion of CH4 and N2O, demonstrating that biochar usage has a considerable positive effect on GHG emissions ...
Zhuoxi Chen   +4 more
wiley   +1 more source

缓释氮比例对一次性施肥单季晚稻生长和氮素利用的影响

open access: yesShuitu Baochi Xuebao, 2021
探明单季晚稻缓释氮肥一次性施用模式中缓释氮占总施氮量的适宜比例,为单季晚稻高效施肥提供理论指导。2019—2020年在浙江省长兴县和平镇开展田间试验。试验共设6个处理:(1)不施氮肥(N0);(2)常规施肥(U1,基肥:分蘖肥:穗肥为4:3:3);(3)常规施肥减氮12.5%(U2,比例同U1);(4)57%缓释氮一次性施用(SRU1);(5)45%缓释氮一次性施用(SRU2);(6)34%缓释氮一次性施用(SRU3)。U1的施氮量为240 kg/hm2,U2和SRU的施氮量均为210 kg/hm2 ...
张金萍   +8 more
doaj  

尿素与复合氮肥增效剂配施对水稻氮素利用的影响

open access: yesShuitu Baochi Xuebao, 2006
采用^15N-尿素进行盆栽和田间试验,研究了复合氮肥增效剂用量、尿素与复合氮肥增效剂配施对水稻生长、籽粒产量和氮素吸收利用的影响。结果表明,适宜用量(施氮量的20%)的复合氮肥增效剂能显著促进水稻幼苗生长发育;尿素全量配施复合氮肥增效剂不影响水稻生长,能显著提高水稻植株Ndff%、氮吸收总量,氮素利用率和^15N的吸收量,尿素减量5%~15%(即减少施氮7.8~23.7kg/hm^2)配施复合氮肥增效剂基本上不影响水稻生长、籽粒产量和吸氮总量,能显著提高氮素的农学效率、生理效率和氮素利用率;植株吸氮总量、
田秀英, 王正银
doaj   +2 more sources

不同肥料类型及用量对坡面氮素流失的影响

open access: yesShuitu Baochi Xuebao, 2021
为研究施用不同肥料类型(尿素、鸡粪)及用量(349.6,174.8 kg/hm2)下坡面氮素流失规律,采用人工模拟降雨试验方法,探究二者氮素流失差异的原因,并阐述肥料用量对氮素流失量的影响。结果表明:施肥后坡面氮素流失以泥沙全氮流失为主,占比可达78.16%~93.46%;径流硝态氮浓度高于铵态氮浓度,且径流总氮流失以硝态氮流失为主要形式,流失量占径流总氮流失量的38.53%~48.62%。肥料类型对坡面泥沙全氮浓度影响不明显,施用鸡粪处理泥沙硝态氮浓度和铵态氮浓度较高。等氮施用鸡粪可以减少坡面径流总氮、
曲芝旭   +5 more
doaj  

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